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7796 lines
200 KiB
7796 lines
200 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* memcontrol.c - Memory Controller |
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* |
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* Copyright IBM Corporation, 2007 |
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* Author Balbir Singh <[email protected]> |
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* |
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* Copyright 2007 OpenVZ SWsoft Inc |
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* Author: Pavel Emelianov <[email protected]> |
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* |
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* Memory thresholds |
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* Copyright (C) 2009 Nokia Corporation |
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* Author: Kirill A. Shutemov |
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* |
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* Kernel Memory Controller |
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* Copyright (C) 2012 Parallels Inc. and Google Inc. |
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* Authors: Glauber Costa and Suleiman Souhlal |
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* |
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* Native page reclaim |
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* Charge lifetime sanitation |
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* Lockless page tracking & accounting |
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* Unified hierarchy configuration model |
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* Copyright (C) 2015 Red Hat, Inc., Johannes Weiner |
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* |
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* Per memcg lru locking |
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* Copyright (C) 2020 Alibaba, Inc, Alex Shi |
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*/ |
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|
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#include <linux/page_counter.h> |
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#include <linux/memcontrol.h> |
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#include <linux/cgroup.h> |
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#include <linux/pagewalk.h> |
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#include <linux/sched/mm.h> |
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#include <linux/shmem_fs.h> |
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#include <linux/hugetlb.h> |
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#include <linux/pagemap.h> |
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#include <linux/vm_event_item.h> |
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#include <linux/smp.h> |
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#include <linux/page-flags.h> |
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#include <linux/backing-dev.h> |
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#include <linux/bit_spinlock.h> |
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#include <linux/rcupdate.h> |
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#include <linux/limits.h> |
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#include <linux/export.h> |
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#include <linux/mutex.h> |
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#include <linux/rbtree.h> |
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#include <linux/slab.h> |
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#include <linux/swap.h> |
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#include <linux/swapops.h> |
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#include <linux/spinlock.h> |
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#include <linux/eventfd.h> |
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#include <linux/poll.h> |
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#include <linux/sort.h> |
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#include <linux/fs.h> |
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#include <linux/seq_file.h> |
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#include <linux/vmpressure.h> |
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#include <linux/memremap.h> |
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#include <linux/mm_inline.h> |
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#include <linux/swap_cgroup.h> |
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#include <linux/cpu.h> |
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#include <linux/oom.h> |
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#include <linux/lockdep.h> |
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#include <linux/file.h> |
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#include <linux/resume_user_mode.h> |
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#include <linux/psi.h> |
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#include <linux/seq_buf.h> |
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#include "internal.h" |
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#include <net/sock.h> |
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#include <net/ip.h> |
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#include "slab.h" |
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#include "swap.h" |
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|
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#include <linux/uaccess.h> |
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|
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#include <trace/events/vmscan.h> |
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struct cgroup_subsys memory_cgrp_subsys __read_mostly; |
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EXPORT_SYMBOL(memory_cgrp_subsys); |
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struct mem_cgroup *root_mem_cgroup __read_mostly; |
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|
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/* Active memory cgroup to use from an interrupt context */ |
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DEFINE_PER_CPU(struct mem_cgroup *, int_active_memcg); |
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EXPORT_PER_CPU_SYMBOL_GPL(int_active_memcg); |
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|
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/* Socket memory accounting disabled? */ |
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static bool cgroup_memory_nosocket __ro_after_init; |
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|
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/* Kernel memory accounting disabled? */ |
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static bool cgroup_memory_nokmem __ro_after_init; |
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#ifdef CONFIG_CGROUP_WRITEBACK |
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static DECLARE_WAIT_QUEUE_HEAD(memcg_cgwb_frn_waitq); |
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#endif |
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|
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/* Whether legacy memory+swap accounting is active */ |
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static bool do_memsw_account(void) |
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{ |
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return !cgroup_subsys_on_dfl(memory_cgrp_subsys); |
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} |
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|
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#define THRESHOLDS_EVENTS_TARGET 128 |
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#define SOFTLIMIT_EVENTS_TARGET 1024 |
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|
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/* |
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* Cgroups above their limits are maintained in a RB-Tree, independent of |
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* their hierarchy representation |
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*/ |
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struct mem_cgroup_tree_per_node { |
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struct rb_root rb_root; |
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struct rb_node *rb_rightmost; |
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spinlock_t lock; |
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}; |
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struct mem_cgroup_tree { |
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struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES]; |
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}; |
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static struct mem_cgroup_tree soft_limit_tree __read_mostly; |
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|
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/* for OOM */ |
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struct mem_cgroup_eventfd_list { |
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struct list_head list; |
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struct eventfd_ctx *eventfd; |
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}; |
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|
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/* |
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* cgroup_event represents events which userspace want to receive. |
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*/ |
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struct mem_cgroup_event { |
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/* |
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* memcg which the event belongs to. |
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*/ |
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struct mem_cgroup *memcg; |
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/* |
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* eventfd to signal userspace about the event. |
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*/ |
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struct eventfd_ctx *eventfd; |
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/* |
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* Each of these stored in a list by the cgroup. |
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*/ |
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struct list_head list; |
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/* |
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* register_event() callback will be used to add new userspace |
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* waiter for changes related to this event. Use eventfd_signal() |
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* on eventfd to send notification to userspace. |
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*/ |
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int (*register_event)(struct mem_cgroup *memcg, |
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struct eventfd_ctx *eventfd, const char *args); |
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/* |
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* unregister_event() callback will be called when userspace closes |
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* the eventfd or on cgroup removing. This callback must be set, |
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* if you want provide notification functionality. |
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*/ |
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void (*unregister_event)(struct mem_cgroup *memcg, |
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struct eventfd_ctx *eventfd); |
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/* |
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* All fields below needed to unregister event when |
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* userspace closes eventfd. |
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*/ |
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poll_table pt; |
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wait_queue_head_t *wqh; |
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wait_queue_entry_t wait; |
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struct work_struct remove; |
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}; |
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static void mem_cgroup_threshold(struct mem_cgroup *memcg); |
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static void mem_cgroup_oom_notify(struct mem_cgroup *memcg); |
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|
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/* Stuffs for move charges at task migration. */ |
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/* |
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* Types of charges to be moved. |
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*/ |
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#define MOVE_ANON 0x1U |
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#define MOVE_FILE 0x2U |
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#define MOVE_MASK (MOVE_ANON | MOVE_FILE) |
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|
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/* "mc" and its members are protected by cgroup_mutex */ |
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static struct move_charge_struct { |
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spinlock_t lock; /* for from, to */ |
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struct mm_struct *mm; |
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struct mem_cgroup *from; |
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struct mem_cgroup *to; |
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unsigned long flags; |
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unsigned long precharge; |
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unsigned long moved_charge; |
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unsigned long moved_swap; |
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struct task_struct *moving_task; /* a task moving charges */ |
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wait_queue_head_t waitq; /* a waitq for other context */ |
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} mc = { |
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.lock = __SPIN_LOCK_UNLOCKED(mc.lock), |
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.waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq), |
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}; |
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/* |
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* Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft |
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* limit reclaim to prevent infinite loops, if they ever occur. |
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*/ |
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#define MEM_CGROUP_MAX_RECLAIM_LOOPS 100 |
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#define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2 |
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|
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/* for encoding cft->private value on file */ |
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enum res_type { |
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_MEM, |
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_MEMSWAP, |
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_KMEM, |
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_TCP, |
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}; |
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|
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#define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val)) |
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#define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff) |
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#define MEMFILE_ATTR(val) ((val) & 0xffff) |
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|
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/* |
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* Iteration constructs for visiting all cgroups (under a tree). If |
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* loops are exited prematurely (break), mem_cgroup_iter_break() must |
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* be used for reference counting. |
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*/ |
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#define for_each_mem_cgroup_tree(iter, root) \ |
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for (iter = mem_cgroup_iter(root, NULL, NULL); \ |
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iter != NULL; \ |
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iter = mem_cgroup_iter(root, iter, NULL)) |
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#define for_each_mem_cgroup(iter) \ |
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for (iter = mem_cgroup_iter(NULL, NULL, NULL); \ |
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iter != NULL; \ |
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iter = mem_cgroup_iter(NULL, iter, NULL)) |
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|
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static inline bool task_is_dying(void) |
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{ |
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return tsk_is_oom_victim(current) || fatal_signal_pending(current) || |
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(current->flags & PF_EXITING); |
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} |
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/* Some nice accessors for the vmpressure. */ |
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struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg) |
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{ |
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if (!memcg) |
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memcg = root_mem_cgroup; |
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return &memcg->vmpressure; |
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} |
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struct mem_cgroup *vmpressure_to_memcg(struct vmpressure *vmpr) |
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{ |
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return container_of(vmpr, struct mem_cgroup, vmpressure); |
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} |
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#ifdef CONFIG_MEMCG_KMEM |
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static DEFINE_SPINLOCK(objcg_lock); |
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|
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bool mem_cgroup_kmem_disabled(void) |
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{ |
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return cgroup_memory_nokmem; |
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} |
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static void obj_cgroup_uncharge_pages(struct obj_cgroup *objcg, |
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unsigned int nr_pages); |
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static void obj_cgroup_release(struct percpu_ref *ref) |
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{ |
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struct obj_cgroup *objcg = container_of(ref, struct obj_cgroup, refcnt); |
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unsigned int nr_bytes; |
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unsigned int nr_pages; |
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unsigned long flags; |
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/* |
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* At this point all allocated objects are freed, and |
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* objcg->nr_charged_bytes can't have an arbitrary byte value. |
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* However, it can be PAGE_SIZE or (x * PAGE_SIZE). |
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* |
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* The following sequence can lead to it: |
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* 1) CPU0: objcg == stock->cached_objcg |
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* 2) CPU1: we do a small allocation (e.g. 92 bytes), |
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* PAGE_SIZE bytes are charged |
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* 3) CPU1: a process from another memcg is allocating something, |
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* the stock if flushed, |
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* objcg->nr_charged_bytes = PAGE_SIZE - 92 |
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* 5) CPU0: we do release this object, |
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* 92 bytes are added to stock->nr_bytes |
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* 6) CPU0: stock is flushed, |
