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9445 lines
262 KiB
9445 lines
262 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* linux/mm/page_alloc.c |
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* |
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* Manages the free list, the system allocates free pages here. |
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* Note that kmalloc() lives in slab.c |
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* |
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* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds |
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* Swap reorganised 29.12.95, Stephen Tweedie |
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* Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 |
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* Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999 |
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* Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999 |
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* Zone balancing, Kanoj Sarcar, SGI, Jan 2000 |
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* Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002 |
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* (lots of bits borrowed from Ingo Molnar & Andrew Morton) |
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*/ |
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|
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#include <linux/stddef.h> |
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#include <linux/mm.h> |
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#include <linux/highmem.h> |
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#include <linux/swap.h> |
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#include <linux/interrupt.h> |
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#include <linux/pagemap.h> |
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#include <linux/jiffies.h> |
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#include <linux/memblock.h> |
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#include <linux/compiler.h> |
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#include <linux/kernel.h> |
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#include <linux/kasan.h> |
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#include <linux/module.h> |
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#include <linux/suspend.h> |
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#include <linux/pagevec.h> |
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#include <linux/blkdev.h> |
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#include <linux/slab.h> |
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#include <linux/ratelimit.h> |
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#include <linux/oom.h> |
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#include <linux/topology.h> |
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#include <linux/sysctl.h> |
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#include <linux/cpu.h> |
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#include <linux/cpuset.h> |
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#include <linux/memory_hotplug.h> |
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#include <linux/nodemask.h> |
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#include <linux/vmalloc.h> |
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#include <linux/vmstat.h> |
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#include <linux/mempolicy.h> |
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#include <linux/memremap.h> |
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#include <linux/stop_machine.h> |
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#include <linux/random.h> |
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#include <linux/sort.h> |
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#include <linux/pfn.h> |
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#include <linux/backing-dev.h> |
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#include <linux/fault-inject.h> |
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#include <linux/page-isolation.h> |
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#include <linux/debugobjects.h> |
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#include <linux/kmemleak.h> |
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#include <linux/compaction.h> |
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#include <trace/events/kmem.h> |
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#include <trace/events/oom.h> |
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#include <linux/prefetch.h> |
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#include <linux/mm_inline.h> |
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#include <linux/mmu_notifier.h> |
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#include <linux/migrate.h> |
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#include <linux/hugetlb.h> |
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#include <linux/sched/rt.h> |
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#include <linux/sched/mm.h> |
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#include <linux/page_owner.h> |
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#include <linux/kthread.h> |
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#include <linux/memcontrol.h> |
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#include <linux/ftrace.h> |
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#include <linux/lockdep.h> |
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#include <linux/nmi.h> |
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#include <linux/psi.h> |
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#include <linux/padata.h> |
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#include <linux/khugepaged.h> |
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#include <linux/buffer_head.h> |
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#include <asm/sections.h> |
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#include <asm/tlbflush.h> |
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#include <asm/div64.h> |
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#include "internal.h" |
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#include "shuffle.h" |
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#include "page_reporting.h" |
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|
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/* Free Page Internal flags: for internal, non-pcp variants of free_pages(). */ |
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typedef int __bitwise fpi_t; |
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|
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/* No special request */ |
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#define FPI_NONE ((__force fpi_t)0) |
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|
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/* |
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* Skip free page reporting notification for the (possibly merged) page. |
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* This does not hinder free page reporting from grabbing the page, |
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* reporting it and marking it "reported" - it only skips notifying |
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* the free page reporting infrastructure about a newly freed page. For |
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* example, used when temporarily pulling a page from a freelist and |
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* putting it back unmodified. |
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*/ |
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#define FPI_SKIP_REPORT_NOTIFY ((__force fpi_t)BIT(0)) |
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|
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/* |
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* Place the (possibly merged) page to the tail of the freelist. Will ignore |
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* page shuffling (relevant code - e.g., memory onlining - is expected to |
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* shuffle the whole zone). |
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* |
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* Note: No code should rely on this flag for correctness - it's purely |
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* to allow for optimizations when handing back either fresh pages |
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* (memory onlining) or untouched pages (page isolation, free page |
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* reporting). |
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*/ |
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#define FPI_TO_TAIL ((__force fpi_t)BIT(1)) |
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|
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/* |
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* Don't poison memory with KASAN (only for the tag-based modes). |
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* During boot, all non-reserved memblock memory is exposed to page_alloc. |
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* Poisoning all that memory lengthens boot time, especially on systems with |
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* large amount of RAM. This flag is used to skip that poisoning. |
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* This is only done for the tag-based KASAN modes, as those are able to |
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* detect memory corruptions with the memory tags assigned by default. |
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* All memory allocated normally after boot gets poisoned as usual. |
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*/ |
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#define FPI_SKIP_KASAN_POISON ((__force fpi_t)BIT(2)) |
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|
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/* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */ |
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static DEFINE_MUTEX(pcp_batch_high_lock); |
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#define MIN_PERCPU_PAGELIST_HIGH_FRACTION (8) |
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|
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struct pagesets { |
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local_lock_t lock; |
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}; |
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static DEFINE_PER_CPU(struct pagesets, pagesets) = { |
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.lock = INIT_LOCAL_LOCK(lock), |
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}; |
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|
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#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID |
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DEFINE_PER_CPU(int, numa_node); |
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EXPORT_PER_CPU_SYMBOL(numa_node); |
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#endif |
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|
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DEFINE_STATIC_KEY_TRUE(vm_numa_stat_key); |
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|
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#ifdef CONFIG_HAVE_MEMORYLESS_NODES |
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/* |
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* N.B., Do NOT reference the '_numa_mem_' per cpu variable directly. |
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* It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined. |
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* Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem() |
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* defined in <linux/topology.h>. |
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*/ |
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DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */ |
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EXPORT_PER_CPU_SYMBOL(_numa_mem_); |
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#endif |
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|
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/* work_structs for global per-cpu drains */ |
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struct pcpu_drain { |
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struct zone *zone; |
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struct work_struct work; |
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}; |
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static DEFINE_MUTEX(pcpu_drain_mutex); |
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static DEFINE_PER_CPU(struct pcpu_drain, pcpu_drain); |
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|
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#ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY |
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volatile unsigned long latent_entropy __latent_entropy; |
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EXPORT_SYMBOL(latent_entropy); |
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#endif |
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|
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/* |
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* Array of node states. |
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*/ |
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nodemask_t node_states[NR_NODE_STATES] __read_mostly = { |
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[N_POSSIBLE] = NODE_MASK_ALL, |
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[N_ONLINE] = { { [0] = 1UL } }, |
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#ifndef CONFIG_NUMA |
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[N_NORMAL_MEMORY] = { { [0] = 1UL } }, |
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#ifdef CONFIG_HIGHMEM |
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[N_HIGH_MEMORY] = { { [0] = 1UL } }, |
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#endif |
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[N_MEMORY] = { { [0] = 1UL } }, |
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[N_CPU] = { { [0] = 1UL } }, |
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#endif /* NUMA */ |
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}; |
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EXPORT_SYMBOL(node_states); |
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|
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atomic_long_t _totalram_pages __read_mostly; |
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EXPORT_SYMBOL(_totalram_pages); |
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unsigned long totalreserve_pages __read_mostly; |
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unsigned long totalcma_pages __read_mostly; |
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|
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int percpu_pagelist_high_fraction; |
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gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK; |
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DEFINE_STATIC_KEY_MAYBE(CONFIG_INIT_ON_ALLOC_DEFAULT_ON, init_on_alloc); |
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EXPORT_SYMBOL(init_on_alloc); |
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DEFINE_STATIC_KEY_MAYBE(CONFIG_INIT_ON_FREE_DEFAULT_ON, init_on_free); |
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EXPORT_SYMBOL(init_on_free); |
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static bool _init_on_alloc_enabled_early __read_mostly |
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= IS_ENABLED(CONFIG_INIT_ON_ALLOC_DEFAULT_ON); |
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static int __init early_init_on_alloc(char *buf) |
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{ |
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|
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return kstrtobool(buf, &_init_on_alloc_enabled_early); |
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} |
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early_param("init_on_alloc", early_init_on_alloc); |
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static bool _init_on_free_enabled_early __read_mostly |
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= IS_ENABLED(CONFIG_INIT_ON_FREE_DEFAULT_ON); |
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static int __init early_init_on_free(char *buf) |
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{ |
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return kstrtobool(buf, &_init_on_free_enabled_early); |
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} |
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early_param("init_on_free", early_init_on_free); |
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|
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/* |
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* A cached value of the page's pageblock's migratetype, used when the page is |
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* put on a pcplist. Used to avoid the pageblock migratetype lookup when |
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* freeing from pcplists in most cases, at the cost of possibly becoming stale. |
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* Also the migratetype set in the page does not necessarily match the pcplist |
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* index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any |
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* other index - this ensures that it will be put on the correct CMA freelist. |
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*/ |
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static inline int get_pcppage_migratetype(struct page *page) |
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{ |
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return page->index; |
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} |
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static inline void set_pcppage_migratetype(struct page *page, int migratetype) |
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{ |
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page->index = migratetype; |
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} |
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#ifdef CONFIG_PM_SLEEP |
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/* |
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* The following functions are used by the suspend/hibernate code to temporarily |
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* change gfp_allowed_mask in order to avoid using I/O during memory allocations |
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* while devices are suspended. To avoid races with the suspend/hibernate code, |
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* they should always be called with system_transition_mutex held |
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* (gfp_allowed_mask also should only be modified with system_transition_mutex |
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* held, unless the suspend/hibernate code is guaranteed not to run in parallel |
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* with that modification). |
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*/ |
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static gfp_t saved_gfp_mask; |
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void pm_restore_gfp_mask(void) |
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{ |
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WARN_ON(!mutex_is_locked(&system_transition_mutex)); |
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if (saved_gfp_mask) { |
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gfp_allowed_mask = saved_gfp_mask; |
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saved_gfp_mask = 0; |
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} |
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} |
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void pm_restrict_gfp_mask(void) |
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{ |
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WARN_ON(!mutex_is_locked(&system_transition_mutex)); |
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WARN_ON(saved_gfp_mask); |
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saved_gfp_mask = gfp_allowed_mask; |
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gfp_allowed_mask &= ~(__GFP_IO | __GFP_FS); |
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} |
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bool pm_suspended_storage(void) |
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{ |
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if ((gfp_allowed_mask & (__GFP_IO | __GFP_FS)) == (__GFP_IO | __GFP_FS)) |
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return false; |
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return true; |
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} |
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#endif /* CONFIG_PM_SLEEP */ |
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#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE |
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unsigned int pageblock_order __read_mostly; |
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#endif |
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static void __free_pages_ok(struct page *page, unsigned int order, |
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fpi_t fpi_flags); |
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|
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/* |
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* results with 256, 32 in the lowmem_reserve sysctl: |
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* 1G machine -> (16M dma, 800M-16M normal, 1G-800M high) |
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* 1G machine -> (16M dma, 784M normal, 224M high) |
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* NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA |
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* HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL |
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* HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA |
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* |
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* TBD: should special case ZONE_DMA32 machines here - in those we normally |
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* don't need any ZONE_NORMAL reservation |
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*/ |
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int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES] = { |
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#ifdef CONFIG_ZONE_DMA |
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[ZONE_DMA] = 256, |
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#endif |
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#ifdef CONFIG_ZONE_DMA32 |
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[ZONE_DMA32] = 256, |
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#endif |
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[ZONE_NORMAL] = 32, |
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#ifdef CONFIG_HIGHMEM |
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[ZONE_HIGHMEM] = 0, |
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#endif |
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[ZONE_MOVABLE] = 0, |
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}; |
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static char * const zone_names[MAX_NR_ZONES] = { |
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#ifdef CONFIG_ZONE_DMA |
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"DMA", |
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#endif |
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#ifdef CONFIG_ZONE_DMA32 |
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"DMA32", |
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#endif |
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"Normal", |
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#ifdef CONFIG_HIGHMEM |
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"HighMem", |
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#endif |
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"Movable", |
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#ifdef CONFIG_ZONE_DEVICE |
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"Device", |
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#endif |
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}; |
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const char * const migratetype_names[MIGRATE_TYPES] = { |
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"Unmovable", |
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"Movable", |
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"Reclaimable", |
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"HighAtomic", |
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#ifdef CONFIG_CMA |
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"CMA", |
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#endif |
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#ifdef CONFIG_MEMORY_ISOLATION |
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"Isolate", |
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#endif |
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}; |
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compound_page_dtor * const compound_page_dtors[NR_COMPOUND_DTORS] = { |
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[NULL_COMPOUND_DTOR] = NULL, |
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[COMPOUND_PAGE_DTOR] = free_compound_page, |
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#ifdef CONFIG_HUGETLB_PAGE |
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[HUGETLB_PAGE_DTOR] = free_huge_page, |
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#endif |
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#ifdef CONFIG_TRANSPARENT_HUGEPAGE |
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[TRANSHUGE_PAGE_DTOR] = free_transhuge_page, |
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#endif |
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}; |
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int min_free_kbytes = 1024; |
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int user_min_free_kbytes = -1; |
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int watermark_boost_factor __read_mostly = 15000; |
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int watermark_scale_factor = 10; |
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static unsigned long nr_kernel_pages __initdata; |
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static unsigned long nr_all_pages __initdata; |
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static unsigned long dma_reserve __initdata; |
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static unsigned long arch_zone_lowest_possible_pfn[MAX_NR_ZONES] __initdata; |
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static unsigned long arch_zone_highest_possible_pfn[MAX_NR_ZONES] __initdata; |
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static unsigned long required_kernelcore __initdata; |
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static unsigned long required_kernelcore_percent __initdata; |
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static unsigned long required_movablecore __initdata; |
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static unsigned long required_movablecore_percent __initdata; |
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static unsigned long zone_movable_pfn[MAX_NUMNODES] __initdata; |
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static bool mirrored_kernelcore __meminitdata; |
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|
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/* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */ |
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int movable_zone; |
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EXPORT_SYMBOL(movable_zone); |
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#if MAX_NUMNODES > 1 |
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unsigned int nr_node_ids __read_mostly = MAX_NUMNODES; |
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unsigned int nr_online_nodes __read_mostly = 1; |
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EXPORT_SYMBOL(nr_node_ids); |
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EXPORT_SYMBOL(nr_online_nodes); |
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#endif |
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int page_group_by_mobility_disabled __read_mostly; |
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|
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#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT |
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/* |
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* During boot we initialize deferred pages on-demand, as needed, but once |
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* page_alloc_init_late() has finished, the deferred pages are all initialized, |
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* and we can permanently disable that path. |
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*/ |
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static DEFINE_STATIC_KEY_TRUE(deferred_pages); |
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|
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/* |
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* Calling kasan_poison_pages() only after deferred memory initialization |
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* has completed. Poisoning pages during deferred memory init will greatly |
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* lengthen the process and cause problem in large memory systems as the |
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* deferred pages initialization is done with interrupt disabled. |
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* |
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* Assuming that there will be no reference to those newly initialized |
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* pages before they are ever allocated, this should have no effect on |
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* KASAN memory tracking as the poison will be properly inserted at page |
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* allocation time. The only corner case is when pages are allocated by |
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* on-demand allocation and then freed again before the deferred pages |
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* initialization is done, but this is not likely to happen. |
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*/ |
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static inline bool should_skip_kasan_poison(struct page *page, fpi_t fpi_flags) |
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{ |
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return static_branch_unlikely(&deferred_pages) || |
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(!IS_ENABLED(CONFIG_KASAN_GENERIC) && |
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(fpi_flags & FPI_SKIP_KASAN_POISON)) || |
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PageSkipKASanPoison(page); |
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} |
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|
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/* Returns true if the struct page for the pfn is uninitialised */ |
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static inline bool __meminit early_page_uninitialised(unsigned long pfn) |
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{ |
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int nid = early_pfn_to_nid(pfn); |
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|
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if (node_online(nid) && pfn >= NODE_DATA(nid)->first_deferred_pfn) |
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return true; |
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|
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return false; |
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} |
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|
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/* |
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* Returns true when the remaining initialisation should be deferred until |
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* later in the boot cycle when it can be parallelised. |
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*/ |
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static bool __meminit |
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defer_init(int nid, unsigned long pfn, unsigned long end_pfn) |
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{ |
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static unsigned long prev_end_pfn, nr_initialised; |
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|
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/* |
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* prev_end_pfn static that contains the end of previous zone |
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* No need to protect because called very early in boot before smp_init. |
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*/ |
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if (prev_end_pfn != end_pfn) { |
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prev_end_pfn = end_pfn; |
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nr_initialised = 0; |
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} |
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|
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/* Always populate low zones for address-constrained allocations */ |
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if (end_pfn < pgdat_end_pfn(NODE_DATA(nid))) |
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return false; |
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|
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if (NODE_DATA(nid)->first_deferred_pfn != ULONG_MAX) |
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return true; |
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/* |
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* We start only with one section of pages, more pages are added as |
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* needed until the rest of deferred pages are initialized. |
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*/ |
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nr_initialised++; |
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if ((nr_initialised > PAGES_PER_SECTION) && |
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(pfn & (PAGES_PER_SECTION - 1)) == 0) { |
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NODE_DATA(nid)->first_deferred_pfn = pfn; |
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return true; |
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} |
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return false; |
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} |
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#else |
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static inline bool should_skip_kasan_poison(struct page *page, fpi_t fpi_flags) |
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{ |
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return (!IS_ENABLED(CONFIG_KASAN_GENERIC) && |
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(fpi_flags & FPI_SKIP_KASAN_POISON)) || |
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PageSkipKASanPoison(page); |
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} |
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|
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static inline bool early_page_uninitialised(unsigned long pfn) |
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{ |
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return false; |
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} |
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|
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static inline bool defer_init(int nid, unsigned long pfn, unsigned long end_pfn) |
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{ |
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return false; |
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} |
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#endif |
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|
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/* Return a pointer to the bitmap storing bits affecting a block of pages */ |
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static inline unsigned long *get_pageblock_bitmap(const struct page *page, |
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unsigned long pfn) |
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{ |
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#ifdef CONFIG_SPARSEMEM |
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return section_to_usemap(__pfn_to_section(pfn)); |
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#else |
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return page_zone(page)->pageblock_flags; |
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#endif /* CONFIG_SPARSEMEM */ |
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} |
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|
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static inline int pfn_to_bitidx(const struct page *page, unsigned long pfn) |
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{ |
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#ifdef CONFIG_SPARSEMEM |
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pfn &= (PAGES_PER_SECTION-1); |
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#else |
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pfn = pfn - round_down(page_zone(page)->zone_start_pfn, pageblock_nr_pages); |