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* 92 bytes are added to objcg->nr_charged_bytes |
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* |
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* In the result, nr_charged_bytes == PAGE_SIZE. |
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* This page will be uncharged in obj_cgroup_release(). |
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*/ |
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nr_bytes = atomic_read(&objcg->nr_charged_bytes); |
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WARN_ON_ONCE(nr_bytes & (PAGE_SIZE - 1)); |
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nr_pages = nr_bytes >> PAGE_SHIFT; |
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if (nr_pages) |
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obj_cgroup_uncharge_pages(objcg, nr_pages); |
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spin_lock_irqsave(&objcg_lock, flags); |
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list_del(&objcg->list); |
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spin_unlock_irqrestore(&objcg_lock, flags); |
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percpu_ref_exit(ref); |
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kfree_rcu(objcg, rcu); |
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} |
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static struct obj_cgroup *obj_cgroup_alloc(void) |
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{ |
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struct obj_cgroup *objcg; |
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int ret; |
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objcg = kzalloc(sizeof(struct obj_cgroup), GFP_KERNEL); |
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if (!objcg) |
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return NULL; |
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ret = percpu_ref_init(&objcg->refcnt, obj_cgroup_release, 0, |
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GFP_KERNEL); |
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if (ret) { |
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kfree(objcg); |
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return NULL; |
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} |
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INIT_LIST_HEAD(&objcg->list); |
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return objcg; |
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} |
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static void memcg_reparent_objcgs(struct mem_cgroup *memcg, |
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struct mem_cgroup *parent) |
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{ |
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struct obj_cgroup *objcg, *iter; |
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objcg = rcu_replace_pointer(memcg->objcg, NULL, true); |
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spin_lock_irq(&objcg_lock); |
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/* 1) Ready to reparent active objcg. */ |
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list_add(&objcg->list, &memcg->objcg_list); |
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/* 2) Reparent active objcg and already reparented objcgs to parent. */ |
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list_for_each_entry(iter, &memcg->objcg_list, list) |
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WRITE_ONCE(iter->memcg, parent); |
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/* 3) Move already reparented objcgs to the parent's list */ |
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list_splice(&memcg->objcg_list, &parent->objcg_list); |
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spin_unlock_irq(&objcg_lock); |
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percpu_ref_kill(&objcg->refcnt); |
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} |
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/* |
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* A lot of the calls to the cache allocation functions are expected to be |
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* inlined by the compiler. Since the calls to memcg_slab_pre_alloc_hook() are |
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* conditional to this static branch, we'll have to allow modules that does |
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* kmem_cache_alloc and the such to see this symbol as well |
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*/ |
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DEFINE_STATIC_KEY_FALSE(memcg_kmem_enabled_key); |
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EXPORT_SYMBOL(memcg_kmem_enabled_key); |
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#endif |
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|
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/** |
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* mem_cgroup_css_from_page - css of the memcg associated with a page |
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* @page: page of interest |
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* |
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* If memcg is bound to the default hierarchy, css of the memcg associated |
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* with @page is returned. The returned css remains associated with @page |
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* until it is released. |
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* |
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* If memcg is bound to a traditional hierarchy, the css of root_mem_cgroup |
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* is returned. |
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*/ |
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struct cgroup_subsys_state *mem_cgroup_css_from_page(struct page *page) |
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{ |
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struct mem_cgroup *memcg; |
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|
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memcg = page_memcg(page); |
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|
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if (!memcg || !cgroup_subsys_on_dfl(memory_cgrp_subsys)) |
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memcg = root_mem_cgroup; |
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|
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return &memcg->css; |
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} |
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|
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/** |
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* page_cgroup_ino - return inode number of the memcg a page is charged to |
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* @page: the page |
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* |
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* Look up the closest online ancestor of the memory cgroup @page is charged to |
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* and return its inode number or 0 if @page is not charged to any cgroup. It |
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* is safe to call this function without holding a reference to @page. |
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* |
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* Note, this function is inherently racy, because there is nothing to prevent |
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* the cgroup inode from getting torn down and potentially reallocated a moment |
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* after page_cgroup_ino() returns, so it only should be used by callers that |
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* do not care (such as procfs interfaces). |
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*/ |
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ino_t page_cgroup_ino(struct page *page) |
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{ |
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struct mem_cgroup *memcg; |
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unsigned long ino = 0; |
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|
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rcu_read_lock(); |
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memcg = page_memcg_check(page); |
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|
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while (memcg && !(memcg->css.flags & CSS_ONLINE)) |
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memcg = parent_mem_cgroup(memcg); |
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if (memcg) |
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ino = cgroup_ino(memcg->css.cgroup); |
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rcu_read_unlock(); |
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return ino; |
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} |
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|
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static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_node *mz, |
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struct mem_cgroup_tree_per_node *mctz, |
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unsigned long new_usage_in_excess) |
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{ |
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struct rb_node **p = &mctz->rb_root.rb_node; |
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struct rb_node *parent = NULL; |
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struct mem_cgroup_per_node *mz_node; |
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bool rightmost = true; |
|
|
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if (mz->on_tree) |
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return; |
|
|
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mz->usage_in_excess = new_usage_in_excess; |
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if (!mz->usage_in_excess) |
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return; |
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while (*p) { |
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parent = *p; |
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mz_node = rb_entry(parent, struct mem_cgroup_per_node, |
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tree_node); |
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if (mz->usage_in_excess < mz_node->usage_in_excess) { |
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p = &(*p)->rb_left; |
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rightmost = false; |
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} else { |
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p = &(*p)->rb_right; |
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} |
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} |
|
|
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if (rightmost) |
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mctz->rb_rightmost = &mz->tree_node; |
|
|
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rb_link_node(&mz->tree_node, parent, p); |
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rb_insert_color(&mz->tree_node, &mctz->rb_root); |
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mz->on_tree = true; |
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} |
|
|
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static void __mem_cgroup_remove_exceeded(struct mem_cgroup_per_node *mz, |
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struct mem_cgroup_tree_per_node *mctz) |
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{ |
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if (!mz->on_tree) |
|
return; |
|
|
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if (&mz->tree_node == mctz->rb_rightmost) |
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mctz->rb_rightmost = rb_prev(&mz->tree_node); |
|
|
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rb_erase(&mz->tree_node, &mctz->rb_root); |
|
mz->on_tree = false; |
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} |
|
|
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static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_node *mz, |
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struct mem_cgroup_tree_per_node *mctz) |
|
{ |
|
unsigned long flags; |
|
|
|
spin_lock_irqsave(&mctz->lock, flags); |
|
__mem_cgroup_remove_exceeded(mz, mctz); |
|
spin_unlock_irqrestore(&mctz->lock, flags); |
|
} |
|
|
|
static unsigned long soft_limit_excess(struct mem_cgroup *memcg) |
|
{ |
|
unsigned long nr_pages = page_counter_read(&memcg->memory); |
|
unsigned long soft_limit = READ_ONCE(memcg->soft_limit); |
|
unsigned long excess = 0; |
|
|
|
if (nr_pages > soft_limit) |
|
excess = nr_pages - soft_limit; |
|
|
|
return excess; |
|
} |
|
|
|
static void mem_cgroup_update_tree(struct mem_cgroup *memcg, int nid) |
|
{ |
|
unsigned long excess; |
|
struct mem_cgroup_per_node *mz; |
|
struct mem_cgroup_tree_per_node *mctz; |
|
|
|
mctz = soft_limit_tree.rb_tree_per_node[nid]; |
|
if (!mctz) |
|
return; |
|
/* |
|
* Necessary to update all ancestors when hierarchy is used. |
|
* because their event counter is not touched. |
|
*/ |
|
for (; memcg; memcg = parent_mem_cgroup(memcg)) { |
|
mz = memcg->nodeinfo[nid]; |
|
excess = soft_limit_excess(memcg); |
|
/* |
|
* We have to update the tree if mz is on RB-tree or |
|
* mem is over its softlimit. |
|
*/ |
|
if (excess || mz->on_tree) { |
|
unsigned long flags; |
|
|
|
spin_lock_irqsave(&mctz->lock, flags); |
|
/* if on-tree, remove it */ |
|
if (mz->on_tree) |
|
__mem_cgroup_remove_exceeded(mz, mctz); |
|
/* |
|
* Insert again. mz->usage_in_excess will be updated. |
|
* If excess is 0, no tree ops. |
|
*/ |
|
__mem_cgroup_insert_exceeded(mz, mctz, excess); |
|
spin_unlock_irqrestore(&mctz->lock, flags); |
|
} |
|
} |
|
} |
|
|
|
static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg) |
|
{ |
|
struct mem_cgroup_tree_per_node *mctz; |
|
struct mem_cgroup_per_node *mz; |
|
int nid; |
|
|
|
for_each_node(nid) { |
|
mz = memcg->nodeinfo[nid]; |
|
mctz = soft_limit_tree.rb_tree_per_node[nid]; |
|
if (mctz) |
|
mem_cgroup_remove_exceeded(mz, mctz); |
|
} |
|
} |
|
|
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static struct mem_cgroup_per_node * |
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__mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_node *mctz) |
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{ |
|
struct mem_cgroup_per_node *mz; |
|
|
|
retry: |
|
mz = NULL; |
|
if (!mctz->rb_rightmost) |
|
goto done; /* Nothing to reclaim from */ |
|
|
|
mz = rb_entry(mctz->rb_rightmost, |
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struct mem_cgroup_per_node, tree_node); |
|
/* |
|
* Remove the node now but someone else can add it back, |
|
* we will to add it back at the end of reclaim to its correct |
|
* position in the tree. |
|
*/ |
|
__mem_cgroup_remove_exceeded(mz, mctz); |
|
if (!soft_limit_excess(mz->memcg) || |
|
!css_tryget(&mz->memcg->css)) |
|
goto retry; |
|
done: |
|
return mz; |
|
} |
|
|
|
static struct mem_cgroup_per_node * |
|
mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_node *mctz) |
|
{ |
|
struct mem_cgroup_per_node *mz; |
|
|
|
spin_lock_irq(&mctz->lock); |
|
mz = __mem_cgroup_largest_soft_limit_node(mctz); |
|
spin_unlock_irq(&mctz->lock); |
|
return mz; |
|
} |
|
|
|
/* |
|
* memcg and lruvec stats flushing |
|
* |
|
* Many codepaths leading to stats update or read are performance sensitive and |
|
* adding stats flushing in such codepaths is not desirable. So, to optimize the |
|
* flushing the kernel does: |
|
* |
|
* 1) Periodically and asynchronously flush the stats every 2 seconds to not let |
|
* rstat update tree grow unbounded. |
|
* |
|
* 2) Flush the stats synchronously on reader side only when there are more than |
|
* (MEMCG_CHARGE_BATCH * nr_cpus) update events. Though this optimization |
|
* will let stats be out of sync by atmost (MEMCG_CHARGE_BATCH * nr_cpus) but |
|
* only for 2 seconds due to (1). |
|
*/ |
|
static void flush_memcg_stats_dwork(struct work_struct *w); |
|
static DECLARE_DEFERRABLE_WORK(stats_flush_dwork, flush_memcg_stats_dwork); |
|
static DEFINE_SPINLOCK(stats_flush_lock); |
|
static DEFINE_PER_CPU(unsigned int, stats_updates); |
|
static atomic_t stats_flush_threshold = ATOMIC_INIT(0); |
|
static u64 flush_next_time; |
|
|
|
#define FLUSH_TIME (2UL*HZ) |
|
|
|
/* |
|
* Accessors to ensure that preemption is disabled on PREEMPT_RT because it can |
|
* not rely on this as part of an acquired spinlock_t lock. These functions are |
|
* never used in hardirq context on PREEMPT_RT and therefore disabling preemtion |
|
* is sufficient. |
|
*/ |
|
static void memcg_stats_lock(void) |
|
{ |
|
preempt_disable_nested(); |
|
VM_WARN_ON_IRQS_ENABLED(); |
|
} |
|
|
|
static void __memcg_stats_lock(void) |
|
{ |
|
preempt_disable_nested(); |
|
} |
|
|
|
static void memcg_stats_unlock(void) |
|
{ |
|
preempt_enable_nested(); |
|
} |
|
|
|
static inline void memcg_rstat_updated(struct mem_cgroup *memcg, int val) |
|
{ |
|
unsigned int x; |
|
|
|
cgroup_rstat_updated(memcg->css.cgroup, smp_processor_id()); |
|
|
|
x = __this_cpu_add_return(stats_updates, abs(val)); |
|
if (x > MEMCG_CHARGE_BATCH) { |
|
/* |
|
* If stats_flush_threshold exceeds the threshold |
|
* (>num_online_cpus()), cgroup stats update will be triggered |
|
* in __mem_cgroup_flush_stats(). Increasing this var further |
|
* is redundant and simply adds overhead in atomic update. |
|
*/ |
|
if (atomic_read(&stats_flush_threshold) <= num_online_cpus()) |
|
atomic_add(x / MEMCG_CHARGE_BATCH, &stats_flush_threshold); |
|
__this_cpu_write(stats_updates, 0); |
|
} |
|
} |
|
|
|
static void __mem_cgroup_flush_stats(void) |
|
{ |
|
unsigned long flag; |
|
|
|
if (!spin_trylock_irqsave(&stats_flush_lock, flag)) |
|
return; |
|
|
|
flush_next_time = jiffies_64 + 2*FLUSH_TIME; |
|
cgroup_rstat_flush_irqsafe(root_mem_cgroup->css.cgroup); |
|
atomic_set(&stats_flush_threshold, 0); |
|
spin_unlock_irqrestore(&stats_flush_lock, flag); |
|
} |
|
|
|
void mem_cgroup_flush_stats(void) |
|
{ |
|
if (atomic_read(&stats_flush_threshold) > num_online_cpus()) |
|
__mem_cgroup_flush_stats(); |
|
} |
|
|
|
void mem_cgroup_flush_stats_delayed(void) |
|
{ |
|
if (time_after64(jiffies_64, flush_next_time)) |
|
mem_cgroup_flush_stats(); |
|
} |
|
|
|
static void flush_memcg_stats_dwork(struct work_struct *w) |
|
{ |
|
__mem_cgroup_flush_stats(); |
|
queue_delayed_work(system_unbound_wq, &stats_flush_dwork, FLUSH_TIME); |
|
} |
|
|
|
/* Subset of vm_event_item to report for memcg event stats */ |
|
static const unsigned int memcg_vm_event_stat[] = { |
|
PGPGIN, |
|
PGPGOUT, |
|
PGSCAN_KSWAPD, |
|
PGSCAN_DIRECT, |
|
PGSTEAL_KSWAPD, |
|
PGSTEAL_DIRECT, |
|
PGFAULT, |
|
PGMAJFAULT, |
|
PGREFILL, |
|
PGACTIVATE, |
|
PGDEACTIVATE, |
|
PGLAZYFREE, |
|
PGLAZYFREED, |
|
#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP) |
|
ZSWPIN, |
|
ZSWPOUT, |
|
#endif |
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE |
|
THP_FAULT_ALLOC, |
|
THP_COLLAPSE_ALLOC, |
|
#endif |
|
}; |
|
|
|
#define NR_MEMCG_EVENTS ARRAY_SIZE(memcg_vm_event_stat) |
|
static int mem_cgroup_events_index[NR_VM_EVENT_ITEMS] __read_mostly; |
|
|
|
static void init_memcg_events(void) |
|
{ |
|
int i; |
|
|
|
for (i = 0; i < NR_MEMCG_EVENTS; ++i) |
|
mem_cgroup_events_index[memcg_vm_event_stat[i]] = i + 1; |
|
} |
|
|
|
static inline int memcg_events_index(enum vm_event_item idx) |
|
{ |
|
return mem_cgroup_events_index[idx] - 1; |
|
} |
|
|
|
struct memcg_vmstats_percpu { |
|
/* Local (CPU and cgroup) page state & events */ |
|
long state[MEMCG_NR_STAT]; |
|
unsigned long events[NR_MEMCG_EVENTS]; |
|
|
|
/* Delta calculation for lockless upward propagation */ |
|
long state_prev[MEMCG_NR_STAT]; |
|
unsigned long events_prev[NR_MEMCG_EVENTS]; |
|
|
|
/* Cgroup1: threshold notifications & softlimit tree updates */ |
|
unsigned long nr_page_events; |
|
unsigned long targets[MEM_CGROUP_NTARGETS]; |
|
}; |
|
|
|
struct memcg_vmstats { |
|
/* Aggregated (CPU and subtree) page state & events */ |
|
long state[MEMCG_NR_STAT]; |
|
unsigned long events[NR_MEMCG_EVENTS]; |
|
|
|
/* Pending child counts during tree propagation */ |
|
long state_pending[MEMCG_NR_STAT]; |
|
unsigned long events_pending[NR_MEMCG_EVENTS]; |
|
}; |
|
|
|
unsigned long memcg_page_state(struct mem_cgroup *memcg, int idx) |
|
{ |
|
long x = READ_ONCE(memcg->vmstats->state[idx]); |
|
#ifdef CONFIG_SMP |
|
if (x < 0) |
|
x = 0; |
|
#endif |
|
return x; |
|
} |
|
|
|
/** |
|
* __mod_memcg_state - update cgroup memory statistics |
|
* @memcg: the memory cgroup |
|
* @idx: the stat item - can be enum memcg_stat_item or enum node_stat_item |
|
* @val: delta to add to the counter, can be negative |
|
*/ |
|
void __mod_memcg_state(struct mem_cgroup *memcg, int idx, int val) |
|
{ |
|
if (mem_cgroup_disabled()) |
|
return; |
|
|
|
__this_cpu_add(memcg->vmstats_percpu->state[idx], val); |
|
memcg_rstat_updated(memcg, val); |
|
} |
|
|
|
/* idx can be of type enum memcg_stat_item or node_stat_item. */ |
|
static unsigned long memcg_page_state_local(struct mem_cgroup *memcg, int idx) |
|
{ |
|
long x = 0; |
|
int cpu; |
|
|
|
for_each_possible_cpu(cpu) |
|
x += per_cpu(memcg->vmstats_percpu->state[idx], cpu); |
|
#ifdef CONFIG_SMP |
|
if (x < 0) |
|
x = 0; |
|
#endif |
|
return x; |
|
} |
|
|
|
void __mod_memcg_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx, |
|
int val) |
|
{ |