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#endif /* CONFIG_SPARSEMEM */ |
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return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; |
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} |
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|
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static __always_inline |
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unsigned long __get_pfnblock_flags_mask(const struct page *page, |
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unsigned long pfn, |
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unsigned long mask) |
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{ |
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unsigned long *bitmap; |
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unsigned long bitidx, word_bitidx; |
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unsigned long word; |
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|
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bitmap = get_pageblock_bitmap(page, pfn); |
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bitidx = pfn_to_bitidx(page, pfn); |
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word_bitidx = bitidx / BITS_PER_LONG; |
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bitidx &= (BITS_PER_LONG-1); |
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|
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word = bitmap[word_bitidx]; |
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return (word >> bitidx) & mask; |
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} |
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|
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/** |
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* get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages |
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* @page: The page within the block of interest |
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* @pfn: The target page frame number |
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* @mask: mask of bits that the caller is interested in |
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* |
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* Return: pageblock_bits flags |
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*/ |
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unsigned long get_pfnblock_flags_mask(const struct page *page, |
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unsigned long pfn, unsigned long mask) |
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{ |
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return __get_pfnblock_flags_mask(page, pfn, mask); |
|
} |
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|
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static __always_inline int get_pfnblock_migratetype(const struct page *page, |
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unsigned long pfn) |
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{ |
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return __get_pfnblock_flags_mask(page, pfn, MIGRATETYPE_MASK); |
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} |
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|
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/** |
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* set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages |
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* @page: The page within the block of interest |
|
* @flags: The flags to set |
|
* @pfn: The target page frame number |
|
* @mask: mask of bits that the caller is interested in |
|
*/ |
|
void set_pfnblock_flags_mask(struct page *page, unsigned long flags, |
|
unsigned long pfn, |
|
unsigned long mask) |
|
{ |
|
unsigned long *bitmap; |
|
unsigned long bitidx, word_bitidx; |
|
unsigned long old_word, word; |
|
|
|
BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4); |
|
BUILD_BUG_ON(MIGRATE_TYPES > (1 << PB_migratetype_bits)); |
|
|
|
bitmap = get_pageblock_bitmap(page, pfn); |
|
bitidx = pfn_to_bitidx(page, pfn); |
|
word_bitidx = bitidx / BITS_PER_LONG; |
|
bitidx &= (BITS_PER_LONG-1); |
|
|
|
VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn), page); |
|
|
|
mask <<= bitidx; |
|
flags <<= bitidx; |
|
|
|
word = READ_ONCE(bitmap[word_bitidx]); |
|
for (;;) { |
|
old_word = cmpxchg(&bitmap[word_bitidx], word, (word & ~mask) | flags); |
|
if (word == old_word) |
|
break; |
|
word = old_word; |
|
} |
|
} |
|
|
|
void set_pageblock_migratetype(struct page *page, int migratetype) |
|
{ |
|
if (unlikely(page_group_by_mobility_disabled && |
|
migratetype < MIGRATE_PCPTYPES)) |
|
migratetype = MIGRATE_UNMOVABLE; |
|
|
|
set_pfnblock_flags_mask(page, (unsigned long)migratetype, |
|
page_to_pfn(page), MIGRATETYPE_MASK); |
|
} |
|
|
|
#ifdef CONFIG_DEBUG_VM |
|
static int page_outside_zone_boundaries(struct zone *zone, struct page *page) |
|
{ |
|
int ret = 0; |
|
unsigned seq; |
|
unsigned long pfn = page_to_pfn(page); |
|
unsigned long sp, start_pfn; |
|
|
|
do { |
|
seq = zone_span_seqbegin(zone); |
|
start_pfn = zone->zone_start_pfn; |
|
sp = zone->spanned_pages; |
|
if (!zone_spans_pfn(zone, pfn)) |
|
ret = 1; |
|
} while (zone_span_seqretry(zone, seq)); |
|
|
|
if (ret) |
|
pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n", |
|
pfn, zone_to_nid(zone), zone->name, |
|
start_pfn, start_pfn + sp); |
|
|
|
return ret; |
|
} |
|
|
|
static int page_is_consistent(struct zone *zone, struct page *page) |
|
{ |
|
if (zone != page_zone(page)) |
|
return 0; |
|
|
|
return 1; |
|
} |
|
/* |
|
* Temporary debugging check for pages not lying within a given zone. |
|
*/ |
|
static int __maybe_unused bad_range(struct zone *zone, struct page *page) |
|
{ |
|
if (page_outside_zone_boundaries(zone, page)) |
|
return 1; |
|
if (!page_is_consistent(zone, page)) |
|
return 1; |
|
|
|
return 0; |
|
} |
|
#else |
|
static inline int __maybe_unused bad_range(struct zone *zone, struct page *page) |
|
{ |
|
return 0; |
|
} |
|
#endif |
|
|
|
static void bad_page(struct page *page, const char *reason) |
|
{ |
|
static unsigned long resume; |
|
static unsigned long nr_shown; |
|
static unsigned long nr_unshown; |
|
|
|
/* |
|
* Allow a burst of 60 reports, then keep quiet for that minute; |
|
* or allow a steady drip of one report per second. |
|
*/ |
|
if (nr_shown == 60) { |
|
if (time_before(jiffies, resume)) { |
|
nr_unshown++; |
|
goto out; |
|
} |
|
if (nr_unshown) { |
|
pr_alert( |
|
"BUG: Bad page state: %lu messages suppressed\n", |
|
nr_unshown); |
|
nr_unshown = 0; |
|
} |
|
nr_shown = 0; |
|
} |
|
if (nr_shown++ == 0) |
|
resume = jiffies + 60 * HZ; |
|
|
|
pr_alert("BUG: Bad page state in process %s pfn:%05lx\n", |
|
current->comm, page_to_pfn(page)); |
|
dump_page(page, reason); |
|
|
|
print_modules(); |
|
dump_stack(); |
|
out: |
|
/* Leave bad fields for debug, except PageBuddy could make trouble */ |
|
page_mapcount_reset(page); /* remove PageBuddy */ |
|
add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); |
|
} |
|
|
|
static inline unsigned int order_to_pindex(int migratetype, int order) |
|
{ |
|
int base = order; |
|
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE |
|
if (order > PAGE_ALLOC_COSTLY_ORDER) { |
|
VM_BUG_ON(order != pageblock_order); |
|
base = PAGE_ALLOC_COSTLY_ORDER + 1; |
|
} |
|
#else |
|
VM_BUG_ON(order > PAGE_ALLOC_COSTLY_ORDER); |
|
#endif |
|
|
|
return (MIGRATE_PCPTYPES * base) + migratetype; |
|
} |
|
|
|
static inline int pindex_to_order(unsigned int pindex) |
|
{ |
|
int order = pindex / MIGRATE_PCPTYPES; |
|
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE |
|
if (order > PAGE_ALLOC_COSTLY_ORDER) { |
|
order = pageblock_order; |
|
VM_BUG_ON(order != pageblock_order); |
|
} |
|
#else |
|
VM_BUG_ON(order > PAGE_ALLOC_COSTLY_ORDER); |
|
#endif |
|
|
|
return order; |
|
} |
|
|
|
static inline bool pcp_allowed_order(unsigned int order) |
|
{ |
|
if (order <= PAGE_ALLOC_COSTLY_ORDER) |
|
return true; |
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE |
|
if (order == pageblock_order) |
|
return true; |
|
#endif |
|
return false; |
|
} |
|
|
|
static inline void free_the_page(struct page *page, unsigned int order) |
|
{ |
|
if (pcp_allowed_order(order)) /* Via pcp? */ |
|
free_unref_page(page, order); |
|
else |
|
__free_pages_ok(page, order, FPI_NONE); |
|
} |
|
|
|
/* |
|
* Higher-order pages are called "compound pages". They are structured thusly: |
|
* |
|
* The first PAGE_SIZE page is called the "head page" and have PG_head set. |
|
* |
|
* The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded |
|
* in bit 0 of page->compound_head. The rest of bits is pointer to head page. |
|
* |
|
* The first tail page's ->compound_dtor holds the offset in array of compound |
|
* page destructors. See compound_page_dtors. |
|
* |
|
* The first tail page's ->compound_order holds the order of allocation. |
|
* This usage means that zero-order pages may not be compound. |
|
*/ |
|
|
|
void free_compound_page(struct page *page) |
|
{ |
|
mem_cgroup_uncharge(page); |
|
free_the_page(page, compound_order(page)); |
|
} |
|
|
|
void prep_compound_page(struct page *page, unsigned int order) |
|
{ |
|
int i; |
|
int nr_pages = 1 << order; |
|
|
|
__SetPageHead(page); |
|
for (i = 1; i < nr_pages; i++) { |
|
struct page *p = page + i; |
|
p->mapping = TAIL_MAPPING; |
|
set_compound_head(p, page); |
|
} |
|
|
|
set_compound_page_dtor(page, COMPOUND_PAGE_DTOR); |
|
set_compound_order(page, order); |
|
atomic_set(compound_mapcount_ptr(page), -1); |
|
if (hpage_pincount_available(page)) |
|
atomic_set(compound_pincount_ptr(page), 0); |
|
} |
|
|
|
#ifdef CONFIG_DEBUG_PAGEALLOC |
|
unsigned int _debug_guardpage_minorder; |
|
|
|
bool _debug_pagealloc_enabled_early __read_mostly |
|
= IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT); |
|
EXPORT_SYMBOL(_debug_pagealloc_enabled_early); |
|
DEFINE_STATIC_KEY_FALSE(_debug_pagealloc_enabled); |
|
EXPORT_SYMBOL(_debug_pagealloc_enabled); |
|
|
|
DEFINE_STATIC_KEY_FALSE(_debug_guardpage_enabled); |
|
|
|
static int __init early_debug_pagealloc(char *buf) |
|
{ |
|
return kstrtobool(buf, &_debug_pagealloc_enabled_early); |
|
} |
|
early_param("debug_pagealloc", early_debug_pagealloc); |
|
|
|
static int __init debug_guardpage_minorder_setup(char *buf) |
|
{ |
|
unsigned long res; |
|
|
|
if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) { |
|
pr_err("Bad debug_guardpage_minorder value\n"); |
|
return 0; |
|
} |
|
_debug_guardpage_minorder = res; |
|
pr_info("Setting debug_guardpage_minorder to %lu\n", res); |
|
return 0; |
|
} |
|
early_param("debug_guardpage_minorder", debug_guardpage_minorder_setup); |
|
|
|
static inline bool set_page_guard(struct zone *zone, struct page *page, |
|
unsigned int order, int migratetype) |
|
{ |
|
if (!debug_guardpage_enabled()) |
|
return false; |
|
|
|
if (order >= debug_guardpage_minorder()) |
|
return false; |
|
|
|
__SetPageGuard(page); |
|
INIT_LIST_HEAD(&page->lru); |
|
set_page_private(page, order); |
|
/* Guard pages are not available for any usage */ |
|
__mod_zone_freepage_state(zone, -(1 << order), migratetype); |
|
|
|
return true; |
|
} |
|
|
|
static inline void clear_page_guard(struct zone *zone, struct page *page, |
|
unsigned int order, int migratetype) |
|
{ |
|
if (!debug_guardpage_enabled()) |
|
return; |
|
|
|
__ClearPageGuard(page); |
|
|
|
set_page_private(page, 0); |
|
if (!is_migrate_isolate(migratetype)) |
|
__mod_zone_freepage_state(zone, (1 << order), migratetype); |
|
} |
|
#else |
|
static inline bool set_page_guard(struct zone *zone, struct page *page, |
|
unsigned int order, int migratetype) { return false; } |
|
static inline void clear_page_guard(struct zone *zone, struct page *page, |
|
unsigned int order, int migratetype) {} |
|
#endif |
|
|
|
/* |
|
* Enable static keys related to various memory debugging and hardening options. |
|
* Some override others, and depend on early params that are evaluated in the |
|
* order of appearance. So we need to first gather the full picture of what was |
|
* enabled, and then make decisions. |
|
*/ |
|
void init_mem_debugging_and_hardening(void) |
|
{ |
|
bool page_poisoning_requested = false; |
|
|
|
#ifdef CONFIG_PAGE_POISONING |
|
/* |
|
* Page poisoning is debug page alloc for some arches. If |
|
* either of those options are enabled, enable poisoning. |
|
*/ |
|
if (page_poisoning_enabled() || |
|
(!IS_ENABLED(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC) && |
|
debug_pagealloc_enabled())) { |
|
static_branch_enable(&_page_poisoning_enabled); |
|
page_poisoning_requested = true; |
|
} |
|
#endif |
|
|
|
if ((_init_on_alloc_enabled_early || _init_on_free_enabled_early) && |
|
page_poisoning_requested) { |
|
pr_info("mem auto-init: CONFIG_PAGE_POISONING is on, " |
|
"will take precedence over init_on_alloc and init_on_free\n"); |
|
_init_on_alloc_enabled_early = false; |
|
_init_on_free_enabled_early = false; |
|
} |
|
|
|
if (_init_on_alloc_enabled_early) |
|
static_branch_enable(&init_on_alloc); |
|
else |
|
static_branch_disable(&init_on_alloc); |
|
|
|
if (_init_on_free_enabled_early) |
|
static_branch_enable(&init_on_free); |
|
else |
|
static_branch_disable(&init_on_free); |
|
|
|
#ifdef CONFIG_DEBUG_PAGEALLOC |
|
if (!debug_pagealloc_enabled()) |
|
return; |
|
|
|
static_branch_enable(&_debug_pagealloc_enabled); |
|
|
|
if (!debug_guardpage_minorder()) |
|
return; |
|
|
|
static_branch_enable(&_debug_guardpage_enabled); |
|
#endif |
|
} |
|
|
|
static inline void set_buddy_order(struct page *page, unsigned int order) |
|
{ |
|
set_page_private(page, order); |
|
__SetPageBuddy(page); |
|
} |
|
|
|
/* |
|
* This function checks whether a page is free && is the buddy |
|
* we can coalesce a page and its buddy if |
|
* (a) the buddy is not in a hole (check before calling!) && |
|
* (b) the buddy is in the buddy system && |
|
* (c) a page and its buddy have the same order && |
|
* (d) a page and its buddy are in the same zone. |
|
* |
|
* For recording whether a page is in the buddy system, we set PageBuddy. |
|
* Setting, clearing, and testing PageBuddy is serialized by zone->lock. |
|
* |
|
* For recording page's order, we use page_private(page). |
|
*/ |
|
static inline bool page_is_buddy(struct page *page, struct page *buddy, |
|
unsigned int order) |
|
{ |
|
if (!page_is_guard(buddy) && !PageBuddy(buddy)) |
|
return false; |
|
|
|
if (buddy_order(buddy) != order) |
|
return false; |
|
|
|
/* |
|
* zone check is done late to avoid uselessly calculating |
|
* zone/node ids for pages that could never merge. |
|
*/ |
|
if (page_zone_id(page) != page_zone_id(buddy)) |
|
return false; |
|
|
|
VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy); |
|
|
|
return true; |
|
} |
|
|
|
#ifdef CONFIG_COMPACTION |
|
static inline struct capture_control *task_capc(struct zone *zone) |
|
{ |
|
struct capture_control *capc = current->capture_control; |
|
|
|
return unlikely(capc) && |
|
!(current->flags & PF_KTHREAD) && |
|
!capc->page && |
|
capc->cc->zone == zone ? capc : NULL; |
|
} |
|
|
|
static inline bool |
|
compaction_capture(struct capture_control *capc, struct page *page, |
|
int order, int migratetype) |
|
{ |
|
if (!capc || order != capc->cc->order) |
|
return false; |
|
|
|
/* Do not accidentally pollute CMA or isolated regions*/ |
|
if (is_migrate_cma(migratetype) || |
|
is_migrate_isolate(migratetype)) |
|
return false; |
|
|
|
/* |
|
* Do not let lower order allocations pollute a movable pageblock. |
|
* This might let an unmovable request use a reclaimable pageblock |
|
* and vice-versa but no more than normal fallback logic which can |
|
* have trouble finding a high-order free page. |
|
*/ |
|
if (order < pageblock_order && migratetype == MIGRATE_MOVABLE) |
|
return false; |
|
|
|
capc->page = page; |
|
return true; |
|
} |
|
|
|
#else |
|
static inline struct capture_control *task_capc(struct zone *zone) |
|
{ |
|
return NULL; |
|
} |
|
|
|
static inline bool |
|
compaction_capture(struct capture_control *capc, struct page *page, |
|
int order, int migratetype) |
|
{ |
|
return false; |
|
} |
|
#endif /* CONFIG_COMPACTION */ |
|
|
|
/* Used for pages not on another list */ |
|
static inline void add_to_free_list(struct page *page, struct zone *zone, |
|
unsigned int order, int migratetype) |
|
{ |
|
struct free_area *area = &zone->free_area[order]; |
|
|
|
list_add(&page->lru, &area->free_list[migratetype]); |
|
area->nr_free++; |
|
} |
|
|
|
/* Used for pages not on another list */ |
|
static inline void add_to_free_list_tail(struct page *page, struct zone *zone, |
|
unsigned int order, int migratetype) |
|
{ |
|
struct free_area *area = &zone->free_area[order]; |
|
|
|
list_add_tail(&page->lru, &area->free_list[migratetype]); |
|
area->nr_free++; |
|
} |
|
|
|
/* |
|
* Used for pages which are on another list. Move the pages to the tail |
|
* of the list - so the moved pages won't immediately be considered for |
|
* allocation again (e.g., optimization for memory onlining). |
|
*/ |
|
static inline void move_to_free_list(struct page *page, struct zone *zone, |
|
unsigned int order, int migratetype) |
|
{ |
|
struct free_area *area = &zone->free_area[order]; |
|
|
|
list_move_tail(&page->lru, &area->free_list[migratetype]); |
|
} |
|
|
|
static inline void del_page_from_free_list(struct page *page, struct zone *zone, |
|
unsigned int order) |
|
{ |
|
/* clear reported state and update reported page count */ |
|
if (page_reported(page)) |
|
__ClearPageReported(page); |
|
|
|
list_del(&page->lru); |
|
__ClearPageBuddy(page); |
|
set_page_private(page, 0); |
|
zone->free_area[order].nr_free--; |
|
} |
|
|
|
/* |
|
* If this is not the largest possible page, check if the buddy |
|
* of the next-highest order is free. If it is, it's possible |
|
* that pages are being freed that will coalesce soon. In case, |
|
* that is happening, add the free page to the tail of the list |
|
* so it's less likely to be used soon and more likely to be merged |
|
* as a higher order page |
|
*/ |
|
static inline bool |
|
buddy_merge_likely(unsigned long pfn, unsigned long buddy_pfn, |
|
struct page *page, unsigned int order) |
|
{ |
|
struct page *higher_page, *higher_buddy; |
|
unsigned long combined_pfn; |
|
|
|
if (order >= MAX_ORDER - 2) |
|
return false; |
|
|
|
combined_pfn = buddy_pfn & pfn; |
|
higher_page = page + (combined_pfn - pfn); |
|
buddy_pfn = __find_buddy_pfn(combined_pfn, order + 1); |
|
higher_buddy = higher_page + (buddy_pfn - combined_pfn); |
|
|
|
return page_is_buddy(higher_page, higher_buddy, order + 1); |
|
} |
|
|
|
/* |
|
* Freeing function for a buddy system allocator. |
|
* |
|
* The concept of a buddy system is to maintain direct-mapped table |
|
* (containing bit values) for memory blocks of various "orders". |
|
* The bottom level table contains the map for the smallest allocatable |
|
* units of memory (here, pages), and each level above it describes |
|
* pairs of units from the levels below, hence, "buddies". |
|
* At a high level, all that happens here is marking the table entry |
|
* at the bottom level available, and propagating the changes upward |
|
* as necessary, plus some accounting needed to play nicely with other |
|
* parts of the VM system. |
|
* At each level, we keep a list of pages, which are heads of continuous |
|
* free pages of length of (1 << order) and marked with PageBuddy. |
|
* Page's order is recorded in page_private(page) field. |
|
* So when we are allocating or freeing one, we can derive the state of the |
|
* other. That is, if we allocate a small block, and both were |
|
* free, the remainder of the region must be split into blocks. |
|
* If a block is freed, and its buddy is also free, then this |
|
* triggers coalescing into a block of larger size. |
|
* |
|
* -- nyc |
|
*/ |
|
|
|
static inline void __free_one_page(struct page *page, |
|
unsigned long pfn, |
|
struct zone *zone, unsigned int order, |
|
int migratetype, fpi_t fpi_flags) |
|
{ |
|
struct capture_control *capc = task_capc(zone); |
|
unsigned long buddy_pfn; |
|
unsigned long combined_pfn; |
|
unsigned int max_order; |
|
struct page *buddy; |
|
bool to_tail; |
|
|
|
max_order = min_t(unsigned int, MAX_ORDER - 1, pageblock_order); |
|
|
|
VM_BUG_ON(!zone_is_initialized(zone)); |
|
VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page); |
|
|
|
VM_BUG_ON(migratetype == -1); |
|
if (likely(!is_migrate_isolate(migratetype))) |
|
__mod_zone_freepage_state(zone, 1 << order, migratetype); |
|
|
|
VM_BUG_ON_PAGE(pfn & ((1 << order) - 1), page); |
|
VM_BUG_ON_PAGE(bad_range(zone, page), page); |
|
|
|
continue_merging: |
|
while (order < max_order) { |
|
if (compaction_capture(capc, page, order, migratetype)) { |
|
__mod_zone_freepage_state(zone, -(1 << order), |
|
migratetype); |
|
return; |
|
} |
|
buddy_pfn = __find_buddy_pfn(pfn, order); |
|
buddy = page + (buddy_pfn - pfn); |
|
|
|
if (!page_is_buddy(page, buddy, order)) |
|
goto done_merging; |
|
/* |
|
* Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page, |
|
* merge with it and move up one order. |
|
*/ |
|
if (page_is_guard(buddy)) |
|
clear_page_guard(zone, buddy, order, migratetype); |
|
else |
|
del_page_from_free_list(buddy, zone, order); |
|
combined_pfn = buddy_pfn & pfn; |
|
page = page + (combined_pfn - pfn); |
|
pfn = combined_pfn; |
|
order++; |
|
} |
|
if (order < MAX_ORDER - 1) { |
|
/* If we are here, it means order is >= pageblock_order. |
|
* We want to prevent merge between freepages on isolate |
|
* pageblock and normal pageblock. Without this, pageblock |
|
* isolation could cause incorrect freepage or CMA accounting. |
|
* |
|
* We don't want to hit this code for the more frequent |
|
* low-order merging. |
|
*/ |
|
if (unlikely(has_isolate_pageblock(zone))) { |
|
int buddy_mt; |
|
|
|
buddy_pfn = __find_buddy_pfn(pfn, order); |
|
buddy = page + (buddy_pfn - pfn); |
|
buddy_mt = get_pageblock_migratetype(buddy); |
|
|
|
if (migratetype != buddy_mt |
|
&& (is_migrate_isolate(migratetype) || |
|
is_migrate_isolate(buddy_mt))) |
|
goto done_merging; |
|
} |
|
max_order = order + 1; |
|
goto continue_merging; |
|
} |
|
|
|
done_merging: |
|
set_buddy_order(page, order); |
|
|
|
if (fpi_flags & FPI_TO_TAIL) |
|
to_tail = true; |
|
else if (is_shuffle_order(order)) |
|
to_tail = shuffle_pick_tail(); |
|
else |
|
to_tail = buddy_merge_likely(pfn, buddy_pfn, page, order); |
|
|
|
if (to_tail) |
|
add_to_free_list_tail(page, zone, order, migratetype); |
|
else |
|
add_to_free_list(page, zone, order, migratetype); |
|
|
|
/* Notify page reporting subsystem of freed page */ |
|
if (!(fpi_flags & FPI_SKIP_REPORT_NOTIFY)) |
|
page_reporting_notify_free(order); |
|
} |
|
|
|
/* |
|
* A bad page could be due to a number of fields. Instead of multiple branches, |
|
* try and check multiple fields with one check. The caller must do a detailed |
|
* check if necessary. |
|
*/ |
|
static inline bool page_expected_state(struct page *page, |
|
unsigned long check_flags) |
|
{ |
|
if (unlikely(atomic_read(&page->_mapcount) != -1)) |
|
return false; |
|
|
|
if (unlikely((unsigned long)page->mapping | |
|
page_ref_count(page) | |
|
#ifdef CONFIG_MEMCG |
|
page->memcg_data | |
|
#endif |
|
(page->flags & check_flags))) |
|
return false; |
|
|
|
return true; |
|
} |
|
|
|
static const char *page_bad_reason(struct page *page, unsigned long flags) |
|
{ |
|
const char *bad_reason = NULL; |
|
|
|
if (unlikely(atomic_read(&page->_mapcount) != -1)) |
|
bad_reason = "nonzero mapcount"; |
|
if (unlikely(page->mapping != NULL)) |
|
bad_reason = "non-NULL mapping"; |
|
if (unlikely(page_ref_count(page) != 0)) |
|
bad_reason = "nonzero _refcount"; |
|
if (unlikely(page->flags & flags)) { |
|
if (flags == PAGE_FLAGS_CHECK_AT_PREP) |
|
bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag(s) set"; |
|
else |
|
bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set"; |
|
} |
|
#ifdef CONFIG_MEMCG |
|
if (unlikely(page->memcg_data)) |
|
bad_reason = "page still charged to cgroup"; |
|
#endif |
|
return bad_reason; |
|
} |
|
|
|
static void check_free_page_bad(struct page *page) |
|
{ |
|
bad_page(page, |
|
page_bad_reason(page, PAGE_FLAGS_CHECK_AT_FREE)); |
|
} |
|
|
|
static inline int check_free_page(struct page *page) |
|
{ |
|
if (likely(page_expected_state(page, PAGE_FLAGS_CHECK_AT_FREE))) |
|
return 0; |
|
|
|
/* Something has gone sideways, find it */ |
|
check_free_page_bad(page); |
|
return 1; |
|
} |
|
|
|
static int free_tail_pages_check(struct page *head_page, struct page *page) |
|
{ |
|
int ret = 1; |
|
|
|
/* |
|
* We rely page->lru.next never has bit 0 set, unless the page |
|
* is PageTail(). Let's make sure that's true even for poisoned ->lru. |
|
*/ |
|
BUILD_BUG_ON((unsigned long)LIST_POISON1 & 1); |
|
|
|
if (!IS_ENABLED(CONFIG_DEBUG_VM)) { |
|
ret = 0; |
|
goto out; |
|
} |
|
switch (page - head_page) { |
|
case 1: |
|
/* the first tail page: ->mapping may be compound_mapcount() */ |
|
if (unlikely(compound_mapcount(page))) { |
|
bad_page(page, "nonzero compound_mapcount"); |
|
goto out; |
|
} |
|
break; |
|
case 2: |
|
/* |
|
* the second tail page: ->mapping is |
|
* deferred_list.next -- ignore value. |
|
*/ |
|
break; |
|
default: |
|
if (page->mapping != TAIL_MAPPING) { |
|
bad_page(page, "corrupted mapping in tail page"); |
|
goto out; |
|
} |
|
break; |
|
} |
|
if (unlikely(!PageTail(page))) { |
|
bad_page(page, "PageTail not set"); |
|
goto out; |
|
} |
|
if (unlikely(compound_head(page) != head_page)) { |
|
bad_page(page, "compound_head not consistent"); |
|
goto out; |
|
} |
|
ret = 0; |
|
out: |
|
page->mapping = NULL; |
|
clear_compound_head(page); |
|
return ret; |
|
} |
|
|
|
static void kernel_init_free_pages(struct page *page, int numpages, bool zero_tags) |
|
{ |
|
int i; |
|
|
|
if (zero_tags) { |
|
for (i = 0; i < numpages; i++) |
|
tag_clear_highpage(page + i); |
|
return; |
|
} |
|
|
|
/* s390's use of memset() could override KASAN redzones. */ |
|
kasan_disable_current(); |
|
for (i = 0; i < numpages; i++) { |
|
u8 tag = page_kasan_tag(page + i); |
|
page_kasan_tag_reset(page + i); |
|
clear_highpage(page + i); |
|
page_kasan_tag_set(page + i, tag); |
|
} |
|
kasan_enable_current(); |
|
} |
|
|
|
static __always_inline bool free_pages_prepare(struct page *page, |
|
unsigned int order, bool check_free, fpi_t fpi_flags) |
|
{ |
|
int bad = 0; |
|
bool skip_kasan_poison = should_skip_kasan_poison(page, fpi_flags); |
|
|
|
VM_BUG_ON_PAGE(PageTail(page), page); |
|
|
|
trace_mm_page_free(page, order); |
|
|
|
if (unlikely(PageHWPoison(page)) && !order) { |
|
/* |
|
* Do not let hwpoison pages hit pcplists/buddy |
|
* Untie memcg state and reset page's owner |
|
*/ |
|
if (memcg_kmem_enabled() && PageMemcgKmem(page)) |
|
__memcg_kmem_uncharge_page(page, order); |
|
reset_page_owner(page, order); |
|
return false; |
|
} |
|
|
|
/* |
|
* Check tail pages before head page information is cleared to |
|
* avoid checking PageCompound for order-0 pages. |
|
*/ |
|
if (unlikely(order)) { |
|
bool compound = PageCompound(page); |
|
int i; |
|
|
|
VM_BUG_ON_PAGE(compound && compound_order(page) != order, page); |
|
|
|
if (compound) |
|
ClearPageDoubleMap(page); |
|
for (i = 1; i < (1 << order); i++) { |
|
if (compound) |
|
bad += free_tail_pages_check(page, page + i); |
|
if (unlikely(check_free_page(page + i))) { |
|
bad++; |
|
continue; |
|
} |
|
(page + i)->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; |
|
} |
|
} |
|
if (PageMappingFlags(page)) |
|
page->mapping = NULL; |
|
if (memcg_kmem_enabled() && PageMemcgKmem(page)) |
|
__memcg_kmem_uncharge_page(page, order); |
|
if (check_free) |
|
bad += check_free_page(page); |
|
if (bad) |
|
return false; |
|
|
|
page_cpupid_reset_last(page); |
|
page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; |
|
reset_page_owner(page, order); |
|
|
|
if (!PageHighMem(page)) { |
|
debug_check_no_locks_freed(page_address(page), |
|
PAGE_SIZE << order); |
|
debug_check_no_obj_freed(page_address(page), |
|
PAGE_SIZE << order); |
|
} |
|
|
|
kernel_poison_pages(page, 1 << order); |
|
|
|
/* |
|
* As memory initialization might be integrated into KASAN, |
|
* kasan_free_pages and kernel_init_free_pages must be |
|
* kept together to avoid discrepancies in behavior. |
|
* |
|
* With hardware tag-based KASAN, memory tags must be set before the |
|
* page becomes unavailable via debug_pagealloc or arch_free_page. |
|
*/ |
|
if (kasan_has_integrated_init()) { |
|
if (!skip_kasan_poison) |
|
kasan_free_pages(page, order); |
|
} else { |
|
bool init = want_init_on_free(); |
|
|
|
if (init) |
|
kernel_init_free_pages(page, 1 << order, false); |
|
if (!skip_kasan_poison) |
|
kasan_poison_pages(page, order, init); |
|
} |
|
|
|
/* |
|
* arch_free_page() can make the page's contents inaccessible. s390 |
|
* does this. So nothing which can access the page's contents should |
|
* happen after this. |
|
*/ |
|
arch_free_page(page, order); |
|
|
|
debug_pagealloc_unmap_pages(page, 1 << order); |
|
|
|
return true; |
|
} |
|
|
|
#ifdef CONFIG_DEBUG_VM |
|
/* |
|
* With DEBUG_VM enabled, order-0 pages are checked immediately when being freed |
|
* to pcp lists. With debug_pagealloc also enabled, they are also rechecked when |
|
* moved from pcp lists to free lists. |
|
*/ |
|
static bool free_pcp_prepare(struct page *page, unsigned int order) |
|
{ |
|
return free_pages_prepare(page, order, true, FPI_NONE); |
|
} |
|
|
|
static bool bulkfree_pcp_prepare(struct page *page) |
|
{ |
|
if (debug_pagealloc_enabled_static()) |
|
return check_free_page(page); |
|
else |
|
return false; |
|
} |
|
#else |
|
/* |
|
* With DEBUG_VM disabled, order-0 pages being freed are checked only when |
|
* moving from pcp lists to free list in order to reduce overhead. With |
|
* debug_pagealloc enabled, they are checked also immediately when being freed |
|
* to the pcp lists. |
|
*/ |
|
static bool free_pcp_prepare(struct page *page, unsigned int order) |
|
{ |
|
if (debug_pagealloc_enabled_static()) |
|
return free_pages_prepare(page, order, true, FPI_NONE); |
|
else |
|
return free_pages_prepare(page, order, false, FPI_NONE); |
|
} |
|
|
|
static bool bulkfree_pcp_prepare(struct page *page) |
|
{ |
|
return check_free_page(page); |
|
} |
|
#endif /* CONFIG_DEBUG_VM */ |
|
|
|
static inline void prefetch_buddy(struct page *page) |
|
{ |
|
unsigned long pfn = page_to_pfn(page); |
|
unsigned long buddy_pfn = __find_buddy_pfn(pfn, 0); |
|
struct page *buddy = page + (buddy_pfn - pfn); |
|
|
|
prefetch(buddy); |
|
} |
|
|
|
/* |
|
* Frees a number of pages from the PCP lists |
|
* Assumes all pages on list are in same zone, and of same order. |
|
* count is the number of pages to free. |
|
* |
|
* If the zone was previously in an "all pages pinned" state then look to |
|
* see if this freeing clears that state. |
|
* |
|
* And clear the zone's pages_scanned counter, to hold off the "all pages are |
|
* pinned" detection logic. |
|
*/ |
|
static void free_pcppages_bulk(struct zone *zone, int count, |
|
struct per_cpu_pages *pcp) |
|
{ |
|
int pindex = 0; |
|
int batch_free = 0; |
|
int nr_freed = 0; |
|
unsigned int order; |
|
int prefetch_nr = READ_ONCE(pcp->batch); |
|
bool isolated_pageblocks; |
|
struct page *page, *tmp; |
|
LIST_HEAD(head); |
|
|
|
/* |
|
* Ensure proper count is passed which otherwise would stuck in the |
|
* below while (list_empty(list)) loop. |
|
*/ |
|
count = min(pcp->count, count); |
|
while (count > 0) { |
|
struct list_head *list; |
|
|
|
/* |
|
* Remove pages from lists in a round-robin fashion. A |
|
* batch_free count is maintained that is incremented when an |
|
* empty list is encountered. This is so more pages are freed |
|
* off fuller lists instead of spinning excessively around empty |
|
* lists |
|
*/ |
|
do { |
|
batch_free++; |
|
if (++pindex == NR_PCP_LISTS) |
|
pindex = 0; |
|
list = &pcp->lists[pindex]; |
|
} while (list_empty(list)); |
|
|
|
/* This is the only non-empty list. Free them all. */ |
|
if (batch_free == NR_PCP_LISTS) |
|
batch_free = count; |
|
|
|
order = pindex_to_order(pindex); |
|
BUILD_BUG_ON(MAX_ORDER >= (1<<NR_PCP_ORDER_WIDTH)); |
|
do { |
|
page = list_last_entry(list, struct page, lru); |
|
/* must delete to avoid corrupting pcp list */ |
|
list_del(&page->lru); |
|
nr_freed += 1 << order; |
|
count -= 1 << order; |
|
|
|
if (bulkfree_pcp_prepare(page)) |
|
continue; |
|
|
|
/* Encode order with the migratetype */ |
|
page->index <<= NR_PCP_ORDER_WIDTH; |
|
page->index |= order; |
|
|
|
list_add_tail(&page->lru, &head); |
|
|
|
/* |
|
* We are going to put the page back to the global |
|
* pool, prefetch its buddy to speed up later access |
|
* under zone->lock. It is believed the overhead of |
|
* an additional test and calculating buddy_pfn here |
|
* can be offset by reduced memory latency later. To |
|
* avoid excessive prefetching due to large count, only |
|
* prefetch buddy for the first pcp->batch nr of pages. |
|
*/ |
|
if (prefetch_nr) { |
|
prefetch_buddy(page); |
|
prefetch_nr--; |
|
} |
|
} while (count > 0 && --batch_free && !list_empty(list)); |
|
} |
|
pcp->count -= nr_freed; |
|
|
|
/* |
|
* local_lock_irq held so equivalent to spin_lock_irqsave for |
|
* both PREEMPT_RT and non-PREEMPT_RT configurations. |
|
*/ |
|
spin_lock(&zone->lock); |
|
isolated_pageblocks = has_isolate_pageblock(zone); |
|
|
|
/* |
|
* Use safe version since after __free_one_page(), |
|
* page->lru.next will not point to original list. |
|
*/ |
|
list_for_each_entry_safe(page, tmp, &head, lru) { |
|
int mt = get_pcppage_migratetype(page); |
|
|
|
/* mt has been encoded with the order (see above) */ |
|
order = mt & NR_PCP_ORDER_MASK; |
|
mt >>= NR_PCP_ORDER_WIDTH; |
|
|
|
/* MIGRATE_ISOLATE page should not go to pcplists */ |
|
VM_BUG_ON_PAGE(is_migrate_isolate(mt), page); |
|
/* Pageblock could have been isolated meanwhile */ |
|
if (unlikely(isolated_pageblocks)) |
|
mt = get_pageblock_migratetype(page); |
|
|
|
__free_one_page(page, page_to_pfn(page), zone, order, mt, FPI_NONE); |
|
trace_mm_page_pcpu_drain(page, order, mt); |
|
} |
|
spin_unlock(&zone->lock); |
|
} |
|
|
|
static void free_one_page(struct zone *zone, |
|
struct page *page, unsigned long pfn, |
|
unsigned int order, |
|
int migratetype, fpi_t fpi_flags) |
|
{ |
|
unsigned long flags; |
|
|
|
spin_lock_irqsave(&zone->lock, flags); |
|
if (unlikely(has_isolate_pageblock(zone) || |
|
is_migrate_isolate(migratetype))) { |
|
migratetype = get_pfnblock_migratetype(page, pfn); |
|
} |
|
__free_one_page(page, pfn, zone, order, migratetype, fpi_flags); |
|
spin_unlock_irqrestore(&zone->lock, flags); |
|
} |
|
|
|
static void __meminit __init_single_page(struct page *page, unsigned long pfn, |
|
unsigned long zone, int nid) |
|
{ |
|
mm_zero_struct_page(page); |
|
set_page_links(page, zone, nid, pfn); |
|
init_page_count(page); |
|
page_mapcount_reset(page); |
|
page_cpupid_reset_last(page); |
|
page_kasan_tag_reset(page); |
|
|
|
INIT_LIST_HEAD(&page->lru); |
|
#ifdef WANT_PAGE_VIRTUAL |
|
/* The shift won't overflow because ZONE_NORMAL is below 4G. */ |
|
if (!is_highmem_idx(zone)) |
|
set_page_address(page, __va(pfn << PAGE_SHIFT)); |
|
#endif |
|
} |
|
|
|
#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT |
|
static void __meminit init_reserved_page(unsigned long pfn) |
|
{ |
|
pg_data_t *pgdat; |
|
int nid, zid; |
|
|
|
if (!early_page_uninitialised(pfn)) |
|
return; |
|
|
|
nid = early_pfn_to_nid(pfn); |
|
pgdat = NODE_DATA(nid); |
|
|
|
for (zid = 0; zid < MAX_NR_ZONES; zid++) { |
|
struct zone *zone = &pgdat->node_zones[zid]; |
|
|
|
if (pfn >= zone->zone_start_pfn && pfn < zone_end_pfn(zone)) |
|
break; |
|
} |
|
__init_single_page(pfn_to_page(pfn), pfn, zid, nid); |
|
} |
|
#else |
|
static inline void init_reserved_page(unsigned long pfn) |
|
{ |
|
} |
|
#endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */ |
|
|
|
/* |
|
* Initialised pages do not have PageReserved set. This function is |
|
* called for each range allocated by the bootmem allocator and |
|
* marks the pages PageReserved. The remaining valid pages are later |
|
* sent to the buddy page allocator. |
|
*/ |
|
void __meminit reserve_bootmem_region(phys_addr_t start, phys_addr_t end) |
|
{ |
|
unsigned long start_pfn = PFN_DOWN(start); |
|
unsigned long end_pfn = PFN_UP(end); |
|
|
|
for (; start_pfn < end_pfn; start_pfn++) { |
|
if (pfn_valid(start_pfn)) { |
|
struct page *page = pfn_to_page(start_pfn); |
|
|
|
init_reserved_page(start_pfn); |
|
|
|
/* Avoid false-positive PageTail() */ |
|
INIT_LIST_HEAD(&page->lru); |
|
|
|
/* |
|
* no need for atomic set_bit because the struct |
|
* page is not visible yet so nobody should |
|
* access it yet. |
|
*/ |
|
__SetPageReserved(page); |
|
} |
|
} |
|
} |
|
|
|
static void __free_pages_ok(struct page *page, unsigned int order, |
|
fpi_t fpi_flags) |
|
{ |
|
unsigned long flags; |
|
int migratetype; |
|
unsigned long pfn = page_to_pfn(page); |
|
struct zone *zone = page_zone(page); |
|
|
|
if (!free_pages_prepare(page, order, true, fpi_flags)) |
|
return; |
|
|
|
migratetype = get_pfnblock_migratetype(page, pfn); |
|
|
|
spin_lock_irqsave(&zone->lock, flags); |
|
if (unlikely(has_isolate_pageblock(zone) || |
|
is_migrate_isolate(migratetype))) { |
|
migratetype = get_pfnblock_migratetype(page, pfn); |
|
} |
|
__free_one_page(page, pfn, zone, order, migratetype, fpi_flags); |
|
spin_unlock_irqrestore(&zone->lock, flags); |
|
|
|
__count_vm_events(PGFREE, 1 << order); |
|
} |
|
|
|
void __free_pages_core(struct page *page, unsigned int order) |
|
{ |
|
unsigned int nr_pages = 1 << order; |
|
struct page *p = page; |
|
unsigned int loop; |
|
|
|
/* |
|
* When initializing the memmap, __init_single_page() sets the refcount |
|
* of all pages to 1 ("allocated"/"not free"). We have to set the |
|
* refcount of all involved pages to 0. |
|
*/ |
|
prefetchw(p); |
|
for (loop = 0; loop < (nr_pages - 1); loop++, p++) { |
|
prefetchw(p + 1); |
|
__ClearPageReserved(p); |
|
set_page_count(p, 0); |
|
} |
|
__ClearPageReserved(p); |
|
set_page_count(p, 0); |
|
|
|
atomic_long_add(nr_pages, &page_zone(page)->managed_pages); |
|
|
|
/* |
|
* Bypass PCP and place fresh pages right to the tail, primarily |
|
* relevant for memory onlining. |
|
*/ |
|
__free_pages_ok(page, order, FPI_TO_TAIL | FPI_SKIP_KASAN_POISON); |
|
} |
|
|
|
#ifdef CONFIG_NUMA |
|
|
|
/* |
|
* During memory init memblocks map pfns to nids. The search is expensive and |
|
* this caches recent lookups. The implementation of __early_pfn_to_nid |
|
* treats start/end as pfns. |
|
*/ |
|
struct mminit_pfnnid_cache { |
|
unsigned long last_start; |
|
unsigned long last_end; |
|
int last_nid; |
|
}; |
|
|
|
static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata; |
|
|
|
/* |
|
* Required by SPARSEMEM. Given a PFN, return what node the PFN is on. |
|
*/ |
|
static int __meminit __early_pfn_to_nid(unsigned long pfn, |
|
struct mminit_pfnnid_cache *state) |
|
{ |
|
unsigned long start_pfn, end_pfn; |
|
int nid; |
|
|
|
if (state->last_start <= pfn && pfn < state->last_end) |
|
return state->last_nid; |
|
|
|
nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn); |
|
if (nid != NUMA_NO_NODE) { |
|
state->last_start = start_pfn; |
|
state->last_end = end_pfn; |
|
state->last_nid = nid; |
|
} |
|
|
|
return nid; |
|
} |
|
|
|
int __meminit early_pfn_to_nid(unsigned long pfn) |
|
{ |
|
static DEFINE_SPINLOCK(early_pfn_lock); |
|
int nid; |
|
|
|
spin_lock(&early_pfn_lock); |
|
nid = __early_pfn_to_nid(pfn, &early_pfnnid_cache); |
|
if (nid < 0) |
|
nid = first_online_node; |
|
spin_unlock(&early_pfn_lock); |
|
|
|
return nid; |
|
} |
|
#endif /* CONFIG_NUMA */ |
|
|
|
void __init memblock_free_pages(struct page *page, unsigned long pfn, |
|
unsigned int order) |
|
{ |
|
if (early_page_uninitialised(pfn)) |
|
return; |
|
__free_pages_core(page, order); |
|
} |
|
|
|
/* |
|
* Check that the whole (or subset of) a pageblock given by the interval of |
|
* [start_pfn, end_pfn) is valid and within the same zone, before scanning it |
|
* with the migration of free compaction scanner. |
|
* |
|
* Return struct page pointer of start_pfn, or NULL if checks were not passed. |
|
* |
|
* It's possible on some configurations to have a setup like node0 node1 node0 |
|
* i.e. it's possible that all pages within a zones range of pages do not |
|
* belong to a single zone. We assume that a border between node0 and node1 |
|
* can occur within a single pageblock, but not a node0 node1 node0 |
|
* interleaving within a single pageblock. It is therefore sufficient to check |
|
* the first and last page of a pageblock and avoid checking each individual |
|
* page in a pageblock. |
|
*/ |
|
struct page *__pageblock_pfn_to_page(unsigned long start_pfn, |
|
unsigned long end_pfn, struct zone *zone) |
|
{ |
|
struct page *start_page; |
|
struct page *end_page; |
|
|
|
/* end_pfn is one past the range we are checking */ |
|
end_pfn--; |
|
|
|
if (!pfn_valid(start_pfn) || !pfn_valid(end_pfn)) |
|
return NULL; |
|
|
|
start_page = pfn_to_online_page(start_pfn); |
|
if (!start_page) |
|
return NULL; |
|
|
|
if (page_zone(start_page) != zone) |
|
return NULL; |
|
|
|
end_page = pfn_to_page(end_pfn); |
|
|
|
/* This gives a shorter code than deriving page_zone(end_page) */ |
|
if (page_zone_id(start_page) != page_zone_id(end_page)) |
|
return NULL; |
|
|
|
return start_page; |
|
} |
|
|
|
void set_zone_contiguous(struct zone *zone) |
|
{ |
|
unsigned long block_start_pfn = zone->zone_start_pfn; |
|
unsigned long block_end_pfn; |
|
|
|
block_end_pfn = ALIGN(block_start_pfn + 1, pageblock_nr_pages); |
|
for (; block_start_pfn < zone_end_pfn(zone); |
|
block_start_pfn = block_end_pfn, |
|
block_end_pfn += pageblock_nr_pages) { |
|
|
|
block_end_pfn = min(block_end_pfn, zone_end_pfn(zone)); |
|
|
|
if (!__pageblock_pfn_to_page(block_start_pfn, |
|
block_end_pfn, zone)) |
|
return; |
|
cond_resched(); |
|
} |
|
|
|
/* We confirm that there is no hole */ |
|
zone->contiguous = true; |
|
} |
|
|
|
void clear_zone_contiguous(struct zone *zone) |
|
{ |
|
zone->contiguous = false; |
|
} |
|
|
|
#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT |
|
static void __init deferred_free_range(unsigned long pfn, |
|
unsigned long nr_pages) |
|
{ |
|
struct page *page; |
|
unsigned long i; |
|
|
|
if (!nr_pages) |
|
return; |
|
|
|
page = pfn_to_page(pfn); |
|
|
|
/* Free a large naturally-aligned chunk if possible */ |
|
if (nr_pages == pageblock_nr_pages && |
|
(pfn & (pageblock_nr_pages - 1)) == 0) { |
|
set_pageblock_migratetype(page, MIGRATE_MOVABLE); |
|
__free_pages_core(page, pageblock_order); |
|
return; |
|
} |
|
|
|
for (i = 0; i < nr_pages; i++, page++, pfn++) { |
|
if ((pfn & (pageblock_nr_pages - 1)) == 0) |
|
set_pageblock_migratetype(page, MIGRATE_MOVABLE); |
|
__free_pages_core(page, 0); |
|
} |
|
} |
|
|
|
/* Completion tracking for deferred_init_memmap() threads */ |
|
static atomic_t pgdat_init_n_undone __initdata; |
|
static __initdata DECLARE_COMPLETION(pgdat_init_all_done_comp); |
|
|
|
static inline void __init pgdat_init_report_one_done(void) |
|
{ |
|
if (atomic_dec_and_test(&pgdat_init_n_undone)) |
|
complete(&pgdat_init_all_done_comp); |
|
} |
|
|
|
/* |
|
* Returns true if page needs to be initialized or freed to buddy allocator. |
|
* |
|
* First we check if pfn is valid on architectures where it is possible to have |
|
* holes within pageblock_nr_pages. On systems where it is not possible, this |
|
* function is optimized out. |
|
* |
|
* Then, we check if a current large page is valid by only checking the validity |
|
* of the head pfn. |
|
*/ |
|
static inline bool __init deferred_pfn_valid(unsigned long pfn) |
|
{ |
|
if (!(pfn & (pageblock_nr_pages - 1)) && !pfn_valid(pfn)) |
|
return false; |
|
return true; |
|
} |
|
|
|
/* |
|
* Free pages to buddy allocator. Try to free aligned pages in |
|
* pageblock_nr_pages sizes. |
|
*/ |
|
static void __init deferred_free_pages(unsigned long pfn, |
|
unsigned long end_pfn) |
|
{ |
|
unsigned long nr_pgmask = pageblock_nr_pages - 1; |
|
unsigned long nr_free = 0; |
|
|
|
for (; pfn < end_pfn; pfn++) { |
|
if (!deferred_pfn_valid(pfn)) { |
|
deferred_free_range(pfn - nr_free, nr_free); |
|
nr_free = 0; |
|
} else if (!(pfn & nr_pgmask)) { |
|
deferred_free_range(pfn - nr_free, nr_free); |
|
nr_free = 1; |
|
} else { |
|
nr_free++; |
|
} |
|
} |
|
/* Free the last block of pages to allocator */ |
|
deferred_free_range(pfn - nr_free, nr_free); |
|
} |
|
|
|
/* |
|
* Initialize struct pages. We minimize pfn page lookups and scheduler checks |
|
* by performing it only once every pageblock_nr_pages. |
|
* Return number of pages initialized. |
|
*/ |
|
static unsigned long __init deferred_init_pages(struct zone *zone, |
|
unsigned long pfn, |
|
unsigned long end_pfn) |
|
{ |
|
unsigned long nr_pgmask = pageblock_nr_pages - 1; |
|
int nid = zone_to_nid(zone); |
|
unsigned long nr_pages = 0; |
|
int zid = zone_idx(zone); |
|
struct page *page = NULL; |
|
|
|
for (; pfn < end_pfn; pfn++) { |
|
if (!deferred_pfn_valid(pfn)) { |
|
page = NULL; |
|
continue; |
|
} else if (!page || !(pfn & nr_pgmask)) { |
|
page = pfn_to_page(pfn); |
|
} else { |
|
page++; |
|
} |
|
__init_single_page(page, pfn, zid, nid); |
|
nr_pages++; |
|
} |
|
return (nr_pages); |
|
} |
|
|
|
/* |
|
* This function is meant to pre-load the iterator for the zone init. |
|
* Specifically it walks through the ranges until we are caught up to the |
|
* first_init_pfn value and exits there. If we never encounter the value we |
|
* return false indicating there are no valid ranges left. |
|
*/ |
|
static bool __init |
|
deferred_init_mem_pfn_range_in_zone(u64 *i, struct zone *zone, |
|
unsigned long *spfn, unsigned long *epfn, |
|
unsigned long first_init_pfn) |
|
{ |
|
u64 j; |
|
|
|
/* |
|
* Start out by walking through the ranges in this zone that have |
|
* already been initialized. We don't need to do anything with them |
|
* so we just need to flush them out of the system. |
|
*/ |
|
for_each_free_mem_pfn_range_in_zone(j, zone, spfn, epfn) { |
|
if (*epfn <= first_init_pfn) |
|
continue; |
|
if (*spfn < first_init_pfn) |
|
*spfn = first_init_pfn; |
|
*i = j; |
|
return true; |
|
} |
|
|
|
return false; |
|
} |
|
|
|
/* |
|
* Initialize and free pages. We do it in two loops: first we initialize |
|
* struct page, then free to buddy allocator, because while we are |
|
* freeing pages we can access pages that are ahead (computing buddy |
|
* page in __free_one_page()). |
|
* |
|
* In order to try and keep some memory in the cache we have the loop |
|
* broken along max page order boundaries. This way we will not cause |
|
* any issues with the buddy page computation. |
|
*/ |
|
static unsigned long __init |
|
deferred_init_maxorder(u64 *i, struct zone *zone, unsigned long *start_pfn, |
|
unsigned long *end_pfn) |
|
{ |
|
unsigned long mo_pfn = ALIGN(*start_pfn + 1, MAX_ORDER_NR_PAGES); |
|
unsigned long spfn = *start_pfn, epfn = *end_pfn; |
|
unsigned long nr_pages = 0; |
|
u64 j = *i; |
|
|
|
/* First we loop through and initialize the page values */ |
|
for_each_free_mem_pfn_range_in_zone_from(j, zone, start_pfn, end_pfn) { |
|
unsigned long t; |
|
|
|
if (mo_pfn <= *start_pfn) |
|
break; |
|
|
|
t = min(mo_pfn, *end_pfn); |
|
nr_pages += deferred_init_pages(zone, *start_pfn, t); |
|
|
|
if (mo_pfn < *end_pfn) { |
|
*start_pfn = mo_pfn; |
|
break; |
|
} |
|
} |
|
|
|
/* Reset values and now loop through freeing pages as needed */ |
|
swap(j, *i); |
|
|
|
for_each_free_mem_pfn_range_in_zone_from(j, zone, &spfn, &epfn) { |
|
unsigned long t; |
|
|
|
if (mo_pfn <= spfn) |
|
break; |
|
|
|
t = min(mo_pfn, epfn); |
|
deferred_free_pages(spfn, t); |
|
|
|
if (mo_pfn <= epfn) |
|
break; |
|
} |
|
|
|
return nr_pages; |
|
} |
|
|
|
static void __init |
|
deferred_init_memmap_chunk(unsigned long start_pfn, unsigned long end_pfn, |
|
void *arg) |
|
{ |
|
unsigned long spfn, epfn; |
|
struct zone *zone = arg; |
|
u64 i; |
|
|
|
deferred_init_mem_pfn_range_in_zone(&i, zone, &spfn, &epfn, start_pfn); |
|
|
|
/* |
|
* Initialize and free pages in MAX_ORDER sized increments so that we |
|
* can avoid introducing any issues with the buddy allocator. |
|
*/ |
|
while (spfn < end_pfn) { |
|
deferred_init_maxorder(&i, zone, &spfn, &epfn); |
|
cond_resched(); |
|
} |
|
} |
|
|
|
/* An arch may override for more concurrency. */ |
|
__weak int __init |
|
deferred_page_init_max_threads(const struct cpumask *node_cpumask) |
|
{ |
|
return 1; |
|
} |
|
|
|
/* Initialise remaining memory on a node */ |
|
static int __init deferred_init_memmap(void *data) |
|
{ |
|
pg_data_t *pgdat = data; |
|
const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id); |
|
unsigned long spfn = 0, epfn = 0; |
|
unsigned long first_init_pfn, flags; |
|
unsigned long start = jiffies; |
|
struct zone *zone; |
|
int zid, max_threads; |
|
u64 i; |
|
|
|
/* Bind memory initialisation thread to a local node if possible */ |
|
if (!cpumask_empty(cpumask)) |
|
set_cpus_allowed_ptr(current, cpumask); |
|
|
|
pgdat_resize_lock(pgdat, &flags); |
|
first_init_pfn = pgdat->first_deferred_pfn; |
|
if (first_init_pfn == ULONG_MAX) { |
|
pgdat_resize_unlock(pgdat, &flags); |
|
pgdat_init_report_one_done(); |
|
return 0; |
|
} |
|
|
|
/* Sanity check boundaries */ |
|
BUG_ON(pgdat->first_deferred_pfn < pgdat->node_start_pfn); |
|
BUG_ON(pgdat->first_deferred_pfn > pgdat_end_pfn(pgdat)); |
|
pgdat->first_deferred_pfn = ULONG_MAX; |
|
|
|
/* |
|
* Once we unlock here, the zone cannot be grown anymore, thus if an |
|
* interrupt thread must allocate this early in boot, zone must be |
|
* pre-grown prior to start of deferred page initialization. |
|
*/ |
|
pgdat_resize_unlock(pgdat, &flags); |
|
|
|
/* Only the highest zone is deferred so find it */ |
|
for (zid = 0; zid < MAX_NR_ZONES; zid++) { |
|
zone = pgdat->node_zones + zid; |
|
if (first_init_pfn < zone_end_pfn(zone)) |
|
break; |
|
} |
|
|
|
/* If the zone is empty somebody else may have cleared out the zone */ |
|
if (!deferred_init_mem_pfn_range_in_zone(&i, zone, &spfn, &epfn, |
|
first_init_pfn)) |
|
goto zone_empty; |
|
|
|
max_threads = deferred_page_init_max_threads(cpumask); |
|
|
|
while (spfn < epfn) { |
|
unsigned long epfn_align = ALIGN(epfn, PAGES_PER_SECTION); |
|
struct padata_mt_job job = { |
|
.thread_fn = deferred_init_memmap_chunk, |
|
.fn_arg = zone, |
|
.start = spfn, |
|
.size = epfn_align - spfn, |
|
.align = PAGES_PER_SECTION, |
|
.min_chunk = PAGES_PER_SECTION, |
|
.max_threads = max_threads, |
|
}; |
|
|
|
padata_do_multithreaded(&job); |
|
deferred_init_mem_pfn_range_in_zone(&i, zone, &spfn, &epfn, |
|
epfn_align); |
|
} |
|
zone_empty: |
|
/* Sanity check that the next zone really is unpopulated */ |
|
WARN_ON(++zid < MAX_NR_ZONES && populated_zone(++zone)); |
|
|
|
pr_info("node %d deferred pages initialised in %ums\n", |
|
pgdat->node_id, jiffies_to_msecs(jiffies - start)); |
|
|
|
pgdat_init_report_one_done(); |
|
return 0; |
|
} |
|
|
|
/* |
|
* If this zone has deferred pages, try to grow it by initializing enough |
|
* deferred pages to satisfy the allocation specified by order, rounded up to |
|
* the nearest PAGES_PER_SECTION boundary. So we're adding memory in increments |
|
* of SECTION_SIZE bytes by initializing struct pages in increments of |
|
* PAGES_PER_SECTION * sizeof(struct page) bytes. |
|
* |
|
* Return true when zone was grown, otherwise return false. We return true even |
|
* when we grow less than requested, to let the caller decide if there are |
|
* enough pages to satisfy the allocation. |
|
* |
|
* Note: We use noinline because this function is needed only during boot, and |
|
* it is called from a __ref function _deferred_grow_zone. This way we are |
|
* making sure that it is not inlined into permanent text section. |
|
*/ |
|
static noinline bool __init |
|
deferred_grow_zone(struct zone *zone, unsigned int order) |
|
{ |
|
unsigned long nr_pages_needed = ALIGN(1 << order, PAGES_PER_SECTION); |
|
pg_data_t *pgdat = zone->zone_pgdat; |
|
unsigned long first_deferred_pfn = pgdat->first_deferred_pfn; |
|
unsigned long spfn, epfn, flags; |
|
unsigned long nr_pages = 0; |
|
u64 i; |
|
|
|
/* Only the last zone may have deferred pages */ |
|
if (zone_end_pfn(zone) != pgdat_end_pfn(pgdat)) |
|
return false; |
|
|
|
pgdat_resize_lock(pgdat, &flags); |
|
|
|
/* |
|
* If someone grew this zone while we were waiting for spinlock, return |
|
* true, as there might be enough pages already. |
|
*/ |
|
if (first_deferred_pfn != pgdat->first_deferred_pfn) { |
|
pgdat_resize_unlock(pgdat, &flags); |
|
return true; |
|
} |
|
|
|
/* If the zone is empty somebody else may have cleared out the zone */ |
|
if (!deferred_init_mem_pfn_range_in_zone(&i, zone, &spfn, &epfn, |
|
first_deferred_pfn)) { |
|
pgdat->first_deferred_pfn = ULONG_MAX; |
|
pgdat_resize_unlock(pgdat, &flags); |
|
/* Retry only once. */ |
|
return first_deferred_pfn != ULONG_MAX; |
|
} |
|
|
|
/* |
|
* Initialize and free pages in MAX_ORDER sized increments so |
|
* that we can avoid introducing any issues with the buddy |
|
* allocator. |
|
*/ |
|
while (spfn < epfn) { |
|
/* update our first deferred PFN for this section */ |
|
first_deferred_pfn = spfn; |
|
|
|
nr_pages += deferred_init_maxorder(&i, zone, &spfn, &epfn); |
|
touch_nmi_watchdog(); |
|
|
|
/* We should only stop along section boundaries */ |
|
if ((first_deferred_pfn ^ spfn) < PAGES_PER_SECTION) |
|
continue; |
|
|
|
/* If our quota has been met we can stop here */ |
|
if (nr_pages >= nr_pages_needed) |
|
break; |
|
} |
|
|
|
pgdat->first_deferred_pfn = spfn; |
|
pgdat_resize_unlock(pgdat, &flags); |
|
|
|
return nr_pages > 0; |
|
} |
|
|
|
/* |
|
* deferred_grow_zone() is __init, but it is called from |
|
* get_page_from_freelist() during early boot until deferred_pages permanently |
|
* disables this call. This is why we have refdata wrapper to avoid warning, |
|
* and to ensure that the function body gets unloaded. |
|
*/ |
|
static bool __ref |
|
_deferred_grow_zone(struct zone *zone, unsigned int order) |
|
{ |
|
return deferred_grow_zone(zone, order); |
|
} |
|
|
|
#endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */ |
|
|
|
void __init page_alloc_init_late(void) |
|
{ |
|
struct zone *zone; |
|
int nid; |
|
|
|
#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT |
|
|
|
/* There will be num_node_state(N_MEMORY) threads */ |
|
atomic_set(&pgdat_init_n_undone, num_node_state(N_MEMORY)); |
|
for_each_node_state(nid, N_MEMORY) { |
|
kthread_run(deferred_init_memmap, NODE_DATA(nid), "pgdatinit%d", nid); |
|
} |
|
|
|
/* Block until all are initialised */ |
|
wait_for_completion(&pgdat_init_all_done_comp); |
|
|
|
/* |
|
* We initialized the rest of the deferred pages. Permanently disable |
|
* on-demand struct page initialization. |
|
*/ |
|
static_branch_disable(&deferred_pages); |
|
|
|
/* Reinit limits that are based on free pages after the kernel is up */ |
|
files_maxfiles_init(); |
|
#endif |
|
|
|
buffer_init(); |
|
|
|
/* Discard memblock private memory */ |
|
memblock_discard(); |
|
|
|
for_each_node_state(nid, N_MEMORY) |
|
shuffle_free_memory(NODE_DATA(nid)); |
|
|
|
for_each_populated_zone(zone) |
|
set_zone_contiguous(zone); |
|
} |
|
|
|
#ifdef CONFIG_CMA |
|
/* Free whole pageblock and set its migration type to MIGRATE_CMA. */ |
|
void __init init_cma_reserved_pageblock(struct page *page) |
|
{ |
|
unsigned i = pageblock_nr_pages; |
|
struct page *p = page; |
|
|
|
do { |
|
__ClearPageReserved(p); |
|
set_page_count(p, 0); |
|
} while (++p, --i); |
|
|
|
set_pageblock_migratetype(page, MIGRATE_CMA); |
|
|
|
if (pageblock_order >= MAX_ORDER) { |
|
i = pageblock_nr_pages; |
|
p = page; |
|
do { |
|
set_page_refcounted(p); |
|
__free_pages(p, MAX_ORDER - 1); |
|
p += MAX_ORDER_NR_PAGES; |
|
} while (i -= MAX_ORDER_NR_PAGES); |
|
} else { |
|
set_page_refcounted(page); |
|
__free_pages(page, pageblock_order); |
|
} |
|
|
|
adjust_managed_page_count(page, pageblock_nr_pages); |
|
page_zone(page)->cma_pages += pageblock_nr_pages; |
|
} |
|
#endif |
|
|
|
/* |
|
* The order of subdivision here is critical for the IO subsystem. |
|
* Please do not alter this order without good reasons and regression |
|
* testing. Specifically, as large blocks of memory are subdivided, |
|
* the order in which smaller blocks are delivered depends on the order |
|
* they're subdivided in this function. This is the primary factor |
|
* influencing the order in which pages are delivered to the IO |
|
* subsystem according to empirical testing, and this is also justified |
|
* by considering the behavior of a buddy system containing a single |
|
* large block of memory acted on by a series of small allocations. |
|
* This behavior is a critical factor in sglist merging's success. |
|
* |
|
* -- nyc |
|
*/ |
|
static inline void expand(struct zone *zone, struct page *page, |
|
int low, int high, int migratetype) |
|
{ |
|
unsigned long size = 1 << high; |
|
|
|
while (high > low) { |
|
high--; |
|
size >>= 1; |
|
VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]); |
|
|
|
/* |
|
* Mark as guard pages (or page), that will allow to |
|
* merge back to allocator when buddy will be freed. |
|
* Corresponding page table entries will not be touched, |
|
* pages will stay not present in virtual address space |
|
*/ |
|
if (set_page_guard(zone, &page[size], high, migratetype)) |
|
continue; |
|
|
|
add_to_free_list(&page[size], zone, high, migratetype); |
|
set_buddy_order(&page[size], high); |
|
} |
|
} |
|
|
|
static void check_new_page_bad(struct page *page) |
|
{ |
|
if (unlikely(page->flags & __PG_HWPOISON)) { |
|
/* Don't complain about hwpoisoned pages */ |
|
page_mapcount_reset(page); /* remove PageBuddy */ |
|
return; |
|
} |
|
|
|
bad_page(page, |
|
page_bad_reason(page, PAGE_FLAGS_CHECK_AT_PREP)); |
|
} |
|
|
|
/* |
|
* This page is about to be returned from the page allocator |
|
*/ |
|
static inline int check_new_page(struct page *page) |
|
{ |
|
if (likely(page_expected_state(page, |
|
PAGE_FLAGS_CHECK_AT_PREP|__PG_HWPOISON))) |
|
return 0; |
|
|
|
check_new_page_bad(page); |
|
return 1; |
|
} |
|
|
|
#ifdef CONFIG_DEBUG_VM |
|
/* |
|
* With DEBUG_VM enabled, order-0 pages are checked for expected state when |
|
* being allocated from pcp lists. With debug_pagealloc also enabled, they are |
|
* also checked when pcp lists are refilled from the free lists. |
|
*/ |
|
static inline bool check_pcp_refill(struct page *page) |
|
{ |
|
if (debug_pagealloc_enabled_static()) |
|
return check_new_page(page); |
|
else |
|
return false; |
|
} |
|
|
|
static inline bool check_new_pcp(struct page *page) |
|
{ |
|
return check_new_page(page); |
|
} |
|
#else |
|
/* |
|
* With DEBUG_VM disabled, free order-0 pages are checked for expected state |
|
* when pcp lists are being refilled from the free lists. With debug_pagealloc |
|
* enabled, they are also checked when being allocated from the pcp lists. |
|
*/ |
|
static inline bool check_pcp_refill(struct page *page) |
|
{ |
|
return check_new_page(page); |
|
} |
|
static inline bool check_new_pcp(struct page *page) |
|
{ |
|
if (debug_pagealloc_enabled_static()) |
|
return check_new_page(page); |
|
else |
|
return false; |
|
} |
|
#endif /* CONFIG_DEBUG_VM */ |
|
|
|
static bool check_new_pages(struct page *page, unsigned int order) |
|
{ |
|
int i; |
|
for (i = 0; i < (1 << order); i++) { |
|
struct page *p = page + i; |
|
|
|
if (unlikely(check_new_page(p))) |
|
return true; |
|
} |
|
|
|
return false; |
|
} |
|
|
|
inline void post_alloc_hook(struct page *page, unsigned int order, |
|
gfp_t gfp_flags) |
|
{ |
|
set_page_private(page, 0); |
|
set_page_refcounted(page); |
|
|
|
arch_alloc_page(page, order); |
|
debug_pagealloc_map_pages(page, 1 << order); |
|
|
|
/* |
|
* Page unpoisoning must happen before memory initialization. |
|
* Otherwise, the poison pattern will be overwritten for __GFP_ZERO |
|
* allocations and the page unpoisoning code will complain. |
|
*/ |
|
kernel_unpoison_pages(page, 1 << order); |
|
|
|
/* |
|
* As memory initialization might be integrated into KASAN, |
|
* kasan_alloc_pages and kernel_init_free_pages must be |
|
* kept together to avoid discrepancies in behavior. |
|
*/ |
|
if (kasan_has_integrated_init()) { |
|
kasan_alloc_pages(page, order, gfp_flags); |
|
} else { |
|
bool init = !want_init_on_free() && want_init_on_alloc(gfp_flags); |
|
|
|
kasan_unpoison_pages(page, order, init); |
|
if (init) |
|
kernel_init_free_pages(page, 1 << order, |
|
gfp_flags & __GFP_ZEROTAGS); |
|
} |
|
|
|
set_page_owner(page, order, gfp_flags); |
|
} |
|
|
|
static void prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags, |
|
unsigned int alloc_flags) |
|
{ |
|
post_alloc_hook(page, order, gfp_flags); |
|
|
|
if (order && (gfp_flags & __GFP_COMP)) |
|
prep_compound_page(page, order); |
|
|
|
/* |
|
* page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to |
|
* allocate the page. The expectation is that the caller is taking |
|
* steps that will free more memory. The caller should avoid the page |
|
* being used for !PFMEMALLOC purposes. |
|
*/ |
|
if (alloc_flags & ALLOC_NO_WATERMARKS) |
|
set_page_pfmemalloc(page); |
|
else |
|
clear_page_pfmemalloc(page); |
|
} |
|
|
|
/* |
|
* Go through the free lists for the given migratetype and remove |
|
* the smallest available page from the freelists |
|
*/ |
|
static __always_inline |
|
struct page *__rmqueue_smallest(struct zone *zone, unsigned int order, |
|
int migratetype) |
|
{ |
|
unsigned int current_order; |
|
struct free_area *area; |
|
struct page *page; |
|
|
|
/* Find a page of the appropriate size in the preferred list */ |
|
for (current_order = order; current_order < MAX_ORDER; ++current_order) { |
|
area = &(zone->free_area[current_order]); |
|
page = get_page_from_free_area(area, migratetype); |
|
if (!page) |
|
continue; |
|
del_page_from_free_list(page, zone, current_order); |
|
expand(zone, page, order, current_order, migratetype); |
|
set_pcppage_migratetype(page, migratetype); |
|
return page; |
|
} |
|
|
|
return NULL; |
|
} |
|
|
|
|
|
/* |
|
* This array describes the order lists are fallen back to when |
|
* the free lists for the desirable migrate type are depleted |
|
*/ |
|
static int fallbacks[MIGRATE_TYPES][3] = { |
|
[MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_TYPES }, |
|
[MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_TYPES }, |
|
[MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_TYPES }, |
|
#ifdef CONFIG_CMA |
|
[MIGRATE_CMA] = { MIGRATE_TYPES }, /* Never used */ |
|
#endif |
|
#ifdef CONFIG_MEMORY_ISOLATION |
|
[MIGRATE_ISOLATE] = { MIGRATE_TYPES }, /* Never used */ |
|
#endif |
|
}; |
|
|
|
#ifdef CONFIG_CMA |
|
static __always_inline struct page *__rmqueue_cma_fallback(struct zone *zone, |
|
unsigned int order) |
|
{ |
|
return __rmqueue_smallest(zone, order, MIGRATE_CMA); |
|
} |
|
#else |
|
static inline struct page *__rmqueue_cma_fallback(struct zone *zone, |
|
unsigned int order) { return NULL; } |
|
#endif |
|
|
|
/* |
|
* Move the free pages in a range to the freelist tail of the requested type. |
|
* Note that start_page and end_pages are not aligned on a pageblock |
|
* boundary. If alignment is required, use move_freepages_block() |
|
*/ |
|
static int move_freepages(struct zone *zone, |
|
unsigned long start_pfn, unsigned long end_pfn, |
|
int migratetype, int *num_movable) |
|
{ |
|
struct page *page; |
|
unsigned long pfn; |
|
unsigned int order; |
|
int pages_moved = 0; |
|
|
|
for (pfn = start_pfn; pfn <= end_pfn;) { |
|
page = pfn_to_page(pfn); |
|
if (!PageBuddy(page)) { |
|
/* |
|
* We assume that pages that could be isolated for |
|
* migration are movable. But we don't actually try |
|
* isolating, as that would be expensive. |
|
*/ |
|
if (num_movable && |
|
(PageLRU(page) || __PageMovable(page))) |
|
(*num_movable)++; |
|
pfn++; |
|
continue; |
|
} |
|
|
|
/* Make sure we are not inadvertently changing nodes */ |
|
VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page); |
|
VM_BUG_ON_PAGE(page_zone(page) != zone, page); |
|
|
|
order = buddy_order(page); |
|
move_to_free_list(page, zone, order, migratetype); |
|
pfn += 1 << order; |
|
pages_moved += 1 << order; |
|
} |
|
|
|
return pages_moved; |
|
} |
|
|
|
int move_freepages_block(struct zone *zone, struct page *page, |
|
int migratetype, int *num_movable) |
|
{ |
|
unsigned long start_pfn, end_pfn, pfn; |
|
|
|
if (num_movable) |
|
*num_movable = 0; |
|
|
|
pfn = page_to_pfn(page); |
|
start_pfn = pfn & ~(pageblock_nr_pages - 1); |
|
end_pfn = start_pfn + pageblock_nr_pages - 1; |
|
|
|
/* Do not cross zone boundaries */ |
|
if (!zone_spans_pfn(zone, start_pfn)) |
|
start_pfn = pfn; |
|
if (!zone_spans_pfn(zone, end_pfn)) |
|
return 0; |
|
|
|
return move_freepages(zone, start_pfn, end_pfn, migratetype, |
|
num_movable); |
|
} |
|
|
|
static void change_pageblock_range(struct page *pageblock_page, |
|
int start_order, int migratetype) |
|
{ |
|
int nr_pageblocks = 1 << (start_order - pageblock_order); |
|
|
|
while (nr_pageblocks--) { |
|
set_pageblock_migratetype(pageblock_page, migratetype); |
|
pageblock_page += pageblock_nr_pages; |
|
} |
|
} |
|
|
|
/* |
|
* When we are falling back to another migratetype during allocation, try to |
|
* steal extra free pages from the same pageblocks to satisfy further |
|
* allocations, instead of polluting multiple pageblocks. |
|
* |
|
* If we are stealing a relatively large buddy page, it is likely there will |
|
* be more free pages in the pageblock, so try to steal them all. For |
|
* reclaimable and unmovable allocations, we steal regardless of page size, |
|
* as fragmentation caused by those allocations polluting movable pageblocks |
|
* is worse than movable allocations stealing from unmovable and reclaimable |
|
* pageblocks. |
|
*/ |
|
static bool can_steal_fallback(unsigned int order, int start_mt) |
|
{ |
|
/* |
|
* Leaving this order check is intended, although there is |
|
* relaxed order check in next check. The reason is that |
|
* we can actually steal whole pageblock if this condition met, |
|
* but, below check doesn't guarantee it and that is just heuristic |
|
* so could be changed anytime. |
|
*/ |
|
if (order >= pageblock_order) |
|
return true; |
|
|
|
if (order >= pageblock_order / 2 || |
|
start_mt == MIGRATE_RECLAIMABLE || |
|
start_mt == MIGRATE_UNMOVABLE || |
|
page_group_by_mobility_disabled) |
|
return true; |
|
|
|
return false; |
|
} |
|
|
|
static inline bool boost_watermark(struct zone *zone) |
|
{ |
|
unsigned long max_boost; |
|
|
|
if (!watermark_boost_factor) |
|
return false; |
|
/* |
|
* Don't bother in zones that are unlikely to produce results. |
|
* On small machines, including kdump capture kernels running |
|
* in a small area, boosting the watermark can cause an out of |
|
* memory situation immediately. |
|
*/ |
|
if ((pageblock_nr_pages * 4) > zone_managed_pages(zone)) |
|
return false; |
|
|
|
max_boost = mult_frac(zone->_watermark[WMARK_HIGH], |
|
watermark_boost_factor, 10000); |
|
|
|
/* |
|
* high watermark may be uninitialised if fragmentation occurs |
|
* very early in boot so do not boost. We do not fall |
|
* through and boost by pageblock_nr_pages as failing |
|
* allocations that early means that reclaim is not going |
|
* to help and it may even be impossible to reclaim the |
|
* boosted watermark resulting in a hang. |
|
*/ |
|
if (!max_boost) |
|
return false; |
|
|
|
max_boost = max(pageblock_nr_pages, max_boost); |
|
|
|
zone->watermark_boost = min(zone->watermark_boost + pageblock_nr_pages, |
|
max_boost); |
|
|
|
return true; |
|
} |
|
|
|
/* |
|
* This function implements actual steal behaviour. If order is large enough, |
|
* we can steal whole pageblock. If not, we first move freepages in this |
|
* pageblock to our migratetype and determine how many already-allocated pages |
|
* are there in the pageblock with a compatible migratetype. If at least half |
|
* of pages are free or compatible, we can change migratetype of the pageblock |
|
* itself, so pages freed in the future will be put on the correct free list. |
|
*/ |
|
static void steal_suitable_fallback(struct zone *zone, struct page *page, |
|
unsigned int alloc_flags, int start_type, bool whole_block) |
|
{ |
|
unsigned int current_order = buddy_order(page); |
|
int free_pages, movable_pages, alike_pages; |
|
int old_block_type; |
|
|
|
old_block_type = get_pageblock_migratetype(page); |
|
|
|
/* |
|
* This can happen due to races and we want to prevent broken |
|
* highatomic accounting. |
|
*/ |
|
if (is_migrate_highatomic(old_block_type)) |
|
goto single_page; |
|
|
|
/* Take ownership for orders >= pageblock_order */ |
|
if (current_order >= pageblock_order) { |
|
change_pageblock_range(page, current_order, start_type); |
|
goto single_page; |
|
} |
|
|
|
/* |
|
* Boost watermarks to increase reclaim pressure to reduce the |
|
* likelihood of future fallbacks. Wake kswapd now as the node |
|
* may be balanced overall and kswapd will not wake naturally. |
|
*/ |
|
if (boost_watermark(zone) && (alloc_flags & ALLOC_KSWAPD)) |
|
set_bit(ZONE_BOOSTED_WATERMARK, &zone->flags); |
|
|
|
/* We are not allowed to try stealing from the whole block */ |
|
if (!whole_block) |
|
goto single_page; |
|
|
|
free_pages = move_freepages_block(zone, page, start_type, |
|
&movable_pages); |
|
/* |
|
* Determine how many pages are compatible with our allocation. |
|
* For movable allocation, it's the number of movable pages which |
|
* we just obtained. For other types it's a bit more tricky. |
|
*/ |
|
if (start_type == MIGRATE_MOVABLE) { |
|
alike_pages = movable_pages; |
|
} else { |
|
/* |
|
* If we are falling back a RECLAIMABLE or UNMOVABLE allocation |
|
* to MOVABLE pageblock, consider all non-movable pages as |
|
* compatible. If it's UNMOVABLE falling back to RECLAIMABLE or |
|
* vice versa, be conservative since we can't distinguish the |
|
* exact migratetype of non-movable pages. |
|
*/ |
|
if (old_block_type == MIGRATE_MOVABLE) |
|
alike_pages = pageblock_nr_pages |
|
- (free_pages + movable_pages); |
|
else |
|
alike_pages = 0; |
|
} |
|
|
|
/* moving whole block can fail due to zone boundary conditions */ |
|
if (!free_pages) |
|
goto single_page; |
|
|
|
/* |
|
* If a sufficient number of pages in the block are either free or of |
|
* comparable migratability as our allocation, claim the whole block. |
|
*/ |
|
if (free_pages + alike_pages >= (1 << (pageblock_order-1)) || |
|
page_group_by_mobility_disabled) |
|
set_pageblock_migratetype(page, start_type); |
|
|
|
return; |
|
|
|
single_page: |
|
move_to_free_list(page, zone, current_order, start_type); |
|
} |
|
|
|
/* |
|
* Check whether there is a suitable fallback freepage with requested order. |
|
* If only_stealable is true, this function returns fallback_mt only if |
|
* we can steal other freepages all together. This would help to reduce |
|
* fragmentation due to mixed migratetype pages in one pageblock. |
|
*/ |
|
int find_suitable_fallback(struct free_area *area, unsigned int order, |
|
int migratetype, bool only_stealable, bool *can_steal) |
|
{ |
|
int i; |
|
int fallback_mt; |
|
|
|
if (area->nr_free == 0) |
|
return -1; |
|
|
|
*can_steal = false; |
|
for (i = 0;; i++) { |
|
fallback_mt = fallbacks[migratetype][i]; |
|
if (fallback_mt == MIGRATE_TYPES) |
|
break; |
|
|
|
if (free_area_empty(area, fallback_mt)) |
|
continue; |
|
|
|
if (can_steal_fallback(order, migratetype)) |
|
*can_steal = true; |
|
|
|
if (!only_stealable) |
|
return fallback_mt; |
|
|
|
if (*can_steal) |
|
return fallback_mt; |
|
} |
|
|
|
return -1; |
|
} |
|
|
|
/* |
|
* Reserve a pageblock for exclusive use of high-order atomic allocations if |
|
* there are no empty page blocks that contain a page with a suitable order |
|
*/ |
|
static void reserve_highatomic_pageblock(struct page *page, struct zone *zone, |
|
unsigned int alloc_order) |
|
{ |
|
int mt; |
|
unsigned long max_managed, flags; |
|
|
|
/* |
|
* Limit the number reserved to 1 pageblock or roughly 1% of a zone. |
|
* Check is race-prone but harmless. |
|
*/ |
|
max_managed = (zone_managed_pages(zone) / 100) + pageblock_nr_pages; |
|
if (zone->nr_reserved_highatomic >= max_managed) |
|
return; |
|
|
|
spin_lock_irqsave(&zone->lock, flags); |
|
|
|
/* Recheck the nr_reserved_highatomic limit under the lock */ |
|
if (zone->nr_reserved_highatomic >= max_managed) |
|
goto out_unlock; |
|
|
|
/* Yoink! */ |
|
mt = get_pageblock_migratetype(page); |
|
if (!is_migrate_highatomic(mt) && !is_migrate_isolate(mt) |
|
&& !is_migrate_cma(mt)) { |
|
zone->nr_reserved_highatomic += pageblock_nr_pages; |
|
set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC); |
|
move_freepages_block(zone, page, MIGRATE_HIGHATOMIC, NULL); |
|
} |
|
|
|
out_unlock: |
|
spin_unlock_irqrestore(&zone->lock, flags); |
|
} |
|
|
|
/* |
|
* Used when an allocation is about to fail under memory pressure. This |
|
* potentially hurts the reliability of high-order allocations when under |
|
* intense memory pressure but failed atomic allocations should be easier |
|
* to recover from than an OOM. |
|
* |
|
* If @force is true, try to unreserve a pageblock even though highatomic |
|
* pageblock is exhausted. |
|
*/ |
|
static bool unreserve_highatomic_pageblock(const struct alloc_context *ac, |
|
bool force) |
|
{ |
|
struct zonelist *zonelist = ac->zonelist; |
|
unsigned long flags; |
|
struct zoneref *z; |
|
struct zone *zone; |
|
struct page *page; |
|
int order; |
|
bool ret; |
|
|
|
for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->highest_zoneidx, |
|
ac->nodemask) { |
|
/* |
|
* Preserve at least one pageblock unless memory pressure |
|
* is really high. |
|
*/ |
|
if (!force && zone->nr_reserved_highatomic <= |
|
pageblock_nr_pages) |
|
continue; |
|
|
|
spin_lock_irqsave(&zone->lock, flags); |
|
for (order = 0; order < MAX_ORDER; order++) { |
|
struct free_area *area = &(zone->free_area[order]); |
|
|
|
page = get_page_from_free_area(area, MIGRATE_HIGHATOMIC); |
|
if (!page) |
|
continue; |
|
|
|
/* |
|
* In page freeing path, migratetype change is racy so |
|
* we can counter several free pages in a pageblock |
|
* in this loop although we changed the pageblock type |
|
* from highatomic to ac->migratetype. So we should |
|
* adjust the count once. |
|
*/ |
|
if (is_migrate_highatomic_page(page)) { |
|
/* |
|
* It should never happen but changes to |
|
* locking could inadvertently allow a per-cpu |
|
* drain to add pages to MIGRATE_HIGHATOMIC |
|
* while unreserving so be safe and watch for |
|
* underflows. |
|
*/ |
|
zone->nr_reserved_highatomic -= min( |
|
pageblock_nr_pages, |
|
zone->nr_reserved_highatomic); |
|
} |
|
|
|
/* |
|
* Convert to ac->migratetype and avoid the normal |
|
* pageblock stealing heuristics. Minimally, the caller |
|
* is doing the work and needs the pages. More |
|
* importantly, if the block was always converted to |
|
* MIGRATE_UNMOVABLE or another type then the number |
|
* of pageblocks that cannot be completely freed |
|
* may increase. |
|
*/ |
|
set_pageblock_migratetype(page, ac->migratetype); |
|
ret = move_freepages_block(zone, page, ac->migratetype, |
|
NULL); |
|
if (ret) { |
|
spin_unlock_irqrestore(&zone->lock, flags); |
|
return ret; |
|
} |
|
} |
|
spin_unlock_irqrestore(&zone->lock, flags); |
|
} |
|
|
|
return false; |
|
} |
|
|
|
/* |
|
* Try finding a free buddy page on the fallback list and put it on the free |
|
* list of requested migratetype, possibly along with other pages from the same |
|
* block, depending on fragmentation avoidance heuristics. Returns true if |
|
* fallback was found so that __rmqueue_smallest() can grab it. |
|
* |
|
* The use of signed ints for order and current_order is a deliberate |
|
* deviation from the rest of this file, to make the for loop |
|
* condition simpler. |
|
*/ |
|
static __always_inline bool |
|
__rmqueue_fallback(struct zone *zone, int order, int start_migratetype, |
|
unsigned int alloc_flags) |
|
{ |
|
struct free_area *area; |
|
int current_order; |
|
int min_order = order; |
|
struct page *page; |
|
int fallback_mt; |
|
bool can_steal; |
|
|
|
/* |
|
* Do not steal pages from freelists belonging to other pageblocks |
|
* i.e. orders < pageblock_order. If there are no local zones free, |
|
* the zonelists will be reiterated without ALLOC_NOFRAGMENT. |
|
*/ |
|
if (alloc_flags & ALLOC_NOFRAGMENT) |
|
min_order = pageblock_order; |
|
|
|
/* |
|
* Find the largest available free page in the other list. This roughly |
|
* approximates finding the pageblock with the most free pages, which |
|
* would be too costly to do exactly. |
|
*/ |
|
for (current_order = MAX_ORDER - 1; current_order >= min_order; |
|
--current_order) { |
|
area = &(zone->free_area[current_order]); |
|
fallback_mt = find_suitable_fallback(area, current_order, |
|
start_migratetype, false, &can_steal); |
|
if (fallback_mt == -1) |
|
continue; |
|
|
|
/* |
|
* We cannot steal all free pages from the pageblock and the |
|
* requested migratetype is movable. In that case it's better to |
|
* steal and split the smallest available page instead of the |
|
* largest available page, because even if the next movable |
|
* allocation falls back into a different pageblock than this |
|
* one, it won't cause permanent fragmentation. |
|
*/ |
|
if (!can_steal && start_migratetype == MIGRATE_MOVABLE |
|
&& current_order > order) |
|
goto find_smallest; |
|
|
|
goto do_steal; |
|
} |
|
|
|
return false; |
|
|
|
find_smallest: |
|
for (current_order = order; current_order < MAX_ORDER; |
|
current_order++) { |
|
area = &(zone->free_area[current_order]); |
|
fallback_mt = find_suitable_fallback(area, current_order, |
|
start_migratetype, false, &can_steal); |
|
if (fallback_mt != -1) |
|
break; |
|
} |
|
|
|
/* |
|
* This should not happen - we already found a suitable fallback |
|
* when looking for the largest page. |
|
*/ |
|
VM_BUG_ON(current_order == MAX_ORDER); |
|
|
|
do_steal: |
|
page = get_page_from_free_area(area, fallback_mt); |
|
|
|
steal_suitable_fallback(zone, page, alloc_flags, start_migratetype, |
|
can_steal); |
|
|
|
trace_mm_page_alloc_extfrag(page, order, current_order, |
|
start_migratetype, fallback_mt); |
|
|
|
return true; |
|
|
|
} |
|
|
|
/* |
|
* Do the hard work of removing an element from the buddy allocator. |
|
* Call me with the zone->lock already held. |
|
*/ |
|
static __always_inline struct page * |
|
__rmqueue(struct zone *zone, unsigned int order, int migratetype, |
|
unsigned int alloc_flags) |
|
{ |
|
struct page *page; |
|
|
|
if (IS_ENABLED(CONFIG_CMA)) { |
|
/* |
|
* Balance movable allocations between regular and CMA areas by |
|
* allocating from CMA when over half of the zone's free memory |
|
* is in the CMA area. |
|
*/ |
|
if (alloc_flags & ALLOC_CMA && |
|
zone_page_state(zone, NR_FREE_CMA_PAGES) > |
|
zone_page_state(zone, NR_FREE_PAGES) / 2) { |
|
page = __rmqueue_cma_fallback(zone, order); |
|
if (page) |
|
goto out; |
|
} |
|
} |
|
retry: |
|
page = __rmqueue_smallest(zone, order, migratetype); |
|
if (unlikely(!page)) { |
|
if (alloc_flags & ALLOC_CMA) |
|
page = __rmqueue_cma_fallback(zone, order); |
|
|
|
if (!page && __rmqueue_fallback(zone, order, migratetype, |
|
alloc_flags)) |
|
goto retry; |
|
} |
|
out: |
|
if (page) |
|
trace_mm_page_alloc_zone_locked(page, order, migratetype); |
|
return page; |
|
} |
|
|