|
struct mem_cgroup_per_node *pn; |
|
struct mem_cgroup *memcg; |
|
|
|
pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec); |
|
memcg = pn->memcg; |
|
|
|
/* |
|
* The caller from rmap relay on disabled preemption becase they never |
|
* update their counter from in-interrupt context. For these two |
|
* counters we check that the update is never performed from an |
|
* interrupt context while other caller need to have disabled interrupt. |
|
*/ |
|
__memcg_stats_lock(); |
|
if (IS_ENABLED(CONFIG_DEBUG_VM)) { |
|
switch (idx) { |
|
case NR_ANON_MAPPED: |
|
case NR_FILE_MAPPED: |
|
case NR_ANON_THPS: |
|
case NR_SHMEM_PMDMAPPED: |
|
case NR_FILE_PMDMAPPED: |
|
WARN_ON_ONCE(!in_task()); |
|
break; |
|
default: |
|
VM_WARN_ON_IRQS_ENABLED(); |
|
} |
|
} |
|
|
|
/* Update memcg */ |
|
__this_cpu_add(memcg->vmstats_percpu->state[idx], val); |
|
|
|
/* Update lruvec */ |
|
__this_cpu_add(pn->lruvec_stats_percpu->state[idx], val); |
|
|
|
memcg_rstat_updated(memcg, val); |
|
memcg_stats_unlock(); |
|
} |
|
|
|
/** |
|
* __mod_lruvec_state - update lruvec memory statistics |
|
* @lruvec: the lruvec |
|
* @idx: the stat item |
|
* @val: delta to add to the counter, can be negative |
|
* |
|
* The lruvec is the intersection of the NUMA node and a cgroup. This |
|
* function updates the all three counters that are affected by a |
|
* change of state at this level: per-node, per-cgroup, per-lruvec. |
|
*/ |
|
void __mod_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx, |
|
int val) |
|
{ |
|
/* Update node */ |
|
__mod_node_page_state(lruvec_pgdat(lruvec), idx, val); |
|
|
|
/* Update memcg and lruvec */ |
|
if (!mem_cgroup_disabled()) |
|
__mod_memcg_lruvec_state(lruvec, idx, val); |
|
} |
|
|
|
void __mod_lruvec_page_state(struct page *page, enum node_stat_item idx, |
|
int val) |
|
{ |
|
struct page *head = compound_head(page); /* rmap on tail pages */ |
|
struct mem_cgroup *memcg; |
|
pg_data_t *pgdat = page_pgdat(page); |
|
struct lruvec *lruvec; |
|
|
|
rcu_read_lock(); |
|
memcg = page_memcg(head); |
|
/* Untracked pages have no memcg, no lruvec. Update only the node */ |
|
if (!memcg) { |
|
rcu_read_unlock(); |
|
__mod_node_page_state(pgdat, idx, val); |
|
return; |
|
} |
|
|
|
lruvec = mem_cgroup_lruvec(memcg, pgdat); |
|
__mod_lruvec_state(lruvec, idx, val); |
|
rcu_read_unlock(); |
|
} |
|
EXPORT_SYMBOL(__mod_lruvec_page_state); |
|
|
|
void __mod_lruvec_kmem_state(void *p, enum node_stat_item idx, int val) |
|
{ |
|
pg_data_t *pgdat = page_pgdat(virt_to_page(p)); |
|
struct mem_cgroup *memcg; |
|
struct lruvec *lruvec; |
|
|
|
rcu_read_lock(); |
|
memcg = mem_cgroup_from_slab_obj(p); |
|
|
|
/* |
|
* Untracked pages have no memcg, no lruvec. Update only the |
|
* node. If we reparent the slab objects to the root memcg, |
|
* when we free the slab object, we need to update the per-memcg |
|
* vmstats to keep it correct for the root memcg. |
|
*/ |
|
if (!memcg) { |
|
__mod_node_page_state(pgdat, idx, val); |
|
} else { |
|
lruvec = mem_cgroup_lruvec(memcg, pgdat); |
|
__mod_lruvec_state(lruvec, idx, val); |
|
} |
|
rcu_read_unlock(); |
|
} |
|
|
|
/** |
|
* __count_memcg_events - account VM events in a cgroup |
|
* @memcg: the memory cgroup |
|
* @idx: the event item |
|
* @count: the number of events that occurred |
|
*/ |
|
void __count_memcg_events(struct mem_cgroup *memcg, enum vm_event_item idx, |
|
unsigned long count) |
|
{ |
|
int index = memcg_events_index(idx); |
|
|
|
if (mem_cgroup_disabled() || index < 0) |
|
return; |
|
|
|
memcg_stats_lock(); |
|
__this_cpu_add(memcg->vmstats_percpu->events[index], count); |
|
memcg_rstat_updated(memcg, count); |
|
memcg_stats_unlock(); |
|
} |
|
|
|
static unsigned long memcg_events(struct mem_cgroup *memcg, int event) |
|
{ |
|
int index = memcg_events_index(event); |
|
|
|
if (index < 0) |
|
return 0; |
|
return READ_ONCE(memcg->vmstats->events[index]); |
|
} |
|
|
|
static unsigned long memcg_events_local(struct mem_cgroup *memcg, int event) |
|
{ |
|
long x = 0; |
|
int cpu; |
|
int index = memcg_events_index(event); |
|
|
|
if (index < 0) |
|
return 0; |
|
|
|
for_each_possible_cpu(cpu) |
|
x += per_cpu(memcg->vmstats_percpu->events[index], cpu); |
|
return x; |
|
} |
|
|
|
static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, |
|
int nr_pages) |
|
{ |
|
/* pagein of a big page is an event. So, ignore page size */ |
|
if (nr_pages > 0) |
|
__count_memcg_events(memcg, PGPGIN, 1); |
|
else { |
|
__count_memcg_events(memcg, PGPGOUT, 1); |
|
nr_pages = -nr_pages; /* for event */ |
|
} |
|
|
|
__this_cpu_add(memcg->vmstats_percpu->nr_page_events, nr_pages); |
|
} |
|
|
|
static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg, |
|
enum mem_cgroup_events_target target) |
|
{ |
|
unsigned long val, next; |
|
|
|
val = __this_cpu_read(memcg->vmstats_percpu->nr_page_events); |
|
next = __this_cpu_read(memcg->vmstats_percpu->targets[target]); |
|
/* from time_after() in jiffies.h */ |
|
if ((long)(next - val) < 0) { |
|
switch (target) { |
|
case MEM_CGROUP_TARGET_THRESH: |
|
next = val + THRESHOLDS_EVENTS_TARGET; |
|
break; |
|
case MEM_CGROUP_TARGET_SOFTLIMIT: |
|
next = val + SOFTLIMIT_EVENTS_TARGET; |
|
break; |
|
default: |
|
break; |
|
} |
|
__this_cpu_write(memcg->vmstats_percpu->targets[target], next); |
|
return true; |
|
} |
|
return false; |
|
} |
|
|
|
/* |
|
* Check events in order. |
|
* |
|
*/ |
|
static void memcg_check_events(struct mem_cgroup *memcg, int nid) |
|
{ |
|
if (IS_ENABLED(CONFIG_PREEMPT_RT)) |
|
return; |
|
|
|
/* threshold event is triggered in finer grain than soft limit */ |
|
if (unlikely(mem_cgroup_event_ratelimit(memcg, |
|
MEM_CGROUP_TARGET_THRESH))) { |
|
bool do_softlimit; |
|
|
|
do_softlimit = mem_cgroup_event_ratelimit(memcg, |
|
MEM_CGROUP_TARGET_SOFTLIMIT); |
|
mem_cgroup_threshold(memcg); |
|
if (unlikely(do_softlimit)) |
|
mem_cgroup_update_tree(memcg, nid); |
|
} |
|
} |
|
|
|
struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) |
|
{ |
|
/* |
|
* mm_update_next_owner() may clear mm->owner to NULL |
|
* if it races with swapoff, page migration, etc. |
|
* So this can be called with p == NULL. |
|
*/ |
|
if (unlikely(!p)) |
|
return NULL; |
|
|
|
return mem_cgroup_from_css(task_css(p, memory_cgrp_id)); |
|
} |
|
EXPORT_SYMBOL(mem_cgroup_from_task); |
|
|
|
static __always_inline struct mem_cgroup *active_memcg(void) |
|
{ |
|
if (!in_task()) |
|
return this_cpu_read(int_active_memcg); |
|
else |
|
return current->active_memcg; |
|
} |
|
|
|
/** |
|
* get_mem_cgroup_from_mm: Obtain a reference on given mm_struct's memcg. |
|
* @mm: mm from which memcg should be extracted. It can be NULL. |
|
* |
|
* Obtain a reference on mm->memcg and returns it if successful. If mm |
|
* is NULL, then the memcg is chosen as follows: |
|
* 1) The active memcg, if set. |
|
* 2) current->mm->memcg, if available |
|
* 3) root memcg |
|
* If mem_cgroup is disabled, NULL is returned. |
|
*/ |
|
struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm) |
|
{ |
|
struct mem_cgroup *memcg; |
|
|
|
if (mem_cgroup_disabled()) |
|
return NULL; |
|
|
|
/* |
|
* Page cache insertions can happen without an |
|
* actual mm context, e.g. during disk probing |
|
* on boot, loopback IO, acct() writes etc. |
|
* |
|
* No need to css_get on root memcg as the reference |
|
* counting is disabled on the root level in the |
|
* cgroup core. See CSS_NO_REF. |
|
*/ |
|
if (unlikely(!mm)) { |
|
memcg = active_memcg(); |
|
if (unlikely(memcg)) { |
|
/* remote memcg must hold a ref */ |
|
css_get(&memcg->css); |
|
return memcg; |
|
} |
|
mm = current->mm; |
|
if (unlikely(!mm)) |
|
return root_mem_cgroup; |
|
} |
|
|
|
rcu_read_lock(); |
|
do { |
|
memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); |
|
if (unlikely(!memcg)) |
|
memcg = root_mem_cgroup; |
|
} while (!css_tryget(&memcg->css)); |
|
rcu_read_unlock(); |
|
return memcg; |
|
} |
|
EXPORT_SYMBOL(get_mem_cgroup_from_mm); |
|
|
|
static __always_inline bool memcg_kmem_bypass(void) |
|
{ |
|
/* Allow remote memcg charging from any context. */ |
|
if (unlikely(active_memcg())) |
|
return false; |
|
|
|
/* Memcg to charge can't be determined. */ |
|
if (!in_task() || !current->mm || (current->flags & PF_KTHREAD)) |
|
return true; |
|
|
|
return false; |
|
} |
|
|
|
/** |
|
* mem_cgroup_iter - iterate over memory cgroup hierarchy |
|
* @root: hierarchy root |
|
* @prev: previously returned memcg, NULL on first invocation |
|
* @reclaim: cookie for shared reclaim walks, NULL for full walks |
|
* |
|
* Returns references to children of the hierarchy below @root, or |
|
* @root itself, or %NULL after a full round-trip. |
|
* |
|
* Caller must pass the return value in @prev on subsequent |
|
* invocations for reference counting, or use mem_cgroup_iter_break() |
|
* to cancel a hierarchy walk before the round-trip is complete. |
|
* |
|
* Reclaimers can specify a node in @reclaim to divide up the memcgs |
|
* in the hierarchy among all concurrent reclaimers operating on the |
|
* same node. |
|
*/ |
|
struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, |
|
struct mem_cgroup *prev, |
|
struct mem_cgroup_reclaim_cookie *reclaim) |
|
{ |
|
struct mem_cgroup_reclaim_iter *iter; |
|
struct cgroup_subsys_state *css = NULL; |
|
struct mem_cgroup *memcg = NULL; |
|
struct mem_cgroup *pos = NULL; |
|
|
|
if (mem_cgroup_disabled()) |
|
return NULL; |
|
|
|
if (!root) |
|
root = root_mem_cgroup; |
|
|
|
rcu_read_lock(); |
|
|
|
if (reclaim) { |
|
struct mem_cgroup_per_node *mz; |
|
|
|
mz = root->nodeinfo[reclaim->pgdat->node_id]; |
|
iter = &mz->iter; |
|
|
|
/* |
|
* On start, join the current reclaim iteration cycle. |
|
* Exit when a concurrent walker completes it. |
|
*/ |
|
if (!prev) |
|
reclaim->generation = iter->generation; |
|
else if (reclaim->generation != iter->generation) |
|
goto out_unlock; |
|
|
|
while (1) { |
|
pos = READ_ONCE(iter->position); |
|
if (!pos || css_tryget(&pos->css)) |
|
break; |
|
/* |
|
* css reference reached zero, so iter->position will |
|
* be cleared by ->css_released. However, we should not |
|
* rely on this happening soon, because ->css_released |
|
* is called from a work queue, and by busy-waiting we |
|
* might block it. So we clear iter->position right |
|
* away. |
|
*/ |
|
(void)cmpxchg(&iter->position, pos, NULL); |
|
} |
|
} else if (prev) { |
|
pos = prev; |
|
} |
|
|
|
if (pos) |
|
css = &pos->css; |
|
|
|
for (;;) { |
|
css = css_next_descendant_pre(css, &root->css); |
|
if (!css) { |
|
/* |
|
* Reclaimers share the hierarchy walk, and a |
|
* new one might jump in right at the end of |
|
* the hierarchy - make sure they see at least |
|
* one group and restart from the beginning. |
|
*/ |
|
if (!prev) |
|
continue; |
|
break; |
|
} |
|
|
|
/* |
|
* Verify the css and acquire a reference. The root |
|
* is provided by the caller, so we know it's alive |
|
* and kicking, and don't take an extra reference. |
|
*/ |
|
if (css == &root->css || css_tryget(css)) { |
|
memcg = mem_cgroup_from_css(css); |
|
break; |
|
} |
|
} |
|
|
|
if (reclaim) { |
|
/* |
|
* The position could have already been updated by a competing |
|
* thread, so check that the value hasn't changed since we read |
|
* it to avoid reclaiming from the same cgroup twice. |
|
*/ |
|
(void)cmpxchg(&iter->position, pos, memcg); |
|
|
|
if (pos) |
|
css_put(&pos->css); |
|
|
|
if (!memcg) |
|
iter->generation++; |
|
} |
|
|
|
out_unlock: |
|
rcu_read_unlock(); |
|
if (prev && prev != root) |
|
css_put(&prev->css); |
|
|
|
return memcg; |
|
} |
|
|
|
/** |
|
* mem_cgroup_iter_break - abort a hierarchy walk prematurely |
|
* @root: hierarchy root |
|
* @prev: last visited hierarchy member as returned by mem_cgroup_iter() |
|
*/ |
|
void mem_cgroup_iter_break(struct mem_cgroup *root, |
|
struct mem_cgroup *prev) |
|
{ |
|
if (!root) |
|
root = root_mem_cgroup; |
|
if (prev && prev != root) |
|
css_put(&prev->css); |
|
} |
|
|
|
static void __invalidate_reclaim_iterators(struct mem_cgroup *from, |
|
struct mem_cgroup *dead_memcg) |
|
{ |
|
struct mem_cgroup_reclaim_iter *iter; |
|
struct mem_cgroup_per_node *mz; |
|
int nid; |
|
|
|
for_each_node(nid) { |
|
mz = from->nodeinfo[nid]; |
|
iter = &mz->iter; |
|
cmpxchg(&iter->position, dead_memcg, NULL); |
|
} |
|
} |
|
|
|
static void invalidate_reclaim_iterators(struct mem_cgroup *dead_memcg) |
|
{ |
|
struct mem_cgroup *memcg = dead_memcg; |
|
struct mem_cgroup *last; |
|
|
|
do { |
|
__invalidate_reclaim_iterators(memcg, dead_memcg); |
|
last = memcg; |
|
} while ((memcg = parent_mem_cgroup(memcg))); |
|
|
|
/* |
|
* When cgroup1 non-hierarchy mode is used, |
|
* parent_mem_cgroup() does not walk all the way up to the |
|
* cgroup root (root_mem_cgroup). So we have to handle |
|
* dead_memcg from cgroup root separately. |
|
*/ |
|
if (last != root_mem_cgroup) |
|
__invalidate_reclaim_iterators(root_mem_cgroup, |
|
dead_memcg); |
|
} |
|
|
|
/** |
|
* mem_cgroup_scan_tasks - iterate over tasks of a memory cgroup hierarchy |
|
* @memcg: hierarchy root |
|
* @fn: function to call for each task |
|
* @arg: argument passed to @fn |
|
* |
|
* This function iterates over tasks attached to @memcg or to any of its |
|
* descendants and calls @fn for each task. If @fn returns a non-zero |
|
* value, the function breaks the iteration loop and returns the value. |
|
* Otherwise, it will iterate over all tasks and return 0. |
|
* |
|
* This function must not be called for the root memory cgroup. |
|
*/ |
|
int mem_cgroup_scan_tasks(struct mem_cgroup *memcg, |
|
int (*fn)(struct task_struct *, void *), void *arg) |
|
{ |
|
struct mem_cgroup *iter; |
|
int ret = 0; |
|
|
|
BUG_ON(memcg == root_mem_cgroup); |
|
|
|
for_each_mem_cgroup_tree(iter, memcg) { |
|
struct css_task_iter it; |
|
struct task_struct *task; |
|
|
|
css_task_iter_start(&iter->css, CSS_TASK_ITER_PROCS, &it); |
|
while (!ret && (task = css_task_iter_next(&it))) |
|
ret = fn(task, arg); |
|
css_task_iter_end(&it); |
|
if (ret) { |
|
mem_cgroup_iter_break(memcg, iter); |
|
break; |
|
} |
|
} |
|
return ret; |
|
} |
|
|
|
#ifdef CONFIG_DEBUG_VM |
|
void lruvec_memcg_debug(struct lruvec *lruvec, struct folio *folio) |
|
{ |
|
struct mem_cgroup *memcg; |
|
|
|
if (mem_cgroup_disabled()) |
|
return; |
|
|
|
memcg = folio_memcg(folio); |
|
|
|
if (!memcg) |
|
VM_BUG_ON_FOLIO(lruvec_memcg(lruvec) != root_mem_cgroup, folio); |
|
else |
|
VM_BUG_ON_FOLIO(lruvec_memcg(lruvec) != memcg, folio); |
|
} |
|
#endif |
|
|
|
/** |
|
* folio_lruvec_lock - Lock the lruvec for a folio. |
|
* @folio: Pointer to the folio. |
|
* |
|
* These functions are safe to use under any of the following conditions: |
|
* - folio locked |
|
* - folio_test_lru false |
|
* - folio_memcg_lock() |
|
* - folio frozen (refcount of 0) |
|
* |
|
* Return: The lruvec this folio is on with its lock held. |
|
*/ |
|
struct lruvec *folio_lruvec_lock(struct folio *folio) |
|
{ |
|
struct lruvec *lruvec = folio_lruvec(folio); |
|
|
|
spin_lock(&lruvec->lru_lock); |
|
lruvec_memcg_debug(lruvec, folio); |
|
|
|
return lruvec; |
|
} |
|
|
|
/** |
|
* folio_lruvec_lock_irq - Lock the lruvec for a folio. |
|
* @folio: Pointer to the folio. |
|
* |
|
* These functions are safe to use under any of the following conditions: |
|
* - folio locked |
|
* - folio_test_lru false |
|
* - folio_memcg_lock() |
|
* - folio frozen (refcount of 0) |
|
* |
|
* Return: The lruvec this folio is on with its lock held and interrupts |
|
* disabled. |
|
*/ |
|
struct lruvec *folio_lruvec_lock_irq(struct folio *folio) |
|
{ |
|
struct lruvec *lruvec = folio_lruvec(folio); |
|
|
|
spin_lock_irq(&lruvec->lru_lock); |
|
lruvec_memcg_debug(lruvec, folio); |
|
|
|
return lruvec; |
|
} |
|
|
|
/** |
|
* folio_lruvec_lock_irqsave - Lock the lruvec for a folio. |
|
* @folio: Pointer to the folio. |
|
* @flags: Pointer to irqsave flags. |
|
* |
|
* These functions are safe to use under any of the following conditions: |
|
* - folio locked |
|
* - folio_test_lru false |
|
* - folio_memcg_lock() |
|
* - folio frozen (refcount of 0) |
|
* |
|
* Return: The lruvec this folio is on with its lock held and interrupts |
|
* disabled. |
|
*/ |
|
struct lruvec *folio_lruvec_lock_irqsave(struct folio *folio, |
|
unsigned long *flags) |
|
{ |
|
struct lruvec *lruvec = folio_lruvec(folio); |
|
|
|
spin_lock_irqsave(&lruvec->lru_lock, *flags); |
|
lruvec_memcg_debug(lruvec, folio); |
|
|
|
return lruvec; |
|
} |
|
|
|
/** |
|
* mem_cgroup_update_lru_size - account for adding or removing an lru page |
|
* @lruvec: mem_cgroup per zone lru vector |
|
* @lru: index of lru list the page is sitting on |
|
* @zid: zone id of the accounted pages |
|
* @nr_pages: positive when adding or negative when removing |
|
* |
|
* This function must be called under lru_lock, just before a page is added |
|
* to or just after a page is removed from an lru list. |
|
*/ |
|
void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru, |
|
int zid, int nr_pages) |
|
{ |
|
struct mem_cgroup_per_node *mz; |
|
unsigned long *lru_size; |
|
long size; |
|
|
|
if (mem_cgroup_disabled()) |
|
return; |
|
|
|
mz = container_of(lruvec, struct mem_cgroup_per_node, lruvec); |
|
lru_size = &mz->lru_zone_size[zid][lru]; |
|
|
|
if (nr_pages < 0) |
|
*lru_size += nr_pages; |
|
|
|
size = *lru_size; |
|
if (WARN_ONCE(size < 0, |
|
"%s(%p, %d, %d): lru_size %ld\n", |
|
__func__, lruvec, lru, nr_pages, size)) { |
|
VM_BUG_ON(1); |
|
*lru_size = 0; |
|
} |
|
|
|
if (nr_pages > 0) |
|
*lru_size += nr_pages; |
|
} |
|
|
|
/** |
|
* mem_cgroup_margin - calculate chargeable space of a memory cgroup |
|
* @memcg: the memory cgroup |
|
* |
|
* Returns the maximum amount of memory @mem can be charged with, in |
|
* pages. |
|
*/ |
|
static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg) |
|
{ |
|
unsigned long margin = 0; |
|
unsigned long count; |
|
unsigned long limit; |
|
|
|
count = page_counter_read(&memcg->memory); |
|
limit = READ_ONCE(memcg->memory.max); |
|
if (count < limit) |
|
margin = limit - count; |
|
|
|
if (do_memsw_account()) { |
|
count = page_counter_read(&memcg->memsw); |
|
limit = READ_ONCE(memcg->memsw.max); |
|
if (count < limit) |
|
margin = min(margin, limit - count); |
|
else |
|
margin = 0; |
|
} |
|
|
|
return margin; |
|
} |
|
|
|
/* |
|
* A routine for checking "mem" is under move_account() or not. |
|
* |
|
* Checking a cgroup is mc.from or mc.to or under hierarchy of |
|
* moving cgroups. This is for waiting at high-memory pressure |
|
* caused by "move". |
|
*/ |
|
static bool mem_cgroup_under_move(struct mem_cgroup *memcg) |
|
{ |
|
struct mem_cgroup *from; |
|
struct mem_cgroup *to; |
|
bool ret = false; |
|
/* |
|
* Unlike task_move routines, we access mc.to, mc.from not under |
|
* mutual exclusion by cgroup_mutex. Here, we take spinlock instead. |
|
*/ |
|
spin_lock(&mc.lock); |
|
from = mc.from; |
|
to = mc.to; |
|
if (!from) |
|
goto unlock; |
|
|
|
ret = mem_cgroup_is_descendant(from, memcg) || |
|
mem_cgroup_is_descendant(to, memcg); |
|
unlock: |
|
spin_unlock(&mc.lock); |
|
return ret; |
|
} |
|
|
|
static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg) |
|
{ |
|
if (mc.moving_task && current != mc.moving_task) { |
|
if (mem_cgroup_under_move(memcg)) { |
|
DEFINE_WAIT(wait); |
|
prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE); |
|
/* moving charge context might have finished. */ |
|
if (mc.moving_task) |
|
schedule(); |
|
finish_wait(&mc.waitq, &wait); |
|
return true; |
|
} |
|
} |
|
return false; |
|
} |
|
|
|
struct memory_stat { |
|
const char *name; |
|
unsigned int idx; |
|
}; |
|
|
|
static const struct memory_stat memory_stats[] = { |
|
{ "anon", NR_ANON_MAPPED }, |
|
{ "file", NR_FILE_PAGES }, |
|
{ "kernel", MEMCG_KMEM }, |
|
{ "kernel_stack", NR_KERNEL_STACK_KB }, |
|
{ "pagetables", NR_PAGETABLE }, |
|
{ "sec_pagetables", NR_SECONDARY_PAGETABLE }, |
|
{ "percpu", MEMCG_PERCPU_B }, |
|
{ "sock", MEMCG_SOCK }, |
|
{ "vmalloc", MEMCG_VMALLOC }, |
|
{ "shmem", NR_SHMEM }, |
|
#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP) |
|
{ "zswap", MEMCG_ZSWAP_B }, |
|
{ "zswapped", MEMCG_ZSWAPPED }, |
|
#endif |
|
{ "file_mapped", NR_FILE_MAPPED }, |
|
{ "file_dirty", NR_FILE_DIRTY }, |
|
{ "file_writeback", NR_WRITEBACK }, |
|
#ifdef CONFIG_SWAP |
|
{ "swapcached", NR_SWAPCACHE }, |
|
#endif |
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE |
|
{ "anon_thp", NR_ANON_THPS }, |
|
{ "file_thp", NR_FILE_THPS }, |
|
{ "shmem_thp", NR_SHMEM_THPS }, |
|
#endif |
|
{ "inactive_anon", NR_INACTIVE_ANON }, |
|
{ "active_anon", NR_ACTIVE_ANON }, |
|
{ "inactive_file", NR_INACTIVE_FILE }, |
|
{ "active_file", NR_ACTIVE_FILE }, |
|
{ "unevictable", NR_UNEVICTABLE }, |
|
{ "slab_reclaimable", NR_SLAB_RECLAIMABLE_B }, |
|
{ "slab_unreclaimable", NR_SLAB_UNRECLAIMABLE_B }, |
|
|
|
/* The memory events */ |
|
{ "workingset_refault_anon", WORKINGSET_REFAULT_ANON }, |
|
{ "workingset_refault_file", WORKINGSET_REFAULT_FILE }, |
|
{ "workingset_activate_anon", WORKINGSET_ACTIVATE_ANON }, |
|
{ "workingset_activate_file", WORKINGSET_ACTIVATE_FILE }, |
|
{ "workingset_restore_anon", WORKINGSET_RESTORE_ANON }, |
|
{ "workingset_restore_file", WORKINGSET_RESTORE_FILE }, |
|
{ "workingset_nodereclaim", WORKINGSET_NODERECLAIM }, |
|
}; |
|
|
|
/* Translate stat items to the correct unit for memory.stat output */ |
|
static int memcg_page_state_unit(int item) |
|
{ |
|
switch (item) { |
|
case MEMCG_PERCPU_B: |
|
case MEMCG_ZSWAP_B: |
|
case NR_SLAB_RECLAIMABLE_B: |
|
case NR_SLAB_UNRECLAIMABLE_B: |
|
case WORKINGSET_REFAULT_ANON: |
|
case WORKINGSET_REFAULT_FILE: |
|
case WORKINGSET_ACTIVATE_ANON: |
|
case WORKINGSET_ACTIVATE_FILE: |
|
case WORKINGSET_RESTORE_ANON: |
|
case WORKINGSET_RESTORE_FILE: |
|
case WORKINGSET_NODERECLAIM: |
|
return 1; |
|
case NR_KERNEL_STACK_KB: |
|
return SZ_1K; |
|
default: |
|
return PAGE_SIZE; |
|
} |
|
} |
|
|
|
static inline unsigned long memcg_page_state_output(struct mem_cgroup *memcg, |
|
int item) |
|
{ |
|
return memcg_page_state(memcg, item) * memcg_page_state_unit(item); |
|
} |
|
|
|