|
/* |
|
* Obtain a specified number of elements from the buddy allocator, all under |
|
* a single hold of the lock, for efficiency. Add them to the supplied list. |
|
* Returns the number of new pages which were placed at *list. |
|
*/ |
|
static int rmqueue_bulk(struct zone *zone, unsigned int order, |
|
unsigned long count, struct list_head *list, |
|
int migratetype, unsigned int alloc_flags) |
|
{ |
|
int i, allocated = 0; |
|
|
|
/* |
|
* local_lock_irq held so equivalent to spin_lock_irqsave for |
|
* both PREEMPT_RT and non-PREEMPT_RT configurations. |
|
*/ |
|
spin_lock(&zone->lock); |
|
for (i = 0; i < count; ++i) { |
|
struct page *page = __rmqueue(zone, order, migratetype, |
|
alloc_flags); |
|
if (unlikely(page == NULL)) |
|
break; |
|
|
|
if (unlikely(check_pcp_refill(page))) |
|
continue; |
|
|
|
/* |
|
* Split buddy pages returned by expand() are received here in |
|
* physical page order. The page is added to the tail of |
|
* caller's list. From the callers perspective, the linked list |
|
* is ordered by page number under some conditions. This is |
|
* useful for IO devices that can forward direction from the |
|
* head, thus also in the physical page order. This is useful |
|
* for IO devices that can merge IO requests if the physical |
|
* pages are ordered properly. |
|
*/ |
|
list_add_tail(&page->lru, list); |
|
allocated++; |
|
if (is_migrate_cma(get_pcppage_migratetype(page))) |
|
__mod_zone_page_state(zone, NR_FREE_CMA_PAGES, |
|
-(1 << order)); |
|
} |
|
|
|
/* |
|
* i pages were removed from the buddy list even if some leak due |
|
* to check_pcp_refill failing so adjust NR_FREE_PAGES based |
|
* on i. Do not confuse with 'allocated' which is the number of |
|
* pages added to the pcp list. |
|
*/ |
|
__mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order)); |
|
spin_unlock(&zone->lock); |
|
return allocated; |
|
} |
|
|
|
#ifdef CONFIG_NUMA |
|
/* |
|
* Called from the vmstat counter updater to drain pagesets of this |
|
* currently executing processor on remote nodes after they have |
|
* expired. |
|
* |
|
* Note that this function must be called with the thread pinned to |
|
* a single processor. |
|
*/ |
|
void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp) |
|
{ |
|
unsigned long flags; |
|
int to_drain, batch; |
|
|
|
local_lock_irqsave(&pagesets.lock, flags); |
|
batch = READ_ONCE(pcp->batch); |
|
to_drain = min(pcp->count, batch); |
|
if (to_drain > 0) |
|
free_pcppages_bulk(zone, to_drain, pcp); |
|
local_unlock_irqrestore(&pagesets.lock, flags); |
|
} |
|
#endif |
|
|
|
/* |
|
* Drain pcplists of the indicated processor and zone. |
|
* |
|
* The processor must either be the current processor and the |
|
* thread pinned to the current processor or a processor that |
|
* is not online. |
|
*/ |
|
static void drain_pages_zone(unsigned int cpu, struct zone *zone) |
|
{ |
|
unsigned long flags; |
|
struct per_cpu_pages *pcp; |
|
|
|
local_lock_irqsave(&pagesets.lock, flags); |
|
|
|
pcp = per_cpu_ptr(zone->per_cpu_pageset, cpu); |
|
if (pcp->count) |
|
free_pcppages_bulk(zone, pcp->count, pcp); |
|
|
|
local_unlock_irqrestore(&pagesets.lock, flags); |
|
} |
|
|
|
/* |
|
* Drain pcplists of all zones on the indicated processor. |
|
* |
|
* The processor must either be the current processor and the |
|
* thread pinned to the current processor or a processor that |
|
* is not online. |
|
*/ |
|
static void drain_pages(unsigned int cpu) |
|
{ |
|
struct zone *zone; |
|
|
|
for_each_populated_zone(zone) { |
|
drain_pages_zone(cpu, zone); |
|
} |
|
} |
|
|
|
/* |
|
* Spill all of this CPU's per-cpu pages back into the buddy allocator. |
|
* |
|
* The CPU has to be pinned. When zone parameter is non-NULL, spill just |
|
* the single zone's pages. |
|
*/ |
|
void drain_local_pages(struct zone *zone) |
|
{ |
|
int cpu = smp_processor_id(); |
|
|
|
if (zone) |
|
drain_pages_zone(cpu, zone); |
|
else |
|
drain_pages(cpu); |
|
} |
|
|
|
static void drain_local_pages_wq(struct work_struct *work) |
|
{ |
|
struct pcpu_drain *drain; |
|
|
|
drain = container_of(work, struct pcpu_drain, work); |
|
|
|
/* |
|
* drain_all_pages doesn't use proper cpu hotplug protection so |
|
* we can race with cpu offline when the WQ can move this from |
|
* a cpu pinned worker to an unbound one. We can operate on a different |
|
* cpu which is alright but we also have to make sure to not move to |
|
* a different one. |
|
*/ |
|
preempt_disable(); |
|
drain_local_pages(drain->zone); |
|
preempt_enable(); |
|
} |
|
|
|
/* |
|
* The implementation of drain_all_pages(), exposing an extra parameter to |
|
* drain on all cpus. |
|
* |
|
* drain_all_pages() is optimized to only execute on cpus where pcplists are |
|
* not empty. The check for non-emptiness can however race with a free to |
|
* pcplist that has not yet increased the pcp->count from 0 to 1. Callers |
|
* that need the guarantee that every CPU has drained can disable the |
|
* optimizing racy check. |
|
*/ |
|
static void __drain_all_pages(struct zone *zone, bool force_all_cpus) |
|
{ |
|
int cpu; |
|
|
|
/* |
|
* Allocate in the BSS so we won't require allocation in |
|
* direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y |
|
*/ |
|
static cpumask_t cpus_with_pcps; |
|
|
|
/* |
|
* Make sure nobody triggers this path before mm_percpu_wq is fully |
|
* initialized. |
|
*/ |
|
if (WARN_ON_ONCE(!mm_percpu_wq)) |
|
return; |
|
|
|
/* |
|
* Do not drain if one is already in progress unless it's specific to |
|
* a zone. Such callers are primarily CMA and memory hotplug and need |
|
* the drain to be complete when the call returns. |
|
*/ |
|
if (unlikely(!mutex_trylock(&pcpu_drain_mutex))) { |
|
if (!zone) |
|
return; |
|
mutex_lock(&pcpu_drain_mutex); |
|
} |
|
|
|
/* |
|
* We don't care about racing with CPU hotplug event |
|
* as offline notification will cause the notified |
|
* cpu to drain that CPU pcps and on_each_cpu_mask |
|
* disables preemption as part of its processing |
|
*/ |
|
for_each_online_cpu(cpu) { |
|
struct per_cpu_pages *pcp; |
|
struct zone *z; |
|
bool has_pcps = false; |
|
|
|
if (force_all_cpus) { |
|
/* |
|
* The pcp.count check is racy, some callers need a |
|
* guarantee that no cpu is missed. |
|
*/ |
|
has_pcps = true; |
|
} else if (zone) { |
|
pcp = per_cpu_ptr(zone->per_cpu_pageset, cpu); |
|
if (pcp->count) |
|
has_pcps = true; |
|
} else { |
|
for_each_populated_zone(z) { |
|
pcp = per_cpu_ptr(z->per_cpu_pageset, cpu); |
|
if (pcp->count) { |
|
has_pcps = true; |
|
break; |
|
} |
|
} |
|
} |
|
|
|
if (has_pcps) |
|
cpumask_set_cpu(cpu, &cpus_with_pcps); |
|
else |
|
cpumask_clear_cpu(cpu, &cpus_with_pcps); |
|
} |
|
|
|
for_each_cpu(cpu, &cpus_with_pcps) { |
|
struct pcpu_drain *drain = per_cpu_ptr(&pcpu_drain, cpu); |
|
|
|
drain->zone = zone; |
|
INIT_WORK(&drain->work, drain_local_pages_wq); |
|
queue_work_on(cpu, mm_percpu_wq, &drain->work); |
|
} |
|
for_each_cpu(cpu, &cpus_with_pcps) |
|
flush_work(&per_cpu_ptr(&pcpu_drain, cpu)->work); |
|
|
|
mutex_unlock(&pcpu_drain_mutex); |
|
} |
|
|
|
/* |
|
* Spill all the per-cpu pages from all CPUs back into the buddy allocator. |
|
* |
|
* When zone parameter is non-NULL, spill just the single zone's pages. |
|
* |
|
* Note that this can be extremely slow as the draining happens in a workqueue. |
|
*/ |
|
void drain_all_pages(struct zone *zone) |
|
{ |
|
__drain_all_pages(zone, false); |
|
} |
|
|
|
#ifdef CONFIG_HIBERNATION |
|
|
|
/* |
|
* Touch the watchdog for every WD_PAGE_COUNT pages. |
|
*/ |
|
#define WD_PAGE_COUNT (128*1024) |
|
|
|
void mark_free_pages(struct zone *zone) |
|
{ |
|
unsigned long pfn, max_zone_pfn, page_count = WD_PAGE_COUNT; |
|
unsigned long flags; |
|
unsigned int order, t; |
|
struct page *page; |
|
|
|
if (zone_is_empty(zone)) |
|
return; |
|
|
|
spin_lock_irqsave(&zone->lock, flags); |
|
|
|
max_zone_pfn = zone_end_pfn(zone); |
|
for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) |
|
if (pfn_valid(pfn)) { |
|
page = pfn_to_page(pfn); |
|
|
|
if (!--page_count) { |
|
touch_nmi_watchdog(); |
|
page_count = WD_PAGE_COUNT; |
|
} |
|
|
|
if (page_zone(page) != zone) |
|
continue; |
|
|
|
if (!swsusp_page_is_forbidden(page)) |
|
swsusp_unset_page_free(page); |
|
} |
|
|
|
for_each_migratetype_order(order, t) { |
|
list_for_each_entry(page, |
|
&zone->free_area[order].free_list[t], lru) { |
|
unsigned long i; |
|
|
|
pfn = page_to_pfn(page); |
|
for (i = 0; i < (1UL << order); i++) { |
|
if (!--page_count) { |
|
touch_nmi_watchdog(); |
|
page_count = WD_PAGE_COUNT; |
|
} |
|
swsusp_set_page_free(pfn_to_page(pfn + i)); |
|
} |
|
} |
|
} |
|
spin_unlock_irqrestore(&zone->lock, flags); |
|
} |
|
#endif /* CONFIG_PM */ |
|
|
|
static bool free_unref_page_prepare(struct page *page, unsigned long pfn, |
|
unsigned int order) |
|
{ |
|
int migratetype; |
|
|
|
if (!free_pcp_prepare(page, order)) |
|
return false; |
|
|
|
migratetype = get_pfnblock_migratetype(page, pfn); |
|
set_pcppage_migratetype(page, migratetype); |
|
return true; |
|
} |
|
|
|
static int nr_pcp_free(struct per_cpu_pages *pcp, int high, int batch) |
|
{ |
|
int min_nr_free, max_nr_free; |
|
|
|
/* Check for PCP disabled or boot pageset */ |
|
if (unlikely(high < batch)) |
|
return 1; |
|
|
|
/* Leave at least pcp->batch pages on the list */ |
|
min_nr_free = batch; |
|
max_nr_free = high - batch; |
|
|
|
/* |
|
* Double the number of pages freed each time there is subsequent |
|
* freeing of pages without any allocation. |
|
*/ |
|
batch <<= pcp->free_factor; |
|
if (batch < max_nr_free) |
|
pcp->free_factor++; |
|
batch = clamp(batch, min_nr_free, max_nr_free); |
|
|
|
return batch; |
|
} |
|
|
|
static int nr_pcp_high(struct per_cpu_pages *pcp, struct zone *zone) |
|
{ |
|
int high = READ_ONCE(pcp->high); |
|
|
|
if (unlikely(!high)) |
|
return 0; |
|
|
|
if (!test_bit(ZONE_RECLAIM_ACTIVE, &zone->flags)) |
|
return high; |
|
|
|
/* |
|
* If reclaim is active, limit the number of pages that can be |
|
* stored on pcp lists |
|
*/ |
|
return min(READ_ONCE(pcp->batch) << 2, high); |
|
} |
|
|
|
static void free_unref_page_commit(struct page *page, unsigned long pfn, |
|
int migratetype, unsigned int order) |
|
{ |
|
struct zone *zone = page_zone(page); |
|
struct per_cpu_pages *pcp; |
|
int high; |
|
int pindex; |
|
|
|
__count_vm_event(PGFREE); |
|
pcp = this_cpu_ptr(zone->per_cpu_pageset); |
|
pindex = order_to_pindex(migratetype, order); |
|
list_add(&page->lru, &pcp->lists[pindex]); |
|
pcp->count += 1 << order; |
|
high = nr_pcp_high(pcp, zone); |
|
if (pcp->count >= high) { |
|
int batch = READ_ONCE(pcp->batch); |
|
|
|
free_pcppages_bulk(zone, nr_pcp_free(pcp, high, batch), pcp); |
|
} |
|
} |
|
|
|
/* |
|
* Free a pcp page |
|
*/ |
|
void free_unref_page(struct page *page, unsigned int order) |
|
{ |
|
unsigned long flags; |
|
unsigned long pfn = page_to_pfn(page); |
|
int migratetype; |
|
|
|
if (!free_unref_page_prepare(page, pfn, order)) |
|
return; |
|
|
|
/* |
|
* We only track unmovable, reclaimable and movable on pcp lists. |
|
* Place ISOLATE pages on the isolated list because they are being |
|
* offlined but treat HIGHATOMIC as movable pages so we can get those |
|
* areas back if necessary. Otherwise, we may have to free |
|
* excessively into the page allocator |
|
*/ |
|
migratetype = get_pcppage_migratetype(page); |
|
if (unlikely(migratetype >= MIGRATE_PCPTYPES)) { |
|
if (unlikely(is_migrate_isolate(migratetype))) { |
|
free_one_page(page_zone(page), page, pfn, order, migratetype, FPI_NONE); |
|
return; |
|
} |
|
migratetype = MIGRATE_MOVABLE; |
|
} |
|
|
|
local_lock_irqsave(&pagesets.lock, flags); |
|
free_unref_page_commit(page, pfn, migratetype, order); |
|
local_unlock_irqrestore(&pagesets.lock, flags); |
|
} |
|
|
|
/* |
|
* Free a list of 0-order pages |
|
*/ |
|
void free_unref_page_list(struct list_head *list) |
|
{ |
|
struct page *page, *next; |
|
unsigned long flags, pfn; |
|
int batch_count = 0; |
|
int migratetype; |
|
|
|
/* Prepare pages for freeing */ |
|
list_for_each_entry_safe(page, next, list, lru) { |
|
pfn = page_to_pfn(page); |
|
if (!free_unref_page_prepare(page, pfn, 0)) { |
|
list_del(&page->lru); |
|
continue; |
|
} |
|
|
|
/* |
|
* Free isolated pages directly to the allocator, see |
|
* comment in free_unref_page. |
|
*/ |
|
migratetype = get_pcppage_migratetype(page); |
|
if (unlikely(is_migrate_isolate(migratetype))) { |
|
list_del(&page->lru); |
|
free_one_page(page_zone(page), page, pfn, 0, migratetype, FPI_NONE); |
|
continue; |
|
} |
|
|
|
set_page_private(page, pfn); |
|
} |
|
|
|
local_lock_irqsave(&pagesets.lock, flags); |
|
list_for_each_entry_safe(page, next, list, lru) { |
|
pfn = page_private(page); |
|
set_page_private(page, 0); |
|
|
|
/* |
|
* Non-isolated types over MIGRATE_PCPTYPES get added |
|
* to the MIGRATE_MOVABLE pcp list. |
|
*/ |
|
migratetype = get_pcppage_migratetype(page); |
|
if (unlikely(migratetype >= MIGRATE_PCPTYPES)) |
|
migratetype = MIGRATE_MOVABLE; |
|
|
|
trace_mm_page_free_batched(page); |
|
free_unref_page_commit(page, pfn, migratetype, 0); |
|
|
|
/* |
|
* Guard against excessive IRQ disabled times when we get |
|
* a large list of pages to free. |
|
*/ |
|
if (++batch_count == SWAP_CLUSTER_MAX) { |
|
local_unlock_irqrestore(&pagesets.lock, flags); |
|
batch_count = 0; |
|
local_lock_irqsave(&pagesets.lock, flags); |
|
} |
|
} |
|
local_unlock_irqrestore(&pagesets.lock, flags); |
|
} |
|
|
|
/* |
|
* split_page takes a non-compound higher-order page, and splits it into |
|
* n (1<<order) sub-pages: page[0..n] |
|
* Each sub-page must be freed individually. |
|
* |
|
* Note: this is probably too low level an operation for use in drivers. |
|
* Please consult with lkml before using this in your driver. |
|
*/ |
|
void split_page(struct page *page, unsigned int order) |
|
{ |
|
int i; |
|
|
|
VM_BUG_ON_PAGE(PageCompound(page), page); |
|
VM_BUG_ON_PAGE(!page_count(page), page); |
|
|
|
for (i = 1; i < (1 << order); i++) |
|
set_page_refcounted(page + i); |
|
split_page_owner(page, 1 << order); |
|
split_page_memcg(page, 1 << order); |
|
} |
|
EXPORT_SYMBOL_GPL(split_page); |
|
|
|
int __isolate_free_page(struct page *page, unsigned int order) |
|
{ |
|
unsigned long watermark; |
|
struct zone *zone; |
|
int mt; |
|
|
|
BUG_ON(!PageBuddy(page)); |
|
|
|
zone = page_zone(page); |
|
mt = get_pageblock_migratetype(page); |
|
|
|
if (!is_migrate_isolate(mt)) { |
|
/* |
|
* Obey watermarks as if the page was being allocated. We can |
|
* emulate a high-order watermark check with a raised order-0 |
|
* watermark, because we already know our high-order page |
|
* exists. |
|
*/ |
|
watermark = zone->_watermark[WMARK_MIN] + (1UL << order); |
|
if (!zone_watermark_ok(zone, 0, watermark, 0, ALLOC_CMA)) |
|
return 0; |
|
|
|
__mod_zone_freepage_state(zone, -(1UL << order), mt); |
|
} |
|
|
|
/* Remove page from free list */ |
|
|
|
del_page_from_free_list(page, zone, order); |
|
|
|
/* |
|
* Set the pageblock if the isolated page is at least half of a |
|
* pageblock |
|
*/ |
|
if (order >= pageblock_order - 1) { |
|
struct page *endpage = page + (1 << order) - 1; |
|
for (; page < endpage; page += pageblock_nr_pages) { |
|
int mt = get_pageblock_migratetype(page); |
|
if (!is_migrate_isolate(mt) && !is_migrate_cma(mt) |
|
&& !is_migrate_highatomic(mt)) |
|
set_pageblock_migratetype(page, |
|
MIGRATE_MOVABLE); |
|
} |
|
} |
|
|
|
|
|
return 1UL << order; |
|
} |
|
|
|
/** |
|
* __putback_isolated_page - Return a now-isolated page back where we got it |
|
* @page: Page that was isolated |
|
* @order: Order of the isolated page |
|
* @mt: The page's pageblock's migratetype |
|
* |
|
* This function is meant to return a page pulled from the free lists via |
|
* __isolate_free_page back to the free lists they were pulled from. |
|
*/ |
|
void __putback_isolated_page(struct page *page, unsigned int order, int mt) |
|
{ |
|
struct zone *zone = page_zone(page); |
|
|
|
/* zone lock should be held when this function is called */ |
|
lockdep_assert_held(&zone->lock); |
|
|
|
/* Return isolated page to tail of freelist. */ |
|
__free_one_page(page, page_to_pfn(page), zone, order, mt, |
|
FPI_SKIP_REPORT_NOTIFY | FPI_TO_TAIL); |
|
} |
|
|
|
/* |
|
* Update NUMA hit/miss statistics |
|
* |
|
* Must be called with interrupts disabled. |
|
*/ |
|
static inline void zone_statistics(struct zone *preferred_zone, struct zone *z, |
|
long nr_account) |
|
{ |
|
#ifdef CONFIG_NUMA |
|
enum numa_stat_item local_stat = NUMA_LOCAL; |
|
|
|
/* skip numa counters update if numa stats is disabled */ |
|
if (!static_branch_likely(&vm_numa_stat_key)) |
|
return; |
|
|
|
if (zone_to_nid(z) != numa_node_id()) |
|
local_stat = NUMA_OTHER; |
|
|
|
if (zone_to_nid(z) == zone_to_nid(preferred_zone)) |
|
__count_numa_events(z, NUMA_HIT, nr_account); |
|
else { |
|
__count_numa_events(z, NUMA_MISS, nr_account); |
|
__count_numa_events(preferred_zone, NUMA_FOREIGN, nr_account); |
|
} |
|
__count_numa_events(z, local_stat, nr_account); |
|
#endif |
|
} |
|
|
|
/* Remove page from the per-cpu list, caller must protect the list */ |
|
static inline |
|
struct page *__rmqueue_pcplist(struct zone *zone, unsigned int order, |
|
int migratetype, |
|
unsigned int alloc_flags, |
|
struct per_cpu_pages *pcp, |
|
struct list_head *list) |
|
{ |
|
struct page *page; |
|
|
|
do { |
|
if (list_empty(list)) { |
|
int batch = READ_ONCE(pcp->batch); |
|
int alloced; |
|
|
|
/* |
|
* Scale batch relative to order if batch implies |
|
* free pages can be stored on the PCP. Batch can |
|
* be 1 for small zones or for boot pagesets which |
|
* should never store free pages as the pages may |
|
* belong to arbitrary zones. |
|
*/ |
|
if (batch > 1) |
|
batch = max(batch >> order, 2); |
|
alloced = rmqueue_bulk(zone, order, |
|
batch, list, |
|
migratetype, alloc_flags); |
|
|
|
pcp->count += alloced << order; |
|
if (unlikely(list_empty(list))) |
|
return NULL; |
|
} |
|
|
|
page = list_first_entry(list, struct page, lru); |
|
list_del(&page->lru); |
|
pcp->count -= 1 << order; |
|
} while (check_new_pcp(page)); |
|
|
|
return page; |
|
} |
|
|
|
/* Lock and remove page from the per-cpu list */ |
|
static struct page *rmqueue_pcplist(struct zone *preferred_zone, |
|
struct zone *zone, unsigned int order, |
|
gfp_t gfp_flags, int migratetype, |
|
unsigned int alloc_flags) |
|
{ |
|
struct per_cpu_pages *pcp; |
|
struct list_head *list; |
|
struct page *page; |
|
unsigned long flags; |
|
|
|
local_lock_irqsave(&pagesets.lock, flags); |
|
|
|
/* |
|
* On allocation, reduce the number of pages that are batch freed. |
|
* See nr_pcp_free() where free_factor is increased for subsequent |
|
* frees. |
|
*/ |
|
pcp = this_cpu_ptr(zone->per_cpu_pageset); |
|
pcp->free_factor >>= 1; |
|
list = &pcp->lists[order_to_pindex(migratetype, order)]; |
|
page = __rmqueue_pcplist(zone, order, migratetype, alloc_flags, pcp, list); |
|
local_unlock_irqrestore(&pagesets.lock, flags); |
|
if (page) { |
|
__count_zid_vm_events(PGALLOC, page_zonenum(page), 1); |
|
zone_statistics(preferred_zone, zone, 1); |
|
} |
|
return page; |
|
} |
|
|
|
/* |
|
* Allocate a page from the given zone. Use pcplists for order-0 allocations. |
|
*/ |
|
static inline |
|
struct page *rmqueue(struct zone *preferred_zone, |
|
struct zone *zone, unsigned int order, |
|
gfp_t gfp_flags, unsigned int alloc_flags, |
|
int migratetype) |
|
{ |
|
unsigned long flags; |
|
struct page *page; |
|
|
|
if (likely(pcp_allowed_order(order))) { |
|
/* |
|
* MIGRATE_MOVABLE pcplist could have the pages on CMA area and |
|
* we need to skip it when CMA area isn't allowed. |
|
*/ |
|
if (!IS_ENABLED(CONFIG_CMA) || alloc_flags & ALLOC_CMA || |
|
migratetype != MIGRATE_MOVABLE) { |
|
page = rmqueue_pcplist(preferred_zone, zone, order, |
|
gfp_flags, migratetype, alloc_flags); |
|
goto out; |
|
} |
|
} |
|
|
|
/* |
|
* We most definitely don't want callers attempting to |
|
* allocate greater than order-1 page units with __GFP_NOFAIL. |
|
*/ |
|
WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1)); |
|
spin_lock_irqsave(&zone->lock, flags); |
|
|
|
do { |
|
page = NULL; |
|
/* |
|
* order-0 request can reach here when the pcplist is skipped |
|
* due to non-CMA allocation context. HIGHATOMIC area is |
|
* reserved for high-order atomic allocation, so order-0 |
|
* request should skip it. |
|
*/ |
|
if (order > 0 && alloc_flags & ALLOC_HARDER) { |
|
page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC); |
|
if (page) |
|
trace_mm_page_alloc_zone_locked(page, order, migratetype); |
|
} |
|
if (!page) |
|
page = __rmqueue(zone, order, migratetype, alloc_flags); |
|
} while (page && check_new_pages(page, order)); |
|
if (!page) |
|
goto failed; |
|
|
|
__mod_zone_freepage_state(zone, -(1 << order), |
|
get_pcppage_migratetype(page)); |
|
spin_unlock_irqrestore(&zone->lock, flags); |
|
|
|
__count_zid_vm_events(PGALLOC, page_zonenum(page), 1 << order); |
|
zone_statistics(preferred_zone, zone, 1); |
|
|
|
out: |
|
/* Separate test+clear to avoid unnecessary atomics */ |
|
if (test_bit(ZONE_BOOSTED_WATERMARK, &zone->flags)) { |
|
clear_bit(ZONE_BOOSTED_WATERMARK, &zone->flags); |
|
wakeup_kswapd(zone, 0, 0, zone_idx(zone)); |
|
} |
|
|
|
VM_BUG_ON_PAGE(page && bad_range(zone, page), page); |
|
return page; |
|
|
|
failed: |
|
spin_unlock_irqrestore(&zone->lock, flags); |
|
return NULL; |
|
} |
|
|
|
#ifdef CONFIG_FAIL_PAGE_ALLOC |
|
|
|
static struct { |
|
struct fault_attr attr; |
|
|
|
bool ignore_gfp_highmem; |
|
bool ignore_gfp_reclaim; |
|
u32 min_order; |
|
} fail_page_alloc = { |
|
.attr = FAULT_ATTR_INITIALIZER, |
|
.ignore_gfp_reclaim = true, |
|
.ignore_gfp_highmem = true, |
|
.min_order = 1, |
|
}; |
|
|
|
static int __init setup_fail_page_alloc(char *str) |
|
{ |
|
return setup_fault_attr(&fail_page_alloc.attr, str); |
|
} |
|
__setup("fail_page_alloc=", setup_fail_page_alloc); |
|
|
|
static bool __should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) |
|
{ |
|
if (order < fail_page_alloc.min_order) |
|
return false; |
|
if (gfp_mask & __GFP_NOFAIL) |
|
return false; |
|
if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM)) |
|
return false; |
|
if (fail_page_alloc.ignore_gfp_reclaim && |
|
(gfp_mask & __GFP_DIRECT_RECLAIM)) |
|
return false; |
|
|
|
return should_fail(&fail_page_alloc.attr, 1 << order); |
|
} |
|
|
|
#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS |
|
|
|
static int __init fail_page_alloc_debugfs(void) |
|
{ |
|
umode_t mode = S_IFREG | 0600; |
|
struct dentry *dir; |
|
|
|
dir = fault_create_debugfs_attr("fail_page_alloc", NULL, |
|
&fail_page_alloc.attr); |
|
|
|
debugfs_create_bool("ignore-gfp-wait", mode, dir, |
|
&fail_page_alloc.ignore_gfp_reclaim); |
|
debugfs_create_bool("ignore-gfp-highmem", mode, dir, |
|
&fail_page_alloc.ignore_gfp_highmem); |
|
debugfs_create_u32("min-order", mode, dir, &fail_page_alloc.min_order); |
|
|
|
return 0; |
|
} |
|
|
|
late_initcall(fail_page_alloc_debugfs); |
|
|
|
#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ |
|
|
|
#else /* CONFIG_FAIL_PAGE_ALLOC */ |
|
|
|
static inline bool __should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) |
|
{ |
|
return false; |
|
} |
|
|
|
#endif /* CONFIG_FAIL_PAGE_ALLOC */ |
|
|
|
noinline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) |
|
{ |
|
return __should_fail_alloc_page(gfp_mask, order); |
|
} |
|
ALLOW_ERROR_INJECTION(should_fail_alloc_page, TRUE); |
|
|
|
static inline long __zone_watermark_unusable_free(struct zone *z, |
|
unsigned int order, unsigned int alloc_flags) |
|
{ |
|
const bool alloc_harder = (alloc_flags & (ALLOC_HARDER|ALLOC_OOM)); |
|
long unusable_free = (1 << order) - 1; |
|
|
|
/* |
|
* If the caller does not have rights to ALLOC_HARDER then subtract |
|
* the high-atomic reserves. This will over-estimate the size of the |
|
* atomic reserve but it avoids a search. |
|
*/ |
|
if (likely(!alloc_harder)) |
|
unusable_free += z->nr_reserved_highatomic; |
|
|
|
#ifdef CONFIG_CMA |
|
/* If allocation can't use CMA areas don't use free CMA pages */ |
|
if (!(alloc_flags & ALLOC_CMA)) |
|
unusable_free += zone_page_state(z, NR_FREE_CMA_PAGES); |
|
#endif |
|
|
|
return unusable_free; |
|
} |
|
|
|
/* |
|
* Return true if free base pages are above 'mark'. For high-order checks it |
|
* will return true of the order-0 watermark is reached and there is at least |
|
* one free page of a suitable size. Checking now avoids taking the zone lock |
|
* to check in the allocation paths if no pages are free. |
|
*/ |
|
bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark, |
|
int highest_zoneidx, unsigned int alloc_flags, |
|
long free_pages) |
|
{ |
|
long min = mark; |
|
int o; |
|
const bool alloc_harder = (alloc_flags & (ALLOC_HARDER|ALLOC_OOM)); |
|
|
|
/* free_pages may go negative - that's OK */ |
|
free_pages -= __zone_watermark_unusable_free(z, order, alloc_flags); |
|
|
|
if (alloc_flags & ALLOC_HIGH) |
|
min -= min / 2; |
|
|
|
if (unlikely(alloc_harder)) { |
|
/* |
|
* OOM victims can try even harder than normal ALLOC_HARDER |
|
* users on the grounds that it's definitely going to be in |
|
* the exit path shortly and free memory. Any allocation it |
|
* makes during the free path will be small and short-lived. |
|
*/ |
|
if (alloc_flags & ALLOC_OOM) |
|
min -= min / 2; |
|
else |
|
min -= min / 4; |
|
} |
|
|
|
/* |
|
* Check watermarks for an order-0 allocation request. If these |
|
* are not met, then a high-order request also cannot go ahead |
|
* even if a suitable page happened to be free. |
|
*/ |
|
if (free_pages <= min + z->lowmem_reserve[highest_zoneidx]) |
|
return false; |
|
|
|
/* If this is an order-0 request then the watermark is fine */ |
|
if (!order) |
|
return true; |
|
|
|
/* For a high-order request, check at least one suitable page is free */ |
|
for (o = order; o < MAX_ORDER; o++) { |
|
struct free_area *area = &z->free_area[o]; |
|
int mt; |
|
|
|
if (!area->nr_free) |
|
continue; |
|
|
|
for (mt = 0; mt < MIGRATE_PCPTYPES; mt++) { |
|
if (!free_area_empty(area, mt)) |
|
return true; |
|
} |
|
|
|
#ifdef CONFIG_CMA |
|
if ((alloc_flags & ALLOC_CMA) && |
|
!free_area_empty(area, MIGRATE_CMA)) { |
|
return true; |
|
} |
|
#endif |
|
if (alloc_harder && !free_area_empty(area, MIGRATE_HIGHATOMIC)) |
|
return true; |
|
} |
|
return false; |
|
} |
|
|
|
bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark, |
|
int highest_zoneidx, unsigned int alloc_flags) |
|
{ |
|
return __zone_watermark_ok(z, order, mark, highest_zoneidx, alloc_flags, |
|
zone_page_state(z, NR_FREE_PAGES)); |
|
} |
|
|
|
static inline bool zone_watermark_fast(struct zone *z, unsigned int order, |
|
unsigned long mark, int highest_zoneidx, |
|
unsigned int alloc_flags, gfp_t gfp_mask) |
|
{ |
|
long free_pages; |
|
|
|
free_pages = zone_page_state(z, NR_FREE_PAGES); |
|
|
|
/* |
|
* Fast check for order-0 only. If this fails then the reserves |
|
* need to be calculated. |
|
*/ |
|
if (!order) { |
|
long fast_free; |
|
|
|
fast_free = free_pages; |
|
fast_free -= __zone_watermark_unusable_free(z, 0, alloc_flags); |
|
if (fast_free > mark + z->lowmem_reserve[highest_zoneidx]) |
|
return true; |
|
} |
|
|
|
if (__zone_watermark_ok(z, order, mark, highest_zoneidx, alloc_flags, |
|
free_pages)) |
|
return true; |
|
/* |
|
* Ignore watermark boosting for GFP_ATOMIC order-0 allocations |
|
* when checking the min watermark. The min watermark is the |
|
* point where boosting is ignored so that kswapd is woken up |
|
* when below the low watermark. |
|
*/ |
|
if (unlikely(!order && (gfp_mask & __GFP_ATOMIC) && z->watermark_boost |
|
&& ((alloc_flags & ALLOC_WMARK_MASK) == WMARK_MIN))) { |
|
mark = z->_watermark[WMARK_MIN]; |
|
return __zone_watermark_ok(z, order, mark, highest_zoneidx, |
|
alloc_flags, free_pages); |
|
} |
|
|
|
return false; |
|
} |
|
|
|
bool zone_watermark_ok_safe(struct zone *z, unsigned int order, |
|
unsigned long mark, int highest_zoneidx) |
|
{ |
|
long free_pages = zone_page_state(z, NR_FREE_PAGES); |
|
|
|
if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark) |
|
free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES); |
|
|
|
return __zone_watermark_ok(z, order, mark, highest_zoneidx, 0, |
|
free_pages); |
|
} |
|
|
|
#ifdef CONFIG_NUMA |
|
static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone) |
|
{ |
|
return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) <= |
|
node_reclaim_distance; |
|
} |
|
#else /* CONFIG_NUMA */ |
|
static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone) |
|
{ |
|
return true; |
|
} |
|
#endif /* CONFIG_NUMA */ |
|
|
|
/* |
|
* The restriction on ZONE_DMA32 as being a suitable zone to use to avoid |
|
* fragmentation is subtle. If the preferred zone was HIGHMEM then |
|
* premature use of a lower zone may cause lowmem pressure problems that |
|
* are worse than fragmentation. If the next zone is ZONE_DMA then it is |
|
* probably too small. It only makes sense to spread allocations to avoid |
|
* fragmentation between the Normal and DMA32 zones. |
|
*/ |
|
static inline unsigned int |
|
alloc_flags_nofragment(struct zone *zone, gfp_t gfp_mask) |
|
{ |
|
unsigned int alloc_flags; |
|
|
|
/* |
|
* __GFP_KSWAPD_RECLAIM is assumed to be the same as ALLOC_KSWAPD |
|
* to save a branch. |
|
*/ |
|
alloc_flags = (__force int) (gfp_mask & __GFP_KSWAPD_RECLAIM); |
|
|
|
#ifdef CONFIG_ZONE_DMA32 |
|
if (!zone) |
|
return alloc_flags; |
|
|
|
if (zone_idx(zone) != ZONE_NORMAL) |
|
return alloc_flags; |
|
|
|
/* |
|
* If ZONE_DMA32 exists, assume it is the one after ZONE_NORMAL and |
|
* the pointer is within zone->zone_pgdat->node_zones[]. Also assume |
|
* on UMA that if Normal is populated then so is DMA32. |
|
*/ |
|
BUILD_BUG_ON(ZONE_NORMAL - ZONE_DMA32 != 1); |
|
if (nr_online_nodes > 1 && !populated_zone(--zone)) |
|
return alloc_flags; |
|
|
|
alloc_flags |= ALLOC_NOFRAGMENT; |
|
#endif /* CONFIG_ZONE_DMA32 */ |
|
return alloc_flags; |
|
} |
|
|
|
/* Must be called after current_gfp_context() which can change gfp_mask */ |
|
static inline unsigned int gfp_to_alloc_flags_cma(gfp_t gfp_mask, |
|
unsigned int alloc_flags) |
|
{ |
|
#ifdef CONFIG_CMA |
|
if (gfp_migratetype(gfp_mask) == MIGRATE_MOVABLE) |
|
alloc_flags |= ALLOC_CMA; |
|
#endif |
|
return alloc_flags; |
|
} |
|
|
|
/* |
|
* get_page_from_freelist goes through the zonelist trying to allocate |
|
* a page. |
|
*/ |
|
static struct page * |
|
get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags, |
|
const struct alloc_context *ac) |
|
{ |
|
struct zoneref *z; |
|
struct zone *zone; |
|
struct pglist_data *last_pgdat_dirty_limit = NULL; |
|
bool no_fallback; |
|
|
|
retry: |
|
/* |
|
* Scan zonelist, looking for a zone with enough free. |
|
* See also __cpuset_node_allowed() comment in kernel/cpuset.c. |
|
*/ |
|
no_fallback = alloc_flags & ALLOC_NOFRAGMENT; |
|
z = ac->preferred_zoneref; |
|
for_next_zone_zonelist_nodemask(zone, z, ac->highest_zoneidx, |
|
ac->nodemask) { |
|
struct page *page; |
|
unsigned long mark; |
|
|
|
if (cpusets_enabled() && |
|
(alloc_flags & ALLOC_CPUSET) && |
|
!__cpuset_zone_allowed(zone, gfp_mask)) |
|
continue; |
|
/* |
|
* When allocating a page cache page for writing, we |
|
* want to get it from a node that is within its dirty |
|
* limit, such that no single node holds more than its |
|
* proportional share of globally allowed dirty pages. |
|
* The dirty limits take into account the node's |
|
* lowmem reserves and high watermark so that kswapd |
|
* should be able to balance it without having to |
|
* write pages from its LRU list. |
|
* |
|
* XXX: For now, allow allocations to potentially |
|
* exceed the per-node dirty limit in the slowpath |
|
* (spread_dirty_pages unset) before going into reclaim, |
|
* which is important when on a NUMA setup the allowed |
|
* nodes are together not big enough to reach the |
|
* global limit. The proper fix for these situations |
|
* will require awareness of nodes in the |
|
* dirty-throttling and the flusher threads. |
|
*/ |
|
if (ac->spread_dirty_pages) { |
|
if (last_pgdat_dirty_limit == zone->zone_pgdat) |
|
continue; |
|
|
|
if (!node_dirty_ok(zone->zone_pgdat)) { |
|
last_pgdat_dirty_limit = zone->zone_pgdat; |
|
continue; |
|
} |
|
} |
|
|
|
if (no_fallback && nr_online_nodes > 1 && |
|
zone != ac->preferred_zoneref->zone) { |
|
int local_nid; |
|
|
|
/* |
|
* If moving to a remote node, retry but allow |
|
* fragmenting fallbacks. Locality is more important |
|
* than fragmentation avoidance. |
|
*/ |
|
local_nid = zone_to_nid(ac->preferred_zoneref->zone); |
|
if (zone_to_nid(zone) != local_nid) { |
|
alloc_flags &= ~ALLOC_NOFRAGMENT; |
|
goto retry; |
|
} |
|
} |
|
|
|
mark = wmark_pages(zone, alloc_flags & ALLOC_WMARK_MASK); |
|
if (!zone_watermark_fast(zone, order, mark, |
|
ac->highest_zoneidx, alloc_flags, |
|
gfp_mask)) { |
|
int ret; |
|
|
|
#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT |
|
/* |
|
* Watermark failed for this zone, but see if we can |
|
* grow this zone if it contains deferred pages. |
|
*/ |
|
if (static_branch_unlikely(&deferred_pages)) { |
|
if (_deferred_grow_zone(zone, order)) |
|
goto try_this_zone; |
|
} |
|
#endif |
|
/* Checked here to keep the fast path fast */ |
|
BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK); |
|
if (alloc_flags & ALLOC_NO_WATERMARKS) |
|
goto try_this_zone; |
|
|
|
if (!node_reclaim_enabled() || |
|
!zone_allows_reclaim(ac->preferred_zoneref->zone, zone)) |
|
continue; |
|
|
|
ret = node_reclaim(zone->zone_pgdat, gfp_mask, order); |
|
switch (ret) { |
|
case NODE_RECLAIM_NOSCAN: |
|
/* did not scan */ |
|
continue; |
|
case NODE_RECLAIM_FULL: |
|
/* scanned but unreclaimable */ |
|
continue; |
|
default: |
|
/* did we reclaim enough */ |
|
if (zone_watermark_ok(zone, order, mark, |
|
ac->highest_zoneidx, alloc_flags)) |
|
goto try_this_zone; |
|
|
|
continue; |
|
} |
|
} |
|
|
|
try_this_zone: |
|
page = rmqueue(ac->preferred_zoneref->zone, zone, order, |
|
gfp_mask, alloc_flags, ac->migratetype); |
|
if (page) { |
|
prep_new_page(page, order, gfp_mask, alloc_flags); |
|
|
|
/* |
|
* If this is a high-order atomic allocation then check |
|
* if the pageblock should be reserved for the future |
|
*/ |
|
if (unlikely(order && (alloc_flags & ALLOC_HARDER))) |
|
reserve_highatomic_pageblock(page, zone, order); |
|
|
|
return page; |
|
} else { |
|
#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT |
|
/* Try again if zone has deferred pages */ |
|
if (static_branch_unlikely(&deferred_pages)) { |
|
if (_deferred_grow_zone(zone, order)) |
|
goto try_this_zone; |
|
} |
|
#endif |
|
} |
|
} |
|
|
|
/* |
|
* It's possible on a UMA machine to get through all zones that are |
|
* fragmented. If avoiding fragmentation, reset and try again. |
|
*/ |
|
if (no_fallback) { |
|
alloc_flags &= ~ALLOC_NOFRAGMENT; |
|
goto retry; |
|
} |
|
|
|
return NULL; |
|
} |
|
|
|
static void warn_alloc_show_mem(gfp_t gfp_mask, nodemask_t *nodemask) |
|
{ |
|
unsigned int filter = SHOW_MEM_FILTER_NODES; |
|
|
|
/* |
|
* This documents exceptions given to allocations in certain |
|
* contexts that are allowed to allocate outside current's set |
|
* of allowed nodes. |
|
*/ |
|
if (!(gfp_mask & __GFP_NOMEMALLOC)) |
|
if (tsk_is_oom_victim(current) || |
|
(current->flags & (PF_MEMALLOC | PF_EXITING))) |
|
filter &= ~SHOW_MEM_FILTER_NODES; |
|
if (!in_task() || !(gfp_mask & __GFP_DIRECT_RECLAIM)) |
|
filter &= ~SHOW_MEM_FILTER_NODES; |
|
|
|
show_mem(filter, nodemask); |
|
} |
|
|
|
void warn_alloc(gfp_t gfp_mask, nodemask_t *nodemask, const char *fmt, ...) |
|
{ |
|
struct va_format vaf; |
|
va_list args; |
|
static DEFINE_RATELIMIT_STATE(nopage_rs, 10*HZ, 1); |
|
|
|
if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs)) |
|
return; |
|
|
|
va_start(args, fmt); |
|
vaf.fmt = fmt; |
|
vaf.va = &args; |
|
pr_warn("%s: %pV, mode:%#x(%pGg), nodemask=%*pbl", |
|
current->comm, &vaf, gfp_mask, &gfp_mask, |
|
nodemask_pr_args(nodemask)); |
|
va_end(args); |
|
|
|
cpuset_print_current_mems_allowed(); |
|
pr_cont("\n"); |
|
dump_stack(); |
|
warn_alloc_show_mem(gfp_mask, nodemask); |
|
} |
|
|
|
static inline struct page * |
|
__alloc_pages_cpuset_fallback(gfp_t gfp_mask, unsigned int order, |
|
unsigned int alloc_flags, |
|
const struct alloc_context *ac) |
|
{ |
|
struct page *page; |
|
|
|
page = get_page_from_freelist(gfp_mask, order, |
|
alloc_flags|ALLOC_CPUSET, ac); |
|
/* |
|
* fallback to ignore cpuset restriction if our nodes |
|
* are depleted |
|
*/ |
|
if (!page) |
|
page = get_page_from_freelist(gfp_mask, order, |
|
alloc_flags, ac); |
|
|
|
return page; |
|
} |
|
|
|
static inline struct page * |
|
__alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order, |
|
const struct alloc_context *ac, unsigned long *did_some_progress) |
|
{ |
|
struct oom_control oc = { |
|
.zonelist = ac->zonelist, |
|
.nodemask = ac->nodemask, |
|
.memcg = NULL, |
|
.gfp_mask = gfp_mask, |
|
.order = order, |
|
}; |
|
struct page *page; |
|
|
|
*did_some_progress = 0; |
|
|
|
/* |
|
* Acquire the oom lock. If that fails, somebody else is |
|
* making progress for us. |
|
*/ |
|
if (!mutex_trylock(&oom_lock)) { |
|
*did_some_progress = 1; |
|
schedule_timeout_uninterruptible(1); |
|
return NULL; |
|
} |
|
|
|
/* |
|
* Go through the zonelist yet one more time, keep very high watermark |
|
* here, this is only to catch a parallel oom killing, we must fail if |
|
* we're still under heavy pressure. But make sure that this reclaim |
|
* attempt shall not depend on __GFP_DIRECT_RECLAIM && !__GFP_NORETRY |
|
* allocation which will never fail due to oom_lock already held. |
|
*/ |
|
page = get_page_from_freelist((gfp_mask | __GFP_HARDWALL) & |
|
~__GFP_DIRECT_RECLAIM, order, |
|
ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac); |
|
if (page) |
|
goto out; |
|
|
|
/* Coredumps can quickly deplete all memory reserves */ |
|
if (current->flags & PF_DUMPCORE) |
|
goto out; |
|
/* The OOM killer will not help higher order allocs */ |
|
if (order > PAGE_ALLOC_COSTLY_ORDER) |
|
goto out; |
|
/* |
|
* We have already exhausted all our reclaim opportunities without any |
|
* success so it is time to admit defeat. We will skip the OOM killer |
|
* because it is very likely that the caller has a more reasonable |
|
* fallback than shooting a random task. |
|
* |
|
* The OOM killer may not free memory on a specific node. |
|
*/ |
|
if (gfp_mask & (__GFP_RETRY_MAYFAIL | __GFP_THISNODE)) |
|
goto out; |
|
/* The OOM killer does not needlessly kill tasks for lowmem */ |
|
if (ac->highest_zoneidx < ZONE_NORMAL) |
|
goto out; |
|
if (pm_suspended_storage()) |
|
goto out; |
|
/* |
|
* XXX: GFP_NOFS allocations should rather fail than rely on |
|
* other request to make a forward progress. |
|
* We are in an unfortunate situation where out_of_memory cannot |
|
* do much for this context but let's try it to at least get |
|
* access to memory reserved if the current task is killed (see |
|
* out_of_memory). Once filesystems are ready to handle allocation |
|
* failures more gracefully we should just bail out here. |
|
*/ |
|
|
|
/* Exhausted what can be done so it's blame time */ |
|
if (out_of_memory(&oc) || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) { |
|
*did_some_progress = 1; |
|
|
|
/* |
|
* Help non-failing allocations by giving them access to memory |
|
* reserves |
|
*/ |
|
if (gfp_mask & __GFP_NOFAIL) |
|
page = __alloc_pages_cpuset_fallback(gfp_mask, order, |
|
ALLOC_NO_WATERMARKS, ac); |
|
} |
|
out: |
|
mutex_unlock(&oom_lock); |
|
return page; |
|
} |
|
|
|
/* |
|
* Maximum number of compaction retries with a progress before OOM |
|
* killer is consider as the only way to move forward. |
|
*/ |
|
#define MAX_COMPACT_RETRIES 16 |
|
|
|
#ifdef CONFIG_COMPACTION |
|