static void memory_stat_format(struct mem_cgroup *memcg, char *buf, int bufsize) |
|
{ |
|
struct seq_buf s; |
|
int i; |
|
|
|
seq_buf_init(&s, buf, bufsize); |
|
|
|
/* |
|
* Provide statistics on the state of the memory subsystem as |
|
* well as cumulative event counters that show past behavior. |
|
* |
|
* This list is ordered following a combination of these gradients: |
|
* 1) generic big picture -> specifics and details |
|
* 2) reflecting userspace activity -> reflecting kernel heuristics |
|
* |
|
* Current memory state: |
|
*/ |
|
mem_cgroup_flush_stats(); |
|
|
|
for (i = 0; i < ARRAY_SIZE(memory_stats); i++) { |
|
u64 size; |
|
|
|
size = memcg_page_state_output(memcg, memory_stats[i].idx); |
|
seq_buf_printf(&s, "%s %llu\n", memory_stats[i].name, size); |
|
|
|
if (unlikely(memory_stats[i].idx == NR_SLAB_UNRECLAIMABLE_B)) { |
|
size += memcg_page_state_output(memcg, |
|
NR_SLAB_RECLAIMABLE_B); |
|
seq_buf_printf(&s, "slab %llu\n", size); |
|
} |
|
} |
|
|
|
/* Accumulated memory events */ |
|
seq_buf_printf(&s, "pgscan %lu\n", |
|
memcg_events(memcg, PGSCAN_KSWAPD) + |
|
memcg_events(memcg, PGSCAN_DIRECT)); |
|
seq_buf_printf(&s, "pgsteal %lu\n", |
|
memcg_events(memcg, PGSTEAL_KSWAPD) + |
|
memcg_events(memcg, PGSTEAL_DIRECT)); |
|
|
|
for (i = 0; i < ARRAY_SIZE(memcg_vm_event_stat); i++) { |
|
if (memcg_vm_event_stat[i] == PGPGIN || |
|
memcg_vm_event_stat[i] == PGPGOUT) |
|
continue; |
|
|
|
seq_buf_printf(&s, "%s %lu\n", |
|
vm_event_name(memcg_vm_event_stat[i]), |
|
memcg_events(memcg, memcg_vm_event_stat[i])); |
|
} |
|
|
|
/* The above should easily fit into one page */ |
|
WARN_ON_ONCE(seq_buf_has_overflowed(&s)); |
|
} |
|
|
|
#define K(x) ((x) << (PAGE_SHIFT-10)) |
|
/** |
|
* mem_cgroup_print_oom_context: Print OOM information relevant to |
|
* memory controller. |
|
* @memcg: The memory cgroup that went over limit |
|
* @p: Task that is going to be killed |
|
* |
|
* NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is |
|
* enabled |
|
*/ |
|
void mem_cgroup_print_oom_context(struct mem_cgroup *memcg, struct task_struct *p) |
|
{ |
|
rcu_read_lock(); |
|
|
|
if (memcg) { |
|
pr_cont(",oom_memcg="); |
|
pr_cont_cgroup_path(memcg->css.cgroup); |
|
} else |
|
pr_cont(",global_oom"); |
|
if (p) { |
|
pr_cont(",task_memcg="); |
|
pr_cont_cgroup_path(task_cgroup(p, memory_cgrp_id)); |
|
} |
|
rcu_read_unlock(); |
|
} |
|
|
|
/** |
|
* mem_cgroup_print_oom_meminfo: Print OOM memory information relevant to |
|
* memory controller. |
|
* @memcg: The memory cgroup that went over limit |
|
*/ |
|
void mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg) |
|
{ |
|
/* Use static buffer, for the caller is holding oom_lock. */ |
|
static char buf[PAGE_SIZE]; |
|
|
|
lockdep_assert_held(&oom_lock); |
|
|
|
pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n", |
|
K((u64)page_counter_read(&memcg->memory)), |
|
K((u64)READ_ONCE(memcg->memory.max)), memcg->memory.failcnt); |
|
if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) |
|
pr_info("swap: usage %llukB, limit %llukB, failcnt %lu\n", |
|
K((u64)page_counter_read(&memcg->swap)), |
|
K((u64)READ_ONCE(memcg->swap.max)), memcg->swap.failcnt); |
|
else { |
|
pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n", |
|
K((u64)page_counter_read(&memcg->memsw)), |
|
K((u64)memcg->memsw.max), memcg->memsw.failcnt); |
|
pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n", |
|
K((u64)page_counter_read(&memcg->kmem)), |
|
K((u64)memcg->kmem.max), memcg->kmem.failcnt); |
|
} |
|
|
|
pr_info("Memory cgroup stats for "); |
|
pr_cont_cgroup_path(memcg->css.cgroup); |
|
pr_cont(":"); |
|
memory_stat_format(memcg, buf, sizeof(buf)); |
|
pr_info("%s", buf); |
|
} |
|
|
|
/* |
|
* Return the memory (and swap, if configured) limit for a memcg. |
|
*/ |
|
unsigned long mem_cgroup_get_max(struct mem_cgroup *memcg) |
|
{ |
|
unsigned long max = READ_ONCE(memcg->memory.max); |
|
|
|
if (do_memsw_account()) { |
|
if (mem_cgroup_swappiness(memcg)) { |
|
/* Calculate swap excess capacity from memsw limit */ |
|
unsigned long swap = READ_ONCE(memcg->memsw.max) - max; |
|
|
|
max += min(swap, (unsigned long)total_swap_pages); |
|
} |
|
} else { |
|
if (mem_cgroup_swappiness(memcg)) |
|
max += min(READ_ONCE(memcg->swap.max), |
|
(unsigned long)total_swap_pages); |
|
} |
|
return max; |
|
} |
|
|
|
unsigned long mem_cgroup_size(struct mem_cgroup *memcg) |
|
{ |
|
return page_counter_read(&memcg->memory); |
|
} |
|
|
|
static bool mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask, |
|
int order) |
|
{ |
|
struct oom_control oc = { |
|
.zonelist = NULL, |
|
.nodemask = NULL, |
|
.memcg = memcg, |
|
.gfp_mask = gfp_mask, |
|
.order = order, |
|
}; |
|
bool ret = true; |
|
|
|
if (mutex_lock_killable(&oom_lock)) |
|
return true; |
|
|
|
if (mem_cgroup_margin(memcg) >= (1 << order)) |
|
goto unlock; |
|
|
|
/* |
|
* A few threads which were not waiting at mutex_lock_killable() can |
|
* fail to bail out. Therefore, check again after holding oom_lock. |
|
*/ |
|
ret = task_is_dying() || out_of_memory(&oc); |
|
|
|
unlock: |
|
mutex_unlock(&oom_lock); |
|
return ret; |
|
} |
|
|
|
static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg, |
|
pg_data_t *pgdat, |
|
gfp_t gfp_mask, |
|
unsigned long *total_scanned) |
|
{ |
|
struct mem_cgroup *victim = NULL; |
|
int total = 0; |
|
int loop = 0; |
|
unsigned long excess; |
|
unsigned long nr_scanned; |
|
struct mem_cgroup_reclaim_cookie reclaim = { |
|
.pgdat = pgdat, |
|
}; |
|
|
|
excess = soft_limit_excess(root_memcg); |
|
|
|
while (1) { |
|
victim = mem_cgroup_iter(root_memcg, victim, &reclaim); |
|
if (!victim) { |
|
loop++; |
|
if (loop >= 2) { |
|
/* |
|
* If we have not been able to reclaim |
|
* anything, it might because there are |
|
* no reclaimable pages under this hierarchy |
|
*/ |
|
if (!total) |
|
break; |
|
/* |
|
* We want to do more targeted reclaim. |
|
* excess >> 2 is not to excessive so as to |
|
* reclaim too much, nor too less that we keep |
|
* coming back to reclaim from this cgroup |
|
*/ |
|
if (total >= (excess >> 2) || |
|
(loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) |
|
break; |
|
} |
|
continue; |
|
} |
|
total += mem_cgroup_shrink_node(victim, gfp_mask, false, |
|
pgdat, &nr_scanned); |
|
*total_scanned += nr_scanned; |
|
if (!soft_limit_excess(root_memcg)) |
|
break; |
|
} |
|
mem_cgroup_iter_break(root_memcg, victim); |
|
return total; |
|
} |
|
|
|
#ifdef CONFIG_LOCKDEP |
|
static struct lockdep_map memcg_oom_lock_dep_map = { |
|
.name = "memcg_oom_lock", |
|
}; |
|
#endif |
|
|
|
static DEFINE_SPINLOCK(memcg_oom_lock); |
|
|
|
/* |
|
* Check OOM-Killer is already running under our hierarchy. |
|
* If someone is running, return false. |
|
*/ |
|
static bool mem_cgroup_oom_trylock(struct mem_cgroup *memcg) |
|
{ |
|
struct mem_cgroup *iter, *failed = NULL; |
|
|
|
spin_lock(&memcg_oom_lock); |
|
|
|
for_each_mem_cgroup_tree(iter, memcg) { |
|
if (iter->oom_lock) { |
|
/* |
|
* this subtree of our hierarchy is already locked |
|
* so we cannot give a lock. |
|
*/ |
|
failed = iter; |
|
mem_cgroup_iter_break(memcg, iter); |
|
break; |
|
} else |
|
iter->oom_lock = true; |
|
} |
|
|
|
if (failed) { |
|
/* |
|
* OK, we failed to lock the whole subtree so we have |
|
* to clean up what we set up to the failing subtree |
|
*/ |
|
for_each_mem_cgroup_tree(iter, memcg) { |
|
if (iter == failed) { |
|
mem_cgroup_iter_break(memcg, iter); |
|
break; |
|
} |
|
iter->oom_lock = false; |
|
} |
|
} else |
|
mutex_acquire(&memcg_oom_lock_dep_map, 0, 1, _RET_IP_); |
|
|
|
spin_unlock(&memcg_oom_lock); |
|
|
|
return !failed; |
|
} |
|
|
|
static void mem_cgroup_oom_unlock(struct mem_cgroup *memcg) |
|
{ |
|
struct mem_cgroup *iter; |
|
|
|
spin_lock(&memcg_oom_lock); |
|
mutex_release(&memcg_oom_lock_dep_map, _RET_IP_); |
|
for_each_mem_cgroup_tree(iter, memcg) |
|
iter->oom_lock = false; |
|
spin_unlock(&memcg_oom_lock); |
|
} |
|
|
|
static void mem_cgroup_mark_under_oom(struct mem_cgroup *memcg) |
|
{ |
|
struct mem_cgroup *iter; |
|
|
|
spin_lock(&memcg_oom_lock); |
|
for_each_mem_cgroup_tree(iter, memcg) |
|
iter->under_oom++; |
|
spin_unlock(&memcg_oom_lock); |
|
} |
|
|
|
static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg) |
|
{ |
|
struct mem_cgroup *iter; |
|
|
|
/* |
|
* Be careful about under_oom underflows because a child memcg |
|
* could have been added after mem_cgroup_mark_under_oom. |
|
*/ |
|
spin_lock(&memcg_oom_lock); |
|
for_each_mem_cgroup_tree(iter, memcg) |
|
if (iter->under_oom > 0) |
|
iter->under_oom--; |
|
spin_unlock(&memcg_oom_lock); |
|
} |
|
|
|
static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq); |
|
|
|
struct oom_wait_info { |
|
struct mem_cgroup *memcg; |
|
wait_queue_entry_t wait; |
|
}; |
|
|
|
static int memcg_oom_wake_function(wait_queue_entry_t *wait, |
|
unsigned mode, int sync, void *arg) |
|
{ |
|
struct mem_cgroup *wake_memcg = (struct mem_cgroup *)arg; |
|
struct mem_cgroup *oom_wait_memcg; |
|
struct oom_wait_info *oom_wait_info; |
|
|
|
oom_wait_info = container_of(wait, struct oom_wait_info, wait); |
|
oom_wait_memcg = oom_wait_info->memcg; |
|
|
|
if (!mem_cgroup_is_descendant(wake_memcg, oom_wait_memcg) && |
|
!mem_cgroup_is_descendant(oom_wait_memcg, wake_memcg)) |
|
return 0; |
|
return autoremove_wake_function(wait, mode, sync, arg); |
|
} |
|
|
|
static void memcg_oom_recover(struct mem_cgroup *memcg) |
|
{ |
|
/* |
|
* For the following lockless ->under_oom test, the only required |
|
* guarantee is that it must see the state asserted by an OOM when |
|
* this function is called as a result of userland actions |
|
* triggered by the notification of the OOM. This is trivially |
|
* achieved by invoking mem_cgroup_mark_under_oom() before |
|
* triggering notification. |
|
*/ |
|
if (memcg && memcg->under_oom) |
|
__wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg); |
|
} |
|
|
|
/* |
|
* Returns true if successfully killed one or more processes. Though in some |
|
* corner cases it can return true even without killing any process. |
|
*/ |
|
static bool mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order) |
|
{ |
|
bool locked, ret; |
|
|
|
if (order > PAGE_ALLOC_COSTLY_ORDER) |
|
return false; |
|
|
|
memcg_memory_event(memcg, MEMCG_OOM); |
|
|
|
/* |
|
* We are in the middle of the charge context here, so we |
|
* don't want to block when potentially sitting on a callstack |
|
* that holds all kinds of filesystem and mm locks. |
|
* |
|
* cgroup1 allows disabling the OOM killer and waiting for outside |
|
* handling until the charge can succeed; remember the context and put |
|
* the task to sleep at the end of the page fault when all locks are |
|
* released. |
|
* |
|
* On the other hand, in-kernel OOM killer allows for an async victim |
|
* memory reclaim (oom_reaper) and that means that we are not solely |
|
* relying on the oom victim to make a forward progress and we can |
|
* invoke the oom killer here. |
|
* |
|
* Please note that mem_cgroup_out_of_memory might fail to find a |
|
* victim and then we have to bail out from the charge path. |
|
*/ |
|
if (memcg->oom_kill_disable) { |
|
if (current->in_user_fault) { |
|
css_get(&memcg->css); |
|
current->memcg_in_oom = memcg; |
|
current->memcg_oom_gfp_mask = mask; |
|
current->memcg_oom_order = order; |
|
} |
|
return false; |
|
} |
|
|
|
mem_cgroup_mark_under_oom(memcg); |
|
|
|
locked = mem_cgroup_oom_trylock(memcg); |
|
|
|
if (locked) |
|
mem_cgroup_oom_notify(memcg); |
|
|
|
mem_cgroup_unmark_under_oom(memcg); |
|
ret = mem_cgroup_out_of_memory(memcg, mask, order); |
|
|
|
if (locked) |
|
mem_cgroup_oom_unlock(memcg); |
|
|
|
return ret; |
|
} |
|
|
|
/** |
|
* mem_cgroup_oom_synchronize - complete memcg OOM handling |
|
* @handle: actually kill/wait or just clean up the OOM state |
|
* |
|
* This has to be called at the end of a page fault if the memcg OOM |
|
* handler was enabled. |
|
* |
|
* Memcg supports userspace OOM handling where failed allocations must |
|
* sleep on a waitqueue until the userspace task resolves the |
|
* situation. Sleeping directly in the charge context with all kinds |
|
* of locks held is not a good idea, instead we remember an OOM state |
|
* in the task and mem_cgroup_oom_synchronize() has to be called at |
|
* the end of the page fault to complete the OOM handling. |
|
* |
|
* Returns %true if an ongoing memcg OOM situation was detected and |
|
* completed, %false otherwise. |
|
*/ |
|
bool mem_cgroup_oom_synchronize(bool handle) |
|
{ |
|
struct mem_cgroup *memcg = current->memcg_in_oom; |
|
struct oom_wait_info owait; |
|
bool locked; |
|
|
|
/* OOM is global, do not handle */ |
|
if (!memcg) |
|
return false; |
|
|
|
if (!handle) |
|
goto cleanup; |
|
|
|
owait.memcg = memcg; |
|
owait.wait.flags = 0; |
|
owait.wait.func = memcg_oom_wake_function; |
|
owait.wait.private = current; |
|
INIT_LIST_HEAD(&owait.wait.entry); |
|
|
|
prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE); |
|
mem_cgroup_mark_under_oom(memcg); |
|
|
|
locked = mem_cgroup_oom_trylock(memcg); |
|
|
|
if (locked) |
|
mem_cgroup_oom_notify(memcg); |
|
|
|
if (locked && !memcg->oom_kill_disable) { |
|
mem_cgroup_unmark_under_oom(memcg); |
|
finish_wait(&memcg_oom_waitq, &owait.wait); |
|
mem_cgroup_out_of_memory(memcg, current->memcg_oom_gfp_mask, |
|
current->memcg_oom_order); |
|
} else { |
|
schedule(); |
|
mem_cgroup_unmark_under_oom(memcg); |
|
finish_wait(&memcg_oom_waitq, &owait.wait); |
|
} |
|
|
|
if (locked) { |
|
mem_cgroup_oom_unlock(memcg); |
|
/* |
|
* There is no guarantee that an OOM-lock contender |
|
* sees the wakeups triggered by the OOM kill |
|
* uncharges. Wake any sleepers explicitly. |
|
*/ |
|
memcg_oom_recover(memcg); |
|
} |
|
cleanup: |
|
current->memcg_in_oom = NULL; |
|
css_put(&memcg->css); |
|
return true; |
|
} |
|
|
|
/** |
|
* mem_cgroup_get_oom_group - get a memory cgroup to clean up after OOM |
|
* @victim: task to be killed by the OOM killer |
|
* @oom_domain: memcg in case of memcg OOM, NULL in case of system-wide OOM |
|
* |
|
* Returns a pointer to a memory cgroup, which has to be cleaned up |
|
* by killing all belonging OOM-killable tasks. |
|
* |
|
* Caller has to call mem_cgroup_put() on the returned non-NULL memcg. |
|
*/ |
|
struct mem_cgroup *mem_cgroup_get_oom_group(struct task_struct *victim, |
|
struct mem_cgroup *oom_domain) |
|
{ |
|
struct mem_cgroup *oom_group = NULL; |
|
struct mem_cgroup *memcg; |
|
|
|
if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) |
|
return NULL; |
|
|
|
if (!oom_domain) |
|
oom_domain = root_mem_cgroup; |
|
|
|
rcu_read_lock(); |
|
|
|
memcg = mem_cgroup_from_task(victim); |
|
if (memcg == root_mem_cgroup) |
|
goto out; |
|
|
|
/* |
|
* If the victim task has been asynchronously moved to a different |
|
* memory cgroup, we might end up killing tasks outside oom_domain. |
|
* In this case it's better to ignore memory.group.oom. |
|
*/ |
|
if (unlikely(!mem_cgroup_is_descendant(memcg, oom_domain))) |
|
goto out; |
|
|
|
/* |
|
* Traverse the memory cgroup hierarchy from the victim task's |
|
* cgroup up to the OOMing cgroup (or root) to find the |
|
* highest-level memory cgroup with oom.group set. |
|
*/ |
|
for (; memcg; memcg = parent_mem_cgroup(memcg)) { |
|
if (memcg->oom_group) |
|
oom_group = memcg; |
|
|
|
if (memcg == oom_domain) |
|
break; |
|
} |
|
|
|
if (oom_group) |
|
css_get(&oom_group->css); |
|
out: |
|
rcu_read_unlock(); |
|
|
|
return oom_group; |
|
} |
|
|
|
void mem_cgroup_print_oom_group(struct mem_cgroup *memcg) |
|
{ |
|
pr_info("Tasks in "); |
|
pr_cont_cgroup_path(memcg->css.cgroup); |
|
pr_cont(" are going to be killed due to memory.oom.group set\n"); |
|
} |
|
|
|
/** |
|
* folio_memcg_lock - Bind a folio to its memcg. |
|
* @folio: The folio. |
|
* |
|
* This function prevents unlocked LRU folios from being moved to |
|
* another cgroup. |
|
* |
|
* It ensures lifetime of the bound memcg. The caller is responsible |
|
* for the lifetime of the folio. |
|
*/ |
|
void folio_memcg_lock(struct folio *folio) |
|
{ |
|
struct mem_cgroup *memcg; |
|
unsigned long flags; |
|
|
|
/* |
|
* The RCU lock is held throughout the transaction. The fast |
|
* path can get away without acquiring the memcg->move_lock |
|
* because page moving starts with an RCU grace period. |
|
*/ |
|
rcu_read_lock(); |
|
|
|
if (mem_cgroup_disabled()) |
|
return; |
|
again: |
|
memcg = folio_memcg(folio); |
|
if (unlikely(!memcg)) |
|
return; |
|
|
|
#ifdef CONFIG_PROVE_LOCKING |
|
local_irq_save(flags); |
|
might_lock(&memcg->move_lock); |
|
local_irq_restore(flags); |
|
#endif |
|
|
|
if (atomic_read(&memcg->moving_account) <= 0) |
|
return; |
|
|
|
spin_lock_irqsave(&memcg->move_lock, flags); |
|
if (memcg != folio_memcg(folio)) { |
|
spin_unlock_irqrestore(&memcg->move_lock, flags); |
|
goto again; |
|
} |
|
|
|
/* |
|
* When charge migration first begins, we can have multiple |
|
* critical sections holding the fast-path RCU lock and one |
|
* holding the slowpath move_lock. Track the task who has the |
|
* move_lock for unlock_page_memcg(). |
|
*/ |
|
memcg->move_lock_task = current; |
|
memcg->move_lock_flags = flags; |
|
} |
|
|
|
void lock_page_memcg(struct page *page) |
|
{ |
|
folio_memcg_lock(page_folio(page)); |
|
} |
|
|
|
static void __folio_memcg_unlock(struct mem_cgroup *memcg) |
|
{ |
|
if (memcg && memcg->move_lock_task == current) { |
|
unsigned long flags = memcg->move_lock_flags; |
|
|
|
memcg->move_lock_task = NULL; |
|
memcg->move_lock_flags = 0; |
|
|
|
spin_unlock_irqrestore(&memcg->move_lock, flags); |
|
} |
|
|
|
rcu_read_unlock(); |
|
} |
|
|
|
/** |
|
* folio_memcg_unlock - Release the binding between a folio and its memcg. |
|
* @folio: The folio. |
|
* |
|
* This releases the binding created by folio_memcg_lock(). This does |
|
* not change the accounting of this folio to its memcg, but it does |
|
* permit others to change it. |
|
*/ |
|
void folio_memcg_unlock(struct folio *folio) |
|
{ |
|
__folio_memcg_unlock(folio_memcg(folio)); |
|
} |
|
|
|
void unlock_page_memcg(struct page *page) |
|
{ |
|
folio_memcg_unlock(page_folio(page)); |
|
} |
|
|
|
struct memcg_stock_pcp { |
|
local_lock_t stock_lock; |
|
struct mem_cgroup *cached; /* this never be root cgroup */ |
|
unsigned int nr_pages; |
|
|
|
#ifdef CONFIG_MEMCG_KMEM |
|
struct obj_cgroup *cached_objcg; |
|
struct pglist_data *cached_pgdat; |
|
unsigned int nr_bytes; |
|
int nr_slab_reclaimable_b; |
|
int nr_slab_unreclaimable_b; |
|
#endif |
|
|
|
struct work_struct work; |
|
unsigned long flags; |
|
#define FLUSHING_CACHED_CHARGE 0 |
|
}; |
|
static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock) = { |
|
.stock_lock = INIT_LOCAL_LOCK(stock_lock), |
|
}; |
|
static DEFINE_MUTEX(percpu_charge_mutex); |
|
|
|
#ifdef CONFIG_MEMCG_KMEM |
|
static struct obj_cgroup *drain_obj_stock(struct memcg_stock_pcp *stock); |
|
static bool obj_stock_flush_required(struct memcg_stock_pcp *stock, |
|
struct mem_cgroup *root_memcg); |
|
static void memcg_account_kmem(struct mem_cgroup *memcg, int nr_pages); |
|
|
|
#else |
|
static inline struct obj_cgroup *drain_obj_stock(struct memcg_stock_pcp *stock) |
|
{ |
|
return NULL; |
|
} |
|
static bool obj_stock_flush_required(struct memcg_stock_pcp *stock, |
|
struct mem_cgroup *root_memcg) |
|
{ |
|
return false; |
|
} |
|
static void memcg_account_kmem(struct mem_cgroup *memcg, int nr_pages) |
|
{ |
|
} |
|
#endif |
|
|
|
/** |
|
* consume_stock: Try to consume stocked charge on this cpu. |
|
* @memcg: memcg to consume from. |
|
* @nr_pages: how many pages to charge. |
|
* |
|
* The charges will only happen if @memcg matches the current cpu's memcg |
|
* stock, and at least @nr_pages are available in that stock. Failure to |
|
* service an allocation will refill the stock. |
|
* |
|
* returns true if successful, false otherwise. |
|
*/ |
|
static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages) |
|
{ |
|
struct memcg_stock_pcp *stock; |
|
unsigned long flags; |
|
bool ret = false; |
|
|
|
if (nr_pages > MEMCG_CHARGE_BATCH) |
|
return ret; |
|
|
|
local_lock_irqsave(&memcg_stock.stock_lock, flags); |
|
|
|
stock = this_cpu_ptr(&memcg_stock); |
|
if (memcg == stock->cached && stock->nr_pages >= nr_pages) { |
|
stock->nr_pages -= nr_pages; |
|
ret = true; |
|
} |
|
|
|
local_unlock_irqrestore(&memcg_stock.stock_lock, flags); |
|
|
|
return ret; |
|
} |
|
|
|
/* |
|
* Returns stocks cached in percpu and reset cached information. |
|
*/ |
|
static void drain_stock(struct memcg_stock_pcp *stock) |
|
{ |
|
struct mem_cgroup *old = stock->cached; |
|
|
|
if (!old) |
|
return; |
|
|
|
if (stock->nr_pages) { |
|
page_counter_uncharge(&old->memory, stock->nr_pages); |
|
if (do_memsw_account()) |
|
page_counter_uncharge(&old->memsw, stock->nr_pages); |
|
stock->nr_pages = 0; |
|
} |
|
|
|
css_put(&old->css); |
|
stock->cached = NULL; |
|
} |
|
|
|
static void drain_local_stock(struct work_struct *dummy) |
|
{ |
|
struct memcg_stock_pcp *stock; |
|
struct obj_cgroup *old = NULL; |
|
unsigned long flags; |
|
|
|
/* |
|
* The only protection from cpu hotplug (memcg_hotplug_cpu_dead) vs. |
|
* drain_stock races is that we always operate on local CPU stock |
|
* here with IRQ disabled |
|
*/ |
|
local_lock_irqsave(&memcg_stock.stock_lock, flags); |
|
|
|
stock = this_cpu_ptr(&memcg_stock); |
|
old = drain_obj_stock(stock); |
|
drain_stock(stock); |
|
clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags); |
|
|
|
local_unlock_irqrestore(&memcg_stock.stock_lock, flags); |
|
if (old) |
|
obj_cgroup_put(old); |
|
} |
|
|
|
/* |
|
* Cache charges(val) to local per_cpu area. |
|
* This will be consumed by consume_stock() function, later. |
|
*/ |
|
static void __refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) |
|
{ |
|
struct memcg_stock_pcp *stock; |
|
|
|
stock = this_cpu_ptr(&memcg_stock); |
|
if (stock->cached != memcg) { /* reset if necessary */ |
|
drain_stock(stock); |
|
css_get(&memcg->css); |
|
stock->cached = memcg; |
|
} |
|
stock->nr_pages += nr_pages; |
|
|
|