/* Try memory compaction for high-order allocations before reclaim */ |
|
static struct page * |
|
__alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, |
|
unsigned int alloc_flags, const struct alloc_context *ac, |
|
enum compact_priority prio, enum compact_result *compact_result) |
|
{ |
|
struct page *page = NULL; |
|
unsigned long pflags; |
|
unsigned int noreclaim_flag; |
|
|
|
if (!order) |
|
return NULL; |
|
|
|
psi_memstall_enter(&pflags); |
|
noreclaim_flag = memalloc_noreclaim_save(); |
|
|
|
*compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac, |
|
prio, &page); |
|
|
|
memalloc_noreclaim_restore(noreclaim_flag); |
|
psi_memstall_leave(&pflags); |
|
|
|
if (*compact_result == COMPACT_SKIPPED) |
|
return NULL; |
|
/* |
|
* At least in one zone compaction wasn't deferred or skipped, so let's |
|
* count a compaction stall |
|
*/ |
|
count_vm_event(COMPACTSTALL); |
|
|
|
/* Prep a captured page if available */ |
|
if (page) |
|
prep_new_page(page, order, gfp_mask, alloc_flags); |
|
|
|
/* Try get a page from the freelist if available */ |
|
if (!page) |
|
page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac); |
|
|
|
if (page) { |
|
struct zone *zone = page_zone(page); |
|
|
|
zone->compact_blockskip_flush = false; |
|
compaction_defer_reset(zone, order, true); |
|
count_vm_event(COMPACTSUCCESS); |
|
return page; |
|
} |
|
|
|
/* |
|
* It's bad if compaction run occurs and fails. The most likely reason |
|
* is that pages exist, but not enough to satisfy watermarks. |
|
*/ |
|
count_vm_event(COMPACTFAIL); |
|
|
|
cond_resched(); |
|
|
|
return NULL; |
|
} |
|
|
|
static inline bool |
|
should_compact_retry(struct alloc_context *ac, int order, int alloc_flags, |
|
enum compact_result compact_result, |
|
enum compact_priority *compact_priority, |
|
int *compaction_retries) |
|
{ |
|
int max_retries = MAX_COMPACT_RETRIES; |
|
int min_priority; |
|
bool ret = false; |
|
int retries = *compaction_retries; |
|
enum compact_priority priority = *compact_priority; |
|
|
|
if (!order) |
|
return false; |
|
|
|
if (fatal_signal_pending(current)) |
|
return false; |
|
|
|
if (compaction_made_progress(compact_result)) |
|
(*compaction_retries)++; |
|
|
|
/* |
|
* compaction considers all the zone as desperately out of memory |
|
* so it doesn't really make much sense to retry except when the |
|
* failure could be caused by insufficient priority |
|
*/ |
|
if (compaction_failed(compact_result)) |
|
goto check_priority; |
|
|
|
/* |
|
* compaction was skipped because there are not enough order-0 pages |
|
* to work with, so we retry only if it looks like reclaim can help. |
|
*/ |
|
if (compaction_needs_reclaim(compact_result)) { |
|
ret = compaction_zonelist_suitable(ac, order, alloc_flags); |
|
goto out; |
|
} |
|
|
|
/* |
|
* make sure the compaction wasn't deferred or didn't bail out early |
|
* due to locks contention before we declare that we should give up. |
|
* But the next retry should use a higher priority if allowed, so |
|
* we don't just keep bailing out endlessly. |
|
*/ |
|
if (compaction_withdrawn(compact_result)) { |
|
goto check_priority; |
|
} |
|
|
|
/* |
|
* !costly requests are much more important than __GFP_RETRY_MAYFAIL |
|
* costly ones because they are de facto nofail and invoke OOM |
|
* killer to move on while costly can fail and users are ready |
|
* to cope with that. 1/4 retries is rather arbitrary but we |
|
* would need much more detailed feedback from compaction to |
|
* make a better decision. |
|
*/ |
|
if (order > PAGE_ALLOC_COSTLY_ORDER) |
|
max_retries /= 4; |
|
if (*compaction_retries <= max_retries) { |
|
ret = true; |
|
goto out; |
|
} |
|
|
|
/* |
|
* Make sure there are attempts at the highest priority if we exhausted |
|
* all retries or failed at the lower priorities. |
|
*/ |
|
check_priority: |
|
min_priority = (order > PAGE_ALLOC_COSTLY_ORDER) ? |
|
MIN_COMPACT_COSTLY_PRIORITY : MIN_COMPACT_PRIORITY; |
|
|
|
if (*compact_priority > min_priority) { |
|
(*compact_priority)--; |
|
*compaction_retries = 0; |
|
ret = true; |
|
} |
|
out: |
|
trace_compact_retry(order, priority, compact_result, retries, max_retries, ret); |
|
return ret; |
|
} |
|
#else |
|
static inline struct page * |
|
__alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, |
|
unsigned int alloc_flags, const struct alloc_context *ac, |
|
enum compact_priority prio, enum compact_result *compact_result) |
|
{ |
|
*compact_result = COMPACT_SKIPPED; |
|
return NULL; |
|
} |
|
|
|
static inline bool |
|
should_compact_retry(struct alloc_context *ac, unsigned int order, int alloc_flags, |
|
enum compact_result compact_result, |
|
enum compact_priority *compact_priority, |
|
int *compaction_retries) |
|
{ |
|
struct zone *zone; |
|
struct zoneref *z; |
|
|
|
if (!order || order > PAGE_ALLOC_COSTLY_ORDER) |
|
return false; |
|
|
|
/* |
|
* There are setups with compaction disabled which would prefer to loop |
|
* inside the allocator rather than hit the oom killer prematurely. |
|
* Let's give them a good hope and keep retrying while the order-0 |
|
* watermarks are OK. |
|
*/ |
|
for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, |
|
ac->highest_zoneidx, ac->nodemask) { |
|
if (zone_watermark_ok(zone, 0, min_wmark_pages(zone), |
|
ac->highest_zoneidx, alloc_flags)) |
|
return true; |
|
} |
|
return false; |
|
} |
|
#endif /* CONFIG_COMPACTION */ |
|
|
|
#ifdef CONFIG_LOCKDEP |
|
static struct lockdep_map __fs_reclaim_map = |
|
STATIC_LOCKDEP_MAP_INIT("fs_reclaim", &__fs_reclaim_map); |
|
|
|
static bool __need_reclaim(gfp_t gfp_mask) |
|
{ |
|
/* no reclaim without waiting on it */ |
|
if (!(gfp_mask & __GFP_DIRECT_RECLAIM)) |
|
return false; |
|
|
|
/* this guy won't enter reclaim */ |
|
if (current->flags & PF_MEMALLOC) |
|
return false; |
|
|
|
if (gfp_mask & __GFP_NOLOCKDEP) |
|
return false; |
|
|
|
return true; |
|
} |
|
|
|
void __fs_reclaim_acquire(unsigned long ip) |
|
{ |
|
lock_acquire_exclusive(&__fs_reclaim_map, 0, 0, NULL, ip); |
|
} |
|
|
|
void __fs_reclaim_release(unsigned long ip) |
|
{ |
|
lock_release(&__fs_reclaim_map, ip); |
|
} |
|
|
|
void fs_reclaim_acquire(gfp_t gfp_mask) |
|
{ |
|
gfp_mask = current_gfp_context(gfp_mask); |
|
|
|
if (__need_reclaim(gfp_mask)) { |
|
if (gfp_mask & __GFP_FS) |
|
__fs_reclaim_acquire(_RET_IP_); |
|
|
|
#ifdef CONFIG_MMU_NOTIFIER |
|
lock_map_acquire(&__mmu_notifier_invalidate_range_start_map); |
|
lock_map_release(&__mmu_notifier_invalidate_range_start_map); |
|
#endif |
|
|
|
} |
|
} |
|
EXPORT_SYMBOL_GPL(fs_reclaim_acquire); |
|
|
|
void fs_reclaim_release(gfp_t gfp_mask) |
|
{ |
|
gfp_mask = current_gfp_context(gfp_mask); |
|
|
|
if (__need_reclaim(gfp_mask)) { |
|
if (gfp_mask & __GFP_FS) |
|
__fs_reclaim_release(_RET_IP_); |
|
} |
|
} |
|
EXPORT_SYMBOL_GPL(fs_reclaim_release); |
|
#endif |
|
|
|
/* Perform direct synchronous page reclaim */ |
|
static unsigned long |
|
__perform_reclaim(gfp_t gfp_mask, unsigned int order, |
|
const struct alloc_context *ac) |
|
{ |
|
unsigned int noreclaim_flag; |
|
unsigned long pflags, progress; |
|
|
|
cond_resched(); |
|
|
|
/* We now go into synchronous reclaim */ |
|
cpuset_memory_pressure_bump(); |
|
psi_memstall_enter(&pflags); |
|
fs_reclaim_acquire(gfp_mask); |
|
noreclaim_flag = memalloc_noreclaim_save(); |
|
|
|
progress = try_to_free_pages(ac->zonelist, order, gfp_mask, |
|
ac->nodemask); |
|
|
|
memalloc_noreclaim_restore(noreclaim_flag); |
|
fs_reclaim_release(gfp_mask); |
|
psi_memstall_leave(&pflags); |
|
|
|
cond_resched(); |
|
|
|
return progress; |
|
} |
|
|
|
/* The really slow allocator path where we enter direct reclaim */ |
|
static inline struct page * |
|
__alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order, |
|
unsigned int alloc_flags, const struct alloc_context *ac, |
|
unsigned long *did_some_progress) |
|
{ |
|
struct page *page = NULL; |
|
bool drained = false; |
|
|
|
*did_some_progress = __perform_reclaim(gfp_mask, order, ac); |
|
if (unlikely(!(*did_some_progress))) |
|
return NULL; |
|
|
|
retry: |
|
page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac); |
|
|
|
/* |
|
* If an allocation failed after direct reclaim, it could be because |
|
* pages are pinned on the per-cpu lists or in high alloc reserves. |
|
* Shrink them and try again |
|
*/ |
|
if (!page && !drained) { |
|
unreserve_highatomic_pageblock(ac, false); |
|
drain_all_pages(NULL); |
|
drained = true; |
|
goto retry; |
|
} |
|
|
|
return page; |
|
} |
|
|
|
static void wake_all_kswapds(unsigned int order, gfp_t gfp_mask, |
|
const struct alloc_context *ac) |
|
{ |
|
struct zoneref *z; |
|
struct zone *zone; |
|
pg_data_t *last_pgdat = NULL; |
|
enum zone_type highest_zoneidx = ac->highest_zoneidx; |
|
|
|
for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, highest_zoneidx, |
|
ac->nodemask) { |
|
if (last_pgdat != zone->zone_pgdat) |
|
wakeup_kswapd(zone, gfp_mask, order, highest_zoneidx); |
|
last_pgdat = zone->zone_pgdat; |
|
} |
|
} |
|
|
|
static inline unsigned int |
|
gfp_to_alloc_flags(gfp_t gfp_mask) |
|
{ |
|
unsigned int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET; |
|
|
|
/* |
|
* __GFP_HIGH is assumed to be the same as ALLOC_HIGH |
|
* and __GFP_KSWAPD_RECLAIM is assumed to be the same as ALLOC_KSWAPD |
|
* to save two branches. |
|
*/ |
|
BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH); |
|
BUILD_BUG_ON(__GFP_KSWAPD_RECLAIM != (__force gfp_t) ALLOC_KSWAPD); |
|
|
|
/* |
|
* The caller may dip into page reserves a bit more if the caller |
|
* cannot run direct reclaim, or if the caller has realtime scheduling |
|
* policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will |
|
* set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH). |
|
*/ |
|
alloc_flags |= (__force int) |
|
(gfp_mask & (__GFP_HIGH | __GFP_KSWAPD_RECLAIM)); |
|
|
|
if (gfp_mask & __GFP_ATOMIC) { |
|
/* |
|
* Not worth trying to allocate harder for __GFP_NOMEMALLOC even |
|
* if it can't schedule. |
|
*/ |
|
if (!(gfp_mask & __GFP_NOMEMALLOC)) |
|
alloc_flags |= ALLOC_HARDER; |
|
/* |
|
* Ignore cpuset mems for GFP_ATOMIC rather than fail, see the |
|
* comment for __cpuset_node_allowed(). |
|
*/ |
|
alloc_flags &= ~ALLOC_CPUSET; |
|
} else if (unlikely(rt_task(current)) && in_task()) |
|
alloc_flags |= ALLOC_HARDER; |
|
|
|
alloc_flags = gfp_to_alloc_flags_cma(gfp_mask, alloc_flags); |
|
|
|
return alloc_flags; |
|
} |
|
|
|
static bool oom_reserves_allowed(struct task_struct *tsk) |
|
{ |
|
if (!tsk_is_oom_victim(tsk)) |
|
return false; |
|
|
|
/* |
|
* !MMU doesn't have oom reaper so give access to memory reserves |
|
* only to the thread with TIF_MEMDIE set |
|
*/ |
|
if (!IS_ENABLED(CONFIG_MMU) && !test_thread_flag(TIF_MEMDIE)) |
|
return false; |
|
|
|
return true; |
|
} |
|
|
|
/* |
|
* Distinguish requests which really need access to full memory |
|
* reserves from oom victims which can live with a portion of it |
|
*/ |
|
static inline int __gfp_pfmemalloc_flags(gfp_t gfp_mask) |
|
{ |
|
if (unlikely(gfp_mask & __GFP_NOMEMALLOC)) |
|
return 0; |
|
if (gfp_mask & __GFP_MEMALLOC) |
|
return ALLOC_NO_WATERMARKS; |
|
if (in_serving_softirq() && (current->flags & PF_MEMALLOC)) |
|
return ALLOC_NO_WATERMARKS; |
|
if (!in_interrupt()) { |
|
if (current->flags & PF_MEMALLOC) |
|
return ALLOC_NO_WATERMARKS; |
|
else if (oom_reserves_allowed(current)) |
|
return ALLOC_OOM; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
bool gfp_pfmemalloc_allowed(gfp_t gfp_mask) |
|
{ |
|
return !!__gfp_pfmemalloc_flags(gfp_mask); |
|
} |
|
|
|
/* |
|
* Checks whether it makes sense to retry the reclaim to make a forward progress |
|
* for the given allocation request. |
|
* |
|
* We give up when we either have tried MAX_RECLAIM_RETRIES in a row |
|
* without success, or when we couldn't even meet the watermark if we |
|
* reclaimed all remaining pages on the LRU lists. |
|
* |
|
* Returns true if a retry is viable or false to enter the oom path. |
|
*/ |
|
static inline bool |
|
should_reclaim_retry(gfp_t gfp_mask, unsigned order, |
|
struct alloc_context *ac, int alloc_flags, |
|
bool did_some_progress, int *no_progress_loops) |
|
{ |
|
struct zone *zone; |
|
struct zoneref *z; |
|
bool ret = false; |
|
|
|
/* |
|
* Costly allocations might have made a progress but this doesn't mean |
|
* their order will become available due to high fragmentation so |
|
* always increment the no progress counter for them |
|
*/ |
|
if (did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER) |
|
*no_progress_loops = 0; |
|
else |
|
(*no_progress_loops)++; |
|
|
|
/* |
|
* Make sure we converge to OOM if we cannot make any progress |
|
* several times in the row. |
|
*/ |
|
if (*no_progress_loops > MAX_RECLAIM_RETRIES) { |
|
/* Before OOM, exhaust highatomic_reserve */ |
|
return unreserve_highatomic_pageblock(ac, true); |
|
} |
|
|
|
/* |
|
* Keep reclaiming pages while there is a chance this will lead |
|
* somewhere. If none of the target zones can satisfy our allocation |
|
* request even if all reclaimable pages are considered then we are |
|
* screwed and have to go OOM. |
|
*/ |
|
for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, |
|
ac->highest_zoneidx, ac->nodemask) { |
|
unsigned long available; |
|
unsigned long reclaimable; |
|
unsigned long min_wmark = min_wmark_pages(zone); |
|
bool wmark; |
|
|
|
available = reclaimable = zone_reclaimable_pages(zone); |
|
available += zone_page_state_snapshot(zone, NR_FREE_PAGES); |
|
|
|
/* |
|
* Would the allocation succeed if we reclaimed all |
|
* reclaimable pages? |
|
*/ |
|
wmark = __zone_watermark_ok(zone, order, min_wmark, |
|
ac->highest_zoneidx, alloc_flags, available); |
|
trace_reclaim_retry_zone(z, order, reclaimable, |
|
available, min_wmark, *no_progress_loops, wmark); |
|
if (wmark) { |
|
/* |
|
* If we didn't make any progress and have a lot of |
|
* dirty + writeback pages then we should wait for |
|
* an IO to complete to slow down the reclaim and |
|
* prevent from pre mature OOM |
|
*/ |
|
if (!did_some_progress) { |
|
unsigned long write_pending; |
|
|
|
write_pending = zone_page_state_snapshot(zone, |
|
NR_ZONE_WRITE_PENDING); |
|
|
|
if (2 * write_pending > reclaimable) { |
|
congestion_wait(BLK_RW_ASYNC, HZ/10); |
|
return true; |
|
} |
|
} |
|
|
|
ret = true; |
|
goto out; |
|
} |
|
} |
|
|
|
out: |
|
/* |
|
* Memory allocation/reclaim might be called from a WQ context and the |
|
* current implementation of the WQ concurrency control doesn't |
|
* recognize that a particular WQ is congested if the worker thread is |
|
* looping without ever sleeping. Therefore we have to do a short sleep |
|
* here rather than calling cond_resched(). |
|
*/ |
|
if (current->flags & PF_WQ_WORKER) |
|
schedule_timeout_uninterruptible(1); |
|
else |
|
cond_resched(); |
|
return ret; |
|
} |
|
|
|
static inline bool |
|
check_retry_cpuset(int cpuset_mems_cookie, struct alloc_context *ac) |
|
{ |
|
/* |
|
* It's possible that cpuset's mems_allowed and the nodemask from |
|
* mempolicy don't intersect. This should be normally dealt with by |
|
* policy_nodemask(), but it's possible to race with cpuset update in |
|
* such a way the check therein was true, and then it became false |
|
* before we got our cpuset_mems_cookie here. |
|
* This assumes that for all allocations, ac->nodemask can come only |
|
* from MPOL_BIND mempolicy (whose documented semantics is to be ignored |
|
* when it does not intersect with the cpuset restrictions) or the |
|
* caller can deal with a violated nodemask. |
|
*/ |
|
if (cpusets_enabled() && ac->nodemask && |
|
!cpuset_nodemask_valid_mems_allowed(ac->nodemask)) { |
|
ac->nodemask = NULL; |
|
return true; |
|
} |
|
|
|
/* |
|
* When updating a task's mems_allowed or mempolicy nodemask, it is |
|
* possible to race with parallel threads in such a way that our |
|
* allocation can fail while the mask is being updated. If we are about |
|
* to fail, check if the cpuset changed during allocation and if so, |
|
* retry. |
|
*/ |
|
if (read_mems_allowed_retry(cpuset_mems_cookie)) |
|
return true; |
|
|
|
return false; |
|
} |
|
|
|
static inline struct page * |
|
__alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, |
|
struct alloc_context *ac) |
|
{ |
|
bool can_direct_reclaim = gfp_mask & __GFP_DIRECT_RECLAIM; |
|
const bool costly_order = order > PAGE_ALLOC_COSTLY_ORDER; |
|
struct page *page = NULL; |
|
unsigned int alloc_flags; |
|
unsigned long did_some_progress; |
|
enum compact_priority compact_priority; |
|
enum compact_result compact_result; |
|
int compaction_retries; |
|
int no_progress_loops; |
|
unsigned int cpuset_mems_cookie; |
|
int reserve_flags; |
|
|
|
/* |
|
* We also sanity check to catch abuse of atomic reserves being used by |
|
* callers that are not in atomic context. |
|
*/ |
|
if (WARN_ON_ONCE((gfp_mask & (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)) == |
|
(__GFP_ATOMIC|__GFP_DIRECT_RECLAIM))) |
|
gfp_mask &= ~__GFP_ATOMIC; |
|
|
|
retry_cpuset: |
|
compaction_retries = 0; |
|
no_progress_loops = 0; |
|
compact_priority = DEF_COMPACT_PRIORITY; |
|
cpuset_mems_cookie = read_mems_allowed_begin(); |
|
|
|
/* |
|
* The fast path uses conservative alloc_flags to succeed only until |
|
* kswapd needs to be woken up, and to avoid the cost of setting up |
|
* alloc_flags precisely. So we do that now. |
|
*/ |
|
alloc_flags = gfp_to_alloc_flags(gfp_mask); |
|
|
|
/* |
|
* We need to recalculate the starting point for the zonelist iterator |
|
* because we might have used different nodemask in the fast path, or |
|
* there was a cpuset modification and we are retrying - otherwise we |
|
* could end up iterating over non-eligible zones endlessly. |
|
*/ |
|
ac->preferred_zoneref = first_zones_zonelist(ac->zonelist, |
|
ac->highest_zoneidx, ac->nodemask); |
|
if (!ac->preferred_zoneref->zone) |
|
goto nopage; |
|
|
|
if (alloc_flags & ALLOC_KSWAPD) |
|
wake_all_kswapds(order, gfp_mask, ac); |
|
|
|
/* |
|
* The adjusted alloc_flags might result in immediate success, so try |
|
* that first |
|
*/ |
|
page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac); |
|
if (page) |
|
goto got_pg; |
|
|
|
/* |
|
* For costly allocations, try direct compaction first, as it's likely |
|
* that we have enough base pages and don't need to reclaim. For non- |
|
* movable high-order allocations, do that as well, as compaction will |
|
* try prevent permanent fragmentation by migrating from blocks of the |
|
* same migratetype. |
|
* Don't try this for allocations that are allowed to ignore |
|
* watermarks, as the ALLOC_NO_WATERMARKS attempt didn't yet happen. |
|
*/ |
|
if (can_direct_reclaim && |
|
(costly_order || |
|
(order > 0 && ac->migratetype != MIGRATE_MOVABLE)) |
|
&& !gfp_pfmemalloc_allowed(gfp_mask)) { |
|
page = __alloc_pages_direct_compact(gfp_mask, order, |
|
alloc_flags, ac, |
|
INIT_COMPACT_PRIORITY, |
|
&compact_result); |
|
if (page) |
|
goto got_pg; |
|
|
|
/* |
|
* Checks for costly allocations with __GFP_NORETRY, which |
|
* includes some THP page fault allocations |
|
*/ |
|
if (costly_order && (gfp_mask & __GFP_NORETRY)) { |
|
/* |
|
* If allocating entire pageblock(s) and compaction |
|
* failed because all zones are below low watermarks |
|
* or is prohibited because it recently failed at this |
|
* order, fail immediately unless the allocator has |
|
* requested compaction and reclaim retry. |
|
* |
|
* Reclaim is |
|
* - potentially very expensive because zones are far |
|
* below their low watermarks or this is part of very |
|
* bursty high order allocations, |
|
* - not guaranteed to help because isolate_freepages() |
|
* may not iterate over freed pages as part of its |
|
* linear scan, and |
|
* - unlikely to make entire pageblocks free on its |
|
* own. |
|
*/ |
|
if (compact_result == COMPACT_SKIPPED || |
|
compact_result == COMPACT_DEFERRED) |
|
goto nopage; |
|
|
|
/* |
|
* Looks like reclaim/compaction is worth trying, but |
|
* sync compaction could be very expensive, so keep |
|
* using async compaction. |
|
*/ |
|
compact_priority = INIT_COMPACT_PRIORITY; |
|
} |
|
} |
|
|
|
retry: |
|
/* Ensure kswapd doesn't accidentally go to sleep as long as we loop */ |
|
if (alloc_flags & ALLOC_KSWAPD) |
|
wake_all_kswapds(order, gfp_mask, ac); |
|
|
|
reserve_flags = __gfp_pfmemalloc_flags(gfp_mask); |
|
if (reserve_flags) |
|
alloc_flags = gfp_to_alloc_flags_cma(gfp_mask, reserve_flags); |
|
|
|
/* |
|
* Reset the nodemask and zonelist iterators if memory policies can be |
|
* ignored. These allocations are high priority and system rather than |
|
* user oriented. |
|
*/ |
|
if (!(alloc_flags & ALLOC_CPUSET) || reserve_flags) { |
|
ac->nodemask = NULL; |
|
ac->preferred_zoneref = first_zones_zonelist(ac->zonelist, |
|
ac->highest_zoneidx, ac->nodemask); |
|
} |
|
|
|
/* Attempt with potentially adjusted zonelist and alloc_flags */ |
|
page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac); |
|
if (page) |
|
goto got_pg; |
|
|
|
/* Caller is not willing to reclaim, we can't balance anything */ |
|
if (!can_direct_reclaim) |
|
goto nopage; |
|
|
|
/* Avoid recursion of direct reclaim */ |
|
if (current->flags & PF_MEMALLOC) |
|
goto nopage; |
|
|
|
/* Try direct reclaim and then allocating */ |
|
page = __alloc_pages_direct_reclaim(gfp_mask, order, alloc_flags, ac, |
|
&did_some_progress); |
|
if (page) |
|
goto got_pg; |
|
|
|
/* Try direct compaction and then allocating */ |
|
page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac, |
|
compact_priority, &compact_result); |
|
if (page) |
|
goto got_pg; |
|
|
|
/* Do not loop if specifically requested */ |
|
if (gfp_mask & __GFP_NORETRY) |
|
goto nopage; |
|
|
|
/* |
|
* Do not retry costly high order allocations unless they are |
|
* __GFP_RETRY_MAYFAIL |
|
*/ |
|
if (costly_order && !(gfp_mask & __GFP_RETRY_MAYFAIL)) |
|
goto nopage; |
|
|
|
if (should_reclaim_retry(gfp_mask, order, ac, alloc_flags, |
|
did_some_progress > 0, &no_progress_loops)) |
|
goto retry; |
|
|
|
/* |
|
* It doesn't make any sense to retry for the compaction if the order-0 |
|
* reclaim is not able to make any progress because the current |
|
* implementation of the compaction depends on the sufficient amount |
|
* of free memory (see __compaction_suitable) |
|
*/ |
|
if (did_some_progress > 0 && |
|
should_compact_retry(ac, order, alloc_flags, |
|
compact_result, &compact_priority, |
|
&compaction_retries)) |
|
goto retry; |
|
|
|
|
|
/* Deal with possible cpuset update races before we start OOM killing */ |
|
if (check_retry_cpuset(cpuset_mems_cookie, ac)) |
|
goto retry_cpuset; |
|
|
|
/* Reclaim has failed us, start killing things */ |
|
page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress); |
|
if (page) |
|
goto got_pg; |
|
|
|
/* Avoid allocations with no watermarks from looping endlessly */ |
|
if (tsk_is_oom_victim(current) && |
|
(alloc_flags & ALLOC_OOM || |
|
(gfp_mask & __GFP_NOMEMALLOC))) |
|
goto nopage; |
|
|
|
/* Retry as long as the OOM killer is making progress */ |
|
if (did_some_progress) { |
|
no_progress_loops = 0; |
|
goto retry; |
|
} |
|
|
|
nopage: |
|
/* Deal with possible cpuset update races before we fail */ |
|
if (check_retry_cpuset(cpuset_mems_cookie, ac)) |
|
goto retry_cpuset; |
|
|
|
/* |
|
* Make sure that __GFP_NOFAIL request doesn't leak out and make sure |
|
* we always retry |
|
*/ |
|
if (gfp_mask & __GFP_NOFAIL) { |
|
/* |
|
* All existing users of the __GFP_NOFAIL are blockable, so warn |
|
* of any new users that actually require GFP_NOWAIT |
|
*/ |
|
if (WARN_ON_ONCE(!can_direct_reclaim)) |
|
goto fail; |
|
|
|
/* |
|
* PF_MEMALLOC request from this context is rather bizarre |
|
* because we cannot reclaim anything and only can loop waiting |
|
* for somebody to do a work for us |
|
*/ |
|
WARN_ON_ONCE(current->flags & PF_MEMALLOC); |
|
|
|
/* |
|
* non failing costly orders are a hard requirement which we |
|
* are not prepared for much so let's warn about these users |
|
* so that we can identify them and convert them to something |
|
* else. |
|
*/ |
|
WARN_ON_ONCE(order > PAGE_ALLOC_COSTLY_ORDER); |
|
|
|
/* |
|
* Help non-failing allocations by giving them access to memory |
|
* reserves but do not use ALLOC_NO_WATERMARKS because this |
|
* could deplete whole memory reserves which would just make |
|
* the situation worse |
|
*/ |
|
page = __alloc_pages_cpuset_fallback(gfp_mask, order, ALLOC_HARDER, ac); |
|
if (page) |
|
goto got_pg; |
|
|
|
cond_resched(); |
|
goto retry; |
|
} |
|
fail: |
|
warn_alloc(gfp_mask, ac->nodemask, |
|
"page allocation failure: order:%u", order); |
|
got_pg: |
|
return page; |
|
} |
|
|
|
static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order, |
|
int preferred_nid, nodemask_t *nodemask, |
|
struct alloc_context *ac, gfp_t *alloc_gfp, |
|
unsigned int *alloc_flags) |
|
{ |
|
ac->highest_zoneidx = gfp_zone(gfp_mask); |
|
ac->zonelist = node_zonelist(preferred_nid, gfp_mask); |
|
ac->nodemask = nodemask; |
|
ac->migratetype = gfp_migratetype(gfp_mask); |
|
|
|
if (cpusets_enabled()) { |
|
*alloc_gfp |= __GFP_HARDWALL; |
|
/* |
|
* When we are in the interrupt context, it is irrelevant |
|
* to the current task context. It means that any node ok. |
|
*/ |
|
if (in_task() && !ac->nodemask) |
|
ac->nodemask = &cpuset_current_mems_allowed; |
|
else |
|
*alloc_flags |= ALLOC_CPUSET; |
|
} |
|
|
|
fs_reclaim_acquire(gfp_mask); |
|
fs_reclaim_release(gfp_mask); |
|
|
|
might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM); |
|
|
|
if (should_fail_alloc_page(gfp_mask, order)) |
|
return false; |
|
|
|
*alloc_flags = gfp_to_alloc_flags_cma(gfp_mask, *alloc_flags); |
|
|
|
/* Dirty zone balancing only done in the fast path */ |
|
ac->spread_dirty_pages = (gfp_mask & __GFP_WRITE); |
|
|
|
/* |
|
* The preferred zone is used for statistics but crucially it is |
|
* also used as the starting point for the zonelist iterator. It |
|
* may get reset for allocations that ignore memory policies. |
|
*/ |
|
ac->preferred_zoneref = first_zones_zonelist(ac->zonelist, |
|
ac->highest_zoneidx, ac->nodemask); |
|
|
|
return true; |
|
} |
|
|
|
/* |
|
* __alloc_pages_bulk - Allocate a number of order-0 pages to a list or array |
|
* @gfp: GFP flags for the allocation |
|
* @preferred_nid: The preferred NUMA node ID to allocate from |
|
* @nodemask: Set of nodes to allocate from, may be NULL |
|
* @nr_pages: The number of pages desired on the list or array |
|
* @page_list: Optional list to store the allocated pages |
|
* @page_array: Optional array to store the pages |
|
* |
|
* This is a batched version of the page allocator that attempts to |
|
* allocate nr_pages quickly. Pages are added to page_list if page_list |
|
* is not NULL, otherwise it is assumed that the page_array is valid. |
|
* |
|
* For lists, nr_pages is the number of pages that should be allocated. |
|
* |
|
* For arrays, only NULL elements are populated with pages and nr_pages |
|
* is the maximum number of pages that will be stored in the array. |
|
* |
|
* Returns the number of pages on the list or array. |
|
*/ |
|
unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid, |
|
nodemask_t *nodemask, int nr_pages, |
|
struct list_head *page_list, |
|
struct page **page_array) |
|
{ |
|
struct page *page; |
|
unsigned long flags; |
|
struct zone *zone; |
|
struct zoneref *z; |
|
struct per_cpu_pages *pcp; |
|
struct list_head *pcp_list; |
|
struct alloc_context ac; |
|
gfp_t alloc_gfp; |
|
unsigned int alloc_flags = ALLOC_WMARK_LOW; |
|
int nr_populated = 0, nr_account = 0; |
|
|
|
/* |
|
* Skip populated array elements to determine if any pages need |
|
* to be allocated before disabling IRQs. |
|
*/ |
|
while (page_array && nr_populated < nr_pages && page_array[nr_populated]) |
|
nr_populated++; |
|
|
|
/* No pages requested? */ |
|
if (unlikely(nr_pages <= 0)) |
|
goto out; |
|
|
|
/* Already populated array? */ |
|
if (unlikely(page_array && nr_pages - nr_populated == 0)) |
|
goto out; |
|
|
|
/* Use the single page allocator for one page. */ |
|
if (nr_pages - nr_populated == 1) |
|
goto failed; |
|
|
|
#ifdef CONFIG_PAGE_OWNER |
|
/* |
|
* PAGE_OWNER may recurse into the allocator to allocate space to |
|
* save the stack with pagesets.lock held. Releasing/reacquiring |
|
* removes much of the performance benefit of bulk allocation so |
|
* force the caller to allocate one page at a time as it'll have |
|
* similar performance to added complexity to the bulk allocator. |
|
*/ |
|
if (static_branch_unlikely(&page_owner_inited)) |
|
goto failed; |
|
#endif |
|
|
|
/* May set ALLOC_NOFRAGMENT, fragmentation will return 1 page. */ |
|
gfp &= gfp_allowed_mask; |
|
alloc_gfp = gfp; |
|
if (!prepare_alloc_pages(gfp, 0, preferred_nid, nodemask, &ac, &alloc_gfp, &alloc_flags)) |
|
goto out; |
|
gfp = alloc_gfp; |
|
|
|
/* Find an allowed local zone that meets the low watermark. */ |
|
for_each_zone_zonelist_nodemask(zone, z, ac.zonelist, ac.highest_zoneidx, ac.nodemask) { |
|
unsigned long mark; |
|
|
|
if (cpusets_enabled() && (alloc_flags & ALLOC_CPUSET) && |
|
!__cpuset_zone_allowed(zone, gfp)) { |
|
continue; |
|
} |
|
|
|
if (nr_online_nodes > 1 && zone != ac.preferred_zoneref->zone && |
|
zone_to_nid(zone) != zone_to_nid(ac.preferred_zoneref->zone)) { |
|
goto failed; |
|
} |
|
|
|
mark = wmark_pages(zone, alloc_flags & ALLOC_WMARK_MASK) + nr_pages; |
|
if (zone_watermark_fast(zone, 0, mark, |
|
zonelist_zone_idx(ac.preferred_zoneref), |
|
alloc_flags, gfp)) { |
|
break; |
|
} |
|
} |
|
|
|
/* |
|
* If there are no allowed local zones that meets the watermarks then |
|
* try to allocate a single page and reclaim if necessary. |
|
*/ |
|
if (unlikely(!zone)) |
|
goto failed; |
|
|
|
/* Attempt the batch allocation */ |
|
local_lock_irqsave(&pagesets.lock, flags); |
|
pcp = this_cpu_ptr(zone->per_cpu_pageset); |
|
pcp_list = &pcp->lists[order_to_pindex(ac.migratetype, 0)]; |
|
|
|
while (nr_populated < nr_pages) { |
|
|
|
/* Skip existing pages */ |
|
if (page_array && page_array[nr_populated]) { |
|
nr_populated++; |
|
continue; |
|
} |
|
|
|
page = __rmqueue_pcplist(zone, 0, ac.migratetype, alloc_flags, |
|
pcp, pcp_list); |
|
if (unlikely(!page)) { |
|
/* Try and get at least one page */ |
|
if (!nr_populated) |
|
goto failed_irq; |
|
break; |
|
} |
|
nr_account++; |
|
|
|
prep_new_page(page, 0, gfp, 0); |
|
if (page_list) |
|
list_add(&page->lru, page_list); |
|
else |
|
page_array[nr_populated] = page; |
|
nr_populated++; |
|
} |
|
|
|
local_unlock_irqrestore(&pagesets.lock, flags); |
|
|
|
__count_zid_vm_events(PGALLOC, zone_idx(zone), nr_account); |
|
zone_statistics(ac.preferred_zoneref->zone, zone, nr_account); |
|
|
|
out: |
|
return nr_populated; |
|
|
|
failed_irq: |
|
local_unlock_irqrestore(&pagesets.lock, flags); |
|
|
|
failed: |
|
page = __alloc_pages(gfp, 0, preferred_nid, nodemask); |
|
if (page) { |
|
if (page_list) |
|
list_add(&page->lru, page_list); |
|
else |
|
page_array[nr_populated] = page; |
|
nr_populated++; |
|
} |
|
|
|
goto out; |
|
} |
|
EXPORT_SYMBOL_GPL(__alloc_pages_bulk); |
|
|
|
/* |
|
* This is the 'heart' of the zoned buddy allocator. |
|
*/ |
|
struct page *__alloc_pages(gfp_t gfp, unsigned int order, int preferred_nid, |
|
nodemask_t *nodemask) |
|
{ |
|
struct page *page; |
|
unsigned int alloc_flags = ALLOC_WMARK_LOW; |
|
gfp_t alloc_gfp; /* The gfp_t that was actually used for allocation */ |
|
struct alloc_context ac = { }; |
|
|
|
/* |
|
* There are several places where we assume that the order value is sane |
|
* so bail out early if the request is out of bound. |
|
*/ |
|
if (unlikely(order >= MAX_ORDER)) { |
|
WARN_ON_ONCE(!(gfp & __GFP_NOWARN)); |
|
return NULL; |
|
} |
|
|
|
gfp &= gfp_allowed_mask; |
|
/* |
|
* Apply scoped allocation constraints. This is mainly about GFP_NOFS |
|
* resp. GFP_NOIO which has to be inherited for all allocation requests |
|
* from a particular context which has been marked by |
|
* memalloc_no{fs,io}_{save,restore}. And PF_MEMALLOC_PIN which ensures |
|
* movable zones are not used during allocation. |
|
*/ |
|
gfp = current_gfp_context(gfp); |
|
alloc_gfp = gfp; |
|
if (!prepare_alloc_pages(gfp, order, preferred_nid, nodemask, &ac, |
|
&alloc_gfp, &alloc_flags)) |
|
return NULL; |
|
|
|
/* |
|
* Forbid the first pass from falling back to types that fragment |
|
* memory until all local zones are considered. |
|
*/ |
|
alloc_flags |= alloc_flags_nofragment(ac.preferred_zoneref->zone, gfp); |
|
|
|
/* First allocation attempt */ |
|
page = get_page_from_freelist(alloc_gfp, order, alloc_flags, &ac); |
|
if (likely(page)) |
|
goto out; |
|
|
|
alloc_gfp = gfp; |
|
ac.spread_dirty_pages = false; |
|
|
|
/* |
|
* Restore the original nodemask if it was potentially replaced with |
|
* &cpuset_current_mems_allowed to optimize the fast-path attempt. |
|
*/ |
|
ac.nodemask = nodemask; |
|
|
|
page = __alloc_pages_slowpath(alloc_gfp, order, &ac); |
|
|
|
out: |
|
if (memcg_kmem_enabled() && (gfp & __GFP_ACCOUNT) && page && |
|
unlikely(__memcg_kmem_charge_page(page, gfp, order) != 0)) { |
|
__free_pages(page, order); |
|
page = NULL; |
|
} |
|
|
|
trace_mm_page_alloc(page, order, alloc_gfp, ac.migratetype); |
|
|
|
return page; |
|
} |
|
EXPORT_SYMBOL(__alloc_pages); |
|
|
|
/* |
|
* Common helper functions. Never use with __GFP_HIGHMEM because the returned |
|
* address cannot represent highmem pages. Use alloc_pages and then kmap if |
|
* you need to access high mem. |
|
*/ |
|
unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order) |
|
{ |
|
struct page *page; |
|
|
|
page = alloc_pages(gfp_mask & ~__GFP_HIGHMEM, order); |
|
if (!page) |
|
return 0; |
|
return (unsigned long) page_address(page); |
|
} |
|
EXPORT_SYMBOL(__get_free_pages); |
|
|
|
unsigned long get_zeroed_page(gfp_t gfp_mask) |
|
{ |
|
return __get_free_pages(gfp_mask | __GFP_ZERO, 0); |
|
} |
|
EXPORT_SYMBOL(get_zeroed_page); |
|
|
|
/** |
|
* __free_pages - Free pages allocated with alloc_pages(). |
|
* @page: The page pointer returned from alloc_pages(). |
|
* @order: The order of the allocation. |
|
* |
|
* This function can free multi-page allocations that are not compound |
|
* pages. It does not check that the @order passed in matches that of |
|
* the allocation, so it is easy to leak memory. Freeing more memory |
|
* than was allocated will probably emit a warning. |
|
* |
|
* If the last reference to this page is speculative, it will be released |
|
* by put_page() which only frees the first page of a non-compound |
|
* allocation. To prevent the remaining pages from being leaked, we free |
|
* the subsequent pages here. If you want to use the page's reference |
|
* count to decide when to free the allocation, you should allocate a |
|
* compound page, and use put_page() instead of __free_pages(). |
|
* |
|
* Context: May be called in interrupt context or while holding a normal |
|
* spinlock, but not in NMI context or while holding a raw spinlock. |
|
*/ |
|
void __free_pages(struct page *page, unsigned int order) |
|
{ |
|
if (put_page_testzero(page)) |
|
free_the_page(page, order); |
|
else if (!PageHead(page)) |
|
while (order-- > 0) |
|
free_the_page(page + (1 << order), order); |
|
} |
|
EXPORT_SYMBOL(__free_pages); |
|
|
|
void free_pages(unsigned long addr, unsigned int order) |
|
{ |
|
if (addr != 0) { |
|
VM_BUG_ON(!virt_addr_valid((void *)addr)); |
|
__free_pages(virt_to_page((void *)addr), order); |
|
} |
|
} |
|
|
|
EXPORT_SYMBOL(free_pages); |
|
|
|
/* |
|
* Page Fragment: |
|
* An arbitrary-length arbitrary-offset area of memory which resides |
|
* within a 0 or higher order page. Multiple fragments within that page |
|
* are individually refcounted, in the page's reference counter. |
|
* |
|
* The page_frag functions below provide a simple allocation framework for |
|
* page fragments. This is used by the network stack and network device |
|
* drivers to provide a backing region of memory for use as either an |
|
* sk_buff->head, or to be used in the "frags" portion of skb_shared_info. |
|
*/ |
|
static struct page *__page_frag_cache_refill(struct page_frag_cache *nc, |
|
gfp_t gfp_mask) |
|
{ |
|
struct page *page = NULL; |
|
gfp_t gfp = gfp_mask; |
|
|
|
#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) |
|
gfp_mask |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY | |
|
__GFP_NOMEMALLOC; |
|
page = alloc_pages_node(NUMA_NO_NODE, gfp_mask, |
|
PAGE_FRAG_CACHE_MAX_ORDER); |
|
nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE; |
|
#endif |
|
if (unlikely(!page)) |
|
page = alloc_pages_node(NUMA_NO_NODE, gfp, 0); |
|
|
|
nc->va = page ? page_address(page) : NULL; |
|
|
|
return page; |
|
} |
|
|
|
void __page_frag_cache_drain(struct page *page, unsigned int count) |
|
{ |
|
VM_BUG_ON_PAGE(page_ref_count(page) == 0, page); |
|
|
|
if (page_ref_sub_and_test(page, count)) |
|
free_the_page(page, compound_order(page)); |
|
} |
|
EXPORT_SYMBOL(__page_frag_cache_drain); |
|
|
|
void *page_frag_alloc_align(struct page_frag_cache *nc, |
|
unsigned int fragsz, gfp_t gfp_mask, |
|
unsigned int align_mask) |
|
{ |
|
unsigned int size = PAGE_SIZE; |
|
struct page *page; |
|
int offset; |
|
|
|
if (unlikely(!nc->va)) { |
|
refill: |
|
page = __page_frag_cache_refill(nc, gfp_mask); |
|
if (!page) |
|
return NULL; |
|
|
|
#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) |
|
/* if size can vary use size else just use PAGE_SIZE */ |
|
size = nc->size; |
|
#endif |
|
/* Even if we own the page, we do not use atomic_set(). |
|
* This would break get_page_unless_zero() users. |
|
*/ |
|
page_ref_add(page, PAGE_FRAG_CACHE_MAX_SIZE); |
|
|
|
/* reset page count bias and offset to start of new frag */ |
|
nc->pfmemalloc = page_is_pfmemalloc(page); |
|
nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1; |
|
nc->offset = size; |
|
} |
|
|
|
offset = nc->offset - fragsz; |
|
if (unlikely(offset < 0)) { |
|
page = virt_to_page(nc->va); |
|
|
|
if (!page_ref_sub_and_test(page, nc->pagecnt_bias)) |
|
goto refill; |
|
|
|
if (unlikely(nc->pfmemalloc)) { |
|
free_the_page(page, compound_order(page)); |
|
goto refill; |
|
} |
|
|
|
#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) |
|
/* if size can vary use size else just use PAGE_SIZE */ |
|
size = nc->size; |
|
#endif |
|
/* OK, page count is 0, we can safely set it */ |
|
set_page_count(page, PAGE_FRAG_CACHE_MAX_SIZE + 1); |
|
|
|
/* reset page count bias and offset to start of new frag */ |
|
nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1; |
|
offset = size - fragsz; |
|
} |
|
|
|
nc->pagecnt_bias--; |
|
offset &= align_mask; |
|
nc->offset = offset; |
|
|
|
return nc->va + offset; |
|
} |
|
EXPORT_SYMBOL(page_frag_alloc_align); |
|
|
|
/* |
|
* Frees a page fragment allocated out of either a compound or order 0 page. |
|
*/ |
|
void page_frag_free(void *addr) |
|
{ |
|
struct page *page = virt_to_head_page(addr); |
|
|
|
if (unlikely(put_page_testzero(page))) |
|
free_the_page(page, compound_order(page)); |
|
} |
|
EXPORT_SYMBOL(page_frag_free); |
|
|
|
static void *make_alloc_exact(unsigned long addr, unsigned int order, |
|
size_t size) |
|
{ |
|
if (addr) { |
|
unsigned long alloc_end = addr + (PAGE_SIZE << order); |
|
unsigned long used = addr + PAGE_ALIGN(size); |
|
|
|
split_page(virt_to_page((void *)addr), order); |
|
while (used < alloc_end) { |
|
free_page(used); |
|
used += PAGE_SIZE; |
|
} |
|
} |
|
return (void *)addr; |
|
} |
|
|
|
/** |
|
* alloc_pages_exact - allocate an exact number physically-contiguous pages. |
|
* @size: the number of bytes to allocate |
|
* @gfp_mask: GFP flags for the allocation, must not contain __GFP_COMP |
|
* |
|
* This function is similar to alloc_pages(), except that it allocates the |
|
* minimum number of pages to satisfy the request. alloc_pages() can only |
|
* allocate memory in power-of-two pages. |
|
* |
|
* This function is also limited by MAX_ORDER. |