if (stock->nr_pages > MEMCG_CHARGE_BATCH) |
|
drain_stock(stock); |
|
} |
|
|
|
static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) |
|
{ |
|
unsigned long flags; |
|
|
|
local_lock_irqsave(&memcg_stock.stock_lock, flags); |
|
__refill_stock(memcg, nr_pages); |
|
local_unlock_irqrestore(&memcg_stock.stock_lock, flags); |
|
} |
|
|
|
/* |
|
* Drains all per-CPU charge caches for given root_memcg resp. subtree |
|
* of the hierarchy under it. |
|
*/ |
|
static void drain_all_stock(struct mem_cgroup *root_memcg) |
|
{ |
|
int cpu, curcpu; |
|
|
|
/* If someone's already draining, avoid adding running more workers. */ |
|
if (!mutex_trylock(&percpu_charge_mutex)) |
|
return; |
|
/* |
|
* Notify other cpus that system-wide "drain" is running |
|
* We do not care about races with the cpu hotplug because cpu down |
|
* as well as workers from this path always operate on the local |
|
* per-cpu data. CPU up doesn't touch memcg_stock at all. |
|
*/ |
|
migrate_disable(); |
|
curcpu = smp_processor_id(); |
|
for_each_online_cpu(cpu) { |
|
struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); |
|
struct mem_cgroup *memcg; |
|
bool flush = false; |
|
|
|
rcu_read_lock(); |
|
memcg = stock->cached; |
|
if (memcg && stock->nr_pages && |
|
mem_cgroup_is_descendant(memcg, root_memcg)) |
|
flush = true; |
|
else if (obj_stock_flush_required(stock, root_memcg)) |
|
flush = true; |
|
rcu_read_unlock(); |
|
|
|
if (flush && |
|
!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) { |
|
if (cpu == curcpu) |
|
drain_local_stock(&stock->work); |
|
else |
|
schedule_work_on(cpu, &stock->work); |
|
} |
|
} |
|
migrate_enable(); |
|
mutex_unlock(&percpu_charge_mutex); |
|
} |
|
|
|
static int memcg_hotplug_cpu_dead(unsigned int cpu) |
|
{ |
|
struct memcg_stock_pcp *stock; |
|
|
|
stock = &per_cpu(memcg_stock, cpu); |
|
drain_stock(stock); |
|
|
|
return 0; |
|
} |
|
|
|
static unsigned long reclaim_high(struct mem_cgroup *memcg, |
|
unsigned int nr_pages, |
|
gfp_t gfp_mask) |
|
{ |
|
unsigned long nr_reclaimed = 0; |
|
|
|
do { |
|
unsigned long pflags; |
|
|
|
if (page_counter_read(&memcg->memory) <= |
|
READ_ONCE(memcg->memory.high)) |
|
continue; |
|
|
|
memcg_memory_event(memcg, MEMCG_HIGH); |
|
|
|
psi_memstall_enter(&pflags); |
|
nr_reclaimed += try_to_free_mem_cgroup_pages(memcg, nr_pages, |
|
gfp_mask, |
|
MEMCG_RECLAIM_MAY_SWAP); |
|
psi_memstall_leave(&pflags); |
|
} while ((memcg = parent_mem_cgroup(memcg)) && |
|
!mem_cgroup_is_root(memcg)); |
|
|
|
return nr_reclaimed; |
|
} |
|
|
|
static void high_work_func(struct work_struct *work) |
|
{ |
|
struct mem_cgroup *memcg; |
|
|
|
memcg = container_of(work, struct mem_cgroup, high_work); |
|
reclaim_high(memcg, MEMCG_CHARGE_BATCH, GFP_KERNEL); |
|
} |
|
|
|
/* |
|
* Clamp the maximum sleep time per allocation batch to 2 seconds. This is |
|
* enough to still cause a significant slowdown in most cases, while still |
|
* allowing diagnostics and tracing to proceed without becoming stuck. |
|
*/ |
|
#define MEMCG_MAX_HIGH_DELAY_JIFFIES (2UL*HZ) |
|
|
|
/* |
|
* When calculating the delay, we use these either side of the exponentiation to |
|
* maintain precision and scale to a reasonable number of jiffies (see the table |
|
* below. |
|
* |
|
* - MEMCG_DELAY_PRECISION_SHIFT: Extra precision bits while translating the |
|
* overage ratio to a delay. |
|
* - MEMCG_DELAY_SCALING_SHIFT: The number of bits to scale down the |
|
* proposed penalty in order to reduce to a reasonable number of jiffies, and |
|
* to produce a reasonable delay curve. |
|
* |
|
* MEMCG_DELAY_SCALING_SHIFT just happens to be a number that produces a |
|
* reasonable delay curve compared to precision-adjusted overage, not |
|
* penalising heavily at first, but still making sure that growth beyond the |
|
* limit penalises misbehaviour cgroups by slowing them down exponentially. For |
|
* example, with a high of 100 megabytes: |
|
* |
|
* +-------+------------------------+ |
|
* | usage | time to allocate in ms | |
|
* +-------+------------------------+ |
|
* | 100M | 0 | |
|
* | 101M | 6 | |
|
* | 102M | 25 | |
|
* | 103M | 57 | |
|
* | 104M | 102 | |
|
* | 105M | 159 | |
|
* | 106M | 230 | |
|
* | 107M | 313 | |
|
* | 108M | 409 | |
|
* | 109M | 518 | |
|
* | 110M | 639 | |
|
* | 111M | 774 | |
|
* | 112M | 921 | |
|
* | 113M | 1081 | |
|
* | 114M | 1254 | |
|
* | 115M | 1439 | |
|
* | 116M | 1638 | |
|
* | 117M | 1849 | |
|
* | 118M | 2000 | |
|
* | 119M | 2000 | |
|
* | 120M | 2000 | |
|
* +-------+------------------------+ |
|
*/ |
|
#define MEMCG_DELAY_PRECISION_SHIFT 20 |
|
#define MEMCG_DELAY_SCALING_SHIFT 14 |
|
|
|
static u64 calculate_overage(unsigned long usage, unsigned long high) |
|
{ |
|
u64 overage; |
|
|
|
if (usage <= high) |
|
return 0; |
|
|
|
/* |
|
* Prevent division by 0 in overage calculation by acting as if |
|
* it was a threshold of 1 page |
|
*/ |
|
high = max(high, 1UL); |
|
|
|
overage = usage - high; |
|
overage <<= MEMCG_DELAY_PRECISION_SHIFT; |
|
return div64_u64(overage, high); |
|
} |
|
|
|
static u64 mem_find_max_overage(struct mem_cgroup *memcg) |
|
{ |
|
u64 overage, max_overage = 0; |
|
|
|
do { |
|
overage = calculate_overage(page_counter_read(&memcg->memory), |
|
READ_ONCE(memcg->memory.high)); |
|
max_overage = max(overage, max_overage); |
|
} while ((memcg = parent_mem_cgroup(memcg)) && |
|
!mem_cgroup_is_root(memcg)); |
|
|
|
return max_overage; |
|
} |
|
|
|
static u64 swap_find_max_overage(struct mem_cgroup *memcg) |
|
{ |
|
u64 overage, max_overage = 0; |
|
|
|
do { |
|
overage = calculate_overage(page_counter_read(&memcg->swap), |
|
READ_ONCE(memcg->swap.high)); |
|
if (overage) |
|
memcg_memory_event(memcg, MEMCG_SWAP_HIGH); |
|
max_overage = max(overage, max_overage); |
|
} while ((memcg = parent_mem_cgroup(memcg)) && |
|
!mem_cgroup_is_root(memcg)); |
|
|
|
return max_overage; |
|
} |
|
|
|
/* |
|
* Get the number of jiffies that we should penalise a mischievous cgroup which |
|
* is exceeding its memory.high by checking both it and its ancestors. |
|
*/ |
|
static unsigned long calculate_high_delay(struct mem_cgroup *memcg, |
|
unsigned int nr_pages, |
|
u64 max_overage) |
|
{ |
|
unsigned long penalty_jiffies; |
|
|
|
if (!max_overage) |
|
return 0; |
|
|
|
/* |
|
* We use overage compared to memory.high to calculate the number of |
|
* jiffies to sleep (penalty_jiffies). Ideally this value should be |
|
* fairly lenient on small overages, and increasingly harsh when the |
|
* memcg in question makes it clear that it has no intention of stopping |
|
* its crazy behaviour, so we exponentially increase the delay based on |
|
* overage amount. |
|
*/ |
|
penalty_jiffies = max_overage * max_overage * HZ; |
|
penalty_jiffies >>= MEMCG_DELAY_PRECISION_SHIFT; |
|
penalty_jiffies >>= MEMCG_DELAY_SCALING_SHIFT; |
|
|
|
/* |
|
* Factor in the task's own contribution to the overage, such that four |
|
* N-sized allocations are throttled approximately the same as one |
|
* 4N-sized allocation. |
|
* |
|
* MEMCG_CHARGE_BATCH pages is nominal, so work out how much smaller or |
|
* larger the current charge patch is than that. |
|
*/ |
|
return penalty_jiffies * nr_pages / MEMCG_CHARGE_BATCH; |
|
} |
|
|
|
/* |
|
* Scheduled by try_charge() to be executed from the userland return path |
|
* and reclaims memory over the high limit. |
|
*/ |
|
void mem_cgroup_handle_over_high(void) |
|
{ |
|
unsigned long penalty_jiffies; |
|
unsigned long pflags; |
|
unsigned long nr_reclaimed; |
|
unsigned int nr_pages = current->memcg_nr_pages_over_high; |
|
int nr_retries = MAX_RECLAIM_RETRIES; |
|
struct mem_cgroup *memcg; |
|
bool in_retry = false; |
|
|
|
if (likely(!nr_pages)) |
|
return; |
|
|
|
memcg = get_mem_cgroup_from_mm(current->mm); |
|
current->memcg_nr_pages_over_high = 0; |
|
|
|
retry_reclaim: |
|
/* |
|
* The allocating task should reclaim at least the batch size, but for |
|
* subsequent retries we only want to do what's necessary to prevent oom |
|
* or breaching resource isolation. |
|
* |
|
* This is distinct from memory.max or page allocator behaviour because |
|
* memory.high is currently batched, whereas memory.max and the page |
|
* allocator run every time an allocation is made. |
|
*/ |
|
nr_reclaimed = reclaim_high(memcg, |
|
in_retry ? SWAP_CLUSTER_MAX : nr_pages, |
|
GFP_KERNEL); |
|
|
|
/* |
|
* memory.high is breached and reclaim is unable to keep up. Throttle |
|
* allocators proactively to slow down excessive growth. |
|
*/ |
|
penalty_jiffies = calculate_high_delay(memcg, nr_pages, |
|
mem_find_max_overage(memcg)); |
|
|
|
penalty_jiffies += calculate_high_delay(memcg, nr_pages, |
|
swap_find_max_overage(memcg)); |
|
|
|
/* |
|
* Clamp the max delay per usermode return so as to still keep the |
|
* application moving forwards and also permit diagnostics, albeit |
|
* extremely slowly. |
|
*/ |
|
penalty_jiffies = min(penalty_jiffies, MEMCG_MAX_HIGH_DELAY_JIFFIES); |
|
|
|
/* |
|
* Don't sleep if the amount of jiffies this memcg owes us is so low |
|
* that it's not even worth doing, in an attempt to be nice to those who |
|
* go only a small amount over their memory.high value and maybe haven't |
|
* been aggressively reclaimed enough yet. |
|
*/ |
|
if (penalty_jiffies <= HZ / 100) |
|
goto out; |
|
|
|
/* |
|
* If reclaim is making forward progress but we're still over |
|
* memory.high, we want to encourage that rather than doing allocator |
|
* throttling. |
|
*/ |
|
if (nr_reclaimed || nr_retries--) { |
|
in_retry = true; |
|
goto retry_reclaim; |
|
} |
|
|
|
/* |
|
* If we exit early, we're guaranteed to die (since |
|
* schedule_timeout_killable sets TASK_KILLABLE). This means we don't |
|
* need to account for any ill-begotten jiffies to pay them off later. |
|
*/ |
|
psi_memstall_enter(&pflags); |
|
schedule_timeout_killable(penalty_jiffies); |
|
psi_memstall_leave(&pflags); |
|
|
|
out: |
|
css_put(&memcg->css); |
|
} |
|
|
|
static int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask, |
|
unsigned int nr_pages) |
|
{ |
|
unsigned int batch = max(MEMCG_CHARGE_BATCH, nr_pages); |
|
int nr_retries = MAX_RECLAIM_RETRIES; |
|
struct mem_cgroup *mem_over_limit; |
|
struct page_counter *counter; |
|
unsigned long nr_reclaimed; |
|
bool passed_oom = false; |
|
unsigned int reclaim_options = MEMCG_RECLAIM_MAY_SWAP; |
|
bool drained = false; |
|
bool raised_max_event = false; |
|
unsigned long pflags; |
|
|
|
retry: |
|
if (consume_stock(memcg, nr_pages)) |
|
return 0; |
|
|
|
if (!do_memsw_account() || |
|
page_counter_try_charge(&memcg->memsw, batch, &counter)) { |
|
if (page_counter_try_charge(&memcg->memory, batch, &counter)) |
|
goto done_restock; |
|
if (do_memsw_account()) |
|
page_counter_uncharge(&memcg->memsw, batch); |
|
mem_over_limit = mem_cgroup_from_counter(counter, memory); |
|
} else { |
|
mem_over_limit = mem_cgroup_from_counter(counter, memsw); |
|
reclaim_options &= ~MEMCG_RECLAIM_MAY_SWAP; |
|
} |
|
|
|
if (batch > nr_pages) { |
|
batch = nr_pages; |
|
goto retry; |
|
} |
|
|
|
/* |
|
* Prevent unbounded recursion when reclaim operations need to |
|
* allocate memory. This might exceed the limits temporarily, |
|
* but we prefer facilitating memory reclaim and getting back |
|
* under the limit over triggering OOM kills in these cases. |
|
*/ |
|
if (unlikely(current->flags & PF_MEMALLOC)) |
|
goto force; |
|
|
|
if (unlikely(task_in_memcg_oom(current))) |
|
goto nomem; |
|
|
|
if (!gfpflags_allow_blocking(gfp_mask)) |
|
goto nomem; |
|
|
|
memcg_memory_event(mem_over_limit, MEMCG_MAX); |
|
raised_max_event = true; |
|
|
|
psi_memstall_enter(&pflags); |
|
nr_reclaimed = try_to_free_mem_cgroup_pages(mem_over_limit, nr_pages, |
|
gfp_mask, reclaim_options); |
|
psi_memstall_leave(&pflags); |
|
|
|
if (mem_cgroup_margin(mem_over_limit) >= nr_pages) |
|
goto retry; |
|
|
|
if (!drained) { |
|
drain_all_stock(mem_over_limit); |
|
drained = true; |
|
goto retry; |
|
} |
|
|
|
if (gfp_mask & __GFP_NORETRY) |
|
goto nomem; |
|
/* |
|
* Even though the limit is exceeded at this point, reclaim |
|
* may have been able to free some pages. Retry the charge |
|
* before killing the task. |
|
* |
|
* Only for regular pages, though: huge pages are rather |
|
* unlikely to succeed so close to the limit, and we fall back |
|
* to regular pages anyway in case of failure. |
|
*/ |
|
if (nr_reclaimed && nr_pages <= (1 << PAGE_ALLOC_COSTLY_ORDER)) |
|
goto retry; |
|
/* |
|
* At task move, charge accounts can be doubly counted. So, it's |
|
* better to wait until the end of task_move if something is going on. |
|
*/ |
|
if (mem_cgroup_wait_acct_move(mem_over_limit)) |
|
goto retry; |
|
|
|
if (nr_retries--) |
|
goto retry; |
|
|
|
if (gfp_mask & __GFP_RETRY_MAYFAIL) |
|
goto nomem; |
|
|
|
/* Avoid endless loop for tasks bypassed by the oom killer */ |
|
if (passed_oom && task_is_dying()) |
|
goto nomem; |
|
|
|
/* |
|
* keep retrying as long as the memcg oom killer is able to make |
|
* a forward progress or bypass the charge if the oom killer |
|
* couldn't make any progress. |
|
*/ |
|
if (mem_cgroup_oom(mem_over_limit, gfp_mask, |
|
get_order(nr_pages * PAGE_SIZE))) { |
|
passed_oom = true; |
|
nr_retries = MAX_RECLAIM_RETRIES; |
|
goto retry; |
|
} |
|
nomem: |
|
/* |
|
* Memcg doesn't have a dedicated reserve for atomic |
|
* allocations. But like the global atomic pool, we need to |
|
* put the burden of reclaim on regular allocation requests |
|
* and let these go through as privileged allocations. |
|
*/ |
|
if (!(gfp_mask & (__GFP_NOFAIL | __GFP_HIGH))) |
|
return -ENOMEM; |
|
force: |
|
/* |
|
* If the allocation has to be enforced, don't forget to raise |
|
* a MEMCG_MAX event. |
|
*/ |
|
if (!raised_max_event) |
|
memcg_memory_event(mem_over_limit, MEMCG_MAX); |
|
|
|
/* |
|
* The allocation either can't fail or will lead to more memory |
|
* being freed very soon. Allow memory usage go over the limit |
|
* temporarily by force charging it. |
|
*/ |
|
page_counter_charge(&memcg->memory, nr_pages); |
|
if (do_memsw_account()) |
|
page_counter_charge(&memcg->memsw, nr_pages); |
|
|
|
return 0; |
|
|
|
done_restock: |
|
if (batch > nr_pages) |
|
refill_stock(memcg, batch - nr_pages); |
|
|
|
/* |
|
* If the hierarchy is above the normal consumption range, schedule |
|
* reclaim on returning to userland. We can perform reclaim here |
|
* if __GFP_RECLAIM but let's always punt for simplicity and so that |
|
* GFP_KERNEL can consistently be used during reclaim. @memcg is |
|
* not recorded as it most likely matches current's and won't |
|
* change in the meantime. As high limit is checked again before |
|
* reclaim, the cost of mismatch is negligible. |
|
*/ |
|
do { |
|
bool mem_high, swap_high; |
|
|
|
mem_high = page_counter_read(&memcg->memory) > |
|
READ_ONCE(memcg->memory.high); |
|
swap_high = page_counter_read(&memcg->swap) > |
|
READ_ONCE(memcg->swap.high); |
|
|
|
/* Don't bother a random interrupted task */ |
|
if (!in_task()) { |
|
if (mem_high) { |
|
schedule_work(&memcg->high_work); |
|
break; |
|
} |
|
continue; |
|
} |
|
|
|
if (mem_high || swap_high) { |
|
/* |
|
* The allocating tasks in this cgroup will need to do |
|
* reclaim or be throttled to prevent further growth |
|
* of the memory or swap footprints. |
|
* |
|
* Target some best-effort fairness between the tasks, |
|
* and distribute reclaim work and delay penalties |
|
* based on how much each task is actually allocating. |
|
*/ |
|
current->memcg_nr_pages_over_high += batch; |
|
set_notify_resume(current); |
|
break; |
|
} |
|
} while ((memcg = parent_mem_cgroup(memcg))); |
|
|
|
if (current->memcg_nr_pages_over_high > MEMCG_CHARGE_BATCH && |
|
!(current->flags & PF_MEMALLOC) && |
|
gfpflags_allow_blocking(gfp_mask)) { |
|
mem_cgroup_handle_over_high(); |
|
} |
|
return 0; |
|
} |
|
|
|
static inline int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, |
|
unsigned int nr_pages) |
|
{ |
|
if (mem_cgroup_is_root(memcg)) |
|
return 0; |
|
|
|
return try_charge_memcg(memcg, gfp_mask, nr_pages); |
|
} |
|
|
|
static inline void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages) |
|
{ |
|
if (mem_cgroup_is_root(memcg)) |
|
return; |
|
|
|
page_counter_uncharge(&memcg->memory, nr_pages); |
|
if (do_memsw_account()) |
|
page_counter_uncharge(&memcg->memsw, nr_pages); |
|
} |
|
|
|
static void commit_charge(struct folio *folio, struct mem_cgroup *memcg) |
|
{ |
|
VM_BUG_ON_FOLIO(folio_memcg(folio), folio); |
|
/* |
|
* Any of the following ensures page's memcg stability: |
|
* |
|
* - the page lock |
|
* - LRU isolation |
|
* - lock_page_memcg() |
|
* - exclusive reference |
|
* - mem_cgroup_trylock_pages() |
|
*/ |
|
folio->memcg_data = (unsigned long)memcg; |
|
} |
|
|
|
#ifdef CONFIG_MEMCG_KMEM |
|
/* |
|
* The allocated objcg pointers array is not accounted directly. |
|
* Moreover, it should not come from DMA buffer and is not readily |
|
* reclaimable. So those GFP bits should be masked off. |
|
*/ |
|
#define OBJCGS_CLEAR_MASK (__GFP_DMA | __GFP_RECLAIMABLE | __GFP_ACCOUNT) |
|
|
|
/* |
|
* mod_objcg_mlstate() may be called with irq enabled, so |
|
* mod_memcg_lruvec_state() should be used. |
|
*/ |
|
static inline void mod_objcg_mlstate(struct obj_cgroup *objcg, |
|
struct pglist_data *pgdat, |
|
enum node_stat_item idx, int nr) |
|
{ |
|
struct mem_cgroup *memcg; |
|
struct lruvec *lruvec; |
|
|
|
rcu_read_lock(); |
|
memcg = obj_cgroup_memcg(objcg); |
|
lruvec = mem_cgroup_lruvec(memcg, pgdat); |
|
mod_memcg_lruvec_state(lruvec, idx, nr); |
|
rcu_read_unlock(); |
|
} |
|
|
|
int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s, |
|
gfp_t gfp, bool new_slab) |
|
{ |
|
unsigned int objects = objs_per_slab(s, slab); |
|
unsigned long memcg_data; |
|
void *vec; |
|
|
|
gfp &= ~OBJCGS_CLEAR_MASK; |
|
vec = kcalloc_node(objects, sizeof(struct obj_cgroup *), gfp, |
|
slab_nid(slab)); |
|
if (!vec) |
|
return -ENOMEM; |
|
|
|
memcg_data = (unsigned long) vec | MEMCG_DATA_OBJCGS; |
|
if (new_slab) { |
|
/* |
|
* If the slab is brand new and nobody can yet access its |
|
* memcg_data, no synchronization is required and memcg_data can |
|
* be simply assigned. |
|
*/ |
|
slab->memcg_data = memcg_data; |
|
} else if (cmpxchg(&slab->memcg_data, 0, memcg_data)) { |
|
/* |
|
* If the slab is already in use, somebody can allocate and |
|
* assign obj_cgroups in parallel. In this case the existing |
|
* objcg vector should be reused. |
|
*/ |
|
kfree(vec); |
|
return 0; |
|
} |
|
|
|
kmemleak_not_leak(vec); |
|
return 0; |
|
} |
|
|
|
static __always_inline |
|
struct mem_cgroup *mem_cgroup_from_obj_folio(struct folio *folio, void *p) |
|
{ |
|
/* |
|
* Slab objects are accounted individually, not per-page. |
|
* Memcg membership data for each individual object is saved in |
|
* slab->memcg_data. |
|
*/ |
|
if (folio_test_slab(folio)) { |
|
struct obj_cgroup **objcgs; |
|
struct slab *slab; |
|
unsigned int off; |
|
|
|
slab = folio_slab(folio); |
|
objcgs = slab_objcgs(slab); |
|
if (!objcgs) |
|
return NULL; |
|
|
|
off = obj_to_index(slab->slab_cache, slab, p); |
|
if (objcgs[off]) |
|
return obj_cgroup_memcg(objcgs[off]); |
|
|
|
return NULL; |
|
} |
|
|
|
/* |
|
* page_memcg_check() is used here, because in theory we can encounter |
|
* a folio where the slab flag has been cleared already, but |
|
* slab->memcg_data has not been freed yet |
|
* page_memcg_check(page) will guarantee that a proper memory |
|
* cgroup pointer or NULL will be returned. |
|
*/ |
|
return page_memcg_check(folio_page(folio, 0)); |
|
} |
|
|
|
/* |
|
* Returns a pointer to the memory cgroup to which the kernel object is charged. |
|
* |
|
* A passed kernel object can be a slab object, vmalloc object or a generic |
|
* kernel page, so different mechanisms for getting the memory cgroup pointer |
|
* should be used. |
|
* |
|
* In certain cases (e.g. kernel stacks or large kmallocs with SLUB) the caller |
|
* can not know for sure how the kernel object is implemented. |
|
* mem_cgroup_from_obj() can be safely used in such cases. |
|
* |
|
* The caller must ensure the memcg lifetime, e.g. by taking rcu_read_lock(), |
|
* cgroup_mutex, etc. |
|
*/ |
|
struct mem_cgroup *mem_cgroup_from_obj(void *p) |
|
{ |
|
struct folio *folio; |
|
|
|
if (mem_cgroup_disabled()) |
|
return NULL; |
|
|
|
if (unlikely(is_vmalloc_addr(p))) |
|
folio = page_folio(vmalloc_to_page(p)); |
|
else |
|
folio = virt_to_folio(p); |
|
|
|
return mem_cgroup_from_obj_folio(folio, p); |
|
} |
|
|
|
/* |
|
* Returns a pointer to the memory cgroup to which the kernel object is charged. |
|
* Similar to mem_cgroup_from_obj(), but faster and not suitable for objects, |
|
* allocated using vmalloc(). |
|
* |
|
* A passed kernel object must be a slab object or a generic kernel page. |
|
* |
|
* The caller must ensure the memcg lifetime, e.g. by taking rcu_read_lock(), |
|
* cgroup_mutex, etc. |
|
*/ |
|
struct mem_cgroup *mem_cgroup_from_slab_obj(void *p) |
|
{ |
|
if (mem_cgroup_disabled()) |
|
return NULL; |
|
|
|
return mem_cgroup_from_obj_folio(virt_to_folio(p), p); |
|
} |
|
|
|
static struct obj_cgroup *__get_obj_cgroup_from_memcg(struct mem_cgroup *memcg) |
|
{ |
|
struct obj_cgroup *objcg = NULL; |
|
|
|
for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg)) { |
|
objcg = rcu_dereference(memcg->objcg); |
|
if (objcg && obj_cgroup_tryget(objcg)) |
|
break; |
|
objcg = NULL; |
|
} |
|
return objcg; |
|
} |
|
|
|
__always_inline struct obj_cgroup *get_obj_cgroup_from_current(void) |
|
{ |
|
struct obj_cgroup *objcg = NULL; |
|
struct mem_cgroup *memcg; |
|
|
|
if (memcg_kmem_bypass()) |
|
return NULL; |
|
|
|
rcu_read_lock(); |
|
if (unlikely(active_memcg())) |
|
memcg = active_memcg(); |
|
else |
|
memcg = mem_cgroup_from_task(current); |
|
objcg = __get_obj_cgroup_from_memcg(memcg); |
|
rcu_read_unlock(); |
|
return objcg; |
|
} |
|
|
|
struct obj_cgroup *get_obj_cgroup_from_page(struct page *page) |
|
{ |
|
struct obj_cgroup *objcg; |
|
|
|
if (!memcg_kmem_enabled()) |
|
return NULL; |
|
|
|
if (PageMemcgKmem(page)) { |
|
objcg = __folio_objcg(page_folio(page)); |
|
obj_cgroup_get(objcg); |
|
} else { |
|
struct mem_cgroup *memcg; |
|
|
|
rcu_read_lock(); |
|
memcg = __folio_memcg(page_folio(page)); |
|
if (memcg) |
|
objcg = __get_obj_cgroup_from_memcg(memcg); |
|
else |
|
objcg = NULL; |
|
rcu_read_unlock(); |
|
} |
|
return objcg; |
|
} |
|
|
|
static void memcg_account_kmem(struct mem_cgroup *memcg, int nr_pages) |
|
{ |
|
mod_memcg_state(memcg, MEMCG_KMEM, nr_pages); |
|
if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) { |
|
if (nr_pages > 0) |
|
page_counter_charge(&memcg->kmem, nr_pages); |
|
else |
|
page_counter_uncharge(&memcg->kmem, -nr_pages); |
|
} |
|
} |
|
|
|
|
|
/* |
|
* obj_cgroup_uncharge_pages: uncharge a number of kernel pages from a objcg |
|
* @objcg: object cgroup to uncharge |
|
* @nr_pages: number of pages to uncharge |
|
*/ |
|
static void obj_cgroup_uncharge_pages(struct obj_cgroup *objcg, |
|
unsigned int nr_pages) |
|
{ |
|
struct mem_cgroup *memcg; |
|
|
|
memcg = get_mem_cgroup_from_objcg(objcg); |
|
|
|
memcg_account_kmem(memcg, -nr_pages); |
|
refill_stock(memcg, nr_pages); |
|
|
|
css_put(&memcg->css); |
|
} |
|
|
|
/* |
|
* obj_cgroup_charge_pages: charge a number of kernel pages to a objcg |
|
* @objcg: object cgroup to charge |
|
* @gfp: reclaim mode |
|
* @nr_pages: number of pages to charge |
|
* |
|
* Returns 0 on success, an error code on failure. |
|
*/ |
|
static int obj_cgroup_charge_pages(struct obj_cgroup *objcg, gfp_t gfp, |
|
unsigned int nr_pages) |
|
{ |
|
struct mem_cgroup *memcg; |
|
int ret; |
|
|
|
memcg = get_mem_cgroup_from_objcg(objcg); |
|
|
|
ret = try_charge_memcg(memcg, gfp, nr_pages); |
|
if (ret) |
|
goto out; |
|
|
|
memcg_account_kmem(memcg, nr_pages); |
|
out: |
|
css_put(&memcg->css); |
|
|
|
return ret; |
|
} |
|
|
|
/** |
|
* __memcg_kmem_charge_page: charge a kmem page to the current memory cgroup |
|
* @page: page to charge |
|
* @gfp: reclaim mode |
|
* @order: allocation order |
|
* |
|
* Returns 0 on success, an error code on failure. |
|
*/ |
|
int __memcg_kmem_charge_page(struct page *page, gfp_t gfp, int order) |
|
{ |
|
struct obj_cgroup *objcg; |
|
int ret = 0; |
|
|
|
objcg = get_obj_cgroup_from_current(); |
|
if (objcg) { |
|
ret = obj_cgroup_charge_pages(objcg, gfp, 1 << order); |
|
if (!ret) { |
|
page->memcg_data = (unsigned long)objcg | |
|
MEMCG_DATA_KMEM; |
|
return 0; |
|
} |
|
obj_cgroup_put(objcg); |
|
} |
|
return ret; |
|
} |
|
|
|
/** |
|
* __memcg_kmem_uncharge_page: uncharge a kmem page |
|
* @page: page to uncharge |
|
* @order: allocation order |
|
*/ |
|
void __memcg_kmem_uncharge_page(struct page *page, int order) |
|
{ |
|
struct folio *folio = page_folio(page); |
|
struct obj_cgroup *objcg; |
|
unsigned int nr_pages = 1 << order; |
|
|
|
if (!folio_memcg_kmem(folio)) |
|
return; |
|
|
|
objcg = __folio_objcg(folio); |
|
obj_cgroup_uncharge_pages(objcg, nr_pages); |
|
folio->memcg_data = 0; |
|
obj_cgroup_put(objcg); |
|
} |
|
|
|
void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat, |
|
enum node_stat_item idx, int nr) |
|
{ |
|
struct memcg_stock_pcp *stock; |
|
struct obj_cgroup *old = NULL; |
|
unsigned long flags; |
|
int *bytes; |
|
|
|
local_lock_irqsave(&memcg_stock.stock_lock, flags); |
|
stock = this_cpu_ptr(&memcg_stock); |
|
|
|
/* |
|
* Save vmstat data in stock and skip vmstat array update unless |
|
* accumulating over a page of vmstat data or when pgdat or idx |
|
* changes. |
|
*/ |
|
if (stock->cached_objcg != objcg) { |
|
old = drain_obj_stock(stock); |
|
obj_cgroup_get(objcg); |
|
stock->nr_bytes = atomic_read(&objcg->nr_charged_bytes) |
|
? atomic_xchg(&objcg->nr_charged_bytes, 0) : 0; |
|
stock->cached_objcg = objcg; |
|
stock->cached_pgdat = pgdat; |
|
} else if (stock->cached_pgdat != pgdat) { |
|
/* Flush the existing cached vmstat data */ |
|
struct pglist_data *oldpg = stock->cached_pgdat; |
|
|
|
if (stock->nr_slab_reclaimable_b) { |
|
mod_objcg_mlstate(objcg, oldpg, NR_SLAB_RECLAIMABLE_B, |
|
stock->nr_slab_reclaimable_b); |
|
stock->nr_slab_reclaimable_b = 0; |
|
} |
|
if (stock->nr_slab_unreclaimable_b) { |
|
mod_objcg_mlstate(objcg, oldpg, NR_SLAB_UNRECLAIMABLE_B, |
|
stock->nr_slab_unreclaimable_b); |
|
stock->nr_slab_unreclaimable_b = 0; |
|
} |
|
stock->cached_pgdat = pgdat; |
|
} |
|
|
|
bytes = (idx == NR_SLAB_RECLAIMABLE_B) ? &stock->nr_slab_reclaimable_b |
|
: &stock->nr_slab_unreclaimable_b; |
|
/* |
|
* Even for large object >= PAGE_SIZE, the vmstat data will still be |
|
* cached locally at least once before pushing it out. |
|
*/ |
|
if (!*bytes) { |
|
*bytes = nr; |
|
nr = 0; |
|
} else { |
|
*bytes += nr; |
|
if (abs(*bytes) > PAGE_SIZE) { |
|
nr = *bytes; |
|
*bytes = 0; |
|
} else { |
|
nr = 0; |
|
} |
|
} |
|
if (nr) |
|
mod_objcg_mlstate(objcg, pgdat, idx, nr); |
|
|
|
local_unlock_irqrestore(&memcg_stock.stock_lock, flags); |
|
if (old) |
|
obj_cgroup_put(old); |
|
} |
|
|
|
static bool consume_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes) |
|
{ |
|
struct memcg_stock_pcp *stock; |
|
unsigned long flags; |
|
bool ret = false; |
|
|
|
local_lock_irqsave(&memcg_stock.stock_lock, flags); |
|
|
|
stock = this_cpu_ptr(&memcg_stock); |
|
if (objcg == stock->cached_objcg && stock->nr_bytes >= nr_bytes) { |
|
stock->nr_bytes -= nr_bytes; |
|
ret = true; |
|
} |
|
|
|
local_unlock_irqrestore(&memcg_stock.stock_lock, flags); |
|
|
|
return ret; |
|
} |
|
|
|
static struct obj_cgroup *drain_obj_stock(struct memcg_stock_pcp *stock) |
|
{ |
|
struct obj_cgroup *old = stock->cached_objcg; |
|
|
|
if (!old) |
|
return NULL; |
|
|
|
if (stock->nr_bytes) { |
|
unsigned int nr_pages = stock->nr_bytes >> PAGE_SHIFT; |
|
unsigned int nr_bytes = stock->nr_bytes & (PAGE_SIZE - 1); |
|
|
|
if (nr_pages) { |
|
struct mem_cgroup *memcg; |
|
|
|
memcg = get_mem_cgroup_from_objcg(old); |
|
|
|
memcg_account_kmem(memcg, -nr_pages); |
|
__refill_stock(memcg, nr_pages); |
|
|
|
css_put(&memcg->css); |
|
} |
|
|
|
/* |
|
* The leftover is flushed to the centralized per-memcg value. |
|
* On the next attempt to refill obj stock it will be moved |
|
* to a per-cpu stock (probably, on an other CPU), see |
|
* refill_obj_stock(). |
|
* |
|
* How often it's flushed is a trade-off between the memory |
|
* limit enforcement accuracy and potential CPU contention, |
|
* so it might be changed in the future. |
|
*/ |
|
atomic_add(nr_bytes, &old->nr_charged_bytes); |
|
stock->nr_bytes = 0; |
|
} |
|
|
|
/* |
|
* Flush the vmstat data in current stock |
|
*/ |
|
if (stock->nr_slab_reclaimable_b || stock->nr_slab_unreclaimable_b) { |
|
if (stock->nr_slab_reclaimable_b) { |
|
mod_objcg_mlstate(old, stock->cached_pgdat, |
|
NR_SLAB_RECLAIMABLE_B, |
|
stock->nr_slab_reclaimable_b); |
|
stock->nr_slab_reclaimable_b = 0; |
|
} |
|
if (stock->nr_slab_unreclaimable_b) { |
|
mod_objcg_mlstate(old, stock->cached_pgdat, |
|
NR_SLAB_UNRECLAIMABLE_B, |
|
stock->nr_slab_unreclaimable_b); |
|
stock->nr_slab_unreclaimable_b = 0; |
|
} |
|
stock->cached_pgdat = NULL; |
|
} |
|
|
|
stock->cached_objcg = NULL; |
|
/* |
|
* The `old' objects needs to be released by the caller via |
|
* obj_cgroup_put() outside of memcg_stock_pcp::stock_lock. |
|
*/ |
|
return old; |
|
} |
|
|
|
static bool obj_stock_flush_required(struct memcg_stock_pcp *stock, |
|
struct mem_cgroup *root_memcg) |
|
{ |
|
struct mem_cgroup *memcg; |
|
|
|
if (stock->cached_objcg) { |
|
memcg = obj_cgroup_memcg(stock->cached_objcg); |
|
if (memcg && mem_cgroup_is_descendant(memcg, root_memcg)) |
|
return true; |
|
} |
|
|
|
return false; |
|
} |
|
|
|
static void refill_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes, |
|
bool allow_uncharge) |
|
{ |
|
struct memcg_stock_pcp *stock; |
|
struct obj_cgroup *old = NULL; |
|
unsigned long flags; |
|
unsigned int nr_pages = 0; |
|
|
|
local_lock_irqsave(&memcg_stock.stock_lock, flags); |
|
|
|
stock = this_cpu_ptr(&memcg_stock); |
|
if (stock->cached_objcg != objcg) { /* reset if necessary */ |
|
old = drain_obj_stock(stock); |
|
obj_cgroup_get(objcg); |
|
stock->cached_objcg = objcg; |
|
stock->nr_bytes = atomic_read(&objcg->nr_charged_bytes) |
|
? atomic_xchg(&objcg->nr_charged_bytes, 0) : 0; |
|
allow_uncharge = true; /* Allow uncharge when objcg changes */ |
|
} |
|
stock->nr_bytes += nr_bytes; |
|
|
|
if (allow_uncharge && (stock->nr_bytes > PAGE_SIZE)) { |
|
nr_pages = stock->nr_bytes >> PAGE_SHIFT; |
|
stock->nr_bytes &= (PAGE_SIZE - 1); |
|
} |
|
|
|
local_unlock_irqrestore(&memcg_stock.stock_lock, flags); |
|
if (old) |
|
obj_cgroup_put(old); |
|
|
|
if (nr_pages) |
|
obj_cgroup_uncharge_pages(objcg, nr_pages); |
|
} |
|
|
|
int obj_cgroup_charge(struct obj_cgroup *objcg, gfp_t gfp, size_t size) |
|
{ |
|
unsigned int nr_pages, nr_bytes; |
|
int ret; |
|
|
|
if (consume_obj_stock(objcg, size)) |
|
return 0; |
|
|
|
/* |
|
* In theory, objcg->nr_charged_bytes can have enough |
|
* pre-charged bytes to satisfy the allocation. However, |
|
* flushing objcg->nr_charged_bytes requires two atomic |
|
* operations, and objcg->nr_charged_bytes can't be big. |
|
* The shared objcg->nr_charged_bytes can also become a |
|
* performance bottleneck if all tasks of the same memcg are |
|
* trying to update it. So it's better to ignore it and try |
|
* grab some new pages. The stock's nr_bytes will be flushed to |
|
* objcg->nr_charged_bytes later on when objcg changes. |
|
* |
|
* The stock's nr_bytes may contain enough pre-charged bytes |
|
* to allow one less page from being charged, but we can't rely |
|
* on the pre-charged bytes not being changed outside of |
|
* consume_obj_stock() or refill_obj_stock(). So ignore those |
|
* pre-charged bytes as well when charging pages. To avoid a |
|
* page uncharge right after a page charge, we set the |
|
* allow_uncharge flag to false when calling refill_obj_stock() |
|
* to temporarily allow the pre-charged bytes to exceed the page |
|
* size limit. The maximum reachable value of the pre-charged |
|
* bytes is (sizeof(object) + PAGE_SIZE - 2) if there is no data |
|
* race. |
|
*/ |
|
nr_pages = size >> PAGE_SHIFT; |
|
nr_bytes = size & (PAGE_SIZE - 1); |
|
|
|
if (nr_bytes) |
|
nr_pages += 1; |
|
|
|
ret = obj_cgroup_charge_pages(objcg, gfp, nr_pages); |
|
if (!ret && nr_bytes) |
|
refill_obj_stock(objcg, PAGE_SIZE - nr_bytes, false); |
|
|
|
return ret; |
|
} |
|
|
|
void obj_cgroup_uncharge(struct obj_cgroup *objcg, size_t size) |
|
{ |
|
refill_obj_stock(objcg, size, true); |
|
} |
|
|
|
#endif /* CONFIG_MEMCG_KMEM */ |
|
|
|
/* |
|
* Because page_memcg(head) is not set on tails, set it now. |
|
*/ |
|
void split_page_memcg(struct page *head, unsigned int nr) |
|
{ |
|
struct folio *folio = page_folio(head); |
|
struct mem_cgroup *memcg = folio_memcg(folio); |
|
int i; |
|
|
|
if (mem_cgroup_disabled() || !memcg) |
|
return; |
|
|
|
for (i = 1; i < nr; i++) |
|
folio_page(folio, i)->memcg_data = folio->memcg_data; |
|
|
|
if (folio_memcg_kmem(folio)) |
|
obj_cgroup_get_many(__folio_objcg(folio), nr - 1); |
|
else |
|
css_get_many(&memcg->css, nr - 1); |
|
} |
|
|
|
#ifdef CONFIG_SWAP |
|
/** |
|
* mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record. |
|
* @entry: swap entry to be moved |
|
* @from: mem_cgroup which the entry is moved from |
|
* @to: mem_cgroup which the entry is moved to |
|
* |
|
* It succeeds only when the swap_cgroup's record for this entry is the same |
|
* as the mem_cgroup's id of @from. |
|
* |
|
* Returns 0 on success, -EINVAL on failure. |
|
* |
|
* The caller must have charged to @to, IOW, called page_counter_charge() about |
|
* both res and memsw, and called css_get(). |
|
*/ |
|
static int mem_cgroup_move_swap_account(swp_entry_t entry, |
|
struct mem_cgroup *from, struct mem_cgroup *to) |
|
{ |
|
unsigned short old_id, new_id; |
|
|
|
old_id = mem_cgroup_id(from); |
|
new_id = mem_cgroup_id(to); |
|
|
|
if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) { |
|
mod_memcg_state(from, MEMCG_SWAP, -1); |
|
mod_memcg_state(to, MEMCG_SWAP, 1); |
|
return 0; |
|
} |
|
return -EINVAL; |
|
} |
|
#else |
|
static inline int mem_cgroup_move_swap_account(swp_entry_t entry, |
|
struct mem_cgroup *from, struct mem_cgroup *to) |
|
{ |
|
return -EINVAL; |
|
} |
|
#endif |
|
|
|
static DEFINE_MUTEX(memcg_max_mutex); |
|
|
|
static int mem_cgroup_resize_max(struct mem_cgroup *memcg, |
|
unsigned long max, bool memsw) |
|
{ |
|
bool enlarge = false; |
|
bool drained = false; |
|
int ret; |
|
bool limits_invariant; |
|
struct page_counter *counter = memsw ? &memcg->memsw : &memcg->memory; |
|
|
|
do { |
|
if (signal_pending(current)) { |
|
ret = -EINTR; |
|
break; |
|
} |
|
|
|
mutex_lock(&memcg_max_mutex); |
|
/* |
|
* Make sure that the new limit (memsw or memory limit) doesn't |
|
* break our basic invariant rule memory.max <= memsw.max. |
|
*/ |
|
limits_invariant = memsw ? max >= READ_ONCE(memcg->memory.max) : |
|
max <= memcg->memsw.max; |
|
if (!limits_invariant) { |
|
mutex_unlock(&memcg_max_mutex); |
|
ret = -EINVAL; |
|
break; |
|
} |
|
if (max > counter->max) |
|
enlarge = true; |
|
ret = page_counter_set_max(counter, max); |
|
mutex_unlock(&memcg_max_mutex); |
|
|
|
if (!ret) |
|
break; |
|
|
|
if (!drained) { |
|
drain_all_stock(memcg); |
|
drained = true; |
|
continue; |
|
} |
|
|
|
if (!try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, |
|
memsw ? 0 : MEMCG_RECLAIM_MAY_SWAP)) { |
|
ret = -EBUSY; |
|
break; |
|
} |
|
} while (true); |
|
|
|
if (!ret && enlarge) |
|
memcg_oom_recover(memcg); |
|
|
|
return ret; |
|
} |
|
|
|
unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order, |
|
gfp_t gfp_mask, |
|
unsigned long *total_scanned) |
|
{ |
|
unsigned long nr_reclaimed = 0; |
|
struct mem_cgroup_per_node *mz, *next_mz = NULL; |
|
unsigned long reclaimed; |
|
int loop = 0; |
|
struct mem_cgroup_tree_per_node *mctz; |
|
unsigned long excess; |
|
|
|
if (order > 0) |
|
return 0; |
|
|
|
mctz = soft_limit_tree.rb_tree_per_node[pgdat->node_id]; |
|
|
|
/* |
|
* Do not even bother to check the largest node if the root |
|
* is empty. Do it lockless to prevent lock bouncing. Races |
|
* are acceptable as soft limit is best effort anyway. |
|
*/ |
|
if (!mctz || RB_EMPTY_ROOT(&mctz->rb_root)) |
|
return 0; |
|
|
|
/* |
|
* This loop can run a while, specially if mem_cgroup's continuously |
|
* keep exceeding their soft limit and putting the system under |
|
* pressure |
|
*/ |
|
do { |
|
if (next_mz) |
|
mz = next_mz; |
|
else |
|
mz = mem_cgroup_largest_soft_limit_node(mctz); |
|
if (!mz) |
|
break; |
|
|
|
reclaimed = mem_cgroup_soft_reclaim(mz->memcg, pgdat, |
|
gfp_mask, total_scanned); |
|
nr_reclaimed += reclaimed; |
|
spin_lock_irq(&mctz->lock); |
|
|
|
/* |
|
* If we failed to reclaim anything from this memory cgroup |
|
* it is time to move on to the next cgroup |
|
*/ |
|
next_mz = NULL; |
|
if (!reclaimed) |
|
next_mz = __mem_cgroup_largest_soft_limit_node(mctz); |
|
|
|
excess = soft_limit_excess(mz->memcg); |
|
/* |
|
* One school of thought says that we should not add |
|
* back the node to the tree if reclaim returns 0. |
|
* But our reclaim could return 0, simply because due |
|
* to priority we are exposing a smaller subset of |
|
* memory to reclaim from. Consider this as a longer |
|
* term TODO. |
|
*/ |
|
/* If excess == 0, no tree ops */ |
|
__mem_cgroup_insert_exceeded(mz, mctz, excess); |
|
spin_unlock_irq(&mctz->lock); |
|
css_put(&mz->memcg->css); |
|
loop++; |
|
/* |
|
* Could not reclaim anything and there are no more |
|
* mem cgroups to try or we seem to be looping without |
|
* reclaiming anything. |
|
*/ |
|
if (!nr_reclaimed && |
|
(next_mz == NULL || |
|
loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS)) |
|
break; |
|
} while (!nr_reclaimed); |
|
if (next_mz) |
|
css_put(&next_mz->memcg->css); |
|
return nr_reclaimed; |
|
} |
|
|
|
/* |
|
* Reclaims as many pages from the given memcg as possible. |
|
* |
|
* Caller is responsible for holding css reference for memcg. |
|
*/ |
|
static int mem_cgroup_force_empty(struct mem_cgroup *memcg) |
|
{ |
|
int nr_retries = MAX_RECLAIM_RETRIES; |
|
|
|
/* we call try-to-free pages for make this cgroup empty */ |
|
lru_add_drain_all(); |
|
|
|
drain_all_stock(memcg); |
|
|
|
/* try to free all pages in this cgroup */ |
|
while (nr_retries && page_counter_read(&memcg->memory)) { |
|
if (signal_pending(current)) |
|
return -EINTR; |
|
|
|
if (!try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, |
|
MEMCG_RECLAIM_MAY_SWAP)) |
|
nr_retries--; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static ssize_t mem_cgroup_force_empty_write(struct kernfs_open_file *of, |
|
char *buf, size_t nbytes, |
|
loff_t off) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); |
|
|
|
if (mem_cgroup_is_root(memcg)) |
|
return -EINVAL; |
|
return mem_cgroup_force_empty(memcg) ?: nbytes; |
|
} |
|
|
|
static u64 mem_cgroup_hierarchy_read(struct cgroup_subsys_state *css, |
|
struct cftype *cft) |
|
{ |
|
return 1; |
|
} |
|
|
|
static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state *css, |
|
struct cftype *cft, u64 val) |
|
{ |
|
if (val == 1) |
|
return 0; |
|
|
|
pr_warn_once("Non-hierarchical mode is deprecated. " |
|
"Please report your usecase to [email protected] if you " |
|
"depend on this functionality.\n"); |
|
|
|
return -EINVAL; |
|
} |
|
|
|
static unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) |
|
{ |
|
unsigned long val; |
|
|
|
if (mem_cgroup_is_root(memcg)) { |
|
mem_cgroup_flush_stats(); |
|
val = memcg_page_state(memcg, NR_FILE_PAGES) + |
|
memcg_page_state(memcg, NR_ANON_MAPPED); |
|
if (swap) |
|
val += memcg_page_state(memcg, MEMCG_SWAP); |
|
} else { |
|
if (!swap) |
|
val = page_counter_read(&memcg->memory); |
|
else |
|
val = page_counter_read(&memcg->memsw); |
|
} |
|
return val; |
|
} |
|
|
|
enum { |
|
RES_USAGE, |
|
RES_LIMIT, |
|
RES_MAX_USAGE, |
|
RES_FAILCNT, |
|
RES_SOFT_LIMIT, |
|
}; |
|
|
|
static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css, |
|
struct cftype *cft) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
|
struct page_counter *counter; |
|
|
|
switch (MEMFILE_TYPE(cft->private)) { |
|
case _MEM: |
|
counter = &memcg->memory; |
|
break; |
|
case _MEMSWAP: |
|
counter = &memcg->memsw; |
|
break; |
|
case _KMEM: |
|
counter = &memcg->kmem; |
|
break; |
|
case _TCP: |
|
counter = &memcg->tcpmem; |
|
break; |
|
default: |
|
BUG(); |
|
} |
|
|
|
switch (MEMFILE_ATTR(cft->private)) { |
|
case RES_USAGE: |
|
if (counter == &memcg->memory) |
|
return (u64)mem_cgroup_usage(memcg, false) * PAGE_SIZE; |
|
if (counter == &memcg->memsw) |
|
return (u64)mem_cgroup_usage(memcg, true) * PAGE_SIZE; |
|
return (u64)page_counter_read(counter) * PAGE_SIZE; |
|
case RES_LIMIT: |
|
return (u64)counter->max * PAGE_SIZE; |
|
case RES_MAX_USAGE: |
|
return (u64)counter->watermark * PAGE_SIZE; |
|
case RES_FAILCNT: |
|
return counter->failcnt; |
|
case RES_SOFT_LIMIT: |
|
return (u64)memcg->soft_limit * PAGE_SIZE; |
|
default: |
|
BUG(); |
|
} |
|
} |
|
|
|
#ifdef CONFIG_MEMCG_KMEM |
|
static int memcg_online_kmem(struct mem_cgroup *memcg) |
|
{ |
|
struct obj_cgroup *objcg; |
|
|
|
if (mem_cgroup_kmem_disabled()) |
|
return 0; |
|
|
|
if (unlikely(mem_cgroup_is_root(memcg))) |
|
return 0; |
|
|
|
objcg = obj_cgroup_alloc(); |
|
if (!objcg) |
|
return -ENOMEM; |
|
|
|
objcg->memcg = memcg; |
|
rcu_assign_pointer(memcg->objcg, objcg); |
|
|
|
static_branch_enable(&memcg_kmem_enabled_key); |
|
|
|
memcg->kmemcg_id = memcg->id.id; |
|
|
|
return 0; |
|
} |
|
|
|
static void memcg_offline_kmem(struct mem_cgroup *memcg) |
|
{ |
|
struct mem_cgroup *parent; |
|
|
|
if (mem_cgroup_kmem_disabled()) |
|
return; |
|
|
|
if (unlikely(mem_cgroup_is_root(memcg))) |
|
return; |
|
|
|
parent = parent_mem_cgroup(memcg); |
|
if (!parent) |
|
parent = root_mem_cgroup; |
|
|
|
memcg_reparent_objcgs(memcg, parent); |
|
|
|
/* |
|
* After we have finished memcg_reparent_objcgs(), all list_lrus |
|
* corresponding to this cgroup are guaranteed to remain empty. |
|
* The ordering is imposed by list_lru_node->lock taken by |
|
* memcg_reparent_list_lrus(). |
|
*/ |
|
memcg_reparent_list_lrus(memcg, parent); |
|
} |
|
#else |
|
static int memcg_online_kmem(struct mem_cgroup *memcg) |
|
{ |
|
return 0; |
|
} |
|
static void memcg_offline_kmem(struct mem_cgroup *memcg) |
|
{ |
|
} |
|
#endif /* CONFIG_MEMCG_KMEM */ |
|
|
|
static int memcg_update_tcp_max(struct mem_cgroup *memcg, unsigned long max) |
|
{ |
|
int ret; |
|
|
|
mutex_lock(&memcg_max_mutex); |
|
|
|
ret = page_counter_set_max(&memcg->tcpmem, max); |
|
if (ret) |
|
goto out; |
|
|
|
if (!memcg->tcpmem_active) { |
|
/* |
|
* The active flag needs to be written after the static_key |
|
* update. This is what guarantees that the socket activation |
|
* function is the last one to run. See mem_cgroup_sk_alloc() |
|
* for details, and note that we don't mark any socket as |
|
* belonging to this memcg until that flag is up. |
|
* |
|
* We need to do this, because static_keys will span multiple |
|
* sites, but we can't control their order. If we mark a socket |
|
* as accounted, but the accounting functions are not patched in |
|
* yet, we'll lose accounting. |
|
* |
|
* We never race with the readers in mem_cgroup_sk_alloc(), |
|
* because when this value change, the code to process it is not |
|
* patched in yet. |
|
*/ |
|
static_branch_inc(&memcg_sockets_enabled_key); |
|
memcg->tcpmem_active = true; |
|
} |
|
out: |
|
mutex_unlock(&memcg_max_mutex); |
|
return ret; |
|
} |
|
|
|
/* |
|
* The user of this function is... |
|
* RES_LIMIT. |
|
*/ |
|
static ssize_t mem_cgroup_write(struct kernfs_open_file *of, |
|
char *buf, size_t nbytes, loff_t off) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); |
|
unsigned long nr_pages; |
|
int ret; |
|
|
|
buf = strstrip(buf); |
|
ret = page_counter_memparse(buf, "-1", &nr_pages); |
|
if (ret) |
|
return ret; |
|
|
|
switch (MEMFILE_ATTR(of_cft(of)->private)) { |
|
case RES_LIMIT: |
|
if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */ |
|
ret = -EINVAL; |
|
break; |
|
} |
|
switch (MEMFILE_TYPE(of_cft(of)->private)) { |
|
case _MEM: |
|