|
* |
|
* Memory allocated by this function must be released by free_pages_exact(). |
|
* |
|
* Return: pointer to the allocated area or %NULL in case of error. |
|
*/ |
|
void *alloc_pages_exact(size_t size, gfp_t gfp_mask) |
|
{ |
|
unsigned int order = get_order(size); |
|
unsigned long addr; |
|
|
|
if (WARN_ON_ONCE(gfp_mask & __GFP_COMP)) |
|
gfp_mask &= ~__GFP_COMP; |
|
|
|
addr = __get_free_pages(gfp_mask, order); |
|
return make_alloc_exact(addr, order, size); |
|
} |
|
EXPORT_SYMBOL(alloc_pages_exact); |
|
|
|
/** |
|
* alloc_pages_exact_nid - allocate an exact number of physically-contiguous |
|
* pages on a node. |
|
* @nid: the preferred node ID where memory should be allocated |
|
* @size: the number of bytes to allocate |
|
* @gfp_mask: GFP flags for the allocation, must not contain __GFP_COMP |
|
* |
|
* Like alloc_pages_exact(), but try to allocate on node nid first before falling |
|
* back. |
|
* |
|
* Return: pointer to the allocated area or %NULL in case of error. |
|
*/ |
|
void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask) |
|
{ |
|
unsigned int order = get_order(size); |
|
struct page *p; |
|
|
|
if (WARN_ON_ONCE(gfp_mask & __GFP_COMP)) |
|
gfp_mask &= ~__GFP_COMP; |
|
|
|
p = alloc_pages_node(nid, gfp_mask, order); |
|
if (!p) |
|
return NULL; |
|
return make_alloc_exact((unsigned long)page_address(p), order, size); |
|
} |
|
|
|
/** |
|
* free_pages_exact - release memory allocated via alloc_pages_exact() |
|
* @virt: the value returned by alloc_pages_exact. |
|
* @size: size of allocation, same value as passed to alloc_pages_exact(). |
|
* |
|
* Release the memory allocated by a previous call to alloc_pages_exact. |
|
*/ |
|
void free_pages_exact(void *virt, size_t size) |
|
{ |
|
unsigned long addr = (unsigned long)virt; |
|
unsigned long end = addr + PAGE_ALIGN(size); |
|
|
|
while (addr < end) { |
|
free_page(addr); |
|
addr += PAGE_SIZE; |
|
} |
|
} |
|
EXPORT_SYMBOL(free_pages_exact); |
|
|
|
/** |
|
* nr_free_zone_pages - count number of pages beyond high watermark |
|
* @offset: The zone index of the highest zone |
|
* |
|
* nr_free_zone_pages() counts the number of pages which are beyond the |
|
* high watermark within all zones at or below a given zone index. For each |
|
* zone, the number of pages is calculated as: |
|
* |
|
* nr_free_zone_pages = managed_pages - high_pages |
|
* |
|
* Return: number of pages beyond high watermark. |
|
*/ |
|
static unsigned long nr_free_zone_pages(int offset) |
|
{ |
|
struct zoneref *z; |
|
struct zone *zone; |
|
|
|
/* Just pick one node, since fallback list is circular */ |
|
unsigned long sum = 0; |
|
|
|
struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL); |
|
|
|
for_each_zone_zonelist(zone, z, zonelist, offset) { |
|
unsigned long size = zone_managed_pages(zone); |
|
unsigned long high = high_wmark_pages(zone); |
|
if (size > high) |
|
sum += size - high; |
|
} |
|
|
|
return sum; |
|
} |
|
|
|
/** |
|
* nr_free_buffer_pages - count number of pages beyond high watermark |
|
* |
|
* nr_free_buffer_pages() counts the number of pages which are beyond the high |
|
* watermark within ZONE_DMA and ZONE_NORMAL. |
|
* |
|
* Return: number of pages beyond high watermark within ZONE_DMA and |
|
* ZONE_NORMAL. |
|
*/ |
|
unsigned long nr_free_buffer_pages(void) |
|
{ |
|
return nr_free_zone_pages(gfp_zone(GFP_USER)); |
|
} |
|
EXPORT_SYMBOL_GPL(nr_free_buffer_pages); |
|
|
|
static inline void show_node(struct zone *zone) |
|
{ |
|
if (IS_ENABLED(CONFIG_NUMA)) |
|
printk("Node %d ", zone_to_nid(zone)); |
|
} |
|
|
|
long si_mem_available(void) |
|
{ |
|
long available; |
|
unsigned long pagecache; |
|
unsigned long wmark_low = 0; |
|
unsigned long pages[NR_LRU_LISTS]; |
|
unsigned long reclaimable; |
|
struct zone *zone; |
|
int lru; |
|
|
|
for (lru = LRU_BASE; lru < NR_LRU_LISTS; lru++) |
|
pages[lru] = global_node_page_state(NR_LRU_BASE + lru); |
|
|
|
for_each_zone(zone) |
|
wmark_low += low_wmark_pages(zone); |
|
|
|
/* |
|
* Estimate the amount of memory available for userspace allocations, |
|
* without causing swapping. |
|
*/ |
|
available = global_zone_page_state(NR_FREE_PAGES) - totalreserve_pages; |
|
|
|
/* |
|
* Not all the page cache can be freed, otherwise the system will |
|
* start swapping. Assume at least half of the page cache, or the |
|
* low watermark worth of cache, needs to stay. |
|
*/ |
|
pagecache = pages[LRU_ACTIVE_FILE] + pages[LRU_INACTIVE_FILE]; |
|
pagecache -= min(pagecache / 2, wmark_low); |
|
available += pagecache; |
|
|
|
/* |
|
* Part of the reclaimable slab and other kernel memory consists of |
|
* items that are in use, and cannot be freed. Cap this estimate at the |
|
* low watermark. |
|
*/ |
|
reclaimable = global_node_page_state_pages(NR_SLAB_RECLAIMABLE_B) + |
|
global_node_page_state(NR_KERNEL_MISC_RECLAIMABLE); |
|
available += reclaimable - min(reclaimable / 2, wmark_low); |
|
|
|
if (available < 0) |
|
available = 0; |
|
return available; |
|
} |
|
EXPORT_SYMBOL_GPL(si_mem_available); |
|
|
|
void si_meminfo(struct sysinfo *val) |
|
{ |
|
val->totalram = totalram_pages(); |
|
val->sharedram = global_node_page_state(NR_SHMEM); |
|
val->freeram = global_zone_page_state(NR_FREE_PAGES); |
|
val->bufferram = nr_blockdev_pages(); |
|
val->totalhigh = totalhigh_pages(); |
|
val->freehigh = nr_free_highpages(); |
|
val->mem_unit = PAGE_SIZE; |
|
} |
|
|
|
EXPORT_SYMBOL(si_meminfo); |
|
|
|
#ifdef CONFIG_NUMA |
|
void si_meminfo_node(struct sysinfo *val, int nid) |
|
{ |
|
int zone_type; /* needs to be signed */ |
|
unsigned long managed_pages = 0; |
|
unsigned long managed_highpages = 0; |
|
unsigned long free_highpages = 0; |
|
pg_data_t *pgdat = NODE_DATA(nid); |
|
|
|
for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) |
|
managed_pages += zone_managed_pages(&pgdat->node_zones[zone_type]); |
|
val->totalram = managed_pages; |
|
val->sharedram = node_page_state(pgdat, NR_SHMEM); |
|
val->freeram = sum_zone_node_page_state(nid, NR_FREE_PAGES); |
|
#ifdef CONFIG_HIGHMEM |
|
for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) { |
|
struct zone *zone = &pgdat->node_zones[zone_type]; |
|
|
|
if (is_highmem(zone)) { |
|
managed_highpages += zone_managed_pages(zone); |
|
free_highpages += zone_page_state(zone, NR_FREE_PAGES); |
|
} |
|
} |
|
val->totalhigh = managed_highpages; |
|
val->freehigh = free_highpages; |
|
#else |
|
val->totalhigh = managed_highpages; |
|
val->freehigh = free_highpages; |
|
#endif |
|
val->mem_unit = PAGE_SIZE; |
|
} |
|
#endif |
|
|
|
/* |
|
* Determine whether the node should be displayed or not, depending on whether |
|
* SHOW_MEM_FILTER_NODES was passed to show_free_areas(). |
|
*/ |
|
static bool show_mem_node_skip(unsigned int flags, int nid, nodemask_t *nodemask) |
|
{ |
|
if (!(flags & SHOW_MEM_FILTER_NODES)) |
|
return false; |
|
|
|
/* |
|
* no node mask - aka implicit memory numa policy. Do not bother with |
|
* the synchronization - read_mems_allowed_begin - because we do not |
|
* have to be precise here. |
|
*/ |
|
if (!nodemask) |
|
nodemask = &cpuset_current_mems_allowed; |
|
|
|
return !node_isset(nid, *nodemask); |
|
} |
|
|
|
#define K(x) ((x) << (PAGE_SHIFT-10)) |
|
|
|
static void show_migration_types(unsigned char type) |
|
{ |
|
static const char types[MIGRATE_TYPES] = { |
|
[MIGRATE_UNMOVABLE] = 'U', |
|
[MIGRATE_MOVABLE] = 'M', |
|
[MIGRATE_RECLAIMABLE] = 'E', |
|
[MIGRATE_HIGHATOMIC] = 'H', |
|
#ifdef CONFIG_CMA |
|
[MIGRATE_CMA] = 'C', |
|
#endif |
|
#ifdef CONFIG_MEMORY_ISOLATION |
|
[MIGRATE_ISOLATE] = 'I', |
|
#endif |
|
}; |
|
char tmp[MIGRATE_TYPES + 1]; |
|
char *p = tmp; |
|
int i; |
|
|
|
for (i = 0; i < MIGRATE_TYPES; i++) { |
|
if (type & (1 << i)) |
|
*p++ = types[i]; |
|
} |
|
|
|
*p = '\0'; |
|
printk(KERN_CONT "(%s) ", tmp); |
|
} |
|
|
|
/* |
|
* Show free area list (used inside shift_scroll-lock stuff) |
|
* We also calculate the percentage fragmentation. We do this by counting the |
|
* memory on each free list with the exception of the first item on the list. |
|
* |
|
* Bits in @filter: |
|
* SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's |
|
* cpuset. |
|
*/ |
|
void show_free_areas(unsigned int filter, nodemask_t *nodemask) |
|
{ |
|
unsigned long free_pcp = 0; |
|
int cpu; |
|
struct zone *zone; |
|
pg_data_t *pgdat; |
|
|
|
for_each_populated_zone(zone) { |
|
if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask)) |
|
continue; |
|
|
|
for_each_online_cpu(cpu) |
|
free_pcp += per_cpu_ptr(zone->per_cpu_pageset, cpu)->count; |
|
} |
|
|
|
printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n" |
|
" active_file:%lu inactive_file:%lu isolated_file:%lu\n" |
|
" unevictable:%lu dirty:%lu writeback:%lu\n" |
|
" slab_reclaimable:%lu slab_unreclaimable:%lu\n" |
|
" mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n" |
|
" kernel_misc_reclaimable:%lu\n" |
|
" free:%lu free_pcp:%lu free_cma:%lu\n", |
|
global_node_page_state(NR_ACTIVE_ANON), |
|
global_node_page_state(NR_INACTIVE_ANON), |
|
global_node_page_state(NR_ISOLATED_ANON), |
|
global_node_page_state(NR_ACTIVE_FILE), |
|
global_node_page_state(NR_INACTIVE_FILE), |
|
global_node_page_state(NR_ISOLATED_FILE), |
|
global_node_page_state(NR_UNEVICTABLE), |
|
global_node_page_state(NR_FILE_DIRTY), |
|
global_node_page_state(NR_WRITEBACK), |
|
global_node_page_state_pages(NR_SLAB_RECLAIMABLE_B), |
|
global_node_page_state_pages(NR_SLAB_UNRECLAIMABLE_B), |
|
global_node_page_state(NR_FILE_MAPPED), |
|
global_node_page_state(NR_SHMEM), |
|
global_node_page_state(NR_PAGETABLE), |
|
global_zone_page_state(NR_BOUNCE), |
|
global_node_page_state(NR_KERNEL_MISC_RECLAIMABLE), |
|
global_zone_page_state(NR_FREE_PAGES), |
|
free_pcp, |
|
global_zone_page_state(NR_FREE_CMA_PAGES)); |
|
|
|
for_each_online_pgdat(pgdat) { |
|
if (show_mem_node_skip(filter, pgdat->node_id, nodemask)) |
|
continue; |
|
|
|
printk("Node %d" |
|
" active_anon:%lukB" |
|
" inactive_anon:%lukB" |
|
" active_file:%lukB" |
|
" inactive_file:%lukB" |
|
" unevictable:%lukB" |
|
" isolated(anon):%lukB" |
|
" isolated(file):%lukB" |
|
" mapped:%lukB" |
|
" dirty:%lukB" |
|
" writeback:%lukB" |
|
" shmem:%lukB" |
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE |
|
" shmem_thp: %lukB" |
|
" shmem_pmdmapped: %lukB" |
|
" anon_thp: %lukB" |
|
#endif |
|
" writeback_tmp:%lukB" |
|
" kernel_stack:%lukB" |
|
#ifdef CONFIG_SHADOW_CALL_STACK |
|
" shadow_call_stack:%lukB" |
|
#endif |
|
" pagetables:%lukB" |
|
" all_unreclaimable? %s" |
|
"\n", |
|
pgdat->node_id, |
|
K(node_page_state(pgdat, NR_ACTIVE_ANON)), |
|
K(node_page_state(pgdat, NR_INACTIVE_ANON)), |
|
K(node_page_state(pgdat, NR_ACTIVE_FILE)), |
|
K(node_page_state(pgdat, NR_INACTIVE_FILE)), |
|
K(node_page_state(pgdat, NR_UNEVICTABLE)), |
|
K(node_page_state(pgdat, NR_ISOLATED_ANON)), |
|
K(node_page_state(pgdat, NR_ISOLATED_FILE)), |
|
K(node_page_state(pgdat, NR_FILE_MAPPED)), |
|
K(node_page_state(pgdat, NR_FILE_DIRTY)), |
|
K(node_page_state(pgdat, NR_WRITEBACK)), |
|
K(node_page_state(pgdat, NR_SHMEM)), |
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE |
|
K(node_page_state(pgdat, NR_SHMEM_THPS)), |
|
K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED)), |
|
K(node_page_state(pgdat, NR_ANON_THPS)), |
|
#endif |
|
K(node_page_state(pgdat, NR_WRITEBACK_TEMP)), |
|
node_page_state(pgdat, NR_KERNEL_STACK_KB), |
|
#ifdef CONFIG_SHADOW_CALL_STACK |
|
node_page_state(pgdat, NR_KERNEL_SCS_KB), |
|
#endif |
|
K(node_page_state(pgdat, NR_PAGETABLE)), |
|
pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES ? |
|
"yes" : "no"); |
|
} |
|
|
|
for_each_populated_zone(zone) { |
|
int i; |
|
|
|
if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask)) |
|
continue; |
|
|
|
free_pcp = 0; |
|
for_each_online_cpu(cpu) |
|
free_pcp += per_cpu_ptr(zone->per_cpu_pageset, cpu)->count; |
|
|
|
show_node(zone); |
|
printk(KERN_CONT |
|
"%s" |
|
" free:%lukB" |
|
" min:%lukB" |
|
" low:%lukB" |
|
" high:%lukB" |
|
" reserved_highatomic:%luKB" |
|
" active_anon:%lukB" |
|
" inactive_anon:%lukB" |
|
" active_file:%lukB" |
|
" inactive_file:%lukB" |
|
" unevictable:%lukB" |
|
" writepending:%lukB" |
|
" present:%lukB" |
|
" managed:%lukB" |
|
" mlocked:%lukB" |
|
" bounce:%lukB" |
|
" free_pcp:%lukB" |
|
" local_pcp:%ukB" |
|
" free_cma:%lukB" |
|
"\n", |
|
zone->name, |
|
K(zone_page_state(zone, NR_FREE_PAGES)), |
|
K(min_wmark_pages(zone)), |
|
K(low_wmark_pages(zone)), |
|
K(high_wmark_pages(zone)), |
|
K(zone->nr_reserved_highatomic), |
|
K(zone_page_state(zone, NR_ZONE_ACTIVE_ANON)), |
|
K(zone_page_state(zone, NR_ZONE_INACTIVE_ANON)), |
|
K(zone_page_state(zone, NR_ZONE_ACTIVE_FILE)), |
|
K(zone_page_state(zone, NR_ZONE_INACTIVE_FILE)), |
|
K(zone_page_state(zone, NR_ZONE_UNEVICTABLE)), |
|
K(zone_page_state(zone, NR_ZONE_WRITE_PENDING)), |
|
K(zone->present_pages), |
|
K(zone_managed_pages(zone)), |
|
K(zone_page_state(zone, NR_MLOCK)), |
|
K(zone_page_state(zone, NR_BOUNCE)), |
|
K(free_pcp), |
|
K(this_cpu_read(zone->per_cpu_pageset->count)), |
|
K(zone_page_state(zone, NR_FREE_CMA_PAGES))); |
|
printk("lowmem_reserve[]:"); |
|
for (i = 0; i < MAX_NR_ZONES; i++) |
|
printk(KERN_CONT " %ld", zone->lowmem_reserve[i]); |
|
printk(KERN_CONT "\n"); |
|
} |
|
|
|
for_each_populated_zone(zone) { |
|
unsigned int order; |
|
unsigned long nr[MAX_ORDER], flags, total = 0; |
|
unsigned char types[MAX_ORDER]; |
|
|
|
if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask)) |
|
continue; |
|
show_node(zone); |
|
printk(KERN_CONT "%s: ", zone->name); |
|
|
|
spin_lock_irqsave(&zone->lock, flags); |
|
for (order = 0; order < MAX_ORDER; order++) { |
|
struct free_area *area = &zone->free_area[order]; |
|
int type; |
|
|
|
nr[order] = area->nr_free; |
|
total += nr[order] << order; |
|
|
|
types[order] = 0; |
|
for (type = 0; type < MIGRATE_TYPES; type++) { |
|
if (!free_area_empty(area, type)) |
|
types[order] |= 1 << type; |
|
} |
|
} |
|
spin_unlock_irqrestore(&zone->lock, flags); |
|
for (order = 0; order < MAX_ORDER; order++) { |
|
printk(KERN_CONT "%lu*%lukB ", |
|
nr[order], K(1UL) << order); |
|
if (nr[order]) |
|
show_migration_types(types[order]); |
|
} |
|
printk(KERN_CONT "= %lukB\n", K(total)); |
|
} |
|
|
|
hugetlb_show_meminfo(); |
|
|
|
printk("%ld total pagecache pages\n", global_node_page_state(NR_FILE_PAGES)); |
|
|
|
show_swap_cache_info(); |
|
} |
|
|
|
static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref) |
|
{ |
|
zoneref->zone = zone; |
|
zoneref->zone_idx = zone_idx(zone); |
|
} |
|
|
|
/* |
|
* Builds allocation fallback zone lists. |
|
* |
|
* Add all populated zones of a node to the zonelist. |
|
*/ |
|
static int build_zonerefs_node(pg_data_t *pgdat, struct zoneref *zonerefs) |
|
{ |
|
struct zone *zone; |
|
enum zone_type zone_type = MAX_NR_ZONES; |
|
int nr_zones = 0; |
|
|
|
do { |
|
zone_type--; |
|
zone = pgdat->node_zones + zone_type; |
|
if (managed_zone(zone)) { |
|
zoneref_set_zone(zone, &zonerefs[nr_zones++]); |
|
check_highest_zone(zone_type); |
|
} |
|
} while (zone_type); |
|
|
|
return nr_zones; |
|
} |
|
|
|
#ifdef CONFIG_NUMA |
|
|
|
static int __parse_numa_zonelist_order(char *s) |
|
{ |
|
/* |
|
* We used to support different zonelists modes but they turned |
|
* out to be just not useful. Let's keep the warning in place |
|
* if somebody still use the cmd line parameter so that we do |
|
* not fail it silently |
|
*/ |
|
if (!(*s == 'd' || *s == 'D' || *s == 'n' || *s == 'N')) { |
|
pr_warn("Ignoring unsupported numa_zonelist_order value: %s\n", s); |
|
return -EINVAL; |
|
} |
|
return 0; |
|
} |
|
|
|
char numa_zonelist_order[] = "Node"; |
|
|
|
/* |
|
* sysctl handler for numa_zonelist_order |
|
*/ |
|
int numa_zonelist_order_handler(struct ctl_table *table, int write, |
|
void *buffer, size_t *length, loff_t *ppos) |
|
{ |
|
if (write) |
|
return __parse_numa_zonelist_order(buffer); |
|
return proc_dostring(table, write, buffer, length, ppos); |
|
} |
|
|
|
|
|
#define MAX_NODE_LOAD (nr_online_nodes) |
|
static int node_load[MAX_NUMNODES]; |
|
|
|
/** |
|
* find_next_best_node - find the next node that should appear in a given node's fallback list |
|
* @node: node whose fallback list we're appending |
|
* @used_node_mask: nodemask_t of already used nodes |
|
* |
|
* We use a number of factors to determine which is the next node that should |
|
* appear on a given node's fallback list. The node should not have appeared |
|
* already in @node's fallback list, and it should be the next closest node |
|
* according to the distance array (which contains arbitrary distance values |
|
* from each node to each node in the system), and should also prefer nodes |
|
* with no CPUs, since presumably they'll have very little allocation pressure |
|
* on them otherwise. |
|
* |
|
* Return: node id of the found node or %NUMA_NO_NODE if no node is found. |
|
*/ |
|
int find_next_best_node(int node, nodemask_t *used_node_mask) |
|
{ |
|
int n, val; |
|
int min_val = INT_MAX; |
|
int best_node = NUMA_NO_NODE; |
|
|
|
/* Use the local node if we haven't already */ |
|
if (!node_isset(node, *used_node_mask)) { |
|
node_set(node, *used_node_mask); |
|
return node; |
|
} |
|
|
|
for_each_node_state(n, N_MEMORY) { |
|
|
|
/* Don't want a node to appear more than once */ |
|
if (node_isset(n, *used_node_mask)) |
|
continue; |
|
|
|
/* Use the distance array to find the distance */ |
|
val = node_distance(node, n); |
|
|
|
/* Penalize nodes under us ("prefer the next node") */ |
|
val += (n < node); |
|
|
|
/* Give preference to headless and unused nodes */ |
|
if (!cpumask_empty(cpumask_of_node(n))) |
|
val += PENALTY_FOR_NODE_WITH_CPUS; |
|
|
|
/* Slight preference for less loaded node */ |
|
val *= (MAX_NODE_LOAD*MAX_NUMNODES); |
|
val += node_load[n]; |
|
|
|
if (val < min_val) { |
|
min_val = val; |
|
best_node = n; |
|
} |
|
} |
|
|
|
if (best_node >= 0) |
|
node_set(best_node, *used_node_mask); |
|
|
|
return best_node; |
|
} |
|
|
|
|
|
/* |
|
* Build zonelists ordered by node and zones within node. |
|
* This results in maximum locality--normal zone overflows into local |
|
* DMA zone, if any--but risks exhausting DMA zone. |
|
*/ |
|
static void build_zonelists_in_node_order(pg_data_t *pgdat, int *node_order, |
|
unsigned nr_nodes) |
|
{ |
|
struct zoneref *zonerefs; |
|
int i; |
|
|
|
zonerefs = pgdat->node_zonelists[ZONELIST_FALLBACK]._zonerefs; |
|
|
|
for (i = 0; i < nr_nodes; i++) { |
|
int nr_zones; |
|
|
|
pg_data_t *node = NODE_DATA(node_order[i]); |
|
|
|
nr_zones = build_zonerefs_node(node, zonerefs); |
|
zonerefs += nr_zones; |
|
} |
|
zonerefs->zone = NULL; |
|
zonerefs->zone_idx = 0; |
|
} |
|
|
|
/* |
|
* Build gfp_thisnode zonelists |
|
*/ |
|
static void build_thisnode_zonelists(pg_data_t *pgdat) |
|
{ |
|
struct zoneref *zonerefs; |
|
int nr_zones; |
|
|
|
zonerefs = pgdat->node_zonelists[ZONELIST_NOFALLBACK]._zonerefs; |
|
nr_zones = build_zonerefs_node(pgdat, zonerefs); |
|
zonerefs += nr_zones; |
|
zonerefs->zone = NULL; |
|
zonerefs->zone_idx = 0; |
|
} |
|
|
|
/* |
|
* Build zonelists ordered by zone and nodes within zones. |
|
* This results in conserving DMA zone[s] until all Normal memory is |
|
* exhausted, but results in overflowing to remote node while memory |
|
* may still exist in local DMA zone. |
|
*/ |
|
|
|
static void build_zonelists(pg_data_t *pgdat) |
|
{ |
|
static int node_order[MAX_NUMNODES]; |
|
int node, load, nr_nodes = 0; |
|
nodemask_t used_mask = NODE_MASK_NONE; |
|
int local_node, prev_node; |
|
|
|
/* NUMA-aware ordering of nodes */ |
|
local_node = pgdat->node_id; |
|
load = nr_online_nodes; |
|
prev_node = local_node; |
|
|
|
memset(node_order, 0, sizeof(node_order)); |
|
while ((node = find_next_best_node(local_node, &used_mask)) >= 0) { |
|
/* |
|
* We don't want to pressure a particular node. |
|
* So adding penalty to the first node in same |
|
* distance group to make it round-robin. |
|
*/ |
|
if (node_distance(local_node, node) != |
|
node_distance(local_node, prev_node)) |
|
node_load[node] = load; |
|
|
|
node_order[nr_nodes++] = node; |
|
prev_node = node; |
|
load--; |
|
} |
|
|
|
build_zonelists_in_node_order(pgdat, node_order, nr_nodes); |
|
build_thisnode_zonelists(pgdat); |
|
} |
|
|
|
#ifdef CONFIG_HAVE_MEMORYLESS_NODES |
|
/* |
|
* Return node id of node used for "local" allocations. |
|
* I.e., first node id of first zone in arg node's generic zonelist. |
|
* Used for initializing percpu 'numa_mem', which is used primarily |
|
* for kernel allocations, so use GFP_KERNEL flags to locate zonelist. |
|
*/ |
|
int local_memory_node(int node) |
|
{ |
|
struct zoneref *z; |
|
|
|
z = first_zones_zonelist(node_zonelist(node, GFP_KERNEL), |
|
gfp_zone(GFP_KERNEL), |
|
NULL); |
|
return zone_to_nid(z->zone); |
|
} |
|
#endif |
|
|
|
static void setup_min_unmapped_ratio(void); |
|
static void setup_min_slab_ratio(void); |
|
#else /* CONFIG_NUMA */ |
|
|
|
static void build_zonelists(pg_data_t *pgdat) |
|
{ |
|
int node, local_node; |
|
struct zoneref *zonerefs; |
|
int nr_zones; |
|
|
|
local_node = pgdat->node_id; |
|
|
|
zonerefs = pgdat->node_zonelists[ZONELIST_FALLBACK]._zonerefs; |
|
nr_zones = build_zonerefs_node(pgdat, zonerefs); |
|
zonerefs += nr_zones; |
|
|
|
/* |
|
* Now we build the zonelist so that it contains the zones |
|
* of all the other nodes. |
|
* We don't want to pressure a particular node, so when |
|
* building the zones for node N, we make sure that the |
|
* zones coming right after the local ones are those from |
|
* node N+1 (modulo N) |
|
*/ |
|
for (node = local_node + 1; node < MAX_NUMNODES; node++) { |
|
if (!node_online(node)) |
|
continue; |
|
nr_zones = build_zonerefs_node(NODE_DATA(node), zonerefs); |
|
zonerefs += nr_zones; |
|
} |
|
for (node = 0; node < local_node; node++) { |
|
if (!node_online(node)) |
|
continue; |
|
nr_zones = build_zonerefs_node(NODE_DATA(node), zonerefs); |
|
zonerefs += nr_zones; |
|
} |
|
|
|
zonerefs->zone = NULL; |
|
zonerefs->zone_idx = 0; |
|
} |
|
|
|
#endif /* CONFIG_NUMA */ |
|
|
|
/* |
|
* Boot pageset table. One per cpu which is going to be used for all |
|
* zones and all nodes. The parameters will be set in such a way |
|
* that an item put on a list will immediately be handed over to |
|
* the buddy list. This is safe since pageset manipulation is done |
|
* with interrupts disabled. |
|
* |
|
* The boot_pagesets must be kept even after bootup is complete for |
|
* unused processors and/or zones. They do play a role for bootstrapping |
|
* hotplugged processors. |
|
* |
|
* zoneinfo_show() and maybe other functions do |
|
* not check if the processor is online before following the pageset pointer. |
|
* Other parts of the kernel may not check if the zone is available. |
|
*/ |
|
static void per_cpu_pages_init(struct per_cpu_pages *pcp, struct per_cpu_zonestat *pzstats); |
|
/* These effectively disable the pcplists in the boot pageset completely */ |
|
#define BOOT_PAGESET_HIGH 0 |
|
#define BOOT_PAGESET_BATCH 1 |
|
static DEFINE_PER_CPU(struct per_cpu_pages, boot_pageset); |
|
static DEFINE_PER_CPU(struct per_cpu_zonestat, boot_zonestats); |
|
static DEFINE_PER_CPU(struct per_cpu_nodestat, boot_nodestats); |
|
|
|
static void __build_all_zonelists(void *data) |
|
{ |
|
int nid; |
|
int __maybe_unused cpu; |
|
pg_data_t *self = data; |
|
static DEFINE_SPINLOCK(lock); |
|
|
|
spin_lock(&lock); |
|
|
|
#ifdef CONFIG_NUMA |
|
memset(node_load, 0, sizeof(node_load)); |
|
#endif |
|
|
|
/* |
|
* This node is hotadded and no memory is yet present. So just |
|
* building zonelists is fine - no need to touch other nodes. |
|
*/ |
|
if (self && !node_online(self->node_id)) { |
|
build_zonelists(self); |
|
} else { |
|
for_each_online_node(nid) { |
|
pg_data_t *pgdat = NODE_DATA(nid); |
|
|
|
build_zonelists(pgdat); |
|
} |
|
|
|
#ifdef CONFIG_HAVE_MEMORYLESS_NODES |
|
/* |
|
* We now know the "local memory node" for each node-- |
|
* i.e., the node of the first zone in the generic zonelist. |
|
* Set up numa_mem percpu variable for on-line cpus. During |
|
* boot, only the boot cpu should be on-line; we'll init the |
|
* secondary cpus' numa_mem as they come on-line. During |
|
* node/memory hotplug, we'll fixup all on-line cpus. |
|
*/ |
|
for_each_online_cpu(cpu) |
|
set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu))); |
|
#endif |
|
} |
|
|
|
spin_unlock(&lock); |
|
} |
|
|
|
static noinline void __init |
|
build_all_zonelists_init(void) |
|
{ |
|
int cpu; |
|
|
|
__build_all_zonelists(NULL); |
|
|
|
/* |
|
* Initialize the boot_pagesets that are going to be used |
|
* for bootstrapping processors. The real pagesets for |
|
* each zone will be allocated later when the per cpu |
|
* allocator is available. |
|
* |
|
* boot_pagesets are used also for bootstrapping offline |
|
* cpus if the system is already booted because the pagesets |
|
* are needed to initialize allocators on a specific cpu too. |
|
* F.e. the percpu allocator needs the page allocator which |
|
* needs the percpu allocator in order to allocate its pagesets |
|
* (a chicken-egg dilemma). |
|
*/ |
|
for_each_possible_cpu(cpu) |
|
per_cpu_pages_init(&per_cpu(boot_pageset, cpu), &per_cpu(boot_zonestats, cpu)); |
|
|
|
mminit_verify_zonelist(); |
|
cpuset_init_current_mems_allowed(); |
|
} |
|
|
|
/* |
|
* unless system_state == SYSTEM_BOOTING. |
|
* |
|
* __ref due to call of __init annotated helper build_all_zonelists_init |
|
* [protected by SYSTEM_BOOTING]. |
|
*/ |
|
void __ref build_all_zonelists(pg_data_t *pgdat) |
|
{ |
|
unsigned long vm_total_pages; |
|
|
|
if (system_state == SYSTEM_BOOTING) { |
|
build_all_zonelists_init(); |
|
} else { |
|
__build_all_zonelists(pgdat); |
|
/* cpuset refresh routine should be here */ |
|
} |
|
/* Get the number of free pages beyond high watermark in all zones. */ |
|
vm_total_pages = nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE)); |
|
/* |
|
* Disable grouping by mobility if the number of pages in the |
|
* system is too low to allow the mechanism to work. It would be |
|
* more accurate, but expensive to check per-zone. This check is |
|
* made on memory-hotadd so a system can start with mobility |
|
* disabled and enable it later |
|
*/ |
|
if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES)) |
|
page_group_by_mobility_disabled = 1; |
|
else |
|
page_group_by_mobility_disabled = 0; |
|
|
|
pr_info("Built %u zonelists, mobility grouping %s. Total pages: %ld\n", |
|
nr_online_nodes, |
|
page_group_by_mobility_disabled ? "off" : "on", |
|
vm_total_pages); |
|
#ifdef CONFIG_NUMA |
|
pr_info("Policy zone: %s\n", zone_names[policy_zone]); |
|
#endif |
|
} |
|
|
|
/* If zone is ZONE_MOVABLE but memory is mirrored, it is an overlapped init */ |
|
static bool __meminit |
|
overlap_memmap_init(unsigned long zone, unsigned long *pfn) |
|
{ |
|
static struct memblock_region *r; |
|
|
|
if (mirrored_kernelcore && zone == ZONE_MOVABLE) { |
|
if (!r || *pfn >= memblock_region_memory_end_pfn(r)) { |
|
for_each_mem_region(r) { |
|
if (*pfn < memblock_region_memory_end_pfn(r)) |
|
break; |
|
} |
|
} |
|
if (*pfn >= memblock_region_memory_base_pfn(r) && |
|
memblock_is_mirror(r)) { |
|
*pfn = memblock_region_memory_end_pfn(r); |
|
return true; |
|
} |
|
} |
|
return false; |
|
} |
|
|
|
/* |
|
* Initially all pages are reserved - free ones are freed |
|
* up by memblock_free_all() once the early boot process is |
|
* done. Non-atomic initialization, single-pass. |
|
* |
|
* All aligned pageblocks are initialized to the specified migratetype |
|
* (usually MIGRATE_MOVABLE). Besides setting the migratetype, no related |
|
* zone stats (e.g., nr_isolate_pageblock) are touched. |
|
*/ |
|
void __meminit memmap_init_range(unsigned long size, int nid, unsigned long zone, |
|
unsigned long start_pfn, unsigned long zone_end_pfn, |
|
enum meminit_context context, |
|
struct vmem_altmap *altmap, int migratetype) |
|
{ |
|
unsigned long pfn, end_pfn = start_pfn + size; |
|
struct page *page; |
|
|
|
if (highest_memmap_pfn < end_pfn - 1) |
|
highest_memmap_pfn = end_pfn - 1; |
|
|
|
#ifdef CONFIG_ZONE_DEVICE |
|
/* |
|
* Honor reservation requested by the driver for this ZONE_DEVICE |
|
* memory. We limit the total number of pages to initialize to just |
|
* those that might contain the memory mapping. We will defer the |
|
* ZONE_DEVICE page initialization until after we have released |
|
* the hotplug lock. |
|
*/ |
|
if (zone == ZONE_DEVICE) { |
|
if (!altmap) |
|
return; |
|
|
|
if (start_pfn == altmap->base_pfn) |
|
start_pfn += altmap->reserve; |
|
end_pfn = altmap->base_pfn + vmem_altmap_offset(altmap); |
|
} |
|
#endif |
|
|
|
for (pfn = start_pfn; pfn < end_pfn; ) { |
|
/* |
|
* There can be holes in boot-time mem_map[]s handed to this |
|
* function. They do not exist on hotplugged memory. |
|
*/ |
|
if (context == MEMINIT_EARLY) { |
|
if (overlap_memmap_init(zone, &pfn)) |
|
continue; |
|
if (defer_init(nid, pfn, zone_end_pfn)) |
|
break; |
|
} |
|
|
|
page = pfn_to_page(pfn); |
|
__init_single_page(page, pfn, zone, nid); |
|
if (context == MEMINIT_HOTPLUG) |
|
__SetPageReserved(page); |
|
|
|
/* |
|
* Usually, we want to mark the pageblock MIGRATE_MOVABLE, |
|
* such that unmovable allocations won't be scattered all |
|
* over the place during system boot. |
|
*/ |
|
if (IS_ALIGNED(pfn, pageblock_nr_pages)) { |
|
set_pageblock_migratetype(page, migratetype); |
|
cond_resched(); |
|
} |
|
pfn++; |
|
} |
|
} |
|
|
|
#ifdef CONFIG_ZONE_DEVICE |
|
void __ref memmap_init_zone_device(struct zone *zone, |
|
unsigned long start_pfn, |
|
unsigned long nr_pages, |
|
struct dev_pagemap *pgmap) |
|
{ |
|
unsigned long pfn, end_pfn = start_pfn + nr_pages; |
|
struct pglist_data *pgdat = zone->zone_pgdat; |
|
struct vmem_altmap *altmap = pgmap_altmap(pgmap); |
|
unsigned long zone_idx = zone_idx(zone); |
|
unsigned long start = jiffies; |
|
int nid = pgdat->node_id; |
|
|
|
if (WARN_ON_ONCE(!pgmap || zone_idx(zone) != ZONE_DEVICE)) |
|
return; |
|
|
|
/* |
|
* The call to memmap_init should have already taken care |
|
* of the pages reserved for the memmap, so we can just jump to |
|
* the end of that region and start processing the device pages. |
|
*/ |
|
if (altmap) { |
|
start_pfn = altmap->base_pfn + vmem_altmap_offset(altmap); |
|
nr_pages = end_pfn - start_pfn; |
|
} |
|
|
|
for (pfn = start_pfn; pfn < end_pfn; pfn++) { |
|
struct page *page = pfn_to_page(pfn); |
|
|
|
__init_single_page(page, pfn, zone_idx, nid); |
|
|
|
/* |
|
* Mark page reserved as it will need to wait for onlining |
|
* phase for it to be fully associated with a zone. |
|
* |
|
* We can use the non-atomic __set_bit operation for setting |
|
* the flag as we are still initializing the pages. |
|
*/ |
|
__SetPageReserved(page); |
|
|
|
/* |
|
* ZONE_DEVICE pages union ->lru with a ->pgmap back pointer |
|
* and zone_device_data. It is a bug if a ZONE_DEVICE page is |
|
* ever freed or placed on a driver-private list. |
|
*/ |
|
page->pgmap = pgmap; |
|
page->zone_device_data = NULL; |
|
|
|
/* |
|
* Mark the block movable so that blocks are reserved for |
|
* movable at startup. This will force kernel allocations |
|
* to reserve their blocks rather than leaking throughout |
|
* the address space during boot when many long-lived |
|
* kernel allocations are made. |
|
* |
|
* Please note that MEMINIT_HOTPLUG path doesn't clear memmap |
|
* because this is done early in section_activate() |
|
*/ |
|
if (IS_ALIGNED(pfn, pageblock_nr_pages)) { |
|
set_pageblock_migratetype(page, MIGRATE_MOVABLE); |
|
cond_resched(); |
|
} |
|
} |
|
|
|
pr_info("%s initialised %lu pages in %ums\n", __func__, |
|
nr_pages, jiffies_to_msecs(jiffies - start)); |
|
} |
|
|
|
#endif |
|
static void __meminit zone_init_free_lists(struct zone *zone) |
|
{ |
|
unsigned int order, t; |
|
for_each_migratetype_order(order, t) { |
|
INIT_LIST_HEAD(&zone->free_area[order].free_list[t]); |
|
zone->free_area[order].nr_free = 0; |
|
} |
|
} |
|
|
|
/* |
|
* Only struct pages that correspond to ranges defined by memblock.memory |
|
* are zeroed and initialized by going through __init_single_page() during |
|
* memmap_init_zone_range(). |
|
* |
|
* But, there could be struct pages that correspond to holes in |
|
* memblock.memory. This can happen because of the following reasons: |
|
* - physical memory bank size is not necessarily the exact multiple of the |
|
* arbitrary section size |
|
* - early reserved memory may not be listed in memblock.memory |
|
* - memory layouts defined with memmap= kernel parameter may not align |
|
* nicely with memmap sections |
|
* |
|
* Explicitly initialize those struct pages so that: |
|
* - PG_Reserved is set |
|
* - zone and node links point to zone and node that span the page if the |
|
* hole is in the middle of a zone |
|
* - zone and node links point to adjacent zone/node if the hole falls on |
|
* the zone boundary; the pages in such holes will be prepended to the |
|
* zone/node above the hole except for the trailing pages in the last |
|
* section that will be appended to the zone/node below. |
|
*/ |
|
static void __init init_unavailable_range(unsigned long spfn, |
|
unsigned long epfn, |
|
int zone, int node) |
|
{ |
|
unsigned long pfn; |
|
u64 pgcnt = 0; |
|
|
|
for (pfn = spfn; pfn < epfn; pfn++) { |
|
if (!pfn_valid(ALIGN_DOWN(pfn, pageblock_nr_pages))) { |
|
pfn = ALIGN_DOWN(pfn, pageblock_nr_pages) |
|
+ pageblock_nr_pages - 1; |
|
continue; |
|
} |
|
__init_single_page(pfn_to_page(pfn), pfn, zone, node); |
|
__SetPageReserved(pfn_to_page(pfn)); |
|
pgcnt++; |
|
} |
|
|
|
if (pgcnt) |
|
pr_info("On node %d, zone %s: %lld pages in unavailable ranges", |
|
node, zone_names[zone], pgcnt); |
|
} |
|
|
|
static void __init memmap_init_zone_range(struct zone *zone, |
|
unsigned long start_pfn, |
|
unsigned long end_pfn, |
|
unsigned long *hole_pfn) |
|
{ |
|
unsigned long zone_start_pfn = zone->zone_start_pfn; |
|
unsigned long zone_end_pfn = zone_start_pfn + zone->spanned_pages; |
|
int nid = zone_to_nid(zone), zone_id = zone_idx(zone); |
|
|
|
start_pfn = clamp(start_pfn, zone_start_pfn, zone_end_pfn); |
|
end_pfn = clamp(end_pfn, zone_start_pfn, zone_end_pfn); |
|
|
|
if (start_pfn >= end_pfn) |
|
return; |
|
|
|
memmap_init_range(end_pfn - start_pfn, nid, zone_id, start_pfn, |
|
zone_end_pfn, MEMINIT_EARLY, NULL, MIGRATE_MOVABLE); |
|
|
|
if (*hole_pfn < start_pfn) |
|
init_unavailable_range(*hole_pfn, start_pfn, zone_id, nid); |
|
|
|
*hole_pfn = end_pfn; |
|
} |
|
|
|
static void __init memmap_init(void) |
|
{ |
|
unsigned long start_pfn, end_pfn; |
|
unsigned long hole_pfn = 0; |
|
int i, j, zone_id = 0, nid; |
|
|
|
for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) { |
|
struct pglist_data *node = NODE_DATA(nid); |
|
|
|
for (j = 0; j < MAX_NR_ZONES; j++) { |
|
struct zone *zone = node->node_zones + j; |
|
|
|
if (!populated_zone(zone)) |
|
continue; |
|
|
|
memmap_init_zone_range(zone, start_pfn, end_pfn, |
|
&hole_pfn); |
|
zone_id = j; |
|
} |
|
} |
|
|
|
#ifdef CONFIG_SPARSEMEM |
|
/* |
|
* Initialize the memory map for hole in the range [memory_end, |
|
* section_end]. |
|
* Append the pages in this hole to the highest zone in the last |
|
* node. |
|
* The call to init_unavailable_range() is outside the ifdef to |
|
* silence the compiler warining about zone_id set but not used; |
|
* for FLATMEM it is a nop anyway |
|
*/ |
|
end_pfn = round_up(end_pfn, PAGES_PER_SECTION); |
|
if (hole_pfn < end_pfn) |
|
#endif |
|
init_unavailable_range(hole_pfn, end_pfn, zone_id, nid); |
|
} |
|
|
|
void __init *memmap_alloc(phys_addr_t size, phys_addr_t align, |
|
phys_addr_t min_addr, int nid, bool exact_nid) |
|
{ |
|
void *ptr; |
|
|
|
if (exact_nid) |
|
ptr = memblock_alloc_exact_nid_raw(size, align, min_addr, |
|
MEMBLOCK_ALLOC_ACCESSIBLE, |
|
nid); |
|
else |
|
ptr = memblock_alloc_try_nid_raw(size, align, min_addr, |
|
MEMBLOCK_ALLOC_ACCESSIBLE, |
|
nid); |
|
|
|
if (ptr && size > 0) |
|
page_init_poison(ptr, size); |
|
|
|
return ptr; |
|
} |
|
|
|
static int zone_batchsize(struct zone *zone) |
|
{ |
|
#ifdef CONFIG_MMU |
|
int batch; |
|
|
|
/* |
|
* The number of pages to batch allocate is either ~0.1% |
|
* of the zone or 1MB, whichever is smaller. The batch |
|
* size is striking a balance between allocation latency |
|
* and zone lock contention. |
|
*/ |
|
batch = min(zone_managed_pages(zone) >> 10, (1024 * 1024) / PAGE_SIZE); |
|
batch /= 4; /* We effectively *= 4 below */ |
|
if (batch < 1) |
|
batch = 1; |
|
|
|
/* |
|
* Clamp the batch to a 2^n - 1 value. Having a power |
|
* of 2 value was found to be more likely to have |
|
* suboptimal cache aliasing properties in some cases. |
|
* |
|
* For example if 2 tasks are alternately allocating |
|
* batches of pages, one task can end up with a lot |
|
* of pages of one half of the possible page colors |
|
* and the other with pages of the other colors. |
|
*/ |
|
batch = rounddown_pow_of_two(batch + batch/2) - 1; |
|
|
|
return batch; |
|
|
|
#else |
|
/* The deferral and batching of frees should be suppressed under NOMMU |
|
* conditions. |
|
* |
|
* The problem is that NOMMU needs to be able to allocate large chunks |
|
* of contiguous memory as there's no hardware page translation to |
|
* assemble apparent contiguous memory from discontiguous pages. |
|
* |
|
* Queueing large contiguous runs of pages for batching, however, |
|
* causes the pages to actually be freed in smaller chunks. As there |
|
* can be a significant delay between the individual batches being |
|
* recycled, this leads to the once large chunks of space being |
|
* fragmented and becoming unavailable for high-order allocations. |
|
*/ |
|
return 0; |
|
#endif |
|
} |
|
|
|
static int zone_highsize(struct zone *zone, int batch, int cpu_online) |
|
{ |
|
#ifdef CONFIG_MMU |
|
int high; |
|
int nr_split_cpus; |
|
unsigned long total_pages; |
|
|
|
if (!percpu_pagelist_high_fraction) { |
|
/* |
|
* By default, the high value of the pcp is based on the zone |
|
* low watermark so that if they are full then background |
|
* reclaim will not be started prematurely. |
|
*/ |
|
total_pages = low_wmark_pages(zone); |
|
} else { |
|
/* |
|
* If percpu_pagelist_high_fraction is configured, the high |
|
* value is based on a fraction of the managed pages in the |
|
* zone. |
|
*/ |
|
total_pages = zone_managed_pages(zone) / percpu_pagelist_high_fraction; |
|
} |
|
|
|
/* |
|
* Split the high value across all online CPUs local to the zone. Note |
|
* that early in boot that CPUs may not be online yet and that during |
|
* CPU hotplug that the cpumask is not yet updated when a CPU is being |
|
* onlined. For memory nodes that have no CPUs, split pcp->high across |
|
* all online CPUs to mitigate the risk that reclaim is triggered |
|
* prematurely due to pages stored on pcp lists. |
|
*/ |
|
nr_split_cpus = cpumask_weight(cpumask_of_node(zone_to_nid(zone))) + cpu_online; |
|
if (!nr_split_cpus) |
|
nr_split_cpus = num_online_cpus(); |
|
high = total_pages / nr_split_cpus; |
|
|
|
/* |
|
* Ensure high is at least batch*4. The multiple is based on the |
|
* historical relationship between high and batch. |
|
*/ |
|
high = max(high, batch << 2); |
|
|
|
return high; |
|
#else |
|
return 0; |
|
#endif |
|
} |
|
|
|
/* |
|
* pcp->high and pcp->batch values are related and generally batch is lower |
|
* than high. They are also related to pcp->count such that count is lower |
|
* than high, and as soon as it reaches high, the pcplist is flushed. |
|
* |
|
* However, guaranteeing these relations at all times would require e.g. write |
|
* barriers here but also careful usage of read barriers at the read side, and |
|
* thus be prone to error and bad for performance. Thus the update only prevents |
|
* store tearing. Any new users of pcp->batch and pcp->high should ensure they |