ret = mem_cgroup_resize_max(memcg, nr_pages, false); |
|
break; |
|
case _MEMSWAP: |
|
ret = mem_cgroup_resize_max(memcg, nr_pages, true); |
|
break; |
|
case _KMEM: |
|
/* kmem.limit_in_bytes is deprecated. */ |
|
ret = -EOPNOTSUPP; |
|
break; |
|
case _TCP: |
|
ret = memcg_update_tcp_max(memcg, nr_pages); |
|
break; |
|
} |
|
break; |
|
case RES_SOFT_LIMIT: |
|
if (IS_ENABLED(CONFIG_PREEMPT_RT)) { |
|
ret = -EOPNOTSUPP; |
|
} else { |
|
memcg->soft_limit = nr_pages; |
|
ret = 0; |
|
} |
|
break; |
|
} |
|
return ret ?: nbytes; |
|
} |
|
|
|
static ssize_t mem_cgroup_reset(struct kernfs_open_file *of, char *buf, |
|
size_t nbytes, loff_t off) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); |
|
struct page_counter *counter; |
|
|
|
switch (MEMFILE_TYPE(of_cft(of)->private)) { |
|
case _MEM: |
|
counter = &memcg->memory; |
|
break; |
|
case _MEMSWAP: |
|
counter = &memcg->memsw; |
|
break; |
|
case _KMEM: |
|
counter = &memcg->kmem; |
|
break; |
|
case _TCP: |
|
counter = &memcg->tcpmem; |
|
break; |
|
default: |
|
BUG(); |
|
} |
|
|
|
switch (MEMFILE_ATTR(of_cft(of)->private)) { |
|
case RES_MAX_USAGE: |
|
page_counter_reset_watermark(counter); |
|
break; |
|
case RES_FAILCNT: |
|
counter->failcnt = 0; |
|
break; |
|
default: |
|
BUG(); |
|
} |
|
|
|
return nbytes; |
|
} |
|
|
|
static u64 mem_cgroup_move_charge_read(struct cgroup_subsys_state *css, |
|
struct cftype *cft) |
|
{ |
|
return mem_cgroup_from_css(css)->move_charge_at_immigrate; |
|
} |
|
|
|
#ifdef CONFIG_MMU |
|
static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css, |
|
struct cftype *cft, u64 val) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
|
|
|
if (val & ~MOVE_MASK) |
|
return -EINVAL; |
|
|
|
/* |
|
* No kind of locking is needed in here, because ->can_attach() will |
|
* check this value once in the beginning of the process, and then carry |
|
* on with stale data. This means that changes to this value will only |
|
* affect task migrations starting after the change. |
|
*/ |
|
memcg->move_charge_at_immigrate = val; |
|
return 0; |
|
} |
|
#else |
|
static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css, |
|
struct cftype *cft, u64 val) |
|
{ |
|
return -ENOSYS; |
|
} |
|
#endif |
|
|
|
#ifdef CONFIG_NUMA |
|
|
|
#define LRU_ALL_FILE (BIT(LRU_INACTIVE_FILE) | BIT(LRU_ACTIVE_FILE)) |
|
#define LRU_ALL_ANON (BIT(LRU_INACTIVE_ANON) | BIT(LRU_ACTIVE_ANON)) |
|
#define LRU_ALL ((1 << NR_LRU_LISTS) - 1) |
|
|
|
static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg, |
|
int nid, unsigned int lru_mask, bool tree) |
|
{ |
|
struct lruvec *lruvec = mem_cgroup_lruvec(memcg, NODE_DATA(nid)); |
|
unsigned long nr = 0; |
|
enum lru_list lru; |
|
|
|
VM_BUG_ON((unsigned)nid >= nr_node_ids); |
|
|
|
for_each_lru(lru) { |
|
if (!(BIT(lru) & lru_mask)) |
|
continue; |
|
if (tree) |
|
nr += lruvec_page_state(lruvec, NR_LRU_BASE + lru); |
|
else |
|
nr += lruvec_page_state_local(lruvec, NR_LRU_BASE + lru); |
|
} |
|
return nr; |
|
} |
|
|
|
static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg, |
|
unsigned int lru_mask, |
|
bool tree) |
|
{ |
|
unsigned long nr = 0; |
|
enum lru_list lru; |
|
|
|
for_each_lru(lru) { |
|
if (!(BIT(lru) & lru_mask)) |
|
continue; |
|
if (tree) |
|
nr += memcg_page_state(memcg, NR_LRU_BASE + lru); |
|
else |
|
nr += memcg_page_state_local(memcg, NR_LRU_BASE + lru); |
|
} |
|
return nr; |
|
} |
|
|
|
static int memcg_numa_stat_show(struct seq_file *m, void *v) |
|
{ |
|
struct numa_stat { |
|
const char *name; |
|
unsigned int lru_mask; |
|
}; |
|
|
|
static const struct numa_stat stats[] = { |
|
{ "total", LRU_ALL }, |
|
{ "file", LRU_ALL_FILE }, |
|
{ "anon", LRU_ALL_ANON }, |
|
{ "unevictable", BIT(LRU_UNEVICTABLE) }, |
|
}; |
|
const struct numa_stat *stat; |
|
int nid; |
|
struct mem_cgroup *memcg = mem_cgroup_from_seq(m); |
|
|
|
mem_cgroup_flush_stats(); |
|
|
|
for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) { |
|
seq_printf(m, "%s=%lu", stat->name, |
|
mem_cgroup_nr_lru_pages(memcg, stat->lru_mask, |
|
false)); |
|
for_each_node_state(nid, N_MEMORY) |
|
seq_printf(m, " N%d=%lu", nid, |
|
mem_cgroup_node_nr_lru_pages(memcg, nid, |
|
stat->lru_mask, false)); |
|
seq_putc(m, '\n'); |
|
} |
|
|
|
for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) { |
|
|
|
seq_printf(m, "hierarchical_%s=%lu", stat->name, |
|
mem_cgroup_nr_lru_pages(memcg, stat->lru_mask, |
|
true)); |
|
for_each_node_state(nid, N_MEMORY) |
|
seq_printf(m, " N%d=%lu", nid, |
|
mem_cgroup_node_nr_lru_pages(memcg, nid, |
|
stat->lru_mask, true)); |
|
seq_putc(m, '\n'); |
|
} |
|
|
|
return 0; |
|
} |
|
#endif /* CONFIG_NUMA */ |
|
|
|
static const unsigned int memcg1_stats[] = { |
|
NR_FILE_PAGES, |
|
NR_ANON_MAPPED, |
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE |
|
NR_ANON_THPS, |
|
#endif |
|
NR_SHMEM, |
|
NR_FILE_MAPPED, |
|
NR_FILE_DIRTY, |
|
NR_WRITEBACK, |
|
WORKINGSET_REFAULT_ANON, |
|
WORKINGSET_REFAULT_FILE, |
|
MEMCG_SWAP, |
|
}; |
|
|
|
static const char *const memcg1_stat_names[] = { |
|
"cache", |
|
"rss", |
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE |
|
"rss_huge", |
|
#endif |
|
"shmem", |
|
"mapped_file", |
|
"dirty", |
|
"writeback", |
|
"workingset_refault_anon", |
|
"workingset_refault_file", |
|
"swap", |
|
}; |
|
|
|
/* Universal VM events cgroup1 shows, original sort order */ |
|
static const unsigned int memcg1_events[] = { |
|
PGPGIN, |
|
PGPGOUT, |
|
PGFAULT, |
|
PGMAJFAULT, |
|
}; |
|
|
|
static int memcg_stat_show(struct seq_file *m, void *v) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_seq(m); |
|
unsigned long memory, memsw; |
|
struct mem_cgroup *mi; |
|
unsigned int i; |
|
|
|
BUILD_BUG_ON(ARRAY_SIZE(memcg1_stat_names) != ARRAY_SIZE(memcg1_stats)); |
|
|
|
mem_cgroup_flush_stats(); |
|
|
|
for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) { |
|
unsigned long nr; |
|
|
|
if (memcg1_stats[i] == MEMCG_SWAP && !do_memsw_account()) |
|
continue; |
|
nr = memcg_page_state_local(memcg, memcg1_stats[i]); |
|
seq_printf(m, "%s %lu\n", memcg1_stat_names[i], |
|
nr * memcg_page_state_unit(memcg1_stats[i])); |
|
} |
|
|
|
for (i = 0; i < ARRAY_SIZE(memcg1_events); i++) |
|
seq_printf(m, "%s %lu\n", vm_event_name(memcg1_events[i]), |
|
memcg_events_local(memcg, memcg1_events[i])); |
|
|
|
for (i = 0; i < NR_LRU_LISTS; i++) |
|
seq_printf(m, "%s %lu\n", lru_list_name(i), |
|
memcg_page_state_local(memcg, NR_LRU_BASE + i) * |
|
PAGE_SIZE); |
|
|
|
/* Hierarchical information */ |
|
memory = memsw = PAGE_COUNTER_MAX; |
|
for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) { |
|
memory = min(memory, READ_ONCE(mi->memory.max)); |
|
memsw = min(memsw, READ_ONCE(mi->memsw.max)); |
|
} |
|
seq_printf(m, "hierarchical_memory_limit %llu\n", |
|
(u64)memory * PAGE_SIZE); |
|
if (do_memsw_account()) |
|
seq_printf(m, "hierarchical_memsw_limit %llu\n", |
|
(u64)memsw * PAGE_SIZE); |
|
|
|
for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) { |
|
unsigned long nr; |
|
|
|
if (memcg1_stats[i] == MEMCG_SWAP && !do_memsw_account()) |
|
continue; |
|
nr = memcg_page_state(memcg, memcg1_stats[i]); |
|
seq_printf(m, "total_%s %llu\n", memcg1_stat_names[i], |
|
(u64)nr * memcg_page_state_unit(memcg1_stats[i])); |
|
} |
|
|
|
for (i = 0; i < ARRAY_SIZE(memcg1_events); i++) |
|
seq_printf(m, "total_%s %llu\n", |
|
vm_event_name(memcg1_events[i]), |
|
(u64)memcg_events(memcg, memcg1_events[i])); |
|
|
|
for (i = 0; i < NR_LRU_LISTS; i++) |
|
seq_printf(m, "total_%s %llu\n", lru_list_name(i), |
|
(u64)memcg_page_state(memcg, NR_LRU_BASE + i) * |
|
PAGE_SIZE); |
|
|
|
#ifdef CONFIG_DEBUG_VM |
|
{ |
|
pg_data_t *pgdat; |
|
struct mem_cgroup_per_node *mz; |
|
unsigned long anon_cost = 0; |
|
unsigned long file_cost = 0; |
|
|
|
for_each_online_pgdat(pgdat) { |
|
mz = memcg->nodeinfo[pgdat->node_id]; |
|
|
|
anon_cost += mz->lruvec.anon_cost; |
|
file_cost += mz->lruvec.file_cost; |
|
} |
|
seq_printf(m, "anon_cost %lu\n", anon_cost); |
|
seq_printf(m, "file_cost %lu\n", file_cost); |
|
} |
|
#endif |
|
|
|
return 0; |
|
} |
|
|
|
static u64 mem_cgroup_swappiness_read(struct cgroup_subsys_state *css, |
|
struct cftype *cft) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
|
|
|
return mem_cgroup_swappiness(memcg); |
|
} |
|
|
|
static int mem_cgroup_swappiness_write(struct cgroup_subsys_state *css, |
|
struct cftype *cft, u64 val) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
|
|
|
if (val > 200) |
|
return -EINVAL; |
|
|
|
if (!mem_cgroup_is_root(memcg)) |
|
memcg->swappiness = val; |
|
else |
|
vm_swappiness = val; |
|
|
|
return 0; |
|
} |
|
|
|
static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap) |
|
{ |
|
struct mem_cgroup_threshold_ary *t; |
|
unsigned long usage; |
|
int i; |
|
|
|
rcu_read_lock(); |
|
if (!swap) |
|
t = rcu_dereference(memcg->thresholds.primary); |
|
else |
|
t = rcu_dereference(memcg->memsw_thresholds.primary); |
|
|
|
if (!t) |
|
goto unlock; |
|
|
|
usage = mem_cgroup_usage(memcg, swap); |
|
|
|
/* |
|
* current_threshold points to threshold just below or equal to usage. |
|
* If it's not true, a threshold was crossed after last |
|
* call of __mem_cgroup_threshold(). |
|
*/ |
|
i = t->current_threshold; |
|
|
|
/* |
|
* Iterate backward over array of thresholds starting from |
|
* current_threshold and check if a threshold is crossed. |
|
* If none of thresholds below usage is crossed, we read |
|
* only one element of the array here. |
|
*/ |
|
for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--) |
|
eventfd_signal(t->entries[i].eventfd, 1); |
|
|
|
/* i = current_threshold + 1 */ |
|
i++; |
|
|
|
/* |
|
* Iterate forward over array of thresholds starting from |
|
* current_threshold+1 and check if a threshold is crossed. |
|
* If none of thresholds above usage is crossed, we read |
|
* only one element of the array here. |
|
*/ |
|
for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++) |
|
eventfd_signal(t->entries[i].eventfd, 1); |
|
|
|
/* Update current_threshold */ |
|
t->current_threshold = i - 1; |
|
unlock: |
|
rcu_read_unlock(); |
|
} |
|
|
|
static void mem_cgroup_threshold(struct mem_cgroup *memcg) |
|
{ |
|
while (memcg) { |
|
__mem_cgroup_threshold(memcg, false); |
|
if (do_memsw_account()) |
|
__mem_cgroup_threshold(memcg, true); |
|
|
|
memcg = parent_mem_cgroup(memcg); |
|
} |
|
} |
|
|
|
static int compare_thresholds(const void *a, const void *b) |
|
{ |
|
const struct mem_cgroup_threshold *_a = a; |
|
const struct mem_cgroup_threshold *_b = b; |
|
|
|
if (_a->threshold > _b->threshold) |
|
return 1; |
|
|
|
if (_a->threshold < _b->threshold) |
|
return -1; |
|
|
|
return 0; |
|
} |
|
|
|
static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg) |
|
{ |
|
struct mem_cgroup_eventfd_list *ev; |
|
|
|
spin_lock(&memcg_oom_lock); |
|
|
|
list_for_each_entry(ev, &memcg->oom_notify, list) |
|
eventfd_signal(ev->eventfd, 1); |
|
|
|
spin_unlock(&memcg_oom_lock); |
|
return 0; |
|
} |
|
|
|
static void mem_cgroup_oom_notify(struct mem_cgroup *memcg) |
|
{ |
|
struct mem_cgroup *iter; |
|
|
|
for_each_mem_cgroup_tree(iter, memcg) |
|
mem_cgroup_oom_notify_cb(iter); |
|
} |
|
|
|
static int __mem_cgroup_usage_register_event(struct mem_cgroup *memcg, |
|
struct eventfd_ctx *eventfd, const char *args, enum res_type type) |
|
{ |
|
struct mem_cgroup_thresholds *thresholds; |
|
struct mem_cgroup_threshold_ary *new; |
|
unsigned long threshold; |
|
unsigned long usage; |
|
int i, size, ret; |
|
|
|
ret = page_counter_memparse(args, "-1", &threshold); |
|
if (ret) |
|
return ret; |
|
|
|
mutex_lock(&memcg->thresholds_lock); |
|
|
|
if (type == _MEM) { |
|
thresholds = &memcg->thresholds; |
|
usage = mem_cgroup_usage(memcg, false); |
|
} else if (type == _MEMSWAP) { |
|
thresholds = &memcg->memsw_thresholds; |
|
usage = mem_cgroup_usage(memcg, true); |
|
} else |
|
BUG(); |
|
|
|
/* Check if a threshold crossed before adding a new one */ |
|
if (thresholds->primary) |
|
__mem_cgroup_threshold(memcg, type == _MEMSWAP); |
|
|
|
size = thresholds->primary ? thresholds->primary->size + 1 : 1; |
|
|
|
/* Allocate memory for new array of thresholds */ |
|
new = kmalloc(struct_size(new, entries, size), GFP_KERNEL); |
|
if (!new) { |
|
ret = -ENOMEM; |
|
goto unlock; |
|
} |
|
new->size = size; |
|
|
|
/* Copy thresholds (if any) to new array */ |
|
if (thresholds->primary) |
|
memcpy(new->entries, thresholds->primary->entries, |
|
flex_array_size(new, entries, size - 1)); |
|
|
|
/* Add new threshold */ |
|
new->entries[size - 1].eventfd = eventfd; |
|
new->entries[size - 1].threshold = threshold; |
|
|
|
/* Sort thresholds. Registering of new threshold isn't time-critical */ |
|
sort(new->entries, size, sizeof(*new->entries), |
|
compare_thresholds, NULL); |
|
|
|
/* Find current threshold */ |
|
new->current_threshold = -1; |
|
for (i = 0; i < size; i++) { |
|
if (new->entries[i].threshold <= usage) { |
|
/* |
|
* new->current_threshold will not be used until |
|
* rcu_assign_pointer(), so it's safe to increment |
|
* it here. |
|
*/ |
|
++new->current_threshold; |
|
} else |
|
break; |
|
} |
|
|
|
/* Free old spare buffer and save old primary buffer as spare */ |
|
kfree(thresholds->spare); |
|
thresholds->spare = thresholds->primary; |
|
|
|
rcu_assign_pointer(thresholds->primary, new); |
|
|
|
/* To be sure that nobody uses thresholds */ |
|
synchronize_rcu(); |
|
|
|
unlock: |
|
mutex_unlock(&memcg->thresholds_lock); |
|
|
|
return ret; |
|
} |
|
|
|
static int mem_cgroup_usage_register_event(struct mem_cgroup *memcg, |
|
struct eventfd_ctx *eventfd, const char *args) |
|
{ |
|
return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEM); |
|
} |
|
|
|
static int memsw_cgroup_usage_register_event(struct mem_cgroup *memcg, |
|
struct eventfd_ctx *eventfd, const char *args) |
|
{ |
|
return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEMSWAP); |
|
} |
|
|
|
static void __mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg, |
|
struct eventfd_ctx *eventfd, enum res_type type) |
|
{ |
|
struct mem_cgroup_thresholds *thresholds; |
|
struct mem_cgroup_threshold_ary *new; |
|
unsigned long usage; |
|
int i, j, size, entries; |
|
|
|
mutex_lock(&memcg->thresholds_lock); |
|
|
|
if (type == _MEM) { |
|
thresholds = &memcg->thresholds; |
|
usage = mem_cgroup_usage(memcg, false); |
|
} else if (type == _MEMSWAP) { |
|
thresholds = &memcg->memsw_thresholds; |
|
usage = mem_cgroup_usage(memcg, true); |
|
} else |
|
BUG(); |
|
|
|
if (!thresholds->primary) |
|
goto unlock; |
|
|
|
/* Check if a threshold crossed before removing */ |
|
__mem_cgroup_threshold(memcg, type == _MEMSWAP); |
|
|
|
/* Calculate new number of threshold */ |
|
size = entries = 0; |
|
for (i = 0; i < thresholds->primary->size; i++) { |
|
if (thresholds->primary->entries[i].eventfd != eventfd) |
|
size++; |
|
else |
|
entries++; |
|
} |
|
|
|
new = thresholds->spare; |
|
|
|
/* If no items related to eventfd have been cleared, nothing to do */ |
|
if (!entries) |
|
goto unlock; |
|
|
|
/* Set thresholds array to NULL if we don't have thresholds */ |
|
if (!size) { |
|
kfree(new); |
|
new = NULL; |
|
goto swap_buffers; |
|
} |
|
|
|
new->size = size; |
|
|
|
/* Copy thresholds and find current threshold */ |
|
new->current_threshold = -1; |
|
for (i = 0, j = 0; i < thresholds->primary->size; i++) { |
|
if (thresholds->primary->entries[i].eventfd == eventfd) |
|
continue; |
|
|
|
new->entries[j] = thresholds->primary->entries[i]; |
|
if (new->entries[j].threshold <= usage) { |
|
/* |
|
* new->current_threshold will not be used |
|
* until rcu_assign_pointer(), so it's safe to increment |
|
* it here. |
|
*/ |
|
++new->current_threshold; |
|
} |
|
j++; |
|
} |
|
|
|
swap_buffers: |
|
/* Swap primary and spare array */ |
|
thresholds->spare = thresholds->primary; |
|
|
|
rcu_assign_pointer(thresholds->primary, new); |
|
|
|
/* To be sure that nobody uses thresholds */ |
|
synchronize_rcu(); |
|
|
|
/* If all events are unregistered, free the spare array */ |
|
if (!new) { |
|
kfree(thresholds->spare); |
|
thresholds->spare = NULL; |
|
} |
|
unlock: |
|
mutex_unlock(&memcg->thresholds_lock); |
|
} |
|
|
|
static void mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg, |
|
struct eventfd_ctx *eventfd) |
|
{ |
|
return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEM); |
|
} |
|
|
|
static void memsw_cgroup_usage_unregister_event(struct mem_cgroup *memcg, |
|
struct eventfd_ctx *eventfd) |
|
{ |
|
return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEMSWAP); |
|
} |
|
|
|
static int mem_cgroup_oom_register_event(struct mem_cgroup *memcg, |
|
struct eventfd_ctx *eventfd, const char *args) |
|
{ |
|
struct mem_cgroup_eventfd_list *event; |
|
|
|
event = kmalloc(sizeof(*event), GFP_KERNEL); |
|
if (!event) |
|
return -ENOMEM; |
|
|
|
spin_lock(&memcg_oom_lock); |
|
|
|
event->eventfd = eventfd; |
|
list_add(&event->list, &memcg->oom_notify); |
|
|
|
/* already in OOM ? */ |
|
if (memcg->under_oom) |
|
eventfd_signal(eventfd, 1); |
|
spin_unlock(&memcg_oom_lock); |
|
|
|
return 0; |
|
} |
|
|
|
static void mem_cgroup_oom_unregister_event(struct mem_cgroup *memcg, |
|
struct eventfd_ctx *eventfd) |
|
{ |
|
struct mem_cgroup_eventfd_list *ev, *tmp; |
|
|
|
spin_lock(&memcg_oom_lock); |
|
|
|
list_for_each_entry_safe(ev, tmp, &memcg->oom_notify, list) { |
|
if (ev->eventfd == eventfd) { |
|
list_del(&ev->list); |
|
kfree(ev); |
|
} |
|
} |
|
|
|
spin_unlock(&memcg_oom_lock); |
|
} |
|
|
|
static int mem_cgroup_oom_control_read(struct seq_file *sf, void *v) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_seq(sf); |
|
|
|
seq_printf(sf, "oom_kill_disable %d\n", memcg->oom_kill_disable); |
|
seq_printf(sf, "under_oom %d\n", (bool)memcg->under_oom); |
|
seq_printf(sf, "oom_kill %lu\n", |
|
atomic_long_read(&memcg->memory_events[MEMCG_OOM_KILL])); |
|
return 0; |
|
} |
|
|
|
static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css, |
|
struct cftype *cft, u64 val) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
|
|
|
/* cannot set to root cgroup and only 0 and 1 are allowed */ |
|
if (mem_cgroup_is_root(memcg) || !((val == 0) || (val == 1))) |
|
return -EINVAL; |
|
|
|
memcg->oom_kill_disable = val; |
|
if (!val) |
|
memcg_oom_recover(memcg); |
|
|
|
return 0; |
|
} |
|
|
|
#ifdef CONFIG_CGROUP_WRITEBACK |
|
|
|
#include <trace/events/writeback.h> |
|
|
|
static int memcg_wb_domain_init(struct mem_cgroup *memcg, gfp_t gfp) |
|
{ |
|
return wb_domain_init(&memcg->cgwb_domain, gfp); |
|
} |
|
|
|
static void memcg_wb_domain_exit(struct mem_cgroup *memcg) |
|
{ |
|
wb_domain_exit(&memcg->cgwb_domain); |
|
} |
|
|
|
static void memcg_wb_domain_size_changed(struct mem_cgroup *memcg) |
|
{ |
|
wb_domain_size_changed(&memcg->cgwb_domain); |
|
} |
|
|
|
struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css); |
|
|
|
if (!memcg->css.parent) |
|
return NULL; |
|
|
|
return &memcg->cgwb_domain; |
|
} |
|
|
|
/** |
|
* mem_cgroup_wb_stats - retrieve writeback related stats from its memcg |
|
* @wb: bdi_writeback in question |
|
* @pfilepages: out parameter for number of file pages |
|
* @pheadroom: out parameter for number of allocatable pages according to memcg |
|
* @pdirty: out parameter for number of dirty pages |
|
* @pwriteback: out parameter for number of pages under writeback |
|
* |
|
* Determine the numbers of file, headroom, dirty, and writeback pages in |
|
* @wb's memcg. File, dirty and writeback are self-explanatory. Headroom |
|
* is a bit more involved. |
|
* |
|
* A memcg's headroom is "min(max, high) - used". In the hierarchy, the |
|
* headroom is calculated as the lowest headroom of itself and the |
|
* ancestors. Note that this doesn't consider the actual amount of |
|
* available memory in the system. The caller should further cap |
|
* *@pheadroom accordingly. |
|
*/ |
|
void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages, |
|
unsigned long *pheadroom, unsigned long *pdirty, |
|
unsigned long *pwriteback) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css); |
|
struct mem_cgroup *parent; |
|
|
|
mem_cgroup_flush_stats(); |
|
|
|
*pdirty = memcg_page_state(memcg, NR_FILE_DIRTY); |
|
*pwriteback = memcg_page_state(memcg, NR_WRITEBACK); |
|
*pfilepages = memcg_page_state(memcg, NR_INACTIVE_FILE) + |
|
memcg_page_state(memcg, NR_ACTIVE_FILE); |
|
|
|
*pheadroom = PAGE_COUNTER_MAX; |
|
while ((parent = parent_mem_cgroup(memcg))) { |
|
unsigned long ceiling = min(READ_ONCE(memcg->memory.max), |
|
READ_ONCE(memcg->memory.high)); |
|
unsigned long used = page_counter_read(&memcg->memory); |
|
|
|
*pheadroom = min(*pheadroom, ceiling - min(ceiling, used)); |
|
memcg = parent; |
|
} |
|
} |
|
|
|
/* |
|
* Foreign dirty flushing |
|
* |
|
* There's an inherent mismatch between memcg and writeback. The former |
|
* tracks ownership per-page while the latter per-inode. This was a |
|
* deliberate design decision because honoring per-page ownership in the |
|
* writeback path is complicated, may lead to higher CPU and IO overheads |
|
* and deemed unnecessary given that write-sharing an inode across |
|
* different cgroups isn't a common use-case. |
|
* |
|
* Combined with inode majority-writer ownership switching, this works well |
|
* enough in most cases but there are some pathological cases. For |
|
* example, let's say there are two cgroups A and B which keep writing to |
|
* different but confined parts of the same inode. B owns the inode and |
|
* A's memory is limited far below B's. A's dirty ratio can rise enough to |
|
* trigger balance_dirty_pages() sleeps but B's can be low enough to avoid |
|
* triggering background writeback. A will be slowed down without a way to |
|
* make writeback of the dirty pages happen. |
|
* |
|
* Conditions like the above can lead to a cgroup getting repeatedly and |
|
* severely throttled after making some progress after each |
|
* dirty_expire_interval while the underlying IO device is almost |
|
* completely idle. |
|
* |
|
* Solving this problem completely requires matching the ownership tracking |
|