|
* can cope with those fields changing asynchronously, and fully trust only the |
|
* pcp->count field on the local CPU with interrupts disabled. |
|
* |
|
* mutex_is_locked(&pcp_batch_high_lock) required when calling this function |
|
* outside of boot time (or some other assurance that no concurrent updaters |
|
* exist). |
|
*/ |
|
static void pageset_update(struct per_cpu_pages *pcp, unsigned long high, |
|
unsigned long batch) |
|
{ |
|
WRITE_ONCE(pcp->batch, batch); |
|
WRITE_ONCE(pcp->high, high); |
|
} |
|
|
|
static void per_cpu_pages_init(struct per_cpu_pages *pcp, struct per_cpu_zonestat *pzstats) |
|
{ |
|
int pindex; |
|
|
|
memset(pcp, 0, sizeof(*pcp)); |
|
memset(pzstats, 0, sizeof(*pzstats)); |
|
|
|
for (pindex = 0; pindex < NR_PCP_LISTS; pindex++) |
|
INIT_LIST_HEAD(&pcp->lists[pindex]); |
|
|
|
/* |
|
* Set batch and high values safe for a boot pageset. A true percpu |
|
* pageset's initialization will update them subsequently. Here we don't |
|
* need to be as careful as pageset_update() as nobody can access the |
|
* pageset yet. |
|
*/ |
|
pcp->high = BOOT_PAGESET_HIGH; |
|
pcp->batch = BOOT_PAGESET_BATCH; |
|
pcp->free_factor = 0; |
|
} |
|
|
|
static void __zone_set_pageset_high_and_batch(struct zone *zone, unsigned long high, |
|
unsigned long batch) |
|
{ |
|
struct per_cpu_pages *pcp; |
|
int cpu; |
|
|
|
for_each_possible_cpu(cpu) { |
|
pcp = per_cpu_ptr(zone->per_cpu_pageset, cpu); |
|
pageset_update(pcp, high, batch); |
|
} |
|
} |
|
|
|
/* |
|
* Calculate and set new high and batch values for all per-cpu pagesets of a |
|
* zone based on the zone's size. |
|
*/ |
|
static void zone_set_pageset_high_and_batch(struct zone *zone, int cpu_online) |
|
{ |
|
int new_high, new_batch; |
|
|
|
new_batch = max(1, zone_batchsize(zone)); |
|
new_high = zone_highsize(zone, new_batch, cpu_online); |
|
|
|
if (zone->pageset_high == new_high && |
|
zone->pageset_batch == new_batch) |
|
return; |
|
|
|
zone->pageset_high = new_high; |
|
zone->pageset_batch = new_batch; |
|
|
|
__zone_set_pageset_high_and_batch(zone, new_high, new_batch); |
|
} |
|
|
|
void __meminit setup_zone_pageset(struct zone *zone) |
|
{ |
|
int cpu; |
|
|
|
/* Size may be 0 on !SMP && !NUMA */ |
|
if (sizeof(struct per_cpu_zonestat) > 0) |
|
zone->per_cpu_zonestats = alloc_percpu(struct per_cpu_zonestat); |
|
|
|
zone->per_cpu_pageset = alloc_percpu(struct per_cpu_pages); |
|
for_each_possible_cpu(cpu) { |
|
struct per_cpu_pages *pcp; |
|
struct per_cpu_zonestat *pzstats; |
|
|
|
pcp = per_cpu_ptr(zone->per_cpu_pageset, cpu); |
|
pzstats = per_cpu_ptr(zone->per_cpu_zonestats, cpu); |
|
per_cpu_pages_init(pcp, pzstats); |
|
} |
|
|
|
zone_set_pageset_high_and_batch(zone, 0); |
|
} |
|
|
|
/* |
|
* Allocate per cpu pagesets and initialize them. |
|
* Before this call only boot pagesets were available. |
|
*/ |
|
void __init setup_per_cpu_pageset(void) |
|
{ |
|
struct pglist_data *pgdat; |
|
struct zone *zone; |
|
int __maybe_unused cpu; |
|
|
|
for_each_populated_zone(zone) |
|
setup_zone_pageset(zone); |
|
|
|
#ifdef CONFIG_NUMA |
|
/* |
|
* Unpopulated zones continue using the boot pagesets. |
|
* The numa stats for these pagesets need to be reset. |
|
* Otherwise, they will end up skewing the stats of |
|
* the nodes these zones are associated with. |
|
*/ |
|
for_each_possible_cpu(cpu) { |
|
struct per_cpu_zonestat *pzstats = &per_cpu(boot_zonestats, cpu); |
|
memset(pzstats->vm_numa_event, 0, |
|
sizeof(pzstats->vm_numa_event)); |
|
} |
|
#endif |
|
|
|
for_each_online_pgdat(pgdat) |
|
pgdat->per_cpu_nodestats = |
|
alloc_percpu(struct per_cpu_nodestat); |
|
} |
|
|
|
static __meminit void zone_pcp_init(struct zone *zone) |
|
{ |
|
/* |
|
* per cpu subsystem is not up at this point. The following code |
|
* relies on the ability of the linker to provide the |
|
* offset of a (static) per cpu variable into the per cpu area. |
|
*/ |
|
zone->per_cpu_pageset = &boot_pageset; |
|
zone->per_cpu_zonestats = &boot_zonestats; |
|
zone->pageset_high = BOOT_PAGESET_HIGH; |
|
zone->pageset_batch = BOOT_PAGESET_BATCH; |
|
|
|
if (populated_zone(zone)) |
|
pr_debug(" %s zone: %lu pages, LIFO batch:%u\n", zone->name, |
|
zone->present_pages, zone_batchsize(zone)); |
|
} |
|
|
|
void __meminit init_currently_empty_zone(struct zone *zone, |
|
unsigned long zone_start_pfn, |
|
unsigned long size) |
|
{ |
|
struct pglist_data *pgdat = zone->zone_pgdat; |
|
int zone_idx = zone_idx(zone) + 1; |
|
|
|
if (zone_idx > pgdat->nr_zones) |
|
pgdat->nr_zones = zone_idx; |
|
|
|
zone->zone_start_pfn = zone_start_pfn; |
|
|
|
mminit_dprintk(MMINIT_TRACE, "memmap_init", |
|
"Initialising map node %d zone %lu pfns %lu -> %lu\n", |
|
pgdat->node_id, |
|
(unsigned long)zone_idx(zone), |
|
zone_start_pfn, (zone_start_pfn + size)); |
|
|
|
zone_init_free_lists(zone); |
|
zone->initialized = 1; |
|
} |
|
|
|
/** |
|
* get_pfn_range_for_nid - Return the start and end page frames for a node |
|
* @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned. |
|
* @start_pfn: Passed by reference. On return, it will have the node start_pfn. |
|
* @end_pfn: Passed by reference. On return, it will have the node end_pfn. |
|
* |
|
* It returns the start and end page frame of a node based on information |
|
* provided by memblock_set_node(). If called for a node |
|
* with no available memory, a warning is printed and the start and end |
|
* PFNs will be 0. |
|
*/ |
|
void __init get_pfn_range_for_nid(unsigned int nid, |
|
unsigned long *start_pfn, unsigned long *end_pfn) |
|
{ |
|
unsigned long this_start_pfn, this_end_pfn; |
|
int i; |
|
|
|
*start_pfn = -1UL; |
|
*end_pfn = 0; |
|
|
|
for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) { |
|
*start_pfn = min(*start_pfn, this_start_pfn); |
|
*end_pfn = max(*end_pfn, this_end_pfn); |
|
} |
|
|
|
if (*start_pfn == -1UL) |
|
*start_pfn = 0; |
|
} |
|
|
|
/* |
|
* This finds a zone that can be used for ZONE_MOVABLE pages. The |
|
* assumption is made that zones within a node are ordered in monotonic |
|
* increasing memory addresses so that the "highest" populated zone is used |
|
*/ |
|
static void __init find_usable_zone_for_movable(void) |
|
{ |
|
int zone_index; |
|
for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) { |
|
if (zone_index == ZONE_MOVABLE) |
|
continue; |
|
|
|
if (arch_zone_highest_possible_pfn[zone_index] > |
|
arch_zone_lowest_possible_pfn[zone_index]) |
|
break; |
|
} |
|
|
|
VM_BUG_ON(zone_index == -1); |
|
movable_zone = zone_index; |
|
} |
|
|
|
/* |
|
* The zone ranges provided by the architecture do not include ZONE_MOVABLE |
|
* because it is sized independent of architecture. Unlike the other zones, |
|
* the starting point for ZONE_MOVABLE is not fixed. It may be different |
|
* in each node depending on the size of each node and how evenly kernelcore |
|
* is distributed. This helper function adjusts the zone ranges |
|
* provided by the architecture for a given node by using the end of the |
|
* highest usable zone for ZONE_MOVABLE. This preserves the assumption that |
|
* zones within a node are in order of monotonic increases memory addresses |
|
*/ |
|
static void __init adjust_zone_range_for_zone_movable(int nid, |
|
unsigned long zone_type, |
|
unsigned long node_start_pfn, |
|
unsigned long node_end_pfn, |
|
unsigned long *zone_start_pfn, |
|
unsigned long *zone_end_pfn) |
|
{ |
|
/* Only adjust if ZONE_MOVABLE is on this node */ |
|
if (zone_movable_pfn[nid]) { |
|
/* Size ZONE_MOVABLE */ |
|
if (zone_type == ZONE_MOVABLE) { |
|
*zone_start_pfn = zone_movable_pfn[nid]; |
|
*zone_end_pfn = min(node_end_pfn, |
|
arch_zone_highest_possible_pfn[movable_zone]); |
|
|
|
/* Adjust for ZONE_MOVABLE starting within this range */ |
|
} else if (!mirrored_kernelcore && |
|
*zone_start_pfn < zone_movable_pfn[nid] && |
|
*zone_end_pfn > zone_movable_pfn[nid]) { |
|
*zone_end_pfn = zone_movable_pfn[nid]; |
|
|
|
/* Check if this whole range is within ZONE_MOVABLE */ |
|
} else if (*zone_start_pfn >= zone_movable_pfn[nid]) |
|
*zone_start_pfn = *zone_end_pfn; |
|
} |
|
} |
|
|
|
/* |
|
* Return the number of pages a zone spans in a node, including holes |
|
* present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node() |
|
*/ |
|
static unsigned long __init zone_spanned_pages_in_node(int nid, |
|
unsigned long zone_type, |
|
unsigned long node_start_pfn, |
|
unsigned long node_end_pfn, |
|
unsigned long *zone_start_pfn, |
|
unsigned long *zone_end_pfn) |
|
{ |
|
unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type]; |
|
unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type]; |
|
/* When hotadd a new node from cpu_up(), the node should be empty */ |
|
if (!node_start_pfn && !node_end_pfn) |
|
return 0; |
|
|
|
/* Get the start and end of the zone */ |
|
*zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high); |
|
*zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high); |
|
adjust_zone_range_for_zone_movable(nid, zone_type, |
|
node_start_pfn, node_end_pfn, |
|
zone_start_pfn, zone_end_pfn); |
|
|
|
/* Check that this node has pages within the zone's required range */ |
|
if (*zone_end_pfn < node_start_pfn || *zone_start_pfn > node_end_pfn) |
|
return 0; |
|
|
|
/* Move the zone boundaries inside the node if necessary */ |
|
*zone_end_pfn = min(*zone_end_pfn, node_end_pfn); |
|
*zone_start_pfn = max(*zone_start_pfn, node_start_pfn); |
|
|
|
/* Return the spanned pages */ |
|
return *zone_end_pfn - *zone_start_pfn; |
|
} |
|
|
|
/* |
|
* Return the number of holes in a range on a node. If nid is MAX_NUMNODES, |
|
* then all holes in the requested range will be accounted for. |
|
*/ |
|
unsigned long __init __absent_pages_in_range(int nid, |
|
unsigned long range_start_pfn, |
|
unsigned long range_end_pfn) |
|
{ |
|
unsigned long nr_absent = range_end_pfn - range_start_pfn; |
|
unsigned long start_pfn, end_pfn; |
|
int i; |
|
|
|
for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) { |
|
start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn); |
|
end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn); |
|
nr_absent -= end_pfn - start_pfn; |
|
} |
|
return nr_absent; |
|
} |
|
|
|
/** |
|
* absent_pages_in_range - Return number of page frames in holes within a range |
|
* @start_pfn: The start PFN to start searching for holes |
|
* @end_pfn: The end PFN to stop searching for holes |
|
* |
|
* Return: the number of pages frames in memory holes within a range. |
|
*/ |
|
unsigned long __init absent_pages_in_range(unsigned long start_pfn, |
|
unsigned long end_pfn) |
|
{ |
|
return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn); |
|
} |
|
|
|
/* Return the number of page frames in holes in a zone on a node */ |
|
static unsigned long __init zone_absent_pages_in_node(int nid, |
|
unsigned long zone_type, |
|
unsigned long node_start_pfn, |
|
unsigned long node_end_pfn) |
|
{ |
|
unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type]; |
|
unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type]; |
|
unsigned long zone_start_pfn, zone_end_pfn; |
|
unsigned long nr_absent; |
|
|
|
/* When hotadd a new node from cpu_up(), the node should be empty */ |
|
if (!node_start_pfn && !node_end_pfn) |
|
return 0; |
|
|
|
zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high); |
|
zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high); |
|
|
|
adjust_zone_range_for_zone_movable(nid, zone_type, |
|
node_start_pfn, node_end_pfn, |
|
&zone_start_pfn, &zone_end_pfn); |
|
nr_absent = __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn); |
|
|
|
/* |
|
* ZONE_MOVABLE handling. |
|
* Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages |
|
* and vice versa. |
|
*/ |
|
if (mirrored_kernelcore && zone_movable_pfn[nid]) { |
|
unsigned long start_pfn, end_pfn; |
|
struct memblock_region *r; |
|
|
|
for_each_mem_region(r) { |
|
start_pfn = clamp(memblock_region_memory_base_pfn(r), |
|
zone_start_pfn, zone_end_pfn); |
|
end_pfn = clamp(memblock_region_memory_end_pfn(r), |
|
zone_start_pfn, zone_end_pfn); |
|
|
|
if (zone_type == ZONE_MOVABLE && |
|
memblock_is_mirror(r)) |
|
nr_absent += end_pfn - start_pfn; |
|
|
|
if (zone_type == ZONE_NORMAL && |
|
!memblock_is_mirror(r)) |
|
nr_absent += end_pfn - start_pfn; |
|
} |
|
} |
|
|
|
return nr_absent; |
|
} |
|
|
|
static void __init calculate_node_totalpages(struct pglist_data *pgdat, |
|
unsigned long node_start_pfn, |
|
unsigned long node_end_pfn) |
|
{ |
|
unsigned long realtotalpages = 0, totalpages = 0; |
|
enum zone_type i; |
|
|
|
for (i = 0; i < MAX_NR_ZONES; i++) { |
|
struct zone *zone = pgdat->node_zones + i; |
|
unsigned long zone_start_pfn, zone_end_pfn; |
|
unsigned long spanned, absent; |
|
unsigned long size, real_size; |
|
|
|
spanned = zone_spanned_pages_in_node(pgdat->node_id, i, |
|
node_start_pfn, |
|
node_end_pfn, |
|
&zone_start_pfn, |
|
&zone_end_pfn); |
|
absent = zone_absent_pages_in_node(pgdat->node_id, i, |
|
node_start_pfn, |
|
node_end_pfn); |
|
|
|
size = spanned; |
|
real_size = size - absent; |
|
|
|
if (size) |
|
zone->zone_start_pfn = zone_start_pfn; |
|
else |
|
zone->zone_start_pfn = 0; |
|
zone->spanned_pages = size; |
|
zone->present_pages = real_size; |
|
#if defined(CONFIG_MEMORY_HOTPLUG) |
|
zone->present_early_pages = real_size; |
|
#endif |
|
|
|
totalpages += size; |
|
realtotalpages += real_size; |
|
} |
|
|
|
pgdat->node_spanned_pages = totalpages; |
|
pgdat->node_present_pages = realtotalpages; |
|
pr_debug("On node %d totalpages: %lu\n", pgdat->node_id, realtotalpages); |
|
} |
|
|
|
#ifndef CONFIG_SPARSEMEM |
|
/* |
|
* Calculate the size of the zone->blockflags rounded to an unsigned long |
|
* Start by making sure zonesize is a multiple of pageblock_order by rounding |
|
* up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally |
|
* round what is now in bits to nearest long in bits, then return it in |
|
* bytes. |
|
*/ |
|
static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize) |
|
{ |
|
unsigned long usemapsize; |
|
|
|
zonesize += zone_start_pfn & (pageblock_nr_pages-1); |
|
usemapsize = roundup(zonesize, pageblock_nr_pages); |
|
usemapsize = usemapsize >> pageblock_order; |
|
usemapsize *= NR_PAGEBLOCK_BITS; |
|
usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long)); |
|
|
|
return usemapsize / 8; |
|
} |
|
|
|
static void __ref setup_usemap(struct zone *zone) |
|
{ |
|
unsigned long usemapsize = usemap_size(zone->zone_start_pfn, |
|
zone->spanned_pages); |
|
zone->pageblock_flags = NULL; |
|
if (usemapsize) { |
|
zone->pageblock_flags = |
|
memblock_alloc_node(usemapsize, SMP_CACHE_BYTES, |
|
zone_to_nid(zone)); |
|
if (!zone->pageblock_flags) |
|
panic("Failed to allocate %ld bytes for zone %s pageblock flags on node %d\n", |
|
usemapsize, zone->name, zone_to_nid(zone)); |
|
} |
|
} |
|
#else |
|
static inline void setup_usemap(struct zone *zone) {} |
|
#endif /* CONFIG_SPARSEMEM */ |
|
|
|
#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE |
|
|
|
/* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */ |
|
void __init set_pageblock_order(void) |
|
{ |
|
unsigned int order; |
|
|
|
/* Check that pageblock_nr_pages has not already been setup */ |
|
if (pageblock_order) |
|
return; |
|
|
|
if (HPAGE_SHIFT > PAGE_SHIFT) |
|
order = HUGETLB_PAGE_ORDER; |
|
else |
|
order = MAX_ORDER - 1; |
|
|
|
/* |
|
* Assume the largest contiguous order of interest is a huge page. |
|
* This value may be variable depending on boot parameters on IA64 and |
|
* powerpc. |
|
*/ |
|
pageblock_order = order; |
|
} |
|
#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ |
|
|
|
/* |
|
* When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order() |
|
* is unused as pageblock_order is set at compile-time. See |
|
* include/linux/pageblock-flags.h for the values of pageblock_order based on |
|
* the kernel config |
|
*/ |
|
void __init set_pageblock_order(void) |
|
{ |
|
} |
|
|
|
#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ |
|
|
|
static unsigned long __init calc_memmap_size(unsigned long spanned_pages, |
|
unsigned long present_pages) |
|
{ |
|
unsigned long pages = spanned_pages; |
|
|
|
/* |
|
* Provide a more accurate estimation if there are holes within |
|
* the zone and SPARSEMEM is in use. If there are holes within the |
|
* zone, each populated memory region may cost us one or two extra |
|
* memmap pages due to alignment because memmap pages for each |
|
* populated regions may not be naturally aligned on page boundary. |
|
* So the (present_pages >> 4) heuristic is a tradeoff for that. |
|
*/ |
|
if (spanned_pages > present_pages + (present_pages >> 4) && |
|
IS_ENABLED(CONFIG_SPARSEMEM)) |
|
pages = present_pages; |
|
|
|
return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT; |
|
} |
|
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE |
|
static void pgdat_init_split_queue(struct pglist_data *pgdat) |
|
{ |
|
struct deferred_split *ds_queue = &pgdat->deferred_split_queue; |
|
|
|
spin_lock_init(&ds_queue->split_queue_lock); |
|
INIT_LIST_HEAD(&ds_queue->split_queue); |
|
ds_queue->split_queue_len = 0; |
|
} |
|
#else |
|
static void pgdat_init_split_queue(struct pglist_data *pgdat) {} |
|
#endif |
|
|
|
#ifdef CONFIG_COMPACTION |
|
static void pgdat_init_kcompactd(struct pglist_data *pgdat) |
|
{ |
|
init_waitqueue_head(&pgdat->kcompactd_wait); |
|
} |
|
#else |
|
static void pgdat_init_kcompactd(struct pglist_data *pgdat) {} |
|
#endif |
|
|
|
static void __meminit pgdat_init_internals(struct pglist_data *pgdat) |
|
{ |
|
pgdat_resize_init(pgdat); |
|
|
|
pgdat_init_split_queue(pgdat); |
|
pgdat_init_kcompactd(pgdat); |
|
|
|
init_waitqueue_head(&pgdat->kswapd_wait); |
|
init_waitqueue_head(&pgdat->pfmemalloc_wait); |
|
|
|
pgdat_page_ext_init(pgdat); |
|
lruvec_init(&pgdat->__lruvec); |
|
} |
|
|
|
static void __meminit zone_init_internals(struct zone *zone, enum zone_type idx, int nid, |
|
unsigned long remaining_pages) |
|
{ |
|
atomic_long_set(&zone->managed_pages, remaining_pages); |
|
zone_set_nid(zone, nid); |
|
zone->name = zone_names[idx]; |
|
zone->zone_pgdat = NODE_DATA(nid); |
|
spin_lock_init(&zone->lock); |
|
zone_seqlock_init(zone); |
|
zone_pcp_init(zone); |
|
} |
|
|
|
/* |
|
* Set up the zone data structures |
|
* - init pgdat internals |
|
* - init all zones belonging to this node |
|
* |
|
* NOTE: this function is only called during memory hotplug |
|
*/ |
|
#ifdef CONFIG_MEMORY_HOTPLUG |
|
void __ref free_area_init_core_hotplug(int nid) |
|
{ |
|
enum zone_type z; |
|
pg_data_t *pgdat = NODE_DATA(nid); |
|
|
|
pgdat_init_internals(pgdat); |
|
for (z = 0; z < MAX_NR_ZONES; z++) |
|
zone_init_internals(&pgdat->node_zones[z], z, nid, 0); |
|
} |
|
#endif |
|
|
|
/* |
|
* Set up the zone data structures: |
|
* - mark all pages reserved |
|
* - mark all memory queues empty |
|
* - clear the memory bitmaps |
|
* |
|
* NOTE: pgdat should get zeroed by caller. |
|
* NOTE: this function is only called during early init. |
|
*/ |
|
static void __init free_area_init_core(struct pglist_data *pgdat) |
|
{ |
|
enum zone_type j; |
|
int nid = pgdat->node_id; |
|
|
|
pgdat_init_internals(pgdat); |
|
pgdat->per_cpu_nodestats = &boot_nodestats; |
|
|
|
for (j = 0; j < MAX_NR_ZONES; j++) { |
|
struct zone *zone = pgdat->node_zones + j; |
|
unsigned long size, freesize, memmap_pages; |
|
|
|
size = zone->spanned_pages; |
|
freesize = zone->present_pages; |
|
|
|
/* |
|
* Adjust freesize so that it accounts for how much memory |
|
* is used by this zone for memmap. This affects the watermark |
|
* and per-cpu initialisations |
|
*/ |
|
memmap_pages = calc_memmap_size(size, freesize); |
|
if (!is_highmem_idx(j)) { |
|
if (freesize >= memmap_pages) { |
|
freesize -= memmap_pages; |
|
if (memmap_pages) |
|
pr_debug(" %s zone: %lu pages used for memmap\n", |
|
zone_names[j], memmap_pages); |
|
} else |
|
pr_warn(" %s zone: %lu memmap pages exceeds freesize %lu\n", |
|
zone_names[j], memmap_pages, freesize); |
|
} |
|
|
|
/* Account for reserved pages */ |
|
if (j == 0 && freesize > dma_reserve) { |
|
freesize -= dma_reserve; |
|
pr_debug(" %s zone: %lu pages reserved\n", zone_names[0], dma_reserve); |
|
} |
|
|
|
if (!is_highmem_idx(j)) |
|
nr_kernel_pages += freesize; |
|
/* Charge for highmem memmap if there are enough kernel pages */ |
|
else if (nr_kernel_pages > memmap_pages * 2) |
|
nr_kernel_pages -= memmap_pages; |
|
nr_all_pages += freesize; |
|
|
|
/* |
|
* Set an approximate value for lowmem here, it will be adjusted |
|
* when the bootmem allocator frees pages into the buddy system. |
|
* And all highmem pages will be managed by the buddy system. |
|
*/ |
|
zone_init_internals(zone, j, nid, freesize); |
|
|
|
if (!size) |
|
continue; |
|
|
|
set_pageblock_order(); |
|
setup_usemap(zone); |
|
init_currently_empty_zone(zone, zone->zone_start_pfn, size); |
|
} |
|
} |
|
|
|
#ifdef CONFIG_FLATMEM |
|
static void __init alloc_node_mem_map(struct pglist_data *pgdat) |
|
{ |
|
unsigned long __maybe_unused start = 0; |
|
unsigned long __maybe_unused offset = 0; |
|
|
|
/* Skip empty nodes */ |
|
if (!pgdat->node_spanned_pages) |
|
return; |
|
|
|
start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1); |
|
offset = pgdat->node_start_pfn - start; |
|
/* ia64 gets its own node_mem_map, before this, without bootmem */ |
|
if (!pgdat->node_mem_map) { |
|
unsigned long size, end; |
|
struct page *map; |
|
|
|
/* |
|
* The zone's endpoints aren't required to be MAX_ORDER |
|
* aligned but the node_mem_map endpoints must be in order |
|
* for the buddy allocator to function correctly. |
|
*/ |
|
end = pgdat_end_pfn(pgdat); |
|
end = ALIGN(end, MAX_ORDER_NR_PAGES); |
|
size = (end - start) * sizeof(struct page); |
|
map = memmap_alloc(size, SMP_CACHE_BYTES, MEMBLOCK_LOW_LIMIT, |
|
pgdat->node_id, false); |
|
if (!map) |
|
panic("Failed to allocate %ld bytes for node %d memory map\n", |
|
size, pgdat->node_id); |
|
pgdat->node_mem_map = map + offset; |
|
} |
|
pr_debug("%s: node %d, pgdat %08lx, node_mem_map %08lx\n", |
|
__func__, pgdat->node_id, (unsigned long)pgdat, |
|
(unsigned long)pgdat->node_mem_map); |
|
#ifndef CONFIG_NUMA |
|
/* |
|
* With no DISCONTIG, the global mem_map is just set as node 0's |
|
*/ |
|
if (pgdat == NODE_DATA(0)) { |
|
mem_map = NODE_DATA(0)->node_mem_map; |
|
if (page_to_pfn(mem_map) != pgdat->node_start_pfn) |
|
mem_map -= offset; |
|
} |
|
#endif |
|
} |
|
#else |
|
static inline void alloc_node_mem_map(struct pglist_data *pgdat) { } |
|
#endif /* CONFIG_FLATMEM */ |
|
|
|
#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT |
|
static inline void pgdat_set_deferred_range(pg_data_t *pgdat) |
|
{ |
|
pgdat->first_deferred_pfn = ULONG_MAX; |
|
} |
|
#else |
|
static inline void pgdat_set_deferred_range(pg_data_t *pgdat) {} |
|
#endif |
|
|
|
static void __init free_area_init_node(int nid) |
|
{ |
|
pg_data_t *pgdat = NODE_DATA(nid); |
|
unsigned long start_pfn = 0; |
|
unsigned long end_pfn = 0; |
|
|
|
/* pg_data_t should be reset to zero when it's allocated */ |
|
WARN_ON(pgdat->nr_zones || pgdat->kswapd_highest_zoneidx); |
|
|
|
get_pfn_range_for_nid(nid, &start_pfn, &end_pfn); |
|
|
|
pgdat->node_id = nid; |
|
pgdat->node_start_pfn = start_pfn; |
|
pgdat->per_cpu_nodestats = NULL; |
|
|
|
pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid, |
|
(u64)start_pfn << PAGE_SHIFT, |
|
end_pfn ? ((u64)end_pfn << PAGE_SHIFT) - 1 : 0); |
|
calculate_node_totalpages(pgdat, start_pfn, end_pfn); |
|
|
|
alloc_node_mem_map(pgdat); |
|
pgdat_set_deferred_range(pgdat); |
|
|
|
free_area_init_core(pgdat); |
|
} |
|
|
|
void __init free_area_init_memoryless_node(int nid) |
|
{ |
|
free_area_init_node(nid); |
|
} |
|
|
|
#if MAX_NUMNODES > 1 |
|
/* |
|
* Figure out the number of possible node ids. |
|
*/ |
|
void __init setup_nr_node_ids(void) |
|
{ |
|
unsigned int highest; |
|
|
|
highest = find_last_bit(node_possible_map.bits, MAX_NUMNODES); |
|
nr_node_ids = highest + 1; |
|
} |
|
#endif |
|
|
|
/** |
|
* node_map_pfn_alignment - determine the maximum internode alignment |
|
* |
|
* This function should be called after node map is populated and sorted. |
|
* It calculates the maximum power of two alignment which can distinguish |
|
* all the nodes. |
|
* |
|
* For example, if all nodes are 1GiB and aligned to 1GiB, the return value |
|
* would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the |
|
* nodes are shifted by 256MiB, 256MiB. Note that if only the last node is |
|
* shifted, 1GiB is enough and this function will indicate so. |
|
* |
|
* This is used to test whether pfn -> nid mapping of the chosen memory |
|
* model has fine enough granularity to avoid incorrect mapping for the |
|
* populated node map. |
|
* |
|
* Return: the determined alignment in pfn's. 0 if there is no alignment |
|
* requirement (single node). |
|
*/ |
|
unsigned long __init node_map_pfn_alignment(void) |
|
{ |
|
unsigned long accl_mask = 0, last_end = 0; |
|
unsigned long start, end, mask; |
|
int last_nid = NUMA_NO_NODE; |
|
int i, nid; |
|
|
|
for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) { |
|
if (!start || last_nid < 0 || last_nid == nid) { |
|
last_nid = nid; |
|
last_end = end; |
|
continue; |
|
} |
|
|
|
/* |
|
* Start with a mask granular enough to pin-point to the |
|
* start pfn and tick off bits one-by-one until it becomes |
|
* too coarse to separate the current node from the last. |
|
*/ |
|
mask = ~((1 << __ffs(start)) - 1); |
|
while (mask && last_end <= (start & (mask << 1))) |
|
mask <<= 1; |
|
|
|
/* accumulate all internode masks */ |
|
accl_mask |= mask; |
|
} |
|
|
|
/* convert mask to number of pages */ |
|
return ~accl_mask + 1; |
|
} |
|
|
|
/** |
|
* find_min_pfn_with_active_regions - Find the minimum PFN registered |
|
* |
|
* Return: the minimum PFN based on information provided via |
|
* memblock_set_node(). |
|
*/ |
|
unsigned long __init find_min_pfn_with_active_regions(void) |
|
{ |
|
return PHYS_PFN(memblock_start_of_DRAM()); |
|
} |
|
|
|
/* |
|
* early_calculate_totalpages() |
|
* Sum pages in active regions for movable zone. |
|
* Populate N_MEMORY for calculating usable_nodes. |
|
*/ |
|
static unsigned long __init early_calculate_totalpages(void) |
|
{ |
|
unsigned long totalpages = 0; |
|
unsigned long start_pfn, end_pfn; |
|
int i, nid; |
|
|
|
for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) { |
|
unsigned long pages = end_pfn - start_pfn; |
|
|
|
totalpages += pages; |
|
if (pages) |
|
node_set_state(nid, N_MEMORY); |
|
} |
|
return totalpages; |
|
} |
|
|
|
/* |
|
* Find the PFN the Movable zone begins in each node. Kernel memory |
|
* is spread evenly between nodes as long as the nodes have enough |
|
* memory. When they don't, some nodes will have more kernelcore than |
|
* others |
|
*/ |
|
static void __init find_zone_movable_pfns_for_nodes(void) |
|
{ |
|
int i, nid; |
|
unsigned long usable_startpfn; |
|
unsigned long kernelcore_node, kernelcore_remaining; |
|
/* save the state before borrow the nodemask */ |
|
nodemask_t saved_node_state = node_states[N_MEMORY]; |
|
unsigned long totalpages = early_calculate_totalpages(); |
|
int usable_nodes = nodes_weight(node_states[N_MEMORY]); |
|
struct memblock_region *r; |
|
|
|
/* Need to find movable_zone earlier when movable_node is specified. */ |
|
find_usable_zone_for_movable(); |
|
|
|
/* |
|
* If movable_node is specified, ignore kernelcore and movablecore |
|
* options. |
|
*/ |
|
if (movable_node_is_enabled()) { |
|
for_each_mem_region(r) { |
|
if (!memblock_is_hotpluggable(r)) |
|
continue; |
|
|
|
nid = memblock_get_region_node(r); |
|
|
|
usable_startpfn = PFN_DOWN(r->base); |
|
zone_movable_pfn[nid] = zone_movable_pfn[nid] ? |
|
min(usable_startpfn, zone_movable_pfn[nid]) : |
|
usable_startpfn; |
|
} |
|
|
|
goto out2; |
|
} |
|
|
|
/* |
|
* If kernelcore=mirror is specified, ignore movablecore option |
|
*/ |
|
if (mirrored_kernelcore) { |
|
bool mem_below_4gb_not_mirrored = false; |
|
|
|
for_each_mem_region(r) { |
|
if (memblock_is_mirror(r)) |
|
continue; |
|
|
|
nid = memblock_get_region_node(r); |
|
|
|
usable_startpfn = memblock_region_memory_base_pfn(r); |
|
|
|
if (usable_startpfn < 0x100000) { |
|
mem_below_4gb_not_mirrored = true; |
|
continue; |
|
} |
|
|
|
zone_movable_pfn[nid] = zone_movable_pfn[nid] ? |
|
min(usable_startpfn, zone_movable_pfn[nid]) : |
|
usable_startpfn; |
|
} |
|
|
|
if (mem_below_4gb_not_mirrored) |
|
pr_warn("This configuration results in unmirrored kernel memory.\n"); |
|
|
|
goto out2; |
|
} |
|
|
|
/* |
|
* If kernelcore=nn% or movablecore=nn% was specified, calculate the |
|
* amount of necessary memory. |
|
*/ |
|
if (required_kernelcore_percent) |
|
required_kernelcore = (totalpages * 100 * required_kernelcore_percent) / |
|
10000UL; |
|
if (required_movablecore_percent) |
|
required_movablecore = (totalpages * 100 * required_movablecore_percent) / |
|
10000UL; |
|
|
|
/* |
|
* If movablecore= was specified, calculate what size of |
|
* kernelcore that corresponds so that memory usable for |
|
* any allocation type is evenly spread. If both kernelcore |
|
* and movablecore are specified, then the value of kernelcore |
|
* will be used for required_kernelcore if it's greater than |
|
* what movablecore would have allowed. |
|
*/ |
|
if (required_movablecore) { |
|
unsigned long corepages; |
|
|
|
/* |
|
* Round-up so that ZONE_MOVABLE is at least as large as what |
|
* was requested by the user |
|
*/ |
|
required_movablecore = |
|
roundup(required_movablecore, MAX_ORDER_NR_PAGES); |
|
required_movablecore = min(totalpages, required_movablecore); |
|
corepages = totalpages - required_movablecore; |
|
|
|
required_kernelcore = max(required_kernelcore, corepages); |
|
} |
|
|
|
/* |
|
* If kernelcore was not specified or kernelcore size is larger |
|
* than totalpages, there is no ZONE_MOVABLE. |
|
*/ |
|
if (!required_kernelcore || required_kernelcore >= totalpages) |
|
goto out; |
|
|
|
/* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */ |
|
usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone]; |
|
|
|
restart: |
|
/* Spread kernelcore memory as evenly as possible throughout nodes */ |
|
kernelcore_node = required_kernelcore / usable_nodes; |
|
for_each_node_state(nid, N_MEMORY) { |
|
unsigned long start_pfn, end_pfn; |
|
|
|
/* |
|
* Recalculate kernelcore_node if the division per node |
|
* now exceeds what is necessary to satisfy the requested |
|
* amount of memory for the kernel |
|
*/ |
|
if (required_kernelcore < kernelcore_node) |
|
kernelcore_node = required_kernelcore / usable_nodes; |
|
|
|
/* |
|
* As the map is walked, we track how much memory is usable |
|
* by the kernel using kernelcore_remaining. When it is |
|
* 0, the rest of the node is usable by ZONE_MOVABLE |
|
*/ |
|
kernelcore_remaining = kernelcore_node; |
|
|
|
/* Go through each range of PFNs within this node */ |
|
for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) { |
|
unsigned long size_pages; |
|
|
|
start_pfn = max(start_pfn, zone_movable_pfn[nid]); |
|
if (start_pfn >= end_pfn) |
|
continue; |
|
|
|
/* Account for what is only usable for kernelcore */ |
|
if (start_pfn < usable_startpfn) { |
|
unsigned long kernel_pages; |
|
kernel_pages = min(end_pfn, usable_startpfn) |
|
- start_pfn; |
|
|
|
kernelcore_remaining -= min(kernel_pages, |
|
kernelcore_remaining); |
|
required_kernelcore -= min(kernel_pages, |
|
required_kernelcore); |
|
|
|
/* Continue if range is now fully accounted */ |
|
if (end_pfn <= usable_startpfn) { |
|
|
|
/* |
|
* Push zone_movable_pfn to the end so |
|
* that if we have to rebalance |
|
* kernelcore across nodes, we will |
|
* not double account here |
|
*/ |
|
zone_movable_pfn[nid] = end_pfn; |
|
continue; |
|
} |
|
start_pfn = usable_startpfn; |
|
} |
|
|
|
/* |
|
* The usable PFN range for ZONE_MOVABLE is from |
|
* start_pfn->end_pfn. Calculate size_pages as the |
|
* number of pages used as kernelcore |
|
*/ |
|
size_pages = end_pfn - start_pfn; |
|
if (size_pages > kernelcore_remaining) |
|
size_pages = kernelcore_remaining; |
|
zone_movable_pfn[nid] = start_pfn + size_pages; |
|
|
|
/* |
|
* Some kernelcore has been met, update counts and |
|
* break if the kernelcore for this node has been |
|
* satisfied |
|
*/ |
|
required_kernelcore -= min(required_kernelcore, |
|
size_pages); |
|
kernelcore_remaining -= size_pages; |
|
if (!kernelcore_remaining) |
|
break; |
|
} |
|
} |
|
|
|
/* |
|
* If there is still required_kernelcore, we do another pass with one |
|
* less node in the count. This will push zone_movable_pfn[nid] further |
|
* along on the nodes that still have memory until kernelcore is |
|
* satisfied |
|
*/ |
|
usable_nodes--; |
|
if (usable_nodes && required_kernelcore > usable_nodes) |
|
goto restart; |
|
|
|
out2: |
|
/* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */ |
|
for (nid = 0; nid < MAX_NUMNODES; nid++) |
|
zone_movable_pfn[nid] = |
|
roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES); |
|
|
|
out: |
|
/* restore the node_state */ |
|
node_states[N_MEMORY] = saved_node_state; |
|
} |
|
|
|
/* Any regular or high memory on that node ? */ |
|
static void check_for_memory(pg_data_t *pgdat, int nid) |
|
{ |
|
enum zone_type zone_type; |
|
|
|
for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) { |
|
struct zone *zone = &pgdat->node_zones[zone_type]; |
|
if (populated_zone(zone)) { |
|
if (IS_ENABLED(CONFIG_HIGHMEM)) |
|
node_set_state(nid, N_HIGH_MEMORY); |
|
if (zone_type <= ZONE_NORMAL) |
|
node_set_state(nid, N_NORMAL_MEMORY); |
|
break; |
|
} |
|
} |
|
} |
|
|
|
/* |
|
* Some architectures, e.g. ARC may have ZONE_HIGHMEM below ZONE_NORMAL. For |
|
* such cases we allow max_zone_pfn sorted in the descending order |
|
*/ |
|
bool __weak arch_has_descending_max_zone_pfns(void) |
|
{ |
|
return false; |
|
} |
|
|
|
/** |
|
* free_area_init - Initialise all pg_data_t and zone data |
|
* @max_zone_pfn: an array of max PFNs for each zone |
|
* |
|
* This will call free_area_init_node() for each active node in the system. |
|
* Using the page ranges provided by memblock_set_node(), the size of each |
|
* zone in each node and their holes is calculated. If the maximum PFN |
|
* between two adjacent zones match, it is assumed that the zone is empty. |
|
* For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed |
|
* that arch_max_dma32_pfn has no pages. It is also assumed that a zone |
|
* starts where the previous one ended. For example, ZONE_DMA32 starts |
|
* at arch_max_dma_pfn. |
|
*/ |
|
void __init free_area_init(unsigned long *max_zone_pfn) |
|
{ |
|
unsigned long start_pfn, end_pfn; |
|
int i, nid, zone; |
|
bool descending; |
|
|
|
/* Record where the zone boundaries are */ |
|
memset(arch_zone_lowest_possible_pfn, 0, |
|
sizeof(arch_zone_lowest_possible_pfn)); |
|
memset(arch_zone_highest_possible_pfn, 0, |
|
sizeof(arch_zone_highest_possible_pfn)); |
|
|
|
start_pfn = find_min_pfn_with_active_regions(); |
|
descending = arch_has_descending_max_zone_pfns(); |
|
|
|
for (i = 0; i < MAX_NR_ZONES; i++) { |
|
if (descending) |
|
zone = MAX_NR_ZONES - i - 1; |
|
else |
|
zone = i; |
|
|
|
if (zone == ZONE_MOVABLE) |
|
continue; |
|
|
|
end_pfn = max(max_zone_pfn[zone], start_pfn); |
|
arch_zone_lowest_possible_pfn[zone] = start_pfn; |
|
arch_zone_highest_possible_pfn[zone] = end_pfn; |
|
|
|
start_pfn = end_pfn; |
|
} |
|
|
|
/* Find the PFNs that ZONE_MOVABLE begins at in each node */ |
|
memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn)); |
|
find_zone_movable_pfns_for_nodes(); |
|
|
|
/* Print out the zone ranges */ |
|
pr_info("Zone ranges:\n"); |
|
for (i = 0; i < MAX_NR_ZONES; i++) { |
|
if (i == ZONE_MOVABLE) |
|
continue; |
|
pr_info(" %-8s ", zone_names[i]); |
|
if (arch_zone_lowest_possible_pfn[i] == |
|
arch_zone_highest_possible_pfn[i]) |
|
pr_cont("empty\n"); |
|
else |
|
pr_cont("[mem %#018Lx-%#018Lx]\n", |
|
(u64)arch_zone_lowest_possible_pfn[i] |
|
<< PAGE_SHIFT, |
|
((u64)arch_zone_highest_possible_pfn[i] |
|
<< PAGE_SHIFT) - 1); |
|
} |
|
|
|
/* Print out the PFNs ZONE_MOVABLE begins at in each node */ |
|
pr_info("Movable zone start for each node\n"); |
|
for (i = 0; i < MAX_NUMNODES; i++) { |
|
if (zone_movable_pfn[i]) |
|
pr_info(" Node %d: %#018Lx\n", i, |
|
(u64)zone_movable_pfn[i] << PAGE_SHIFT); |
|
} |
|
|
|
/* |
|
* Print out the early node map, and initialize the |
|
* subsection-map relative to active online memory ranges to |
|
* enable future "sub-section" extensions of the memory map. |
|
*/ |
|
pr_info("Early memory node ranges\n"); |
|
for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) { |
|
pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid, |
|
(u64)start_pfn << PAGE_SHIFT, |
|
((u64)end_pfn << PAGE_SHIFT) - 1); |
|
subsection_map_init(start_pfn, end_pfn - start_pfn); |
|
} |
|
|
|
/* Initialise every node */ |
|
mminit_verify_pageflags_layout(); |
|
setup_nr_node_ids(); |
|
for_each_online_node(nid) { |
|
pg_data_t *pgdat = NODE_DATA(nid); |
|
free_area_init_node(nid); |
|
|
|
/* Any memory on that node */ |
|
if (pgdat->node_present_pages) |
|
node_set_state(nid, N_MEMORY); |
|
check_for_memory(pgdat, nid); |
|
} |
|
|
|
memmap_init(); |
|
} |
|
|
|
static int __init cmdline_parse_core(char *p, unsigned long *core, |
|
unsigned long *percent) |
|
{ |
|
unsigned long long coremem; |
|
char *endptr; |
|
|
|
if (!p) |
|
return -EINVAL; |
|
|
|
/* Value may be a percentage of total memory, otherwise bytes */ |
|
coremem = simple_strtoull(p, &endptr, 0); |
|
if (*endptr == '%') { |
|
/* Paranoid check for percent values greater than 100 */ |
|
WARN_ON(coremem > 100); |
|
|
|
*percent = coremem; |
|
} else { |
|
coremem = memparse(p, &p); |
|
/* Paranoid check that UL is enough for the coremem value */ |
|
WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX); |
|
|
|
*core = coremem >> PAGE_SHIFT; |
|
*percent = 0UL; |
|
} |
|
return 0; |
|
} |
|
|
|
/* |
|
* kernelcore=size sets the amount of memory for use for allocations that |
|
* cannot be reclaimed or migrated. |
|
*/ |
|
static int __init cmdline_parse_kernelcore(char *p) |
|
{ |
|
/* parse kernelcore=mirror */ |
|
if (parse_option_str(p, "mirror")) { |
|
mirrored_kernelcore = true; |
|
return 0; |
|
} |
|
|
|
return cmdline_parse_core(p, &required_kernelcore, |
|
&required_kernelcore_percent); |
|
} |
|
|
|
/* |
|
* movablecore=size sets the amount of memory for use for allocations that |
|
* can be reclaimed or migrated. |
|
*/ |
|
static int __init cmdline_parse_movablecore(char *p) |
|
{ |
|
return cmdline_parse_core(p, &required_movablecore, |
|
&required_movablecore_percent); |
|
} |
|
|
|
early_param("kernelcore", cmdline_parse_kernelcore); |
|
early_param("movablecore", cmdline_parse_movablecore); |
|
|
|
void adjust_managed_page_count(struct page *page, long count) |
|
{ |
|
atomic_long_add(count, &page_zone(page)->managed_pages); |
|
totalram_pages_add(count); |
|
#ifdef CONFIG_HIGHMEM |
|
if (PageHighMem(page)) |
|
totalhigh_pages_add(count); |
|
#endif |
|
} |
|
EXPORT_SYMBOL(adjust_managed_page_count); |
|
|
|
unsigned long free_reserved_area(void *start, void *end, int poison, const char *s) |
|
{ |
|
void *pos; |
|
unsigned long pages = 0; |
|
|
|
start = (void *)PAGE_ALIGN((unsigned long)start); |
|
end = (void *)((unsigned long)end & PAGE_MASK); |
|
for (pos = start; pos < end; pos += PAGE_SIZE, pages++) { |
|
struct page *page = virt_to_page(pos); |
|
void *direct_map_addr; |
|
|
|
/* |
|
* 'direct_map_addr' might be different from 'pos' |
|
* because some architectures' virt_to_page() |
|
* work with aliases. Getting the direct map |
|
* address ensures that we get a _writeable_ |
|
* alias for the memset(). |
|
*/ |
|
direct_map_addr = page_address(page); |
|
/* |
|
* Perform a kasan-unchecked memset() since this memory |
|
* has not been initialized. |
|
*/ |
|
direct_map_addr = kasan_reset_tag(direct_map_addr); |
|
if ((unsigned int)poison <= 0xFF) |
|
memset(direct_map_addr, poison, PAGE_SIZE); |
|
|
|
free_reserved_page(page); |
|
} |
|
|
|
if (pages && s) |
|
pr_info("Freeing %s memory: %ldK\n", |
|
s, pages << (PAGE_SHIFT - 10)); |
|
|
|
return pages; |
|
} |
|
|
|
void __init mem_init_print_info(void) |
|
{ |
|
unsigned long physpages, codesize, datasize, rosize, bss_size; |
|
unsigned long init_code_size, init_data_size; |
|
|
|
physpages = get_num_physpages(); |
|
codesize = _etext - _stext; |
|
datasize = _edata - _sdata; |
|
rosize = __end_rodata - __start_rodata; |
|
bss_size = __bss_stop - __bss_start; |
|
init_data_size = __init_end - __init_begin; |
|
init_code_size = _einittext - _sinittext; |
|
|
|
/* |
|
* Detect special cases and adjust section sizes accordingly: |
|
* 1) .init.* may be embedded into .data sections |
|
* 2) .init.text.* may be out of [__init_begin, __init_end], |
|
* please refer to arch/tile/kernel/vmlinux.lds.S. |
|
* 3) .rodata.* may be embedded into .text or .data sections. |
|
*/ |
|
#define adj_init_size(start, end, size, pos, adj) \ |
|
do { \ |
|
if (start <= pos && pos < end && size > adj) \ |
|
size -= adj; \ |
|
} while (0) |
|
|
|
adj_init_size(__init_begin, __init_end, init_data_size, |
|
_sinittext, init_code_size); |
|
adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size); |
|
adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size); |
|
adj_init_size(_stext, _etext, codesize, __start_rodata, rosize); |
|
adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize); |
|
|
|
#undef adj_init_size |
|
|
|
pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved" |
|
#ifdef CONFIG_HIGHMEM |
|
", %luK highmem" |
|
#endif |
|
")\n", |
|
nr_free_pages() << (PAGE_SHIFT - 10), |
|
physpages << (PAGE_SHIFT - 10), |
|
codesize >> 10, datasize >> 10, rosize >> 10, |
|
(init_data_size + init_code_size) >> 10, bss_size >> 10, |
|
(physpages - totalram_pages() - totalcma_pages) << (PAGE_SHIFT - 10), |
|
totalcma_pages << (PAGE_SHIFT - 10) |
|
#ifdef CONFIG_HIGHMEM |
|
, totalhigh_pages() << (PAGE_SHIFT - 10) |
|
#endif |
|
); |
|
} |
|
|
|
/** |
|
* set_dma_reserve - set the specified number of pages reserved in the first zone |
|
* @new_dma_reserve: The number of pages to mark reserved |
|
* |
|
* The per-cpu batchsize and zone watermarks are determined by managed_pages. |
|
* In the DMA zone, a significant percentage may be consumed by kernel image |
|
* and other unfreeable allocations which can skew the watermarks badly. This |
|
* function may optionally be used to account for unfreeable pages in the |
|
* first zone (e.g., ZONE_DMA). The effect will be lower watermarks and |
|
* smaller per-cpu batchsize. |
|
*/ |
|
void __init set_dma_reserve(unsigned long new_dma_reserve) |
|
{ |
|
dma_reserve = new_dma_reserve; |
|
} |
|
|
|
static int page_alloc_cpu_dead(unsigned int cpu) |
|
{ |
|
struct zone *zone; |
|
|
|
lru_add_drain_cpu(cpu); |
|
drain_pages(cpu); |
|
|
|
/* |
|
* Spill the event counters of the dead processor |
|
* into the current processors event counters. |
|
* This artificially elevates the count of the current |
|
* processor. |
|
*/ |
|
vm_events_fold_cpu(cpu); |
|
|
|
/* |
|
* Zero the differential counters of the dead processor |
|
* so that the vm statistics are consistent. |
|
* |
|
* This is only okay since the processor is dead and cannot |
|
* race with what we are doing. |
|
*/ |
|
cpu_vm_stats_fold(cpu); |
|
|
|
for_each_populated_zone(zone) |
|
zone_pcp_update(zone, 0); |
|
|
|
return 0; |
|
} |
|
|
|
static int page_alloc_cpu_online(unsigned int cpu) |
|
{ |
|
struct zone *zone; |
|
|
|
for_each_populated_zone(zone) |
|
zone_pcp_update(zone, 1); |
|
return 0; |
|
} |
|
|
|
#ifdef CONFIG_NUMA |
|
int hashdist = HASHDIST_DEFAULT; |
|
|
|
static int __init set_hashdist(char *str) |
|
{ |
|
if (!str) |
|
return 0; |
|
hashdist = simple_strtoul(str, &str, 0); |
|
return 1; |
|
} |
|
__setup("hashdist=", set_hashdist); |
|
#endif |
|
|
|
void __init page_alloc_init(void) |
|
{ |
|
int ret; |
|
|
|
#ifdef CONFIG_NUMA |
|
if (num_node_state(N_MEMORY) == 1) |
|
hashdist = 0; |
|
#endif |
|
|
|
ret = cpuhp_setup_state_nocalls(CPUHP_PAGE_ALLOC, |
|
"mm/page_alloc:pcp", |
|
page_alloc_cpu_online, |
|
page_alloc_cpu_dead); |
|
WARN_ON(ret < 0); |
|
} |
|
|
|
/* |
|
* calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio |
|
* or min_free_kbytes changes. |
|
*/ |
|
static void calculate_totalreserve_pages(void) |
|
{ |
|
struct pglist_data *pgdat; |
|
unsigned long reserve_pages = 0; |
|
enum zone_type i, j; |
|
|
|
for_each_online_pgdat(pgdat) { |
|
|
|
pgdat->totalreserve_pages = 0; |
|
|
|
for (i = 0; i < MAX_NR_ZONES; i++) { |
|
struct zone *zone = pgdat->node_zones + i; |
|
long max = 0; |
|
unsigned long managed_pages = zone_managed_pages(zone); |
|
|
|
/* Find valid and maximum lowmem_reserve in the zone */ |
|
for (j = i; j < MAX_NR_ZONES; j++) { |
|
if (zone->lowmem_reserve[j] > max) |
|
max = zone->lowmem_reserve[j]; |
|
} |
|
|
|
/* we treat the high watermark as reserved pages. */ |
|
max += high_wmark_pages(zone); |
|
|
|
if (max > managed_pages) |
|
max = managed_pages; |
|
|
|
pgdat->totalreserve_pages += max; |
|
|
|
reserve_pages += max; |
|
} |
|
} |
|
totalreserve_pages = reserve_pages; |
|
} |
|
|
|
/* |
|
* setup_per_zone_lowmem_reserve - called whenever |
|
* sysctl_lowmem_reserve_ratio changes. Ensures that each zone |
|
* has a correct pages reserved value, so an adequate number of |
|
* pages are left in the zone after a successful __alloc_pages(). |
|
*/ |
|
static void setup_per_zone_lowmem_reserve(void) |
|
{ |
|
struct pglist_data *pgdat; |
|
enum zone_type i, j; |
|
|
|
for_each_online_pgdat(pgdat) { |
|
for (i = 0; i < MAX_NR_ZONES - 1; i++) { |
|
struct zone *zone = &pgdat->node_zones[i]; |
|
int ratio = sysctl_lowmem_reserve_ratio[i]; |
|
bool clear = !ratio || !zone_managed_pages(zone); |
|
unsigned long managed_pages = 0; |
|
|
|
for (j = i + 1; j < MAX_NR_ZONES; j++) { |
|
struct zone *upper_zone = &pgdat->node_zones[j]; |
|
|
|
managed_pages += zone_managed_pages(upper_zone); |
|
|
|
if (clear) |
|
zone->lowmem_reserve[j] = 0; |
|
else |
|
zone->lowmem_reserve[j] = managed_pages / ratio; |
|
} |
|
} |
|
} |
|
|
|
/* update totalreserve_pages */ |
|
calculate_totalreserve_pages(); |
|
} |
|
|
|
static void __setup_per_zone_wmarks(void) |
|
{ |
|
unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10); |
|
unsigned long lowmem_pages = 0; |
|
struct zone *zone; |
|
unsigned long flags; |
|
|
|
/* Calculate total number of !ZONE_HIGHMEM pages */ |
|
for_each_zone(zone) { |
|
if (!is_highmem(zone)) |
|
lowmem_pages += zone_managed_pages(zone); |
|
} |
|
|
|
for_each_zone(zone) { |
|
u64 tmp; |
|
|
|
spin_lock_irqsave(&zone->lock, flags); |
|
tmp = (u64)pages_min * zone_managed_pages(zone); |
|
do_div(tmp, lowmem_pages); |
|
if (is_highmem(zone)) { |
|
/* |
|
* __GFP_HIGH and PF_MEMALLOC allocations usually don't |
|
* need highmem pages, so cap pages_min to a small |
|
* value here. |
|
* |
|
* The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN) |
|
* deltas control async page reclaim, and so should |
|
* not be capped for highmem. |
|
*/ |
|
unsigned long min_pages; |
|
|
|
min_pages = zone_managed_pages(zone) / 1024; |
|
min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL); |
|
zone->_watermark[WMARK_MIN] = min_pages; |
|
} else { |
|
/* |
|
* If it's a lowmem zone, reserve a number of pages |
|
* proportionate to the zone's size. |
|
*/ |
|
zone->_watermark[WMARK_MIN] = tmp; |
|
} |
|
|
|
/* |
|
* Set the kswapd watermarks distance according to the |
|
* scale factor in proportion to available memory, but |
|
* ensure a minimum size on small systems. |
|
*/ |
|
tmp = max_t(u64, tmp >> 2, |
|
mult_frac(zone_managed_pages(zone), |
|
watermark_scale_factor, 10000)); |
|
|
|
zone->watermark_boost = 0; |
|
zone->_watermark[WMARK_LOW] = min_wmark_pages(zone) + tmp; |
|
zone->_watermark[WMARK_HIGH] = min_wmark_pages(zone) + tmp * 2; |
|
|
|
spin_unlock_irqrestore(&zone->lock, flags); |
|
} |
|
|
|
/* update totalreserve_pages */ |
|
calculate_totalreserve_pages(); |
|
} |
|
|
|
/** |
|
* setup_per_zone_wmarks - called when min_free_kbytes changes |
|
* or when memory is hot-{added|removed} |
|
* |
|
* Ensures that the watermark[min,low,high] values for each zone are set |
|
* correctly with respect to min_free_kbytes. |
|
*/ |
|
void setup_per_zone_wmarks(void) |
|
{ |
|
struct zone *zone; |
|
static DEFINE_SPINLOCK(lock); |
|
|
|
spin_lock(&lock); |
|
__setup_per_zone_wmarks(); |
|
spin_unlock(&lock); |
|
|
|
/* |
|
* The watermark size have changed so update the pcpu batch |
|
* and high limits or the limits may be inappropriate. |
|
*/ |
|
for_each_zone(zone) |
|
zone_pcp_update(zone, 0); |
|
} |
|
|
|
/* |
|
* Initialise min_free_kbytes. |
|
* |
|
* For small machines we want it small (128k min). For large machines |
|
* we want it large (256MB max). But it is not linear, because network |
|
* bandwidth does not increase linearly with machine size. We use |
|
* |
|
* min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy: |
|
* min_free_kbytes = sqrt(lowmem_kbytes * 16) |
|
* |
|
* which yields |
|
* |
|
* 16MB: 512k |
|
* 32MB: 724k |
|
* 64MB: 1024k |
|
* 128MB: 1448k |
|
* 256MB: 2048k |
|
* 512MB: 2896k |
|
* 1024MB: 4096k |
|
* 2048MB: 5792k |
|
* 4096MB: 8192k |
|
* 8192MB: 11584k |
|
* 16384MB: 16384k |
|
*/ |
|
int __meminit init_per_zone_wmark_min(void) |
|
{ |
|
unsigned long lowmem_kbytes; |
|
int new_min_free_kbytes; |
|
|
|
lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10); |
|
new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16); |
|
|
|
if (new_min_free_kbytes > user_min_free_kbytes) { |
|
min_free_kbytes = new_min_free_kbytes; |
|
if (min_free_kbytes < 128) |
|
min_free_kbytes = 128; |
|
if (min_free_kbytes > 262144) |
|
min_free_kbytes = 262144; |
|
} else { |
|
pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n", |
|
new_min_free_kbytes, user_min_free_kbytes); |
|
} |
|
setup_per_zone_wmarks(); |
|
refresh_zone_stat_thresholds(); |
|
setup_per_zone_lowmem_reserve(); |
|
|
|
#ifdef CONFIG_NUMA |
|
setup_min_unmapped_ratio(); |
|
setup_min_slab_ratio(); |
|
#endif |
|
|
|
khugepaged_min_free_kbytes_update(); |
|
|
|
return 0; |
|
} |
|
postcore_initcall(init_per_zone_wmark_min) |
|
|
|
/* |
|
* min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so |
|
* that we can call two helper functions whenever min_free_kbytes |
|
* changes. |
|
*/ |
|
int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write, |
|
void *buffer, size_t *length, loff_t *ppos) |
|
{ |
|
int rc; |
|
|
|
rc = proc_dointvec_minmax(table, write, buffer, length, ppos); |
|
if (rc) |
|
return rc; |
|
|
|
if (write) { |
|
user_min_free_kbytes = min_free_kbytes; |
|
setup_per_zone_wmarks(); |
|
} |
|
return 0; |
|
} |
|
|
|
int watermark_scale_factor_sysctl_handler(struct ctl_table *table, int write, |
|
void *buffer, size_t *length, loff_t *ppos) |
|
{ |
|
int rc; |
|
|
|
rc = proc_dointvec_minmax(table, write, buffer, length, ppos); |
|
if (rc) |
|
return rc; |
|
|
|
if (write) |
|
setup_per_zone_wmarks(); |
|
|
|
return 0; |
|
} |
|
|
|
#ifdef CONFIG_NUMA |
|
static void setup_min_unmapped_ratio(void) |
|
{ |
|
pg_data_t *pgdat; |
|
struct zone *zone; |
|
|
|
for_each_online_pgdat(pgdat) |
|
pgdat->min_unmapped_pages = 0; |
|
|
|
for_each_zone(zone) |
|
zone->zone_pgdat->min_unmapped_pages += (zone_managed_pages(zone) * |
|
sysctl_min_unmapped_ratio) / 100; |
|
} |
|
|
|
|
|
int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write, |
|
void *buffer, size_t *length, loff_t *ppos) |
|
{ |
|
int rc; |
|
|
|
rc = proc_dointvec_minmax(table, write, buffer, length, ppos); |
|
if (rc) |
|
return rc; |
|
|
|
setup_min_unmapped_ratio(); |
|
|
|
return 0; |
|
} |
|
|
|
static void setup_min_slab_ratio(void) |
|
{ |
|
pg_data_t *pgdat; |
|
struct zone *zone; |
|
|
|
for_each_online_pgdat(pgdat) |
|
pgdat->min_slab_pages = 0; |
|
|
|
for_each_zone(zone) |
|
zone->zone_pgdat->min_slab_pages += (zone_managed_pages(zone) * |
|
sysctl_min_slab_ratio) / 100; |
|
} |
|
|
|
int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write, |
|
void *buffer, size_t *length, loff_t *ppos) |
|
{ |
|
int rc; |
|
|
|
rc = proc_dointvec_minmax(table, write, buffer, length, ppos); |
|
if (rc) |
|
return rc; |
|
|
|
setup_min_slab_ratio(); |
|
|
|
return 0; |
|
} |
|
#endif |
|
|
|
/* |
|
* lowmem_reserve_ratio_sysctl_handler - just a wrapper around |
|
* proc_dointvec() so that we can call setup_per_zone_lowmem_reserve() |
|
* whenever sysctl_lowmem_reserve_ratio changes. |
|
* |
|
* The reserve ratio obviously has absolutely no relation with the |
|
* minimum watermarks. The lowmem reserve ratio can only make sense |
|
* if in function of the boot time zone sizes. |
|
*/ |
|
int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write, |
|
void *buffer, size_t *length, loff_t *ppos) |
|
{ |
|
int i; |
|
|
|
proc_dointvec_minmax(table, write, buffer, length, ppos); |
|
|
|
for (i = 0; i < MAX_NR_ZONES; i++) { |
|
if (sysctl_lowmem_reserve_ratio[i] < 1) |
|
sysctl_lowmem_reserve_ratio[i] = 0; |
|
} |
|
|
|
setup_per_zone_lowmem_reserve(); |
|
return 0; |
|
} |
|
|
|
/* |
|
* percpu_pagelist_high_fraction - changes the pcp->high for each zone on each |
|
* cpu. It is the fraction of total pages in each zone that a hot per cpu |
|
* pagelist can have before it gets flushed back to buddy allocator. |
|
*/ |
|
int percpu_pagelist_high_fraction_sysctl_handler(struct ctl_table *table, |
|
int write, void *buffer, size_t *length, loff_t *ppos) |
|
{ |
|
struct zone *zone; |
|
int old_percpu_pagelist_high_fraction; |
|
int ret; |
|
|
|
mutex_lock(&pcp_batch_high_lock); |
|
old_percpu_pagelist_high_fraction = percpu_pagelist_high_fraction; |
|
|
|
ret = proc_dointvec_minmax(table, write, buffer, length, ppos); |
|
if (!write || ret < 0) |
|
goto out; |
|
|
|
/* Sanity checking to avoid pcp imbalance */ |
|
if (percpu_pagelist_high_fraction && |
|
percpu_pagelist_high_fraction < MIN_PERCPU_PAGELIST_HIGH_FRACTION) { |
|
percpu_pagelist_high_fraction = old_percpu_pagelist_high_fraction; |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
|
|
/* No change? */ |
|
if (percpu_pagelist_high_fraction == old_percpu_pagelist_high_fraction) |
|
goto out; |
|
|
|
for_each_populated_zone(zone) |
|
zone_set_pageset_high_and_batch(zone, 0); |
|
out: |
|
mutex_unlock(&pcp_batch_high_lock); |
|
return ret; |
|
} |
|
|
|
#ifndef __HAVE_ARCH_RESERVED_KERNEL_PAGES |
|
/* |
|
* Returns the number of pages that arch has reserved but |
|
* is not known to alloc_large_system_hash(). |
|
*/ |
|
static unsigned long __init arch_reserved_kernel_pages(void) |
|
{ |
|
return 0; |
|
} |
|
#endif |
|
|
|
/* |
|
* Adaptive scale is meant to reduce sizes of hash tables on large memory |
|
* machines. As memory size is increased the scale is also increased but at |
|
* slower pace. Starting from ADAPT_SCALE_BASE (64G), every time memory |
|
* quadruples the scale is increased by one, which means the size of hash table |
|
* only doubles, instead of quadrupling as well. |
|
* Because 32-bit systems cannot have large physical memory, where this scaling |
|
* makes sense, it is disabled on such platforms. |
|
*/ |
|
#if __BITS_PER_LONG > 32 |
|
#define ADAPT_SCALE_BASE (64ul << 30) |
|
#define ADAPT_SCALE_SHIFT 2 |
|
#define ADAPT_SCALE_NPAGES (ADAPT_SCALE_BASE >> PAGE_SHIFT) |
|
#endif |
|
|
|
/* |
|
* allocate a large system hash table from bootmem |
|
* - it is assumed that the hash table must contain an exact power-of-2 |
|
* quantity of entries |
|
* - limit is the number of hash buckets, not the total allocation size |
|
*/ |
|
void *__init alloc_large_system_hash(const char *tablename, |
|
unsigned long bucketsize, |
|
unsigned long numentries, |
|
int scale, |
|
int flags, |
|
unsigned int *_hash_shift, |
|
unsigned int *_hash_mask, |
|
unsigned long low_limit, |
|
unsigned long high_limit) |
|
{ |
|
unsigned long long max = high_limit; |
|
unsigned long log2qty, size; |
|
void *table = NULL; |
|
gfp_t gfp_flags; |
|
bool virt; |
|
bool huge; |
|
|
|
/* allow the kernel cmdline to have a say */ |
|
if (!numentries) { |
|
/* round applicable memory size up to nearest megabyte */ |
|
numentries = nr_kernel_pages; |
|
numentries -= arch_reserved_kernel_pages(); |
|
|
|
/* It isn't necessary when PAGE_SIZE >= 1MB */ |
|
if (PAGE_SHIFT < 20) |
|
numentries = round_up(numentries, (1<<20)/PAGE_SIZE); |
|
|
|
#if __BITS_PER_LONG > 32 |
|
if (!high_limit) { |
|
unsigned long adapt; |
|
|
|
for (adapt = ADAPT_SCALE_NPAGES; adapt < numentries; |
|
adapt <<= ADAPT_SCALE_SHIFT) |
|
scale++; |
|
} |
|
#endif |
|
|
|
/* limit to 1 bucket per 2^scale bytes of low memory */ |
|
if (scale > PAGE_SHIFT) |
|
numentries >>= (scale - PAGE_SHIFT); |
|
else |
|
numentries <<= (PAGE_SHIFT - scale); |
|
|
|
/* Make sure we've got at least a 0-order allocation.. */ |
|
if (unlikely(flags & HASH_SMALL)) { |
|
/* Makes no sense without HASH_EARLY */ |
|
WARN_ON(!(flags & HASH_EARLY)); |
|
if (!(numentries >> *_hash_shift)) { |
|
numentries = 1UL << *_hash_shift; |
|
BUG_ON(!numentries); |
|
} |
|
} else if (unlikely((numentries * bucketsize) < PAGE_SIZE)) |
|
numentries = PAGE_SIZE / bucketsize; |
|
} |
|
numentries = roundup_pow_of_two(numentries); |
|
|
|
/* limit allocation size to 1/16 total memory by default */ |
|
if (max == 0) { |
|
max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4; |
|
do_div(max, bucketsize); |
|
} |
|
max = min(max, 0x80000000ULL); |
|
|
|
if (numentries < low_limit) |
|
numentries = low_limit; |
|
if (numentries > max) |
|
numentries = max; |
|
|
|
log2qty = ilog2(numentries); |
|
|
|
gfp_flags = (flags & HASH_ZERO) ? GFP_ATOMIC | __GFP_ZERO : GFP_ATOMIC; |
|
do { |
|
virt = false; |
|
size = bucketsize << log2qty; |
|
if (flags & HASH_EARLY) { |
|
if (flags & HASH_ZERO) |
|
table = memblock_alloc(size, SMP_CACHE_BYTES); |
|
else |
|
table = memblock_alloc_raw(size, |
|
SMP_CACHE_BYTES); |
|
} else if (get_order(size) >= MAX_ORDER || hashdist) { |
|
table = __vmalloc(size, gfp_flags); |
|
virt = true; |
|
huge = is_vm_area_hugepages(table); |
|
} else { |
|
/* |
|
* If bucketsize is not a power-of-two, we may free |
|
* some pages at the end of hash table which |
|
* alloc_pages_exact() automatically does |
|
*/ |
|
table = alloc_pages_exact(size, gfp_flags); |
|
kmemleak_alloc(table, size, 1, gfp_flags); |
|
} |
|
} while (!table && size > PAGE_SIZE && --log2qty); |
|
|
|
if (!table) |
|
panic("Failed to allocate %s hash table\n", tablename); |
|
|
|
pr_info("%s hash table entries: %ld (order: %d, %lu bytes, %s)\n", |
|
tablename, 1UL << log2qty, ilog2(size) - PAGE_SHIFT, size, |
|
virt ? (huge ? "vmalloc hugepage" : "vmalloc") : "linear"); |
|
|
|
if (_hash_shift) |
|
*_hash_shift = log2qty; |
|
if (_hash_mask) |
|
*_hash_mask = (1 << log2qty) - 1; |
|
|
|
return table; |
|
} |
|
|
|
/* |
|
* This function checks whether pageblock includes unmovable pages or not. |
|
* |
|
* PageLRU check without isolation or lru_lock could race so that |
|
* MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable |
|
* check without lock_page also may miss some movable non-lru pages at |
|
* race condition. So you can't expect this function should be exact. |
|
* |
|
* Returns a page without holding a reference. If the caller wants to |
|
* dereference that page (e.g., dumping), it has to make sure that it |
|
* cannot get removed (e.g., via memory unplug) concurrently. |
|
* |
|
*/ |
|
struct page *has_unmovable_pages(struct zone *zone, struct page *page, |
|
int migratetype, int flags) |
|
{ |
|
unsigned long iter = 0; |
|
unsigned long pfn = page_to_pfn(page); |
|
unsigned long offset = pfn % pageblock_nr_pages; |
|
|
|
if (is_migrate_cma_page(page)) { |
|
/* |
|
* CMA allocations (alloc_contig_range) really need to mark |
|
* isolate CMA pageblocks even when they are not movable in fact |
|
* so consider them movable here. |
|
*/ |
|
if (is_migrate_cma(migratetype)) |
|
return NULL; |
|
|
|
return page; |
|
} |
|
|
|
for (; iter < pageblock_nr_pages - offset; iter++) { |
|
page = pfn_to_page(pfn + iter); |
|
|
|
/* |
|
* Both, bootmem allocations and memory holes are marked |
|
* PG_reserved and are unmovable. We can even have unmovable |
|
* allocations inside ZONE_MOVABLE, for example when |
|
* specifying "movablecore". |
|
*/ |
|
if (PageReserved(page)) |
|
return page; |
|
|
|
/* |
|
* If the zone is movable and we have ruled out all reserved |
|
* pages then it should be reasonably safe to assume the rest |
|
* is movable. |
|
*/ |
|
if (zone_idx(zone) == ZONE_MOVABLE) |
|
continue; |
|
|
|
/* |
|
* Hugepages are not in LRU lists, but they're movable. |
|
* THPs are on the LRU, but need to be counted as #small pages. |
|
* We need not scan over tail pages because we don't |
|
* handle each tail page individually in migration. |
|
*/ |
|
if (PageHuge(page) || PageTransCompound(page)) { |
|
struct page *head = compound_head(page); |
|
unsigned int skip_pages; |
|
|
|
if (PageHuge(page)) { |
|
if (!hugepage_migration_supported(page_hstate(head))) |
|
return page; |
|
} else if (!PageLRU(head) && !__PageMovable(head)) { |
|
return page; |
|
} |
|
|
|
skip_pages = compound_nr(head) - (page - head); |
|
iter += skip_pages - 1; |
|
continue; |
|
} |
|
|
|
/* |
|
* We can't use page_count without pin a page |
|
* because another CPU can free compound page. |
|
* This check already skips compound tails of THP |
|
* because their page->_refcount is zero at all time. |
|
*/ |
|
if (!page_ref_count(page)) { |
|
if (PageBuddy(page)) |
|
iter += (1 << buddy_order(page)) - 1; |
|
continue; |
|
} |
|
|
|
/* |
|
* The HWPoisoned page may be not in buddy system, and |
|
* page_count() is not 0. |
|
*/ |
|
if ((flags & MEMORY_OFFLINE) && PageHWPoison(page)) |
|
continue; |
|
|
|
/* |
|
* We treat all PageOffline() pages as movable when offlining |
|
* to give drivers a chance to decrement their reference count |
|
* in MEM_GOING_OFFLINE in order to indicate that these pages |
|
* can be offlined as there are no direct references anymore. |
|
* For actually unmovable PageOffline() where the driver does |
|
* not support this, we will fail later when trying to actually |
|
* move these pages that still have a reference count > 0. |
|
* (false negatives in this function only) |
|
*/ |
|
if ((flags & MEMORY_OFFLINE) && PageOffline(page)) |
|
continue; |
|
|
|
if (__PageMovable(page) || PageLRU(page)) |
|
continue; |
|
|
|
/* |
|
* If there are RECLAIMABLE pages, we need to check |
|
* it. But now, memory offline itself doesn't call |
|
* shrink_node_slabs() and it still to be fixed. |
|
*/ |
|
return page; |
|
} |
|
return NULL; |
|
} |
|
|
|
#ifdef CONFIG_CONTIG_ALLOC |
|
static unsigned long pfn_max_align_down(unsigned long pfn) |
|
{ |
|
return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES, |
|
pageblock_nr_pages) - 1); |
|
} |
|
|
|
static unsigned long pfn_max_align_up(unsigned long pfn) |
|
{ |
|
return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES, |
|
pageblock_nr_pages)); |
|
} |
|
|
|
#if defined(CONFIG_DYNAMIC_DEBUG) || \ |
|
(defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE)) |
|
/* Usage: See admin-guide/dynamic-debug-howto.rst */ |
|
static void alloc_contig_dump_pages(struct list_head *page_list) |
|
{ |
|
DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, "migrate failure"); |
|
|
|
if (DYNAMIC_DEBUG_BRANCH(descriptor)) { |
|
struct page *page; |
|
|
|
dump_stack(); |
|
list_for_each_entry(page, page_list, lru) |
|
dump_page(page, "migration failure"); |
|
} |
|
} |
|
#else |
|
static inline void alloc_contig_dump_pages(struct list_head *page_list) |
|
{ |
|
} |
|
#endif |
|
|
|
/* [start, end) must belong to a single zone. */ |
|
static int __alloc_contig_migrate_range(struct compact_control *cc, |
|
unsigned long start, unsigned long end) |
|
{ |
|
/* This function is based on compact_zone() from compaction.c. */ |
|
unsigned int nr_reclaimed; |
|
unsigned long pfn = start; |
|
unsigned int tries = 0; |
|
int ret = 0; |
|
struct migration_target_control mtc = { |
|
.nid = zone_to_nid(cc->zone), |
|
.gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL, |
|
}; |
|
|
|
lru_cache_disable(); |
|
|
|
while (pfn < end || !list_empty(&cc->migratepages)) { |
|
if (fatal_signal_pending(current)) { |
|
ret = -EINTR; |
|
break; |
|
} |
|
|
|
if (list_empty(&cc->migratepages)) { |
|
cc->nr_migratepages = 0; |
|
ret = isolate_migratepages_range(cc, pfn, end); |
|
if (ret && ret != -EAGAIN) |
|
break; |
|
pfn = cc->migrate_pfn; |
|
tries = 0; |
|
} else if (++tries == 5) { |
|
ret = -EBUSY; |
|
break; |
|
} |
|
|
|
nr_reclaimed = reclaim_clean_pages_from_list(cc->zone, |
|
&cc->migratepages); |
|
cc->nr_migratepages -= nr_reclaimed; |
|
|
|
ret = migrate_pages(&cc->migratepages, alloc_migration_target, |
|
NULL, (unsigned long)&mtc, cc->mode, MR_CONTIG_RANGE, NULL); |
|
|
|
/* |
|
* On -ENOMEM, migrate_pages() bails out right away. It is pointless |
|
* to retry again over this error, so do the same here. |
|
*/ |
|
if (ret == -ENOMEM) |
|
break; |
|
} |
|
|
|
lru_cache_enable(); |
|
if (ret < 0) { |
|
if (ret == -EBUSY) |
|
alloc_contig_dump_pages(&cc->migratepages); |
|
putback_movable_pages(&cc->migratepages); |
|
return ret; |
|
} |
|
return 0; |
|
} |
|
|
|
/** |
|
* alloc_contig_range() -- tries to allocate given range of pages |
|
* @start: start PFN to allocate |
|
* @end: one-past-the-last PFN to allocate |
|
* @migratetype: migratetype of the underlying pageblocks (either |
|
* #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks |
|
* in range must have the same migratetype and it must |
|
* be either of the two. |
|
* @gfp_mask: GFP mask to use during compaction |
|
* |
|
* The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES |
|
* aligned. The PFN range must belong to a single zone. |
|
* |
|
* The first thing this routine does is attempt to MIGRATE_ISOLATE all |
|
* pageblocks in the range. Once isolated, the pageblocks should not |
|
* be modified by others. |
|
* |
|
* Return: zero on success or negative error code. On success all |
|
* pages which PFN is in [start, end) are allocated for the caller and |
|
* need to be freed with free_contig_range(). |
|
*/ |
|
int alloc_contig_range(unsigned long start, unsigned long end, |
|
unsigned migratetype, gfp_t gfp_mask) |
|
{ |
|
unsigned long outer_start, outer_end; |
|
unsigned int order; |
|
int ret = 0; |
|
|
|
struct compact_control cc = { |
|
.nr_migratepages = 0, |
|
.order = -1, |
|
.zone = page_zone(pfn_to_page(start)), |
|
.mode = MIGRATE_SYNC, |
|
.ignore_skip_hint = true, |
|
.no_set_skip_hint = true, |
|
.gfp_mask = current_gfp_context(gfp_mask), |
|
.alloc_contig = true, |
|
}; |
|
INIT_LIST_HEAD(&cc.migratepages); |
|
|
|
/* |
|
* What we do here is we mark all pageblocks in range as |
|
* MIGRATE_ISOLATE. Because pageblock and max order pages may |
|
* have different sizes, and due to the way page allocator |
|
* work, we align the range to biggest of the two pages so |
|
* that page allocator won't try to merge buddies from |
|
* different pageblocks and change MIGRATE_ISOLATE to some |
|
* other migration type. |
|
* |
|
* Once the pageblocks are marked as MIGRATE_ISOLATE, we |
|
* migrate the pages from an unaligned range (ie. pages that |
|
* we are interested in). This will put all the pages in |
|
* range back to page allocator as MIGRATE_ISOLATE. |
|
* |
|
* When this is done, we take the pages in range from page |
|
* allocator removing them from the buddy system. This way |
|
* page allocator will never consider using them. |
|
* |
|
* This lets us mark the pageblocks back as |
|
* MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the |
|
* aligned range but not in the unaligned, original range are |
|
* put back to page allocator so that buddy can use them. |
|
*/ |
|
|
|
ret = start_isolate_page_range(pfn_max_align_down(start), |
|
pfn_max_align_up(end), migratetype, 0); |
|
if (ret) |
|
return ret; |
|
|
|
drain_all_pages(cc.zone); |
|
|
|
/* |
|
* In case of -EBUSY, we'd like to know which page causes problem. |
|
* So, just fall through. test_pages_isolated() has a tracepoint |
|
* which will report the busy page. |
|
* |
|
* It is possible that busy pages could become available before |
|
* the call to test_pages_isolated, and the range will actually be |
|
* allocated. So, if we fall through be sure to clear ret so that |
|
* -EBUSY is not accidentally used or returned to caller. |
|
*/ |
|
ret = __alloc_contig_migrate_range(&cc, start, end); |
|
if (ret && ret != -EBUSY) |
|
goto done; |
|
ret = 0; |
|
|
|
/* |
|
* Pages from [start, end) are within a MAX_ORDER_NR_PAGES |
|
* aligned blocks that are marked as MIGRATE_ISOLATE. What's |
|
* more, all pages in [start, end) are free in page allocator. |
|
* What we are going to do is to allocate all pages from |
|
* [start, end) (that is remove them from page allocator). |
|
* |
|
* The only problem is that pages at the beginning and at the |
|
* end of interesting range may be not aligned with pages that |
|
* page allocator holds, ie. they can be part of higher order |
|
* pages. Because of this, we reserve the bigger range and |
|
* once this is done free the pages we are not interested in. |
|
* |
|
* We don't have to hold zone->lock here because the pages are |
|
* isolated thus they won't get removed from buddy. |
|
*/ |
|
|
|
order = 0; |
|
outer_start = start; |
|
while (!PageBuddy(pfn_to_page(outer_start))) { |
|
if (++order >= MAX_ORDER) { |
|
outer_start = start; |
|
break; |
|
} |
|
outer_start &= ~0UL << order; |
|
} |
|
|
|
if (outer_start != start) { |
|
order = buddy_order(pfn_to_page(outer_start)); |
|
|
|
/* |
|
* outer_start page could be small order buddy page and |
|
* it doesn't include start page. Adjust outer_start |
|
* in this case to report failed page properly |
|
* on tracepoint in test_pages_isolated() |
|
*/ |
|
if (outer_start + (1UL << order) <= start) |
|
outer_start = start; |
|
} |
|
|
|
/* Make sure the range is really isolated. */ |
|
if (test_pages_isolated(outer_start, end, 0)) { |
|
ret = -EBUSY; |
|
goto done; |
|
} |
|
|
|
/* Grab isolated pages from freelists. */ |
|
outer_end = isolate_freepages_range(&cc, outer_start, end); |
|
if (!outer_end) { |
|
ret = -EBUSY; |
|
goto done; |
|
} |
|
|
|
/* Free head and tail (if any) */ |
|
if (start != outer_start) |
|
free_contig_range(outer_start, start - outer_start); |
|
if (end != outer_end) |
|
free_contig_range(end, outer_end - end); |
|
|
|
done: |
|
undo_isolate_page_range(pfn_max_align_down(start), |
|
pfn_max_align_up(end), migratetype); |
|
return ret; |
|
} |
|
EXPORT_SYMBOL(alloc_contig_range); |
|
|
|
static int __alloc_contig_pages(unsigned long start_pfn, |
|
unsigned long nr_pages, gfp_t gfp_mask) |
|
{ |
|
unsigned long end_pfn = start_pfn + nr_pages; |
|
|
|
return alloc_contig_range(start_pfn, end_pfn, MIGRATE_MOVABLE, |
|
gfp_mask); |
|
} |
|
|
|
static bool pfn_range_valid_contig(struct zone *z, unsigned long start_pfn, |
|
unsigned long nr_pages) |
|
{ |
|
unsigned long i, end_pfn = start_pfn + nr_pages; |
|
struct page *page; |
|
|
|
for (i = start_pfn; i < end_pfn; i++) { |
|
page = pfn_to_online_page(i); |
|
if (!page) |
|
return false; |
|
|
|
if (page_zone(page) != z) |
|
return false; |
|
|
|
if (PageReserved(page)) |
|
return false; |
|
} |
|
return true; |
|
} |
|
|
|
static bool zone_spans_last_pfn(const struct zone *zone, |
|
unsigned long start_pfn, unsigned long nr_pages) |
|
{ |
|
unsigned long last_pfn = start_pfn + nr_pages - 1; |
|
|
|
return zone_spans_pfn(zone, last_pfn); |
|
} |
|
|
|
/** |
|
* alloc_contig_pages() -- tries to find and allocate contiguous range of pages |
|
* @nr_pages: Number of contiguous pages to allocate |
|
* @gfp_mask: GFP mask to limit search and used during compaction |
|
* @nid: Target node |
|
* @nodemask: Mask for other possible nodes |
|
* |
|
* This routine is a wrapper around alloc_contig_range(). It scans over zones |
|
* on an applicable zonelist to find a contiguous pfn range which can then be |
|
* tried for allocation with alloc_contig_range(). This routine is intended |
|
* for allocation requests which can not be fulfilled with the buddy allocator. |
|
* |
|
* The allocated memory is always aligned to a page boundary. If nr_pages is a |
|
* power of two then the alignment is guaranteed to be to the given nr_pages |
|
* (e.g. 1GB request would be aligned to 1GB). |
|
* |
|
* Allocated pages can be freed with free_contig_range() or by manually calling |
|
* __free_page() on each allocated page. |
|
* |
|
* Return: pointer to contiguous pages on success, or NULL if not successful. |
|
*/ |
|
struct page *alloc_contig_pages(unsigned long nr_pages, gfp_t gfp_mask, |
|
int nid, nodemask_t *nodemask) |
|
{ |
|
unsigned long ret, pfn, flags; |
|
struct zonelist *zonelist; |
|
struct zone *zone; |
|
struct zoneref *z; |
|
|
|
zonelist = node_zonelist(nid, gfp_mask); |
|
for_each_zone_zonelist_nodemask(zone, z, zonelist, |
|
gfp_zone(gfp_mask), nodemask) { |
|
spin_lock_irqsave(&zone->lock, flags); |
|
|
|
pfn = ALIGN(zone->zone_start_pfn, nr_pages); |
|
while (zone_spans_last_pfn(zone, pfn, nr_pages)) { |
|
if (pfn_range_valid_contig(zone, pfn, nr_pages)) { |
|
/* |
|
* We release the zone lock here because |
|
* alloc_contig_range() will also lock the zone |
|
* at some point. If there's an allocation |
|
* spinning on this lock, it may win the race |
|
* and cause alloc_contig_range() to fail... |
|
*/ |
|
spin_unlock_irqrestore(&zone->lock, flags); |
|
ret = __alloc_contig_pages(pfn, nr_pages, |
|
gfp_mask); |
|
if (!ret) |
|
return pfn_to_page(pfn); |
|
spin_lock_irqsave(&zone->lock, flags); |
|
} |
|
pfn += nr_pages; |
|
} |
|
spin_unlock_irqrestore(&zone->lock, flags); |
|
} |
|
return NULL; |
|
} |
|
#endif /* CONFIG_CONTIG_ALLOC */ |
|
|
|
void free_contig_range(unsigned long pfn, unsigned long nr_pages) |
|
{ |
|
unsigned long count = 0; |
|
|
|
for (; nr_pages--; pfn++) { |
|
struct page *page = pfn_to_page(pfn); |
|
|
|
count += page_count(page) != 1; |
|
__free_page(page); |
|
} |
|
WARN(count != 0, "%lu pages are still in use!\n", count); |
|
} |
|
EXPORT_SYMBOL(free_contig_range); |
|
|
|
/* |
|
* The zone indicated has a new number of managed_pages; batch sizes and percpu |
|
* page high values need to be recalculated. |
|
*/ |
|
void zone_pcp_update(struct zone *zone, int cpu_online) |
|
{ |
|
mutex_lock(&pcp_batch_high_lock); |
|
zone_set_pageset_high_and_batch(zone, cpu_online); |
|
mutex_unlock(&pcp_batch_high_lock); |
|
} |
|
|
|
/* |
|
* Effectively disable pcplists for the zone by setting the high limit to 0 |
|
* and draining all cpus. A concurrent page freeing on another CPU that's about |
|
* to put the page on pcplist will either finish before the drain and the page |
|
* will be drained, or observe the new high limit and skip the pcplist. |
|
* |
|
* Must be paired with a call to zone_pcp_enable(). |
|
*/ |
|
void zone_pcp_disable(struct zone *zone) |
|
{ |
|
mutex_lock(&pcp_batch_high_lock); |
|
__zone_set_pageset_high_and_batch(zone, 0, 1); |
|
__drain_all_pages(zone, true); |
|
} |
|
|
|
void zone_pcp_enable(struct zone *zone) |
|
{ |
|
__zone_set_pageset_high_and_batch(zone, zone->pageset_high, zone->pageset_batch); |
|
mutex_unlock(&pcp_batch_high_lock); |
|
} |
|
|
|
void zone_pcp_reset(struct zone *zone) |
|
{ |
|
int cpu; |
|
struct per_cpu_zonestat *pzstats; |
|
|
|
if (zone->per_cpu_pageset != &boot_pageset) { |
|
for_each_online_cpu(cpu) { |
|
pzstats = per_cpu_ptr(zone->per_cpu_zonestats, cpu); |
|
drain_zonestat(zone, pzstats); |
|
} |
|
free_percpu(zone->per_cpu_pageset); |
|
free_percpu(zone->per_cpu_zonestats); |
|
zone->per_cpu_pageset = &boot_pageset; |
|
zone->per_cpu_zonestats = &boot_zonestats; |
|
} |
|
} |
|
|
|
#ifdef CONFIG_MEMORY_HOTREMOVE |
|
/* |
|
* All pages in the range must be in a single zone, must not contain holes, |
|
* must span full sections, and must be isolated before calling this function. |
|
*/ |
|
void __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) |
|
{ |
|
unsigned long pfn = start_pfn; |
|
struct page *page; |
|
struct zone *zone; |
|
unsigned int order; |
|
unsigned long flags; |
|
|
|
offline_mem_sections(pfn, end_pfn); |
|
zone = page_zone(pfn_to_page(pfn)); |
|
spin_lock_irqsave(&zone->lock, flags); |
|
while (pfn < end_pfn) { |
|
page = pfn_to_page(pfn); |
|
/* |
|
* The HWPoisoned page may be not in buddy system, and |
|
* page_count() is not 0. |
|
*/ |
|
if (unlikely(!PageBuddy(page) && PageHWPoison(page))) { |
|
pfn++; |
|
continue; |
|
} |
|
/* |
|
* At this point all remaining PageOffline() pages have a |
|
* reference count of 0 and can simply be skipped. |
|
*/ |
|
if (PageOffline(page)) { |
|
BUG_ON(page_count(page)); |
|
BUG_ON(PageBuddy(page)); |
|
pfn++; |
|
continue; |
|
} |
|
|
|
BUG_ON(page_count(page)); |
|
BUG_ON(!PageBuddy(page)); |
|
order = buddy_order(page); |
|
del_page_from_free_list(page, zone, order); |
|
pfn += (1 << order); |
|
} |
|
spin_unlock_irqrestore(&zone->lock, flags); |
|
} |
|
#endif |
|
|
|
bool is_free_buddy_page(struct page *page) |
|
{ |
|
struct zone *zone = page_zone(page); |
|
unsigned long pfn = page_to_pfn(page); |
|
unsigned long flags; |
|
unsigned int order; |
|
|
|
spin_lock_irqsave(&zone->lock, flags); |
|
for (order = 0; order < MAX_ORDER; order++) { |
|
struct page *page_head = page - (pfn & ((1 << order) - 1)); |
|
|
|
if (PageBuddy(page_head) && buddy_order(page_head) >= order) |
|
break; |
|
} |
|
spin_unlock_irqrestore(&zone->lock, flags); |
|
|
|
return order < MAX_ORDER; |
|
} |
|
|
|
#ifdef CONFIG_MEMORY_FAILURE |
|
/* |
|
* Break down a higher-order page in sub-pages, and keep our target out of |
|
* buddy allocator. |
|
*/ |
|
static void break_down_buddy_pages(struct zone *zone, struct page *page, |
|
struct page *target, int low, int high, |
|
int migratetype) |
|
{ |
|
unsigned long size = 1 << high; |
|
struct page *current_buddy, *next_page; |
|
|
|
while (high > low) { |
|
high--; |
|
size >>= 1; |
|
|
|
if (target >= &page[size]) { |
|
next_page = page + size; |
|
current_buddy = page; |
|
} else { |
|
next_page = page; |
|
current_buddy = page + size; |
|
} |
|
|
|
if (set_page_guard(zone, current_buddy, high, migratetype)) |
|
continue; |
|
|
|
if (current_buddy != target) { |
|
add_to_free_list(current_buddy, zone, high, migratetype); |
|
set_buddy_order(current_buddy, high); |
|
page = next_page; |
|
} |
|
} |
|
} |
|
|
|
/* |
|
* Take a page that will be marked as poisoned off the buddy allocator. |
|
*/ |
|
bool take_page_off_buddy(struct page *page) |
|
{ |
|
struct zone *zone = page_zone(page); |
|
unsigned long pfn = page_to_pfn(page); |
|
unsigned long flags; |
|
unsigned int order; |
|
bool ret = false; |
|
|
|
spin_lock_irqsave(&zone->lock, flags); |
|
for (order = 0; order < MAX_ORDER; order++) { |
|
struct page *page_head = page - (pfn & ((1 << order) - 1)); |
|
int page_order = buddy_order(page_head); |
|
|
|
if (PageBuddy(page_head) && page_order >= order) { |
|
unsigned long pfn_head = page_to_pfn(page_head); |
|
int migratetype = get_pfnblock_migratetype(page_head, |
|
pfn_head); |
|
|
|
del_page_from_free_list(page_head, zone, page_order); |
|
break_down_buddy_pages(zone, page_head, page, 0, |
|
page_order, migratetype); |
|
if (!is_migrate_isolate(migratetype)) |
|
__mod_zone_freepage_state(zone, -1, migratetype); |
|
ret = true; |
|
break; |
|
} |
|
if (page_count(page_head) > 0) |
|
break; |
|
} |
|
spin_unlock_irqrestore(&zone->lock, flags); |
|
return ret; |
|
} |
|
#endif
|
|
|