* granularities between memcg and writeback in either direction. However, |
|
* the more egregious behaviors can be avoided by simply remembering the |
|
* most recent foreign dirtying events and initiating remote flushes on |
|
* them when local writeback isn't enough to keep the memory clean enough. |
|
* |
|
* The following two functions implement such mechanism. When a foreign |
|
* page - a page whose memcg and writeback ownerships don't match - is |
|
* dirtied, mem_cgroup_track_foreign_dirty() records the inode owning |
|
* bdi_writeback on the page owning memcg. When balance_dirty_pages() |
|
* decides that the memcg needs to sleep due to high dirty ratio, it calls |
|
* mem_cgroup_flush_foreign() which queues writeback on the recorded |
|
* foreign bdi_writebacks which haven't expired. Both the numbers of |
|
* recorded bdi_writebacks and concurrent in-flight foreign writebacks are |
|
* limited to MEMCG_CGWB_FRN_CNT. |
|
* |
|
* The mechanism only remembers IDs and doesn't hold any object references. |
|
* As being wrong occasionally doesn't matter, updates and accesses to the |
|
* records are lockless and racy. |
|
*/ |
|
void mem_cgroup_track_foreign_dirty_slowpath(struct folio *folio, |
|
struct bdi_writeback *wb) |
|
{ |
|
struct mem_cgroup *memcg = folio_memcg(folio); |
|
struct memcg_cgwb_frn *frn; |
|
u64 now = get_jiffies_64(); |
|
u64 oldest_at = now; |
|
int oldest = -1; |
|
int i; |
|
|
|
trace_track_foreign_dirty(folio, wb); |
|
|
|
/* |
|
* Pick the slot to use. If there is already a slot for @wb, keep |
|
* using it. If not replace the oldest one which isn't being |
|
* written out. |
|
*/ |
|
for (i = 0; i < MEMCG_CGWB_FRN_CNT; i++) { |
|
frn = &memcg->cgwb_frn[i]; |
|
if (frn->bdi_id == wb->bdi->id && |
|
frn->memcg_id == wb->memcg_css->id) |
|
break; |
|
if (time_before64(frn->at, oldest_at) && |
|
atomic_read(&frn->done.cnt) == 1) { |
|
oldest = i; |
|
oldest_at = frn->at; |
|
} |
|
} |
|
|
|
if (i < MEMCG_CGWB_FRN_CNT) { |
|
/* |
|
* Re-using an existing one. Update timestamp lazily to |
|
* avoid making the cacheline hot. We want them to be |
|
* reasonably up-to-date and significantly shorter than |
|
* dirty_expire_interval as that's what expires the record. |
|
* Use the shorter of 1s and dirty_expire_interval / 8. |
|
*/ |
|
unsigned long update_intv = |
|
min_t(unsigned long, HZ, |
|
msecs_to_jiffies(dirty_expire_interval * 10) / 8); |
|
|
|
if (time_before64(frn->at, now - update_intv)) |
|
frn->at = now; |
|
} else if (oldest >= 0) { |
|
/* replace the oldest free one */ |
|
frn = &memcg->cgwb_frn[oldest]; |
|
frn->bdi_id = wb->bdi->id; |
|
frn->memcg_id = wb->memcg_css->id; |
|
frn->at = now; |
|
} |
|
} |
|
|
|
/* issue foreign writeback flushes for recorded foreign dirtying events */ |
|
void mem_cgroup_flush_foreign(struct bdi_writeback *wb) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css); |
|
unsigned long intv = msecs_to_jiffies(dirty_expire_interval * 10); |
|
u64 now = jiffies_64; |
|
int i; |
|
|
|
for (i = 0; i < MEMCG_CGWB_FRN_CNT; i++) { |
|
struct memcg_cgwb_frn *frn = &memcg->cgwb_frn[i]; |
|
|
|
/* |
|
* If the record is older than dirty_expire_interval, |
|
* writeback on it has already started. No need to kick it |
|
* off again. Also, don't start a new one if there's |
|
* already one in flight. |
|
*/ |
|
if (time_after64(frn->at, now - intv) && |
|
atomic_read(&frn->done.cnt) == 1) { |
|
frn->at = 0; |
|
trace_flush_foreign(wb, frn->bdi_id, frn->memcg_id); |
|
cgroup_writeback_by_id(frn->bdi_id, frn->memcg_id, |
|
WB_REASON_FOREIGN_FLUSH, |
|
&frn->done); |
|
} |
|
} |
|
} |
|
|
|
#else /* CONFIG_CGROUP_WRITEBACK */ |
|
|
|
static int memcg_wb_domain_init(struct mem_cgroup *memcg, gfp_t gfp) |
|
{ |
|
return 0; |
|
} |
|
|
|
static void memcg_wb_domain_exit(struct mem_cgroup *memcg) |
|
{ |
|
} |
|
|
|
static void memcg_wb_domain_size_changed(struct mem_cgroup *memcg) |
|
{ |
|
} |
|
|
|
#endif /* CONFIG_CGROUP_WRITEBACK */ |
|
|
|
/* |
|
* DO NOT USE IN NEW FILES. |
|
* |
|
* "cgroup.event_control" implementation. |
|
* |
|
* This is way over-engineered. It tries to support fully configurable |
|
* events for each user. Such level of flexibility is completely |
|
* unnecessary especially in the light of the planned unified hierarchy. |
|
* |
|
* Please deprecate this and replace with something simpler if at all |
|
* possible. |
|
*/ |
|
|
|
/* |
|
* Unregister event and free resources. |
|
* |
|
* Gets called from workqueue. |
|
*/ |
|
static void memcg_event_remove(struct work_struct *work) |
|
{ |
|
struct mem_cgroup_event *event = |
|
container_of(work, struct mem_cgroup_event, remove); |
|
struct mem_cgroup *memcg = event->memcg; |
|
|
|
remove_wait_queue(event->wqh, &event->wait); |
|
|
|
event->unregister_event(memcg, event->eventfd); |
|
|
|
/* Notify userspace the event is going away. */ |
|
eventfd_signal(event->eventfd, 1); |
|
|
|
eventfd_ctx_put(event->eventfd); |
|
kfree(event); |
|
css_put(&memcg->css); |
|
} |
|
|
|
/* |
|
* Gets called on EPOLLHUP on eventfd when user closes it. |
|
* |
|
* Called with wqh->lock held and interrupts disabled. |
|
*/ |
|
static int memcg_event_wake(wait_queue_entry_t *wait, unsigned mode, |
|
int sync, void *key) |
|
{ |
|
struct mem_cgroup_event *event = |
|
container_of(wait, struct mem_cgroup_event, wait); |
|
struct mem_cgroup *memcg = event->memcg; |
|
__poll_t flags = key_to_poll(key); |
|
|
|
if (flags & EPOLLHUP) { |
|
/* |
|
* If the event has been detached at cgroup removal, we |
|
* can simply return knowing the other side will cleanup |
|
* for us. |
|
* |
|
* We can't race against event freeing since the other |
|
* side will require wqh->lock via remove_wait_queue(), |
|
* which we hold. |
|
*/ |
|
spin_lock(&memcg->event_list_lock); |
|
if (!list_empty(&event->list)) { |
|
list_del_init(&event->list); |
|
/* |
|
* We are in atomic context, but cgroup_event_remove() |
|
* may sleep, so we have to call it in workqueue. |
|
*/ |
|
schedule_work(&event->remove); |
|
} |
|
spin_unlock(&memcg->event_list_lock); |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static void memcg_event_ptable_queue_proc(struct file *file, |
|
wait_queue_head_t *wqh, poll_table *pt) |
|
{ |
|
struct mem_cgroup_event *event = |
|
container_of(pt, struct mem_cgroup_event, pt); |
|
|
|
event->wqh = wqh; |
|
add_wait_queue(wqh, &event->wait); |
|
} |
|
|
|
/* |
|
* DO NOT USE IN NEW FILES. |
|
* |
|
* Parse input and register new cgroup event handler. |
|
* |
|
* Input must be in format '<event_fd> <control_fd> <args>'. |
|
* Interpretation of args is defined by control file implementation. |
|
*/ |
|
static ssize_t memcg_write_event_control(struct kernfs_open_file *of, |
|
char *buf, size_t nbytes, loff_t off) |
|
{ |
|
struct cgroup_subsys_state *css = of_css(of); |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
|
struct mem_cgroup_event *event; |
|
struct cgroup_subsys_state *cfile_css; |
|
unsigned int efd, cfd; |
|
struct fd efile; |
|
struct fd cfile; |
|
struct dentry *cdentry; |
|
const char *name; |
|
char *endp; |
|
int ret; |
|
|
|
if (IS_ENABLED(CONFIG_PREEMPT_RT)) |
|
return -EOPNOTSUPP; |
|
|
|
buf = strstrip(buf); |
|
|
|
efd = simple_strtoul(buf, &endp, 10); |
|
if (*endp != ' ') |
|
return -EINVAL; |
|
buf = endp + 1; |
|
|
|
cfd = simple_strtoul(buf, &endp, 10); |
|
if ((*endp != ' ') && (*endp != '\0')) |
|
return -EINVAL; |
|
buf = endp + 1; |
|
|
|
event = kzalloc(sizeof(*event), GFP_KERNEL); |
|
if (!event) |
|
return -ENOMEM; |
|
|
|
event->memcg = memcg; |
|
INIT_LIST_HEAD(&event->list); |
|
init_poll_funcptr(&event->pt, memcg_event_ptable_queue_proc); |
|
init_waitqueue_func_entry(&event->wait, memcg_event_wake); |
|
INIT_WORK(&event->remove, memcg_event_remove); |
|
|
|
efile = fdget(efd); |
|
if (!efile.file) { |
|
ret = -EBADF; |
|
goto out_kfree; |
|
} |
|
|
|
event->eventfd = eventfd_ctx_fileget(efile.file); |
|
if (IS_ERR(event->eventfd)) { |
|
ret = PTR_ERR(event->eventfd); |
|
goto out_put_efile; |
|
} |
|
|
|
cfile = fdget(cfd); |
|
if (!cfile.file) { |
|
ret = -EBADF; |
|
goto out_put_eventfd; |
|
} |
|
|
|
/* the process need read permission on control file */ |
|
/* AV: shouldn't we check that it's been opened for read instead? */ |
|
ret = file_permission(cfile.file, MAY_READ); |
|
if (ret < 0) |
|
goto out_put_cfile; |
|
|
|
/* |
|
* The control file must be a regular cgroup1 file. As a regular cgroup |
|
* file can't be renamed, it's safe to access its name afterwards. |
|
*/ |
|
cdentry = cfile.file->f_path.dentry; |
|
if (cdentry->d_sb->s_type != &cgroup_fs_type || !d_is_reg(cdentry)) { |
|
ret = -EINVAL; |
|
goto out_put_cfile; |
|
} |
|
|
|
/* |
|
* Determine the event callbacks and set them in @event. This used |
|
* to be done via struct cftype but cgroup core no longer knows |
|
* about these events. The following is crude but the whole thing |
|
* is for compatibility anyway. |
|
* |
|
* DO NOT ADD NEW FILES. |
|
*/ |
|
name = cdentry->d_name.name; |
|
|
|
if (!strcmp(name, "memory.usage_in_bytes")) { |
|
event->register_event = mem_cgroup_usage_register_event; |
|
event->unregister_event = mem_cgroup_usage_unregister_event; |
|
} else if (!strcmp(name, "memory.oom_control")) { |
|
event->register_event = mem_cgroup_oom_register_event; |
|
event->unregister_event = mem_cgroup_oom_unregister_event; |
|
} else if (!strcmp(name, "memory.pressure_level")) { |
|
event->register_event = vmpressure_register_event; |
|
event->unregister_event = vmpressure_unregister_event; |
|
} else if (!strcmp(name, "memory.memsw.usage_in_bytes")) { |
|
event->register_event = memsw_cgroup_usage_register_event; |
|
event->unregister_event = memsw_cgroup_usage_unregister_event; |
|
} else { |
|
ret = -EINVAL; |
|
goto out_put_cfile; |
|
} |
|
|
|
/* |
|
* Verify @cfile should belong to @css. Also, remaining events are |
|
* automatically removed on cgroup destruction but the removal is |
|
* asynchronous, so take an extra ref on @css. |
|
*/ |
|
cfile_css = css_tryget_online_from_dir(cdentry->d_parent, |
|
&memory_cgrp_subsys); |
|
ret = -EINVAL; |
|
if (IS_ERR(cfile_css)) |
|
goto out_put_cfile; |
|
if (cfile_css != css) { |
|
css_put(cfile_css); |
|
goto out_put_cfile; |
|
} |
|
|
|
ret = event->register_event(memcg, event->eventfd, buf); |
|
if (ret) |
|
goto out_put_css; |
|
|
|
vfs_poll(efile.file, &event->pt); |
|
|
|
spin_lock_irq(&memcg->event_list_lock); |
|
list_add(&event->list, &memcg->event_list); |
|
spin_unlock_irq(&memcg->event_list_lock); |
|
|
|
fdput(cfile); |
|
fdput(efile); |
|
|
|
return nbytes; |
|
|
|
out_put_css: |
|
css_put(css); |
|
out_put_cfile: |
|
fdput(cfile); |
|
out_put_eventfd: |
|
eventfd_ctx_put(event->eventfd); |
|
out_put_efile: |
|
fdput(efile); |
|
out_kfree: |
|
kfree(event); |
|
|
|
return ret; |
|
} |
|
|
|
#if defined(CONFIG_MEMCG_KMEM) && (defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)) |
|
static int mem_cgroup_slab_show(struct seq_file *m, void *p) |
|
{ |
|
/* |
|
* Deprecated. |
|
* Please, take a look at tools/cgroup/memcg_slabinfo.py . |
|
*/ |
|
return 0; |
|
} |
|
#endif |
|
|
|
static struct cftype mem_cgroup_legacy_files[] = { |
|
{ |
|
.name = "usage_in_bytes", |
|
.private = MEMFILE_PRIVATE(_MEM, RES_USAGE), |
|
.read_u64 = mem_cgroup_read_u64, |
|
}, |
|
{ |
|
.name = "max_usage_in_bytes", |
|
.private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE), |
|
.write = mem_cgroup_reset, |
|
.read_u64 = mem_cgroup_read_u64, |
|
}, |
|
{ |
|
.name = "limit_in_bytes", |
|
.private = MEMFILE_PRIVATE(_MEM, RES_LIMIT), |
|
.write = mem_cgroup_write, |
|
.read_u64 = mem_cgroup_read_u64, |
|
}, |
|
{ |
|
.name = "soft_limit_in_bytes", |
|
.private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT), |
|
.write = mem_cgroup_write, |
|
.read_u64 = mem_cgroup_read_u64, |
|
}, |
|
{ |
|
.name = "failcnt", |
|
.private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT), |
|
.write = mem_cgroup_reset, |
|
.read_u64 = mem_cgroup_read_u64, |
|
}, |
|
{ |
|
.name = "stat", |
|
.seq_show = memcg_stat_show, |
|
}, |
|
{ |
|
.name = "force_empty", |
|
.write = mem_cgroup_force_empty_write, |
|
}, |
|
{ |
|
.name = "use_hierarchy", |
|
.write_u64 = mem_cgroup_hierarchy_write, |
|
.read_u64 = mem_cgroup_hierarchy_read, |
|
}, |
|
{ |
|
.name = "cgroup.event_control", /* XXX: for compat */ |
|
.write = memcg_write_event_control, |
|
.flags = CFTYPE_NO_PREFIX | CFTYPE_WORLD_WRITABLE, |
|
}, |
|
{ |
|
.name = "swappiness", |
|
.read_u64 = mem_cgroup_swappiness_read, |
|
.write_u64 = mem_cgroup_swappiness_write, |
|
}, |
|
{ |
|
.name = "move_charge_at_immigrate", |
|
.read_u64 = mem_cgroup_move_charge_read, |
|
.write_u64 = mem_cgroup_move_charge_write, |
|
}, |
|
{ |
|
.name = "oom_control", |
|
.seq_show = mem_cgroup_oom_control_read, |
|
.write_u64 = mem_cgroup_oom_control_write, |
|
}, |
|
{ |
|
.name = "pressure_level", |
|
}, |
|
#ifdef CONFIG_NUMA |
|
{ |
|
.name = "numa_stat", |
|
.seq_show = memcg_numa_stat_show, |
|
}, |
|
#endif |
|
{ |
|
.name = "kmem.limit_in_bytes", |
|
.private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT), |
|
.write = mem_cgroup_write, |
|
.read_u64 = mem_cgroup_read_u64, |
|
}, |
|
{ |
|
.name = "kmem.usage_in_bytes", |
|
.private = MEMFILE_PRIVATE(_KMEM, RES_USAGE), |
|
.read_u64 = mem_cgroup_read_u64, |
|
}, |
|
{ |
|
.name = "kmem.failcnt", |
|
.private = MEMFILE_PRIVATE(_KMEM, RES_FAILCNT), |
|
.write = mem_cgroup_reset, |
|
.read_u64 = mem_cgroup_read_u64, |
|
}, |
|
{ |
|
.name = "kmem.max_usage_in_bytes", |
|
.private = MEMFILE_PRIVATE(_KMEM, RES_MAX_USAGE), |
|
.write = mem_cgroup_reset, |
|
.read_u64 = mem_cgroup_read_u64, |
|
}, |
|
#if defined(CONFIG_MEMCG_KMEM) && \ |
|
(defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)) |
|
{ |
|
.name = "kmem.slabinfo", |
|
.seq_show = mem_cgroup_slab_show, |
|
}, |
|
#endif |
|
{ |
|
.name = "kmem.tcp.limit_in_bytes", |
|
.private = MEMFILE_PRIVATE(_TCP, RES_LIMIT), |
|
.write = mem_cgroup_write, |
|
.read_u64 = mem_cgroup_read_u64, |
|
}, |
|
{ |
|
.name = "kmem.tcp.usage_in_bytes", |
|
.private = MEMFILE_PRIVATE(_TCP, RES_USAGE), |
|
.read_u64 = mem_cgroup_read_u64, |
|
}, |
|
{ |
|
.name = "kmem.tcp.failcnt", |
|
.private = MEMFILE_PRIVATE(_TCP, RES_FAILCNT), |
|
.write = mem_cgroup_reset, |
|
.read_u64 = mem_cgroup_read_u64, |
|
}, |
|
{ |
|
.name = "kmem.tcp.max_usage_in_bytes", |
|
.private = MEMFILE_PRIVATE(_TCP, RES_MAX_USAGE), |
|
.write = mem_cgroup_reset, |
|
.read_u64 = mem_cgroup_read_u64, |
|
}, |
|
{ }, /* terminate */ |
|
}; |
|
|
|
/* |
|
* Private memory cgroup IDR |
|
* |
|
* Swap-out records and page cache shadow entries need to store memcg |
|
* references in constrained space, so we maintain an ID space that is |
|
* limited to 16 bit (MEM_CGROUP_ID_MAX), limiting the total number of |
|
* memory-controlled cgroups to 64k. |
|
* |
|
* However, there usually are many references to the offline CSS after |
|
* the cgroup has been destroyed, such as page cache or reclaimable |
|
* slab objects, that don't need to hang on to the ID. We want to keep |
|
* those dead CSS from occupying IDs, or we might quickly exhaust the |
|
* relatively small ID space and prevent the creation of new cgroups |
|
* even when there are much fewer than 64k cgroups - possibly none. |
|
* |
|
* Maintain a private 16-bit ID space for memcg, and allow the ID to |
|
* be freed and recycled when it's no longer needed, which is usually |
|
* when the CSS is offlined. |
|
* |
|
* The only exception to that are records of swapped out tmpfs/shmem |
|
* pages that need to be attributed to live ancestors on swapin. But |
|
* those references are manageable from userspace. |
|
*/ |
|
|
|
static DEFINE_IDR(mem_cgroup_idr); |
|
|
|
static void mem_cgroup_id_remove(struct mem_cgroup *memcg) |
|
{ |
|
if (memcg->id.id > 0) { |
|
idr_remove(&mem_cgroup_idr, memcg->id.id); |
|
memcg->id.id = 0; |
|
} |
|
} |
|
|
|
static void __maybe_unused mem_cgroup_id_get_many(struct mem_cgroup *memcg, |
|
unsigned int n) |
|
{ |
|
refcount_add(n, &memcg->id.ref); |
|
} |
|
|
|
static void mem_cgroup_id_put_many(struct mem_cgroup *memcg, unsigned int n) |
|
{ |
|
if (refcount_sub_and_test(n, &memcg->id.ref)) { |
|
mem_cgroup_id_remove(memcg); |
|
|
|
/* Memcg ID pins CSS */ |
|
css_put(&memcg->css); |
|
} |
|
} |
|
|
|
static inline void mem_cgroup_id_put(struct mem_cgroup *memcg) |
|
{ |
|
mem_cgroup_id_put_many(memcg, 1); |
|
} |
|
|
|
/** |
|
* mem_cgroup_from_id - look up a memcg from a memcg id |
|
* @id: the memcg id to look up |
|
* |
|
* Caller must hold rcu_read_lock(). |
|
*/ |
|
struct mem_cgroup *mem_cgroup_from_id(unsigned short id) |
|
{ |
|
WARN_ON_ONCE(!rcu_read_lock_held()); |
|
return idr_find(&mem_cgroup_idr, id); |
|
} |
|
|
|
#ifdef CONFIG_SHRINKER_DEBUG |
|
struct mem_cgroup *mem_cgroup_get_from_ino(unsigned long ino) |
|
{ |
|
struct cgroup *cgrp; |
|
struct cgroup_subsys_state *css; |
|
struct mem_cgroup *memcg; |
|
|
|
cgrp = cgroup_get_from_id(ino); |
|
if (IS_ERR(cgrp)) |
|
return ERR_CAST(cgrp); |
|
|
|
css = cgroup_get_e_css(cgrp, &memory_cgrp_subsys); |
|
if (css) |
|
memcg = container_of(css, struct mem_cgroup, css); |
|
else |
|
memcg = ERR_PTR(-ENOENT); |
|
|
|
cgroup_put(cgrp); |
|
|
|
return memcg; |
|
} |
|
#endif |
|
|
|
static int alloc_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node) |
|
{ |
|
struct mem_cgroup_per_node *pn; |
|
|
|
pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, node); |
|
if (!pn) |
|
return 1; |
|
|
|
pn->lruvec_stats_percpu = alloc_percpu_gfp(struct lruvec_stats_percpu, |
|
GFP_KERNEL_ACCOUNT); |
|
if (!pn->lruvec_stats_percpu) { |
|
kfree(pn); |
|
return 1; |
|
} |
|
|
|
lruvec_init(&pn->lruvec); |
|
pn->memcg = memcg; |
|
|
|
memcg->nodeinfo[node] = pn; |
|
return 0; |
|
} |
|
|
|
static void free_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node) |
|
{ |
|
struct mem_cgroup_per_node *pn = memcg->nodeinfo[node]; |
|
|
|
if (!pn) |
|
return; |
|
|
|
free_percpu(pn->lruvec_stats_percpu); |
|
kfree(pn); |
|
} |
|
|
|
static void __mem_cgroup_free(struct mem_cgroup *memcg) |
|
{ |
|
int node; |
|
|
|
for_each_node(node) |
|
free_mem_cgroup_per_node_info(memcg, node); |
|
kfree(memcg->vmstats); |
|
free_percpu(memcg->vmstats_percpu); |
|
kfree(memcg); |
|
} |
|
|
|
static void mem_cgroup_free(struct mem_cgroup *memcg) |
|
{ |
|
lru_gen_exit_memcg(memcg); |
|
memcg_wb_domain_exit(memcg); |
|
__mem_cgroup_free(memcg); |
|
} |
|
|
|
static struct mem_cgroup *mem_cgroup_alloc(void) |
|
{ |
|
struct mem_cgroup *memcg; |
|
int node; |
|
int __maybe_unused i; |
|
long error = -ENOMEM; |
|
|
|
memcg = kzalloc(struct_size(memcg, nodeinfo, nr_node_ids), GFP_KERNEL); |
|
if (!memcg) |
|
return ERR_PTR(error); |
|
|
|
memcg->id.id = idr_alloc(&mem_cgroup_idr, NULL, |
|
1, MEM_CGROUP_ID_MAX + 1, GFP_KERNEL); |
|
if (memcg->id.id < 0) { |
|
error = memcg->id.id; |
|
goto fail; |
|
} |
|
|
|
memcg->vmstats = kzalloc(sizeof(struct memcg_vmstats), GFP_KERNEL); |
|
if (!memcg->vmstats) |
|
goto fail; |
|
|
|
memcg->vmstats_percpu = alloc_percpu_gfp(struct memcg_vmstats_percpu, |
|
GFP_KERNEL_ACCOUNT); |
|
if (!memcg->vmstats_percpu) |
|
goto fail; |
|
|
|
for_each_node(node) |
|
if (alloc_mem_cgroup_per_node_info(memcg, node)) |
|
goto fail; |
|
|
|
if (memcg_wb_domain_init(memcg, GFP_KERNEL)) |
|
goto fail; |
|
|
|
INIT_WORK(&memcg->high_work, high_work_func); |
|
INIT_LIST_HEAD(&memcg->oom_notify); |
|
mutex_init(&memcg->thresholds_lock); |
|
spin_lock_init(&memcg->move_lock); |
|
vmpressure_init(&memcg->vmpressure); |
|
INIT_LIST_HEAD(&memcg->event_list); |
|
spin_lock_init(&memcg->event_list_lock); |
|
memcg->socket_pressure = jiffies; |
|
#ifdef CONFIG_MEMCG_KMEM |
|
memcg->kmemcg_id = -1; |
|
INIT_LIST_HEAD(&memcg->objcg_list); |
|
#endif |
|
#ifdef CONFIG_CGROUP_WRITEBACK |
|
INIT_LIST_HEAD(&memcg->cgwb_list); |
|
for (i = 0; i < MEMCG_CGWB_FRN_CNT; i++) |
|
memcg->cgwb_frn[i].done = |
|
__WB_COMPLETION_INIT(&memcg_cgwb_frn_waitq); |
|
#endif |
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE |
|
spin_lock_init(&memcg->deferred_split_queue.split_queue_lock); |
|
INIT_LIST_HEAD(&memcg->deferred_split_queue.split_queue); |
|
memcg->deferred_split_queue.split_queue_len = 0; |
|
#endif |
|
idr_replace(&mem_cgroup_idr, memcg, memcg->id.id); |
|
lru_gen_init_memcg(memcg); |
|
return memcg; |
|
fail: |
|
mem_cgroup_id_remove(memcg); |
|
__mem_cgroup_free(memcg); |
|
return ERR_PTR(error); |
|
} |
|
|
|
static struct cgroup_subsys_state * __ref |
|
mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) |
|
{ |
|
struct mem_cgroup *parent = mem_cgroup_from_css(parent_css); |
|
struct mem_cgroup *memcg, *old_memcg; |
|
|
|
old_memcg = set_active_memcg(parent); |
|
memcg = mem_cgroup_alloc(); |
|
set_active_memcg(old_memcg); |
|
if (IS_ERR(memcg)) |
|
return ERR_CAST(memcg); |
|
|
|
page_counter_set_high(&memcg->memory, PAGE_COUNTER_MAX); |
|
memcg->soft_limit = PAGE_COUNTER_MAX; |
|
#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP) |
|
memcg->zswap_max = PAGE_COUNTER_MAX; |
|
#endif |
|
page_counter_set_high(&memcg->swap, PAGE_COUNTER_MAX); |
|
if (parent) { |
|
memcg->swappiness = mem_cgroup_swappiness(parent); |
|
memcg->oom_kill_disable = parent->oom_kill_disable; |
|
|
|
page_counter_init(&memcg->memory, &parent->memory); |
|
page_counter_init(&memcg->swap, &parent->swap); |
|
page_counter_init(&memcg->kmem, &parent->kmem); |
|
page_counter_init(&memcg->tcpmem, &parent->tcpmem); |
|
} else { |
|
init_memcg_events(); |
|
page_counter_init(&memcg->memory, NULL); |
|
page_counter_init(&memcg->swap, NULL); |
|
page_counter_init(&memcg->kmem, NULL); |
|
page_counter_init(&memcg->tcpmem, NULL); |
|
|
|
root_mem_cgroup = memcg; |
|
return &memcg->css; |
|
} |
|
|
|
if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket) |
|
static_branch_inc(&memcg_sockets_enabled_key); |
|
|
|
return &memcg->css; |
|
} |
|
|
|
static int mem_cgroup_css_online(struct cgroup_subsys_state *css) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
|
|
|
if (memcg_online_kmem(memcg)) |
|
goto remove_id; |
|
|
|
/* |
|
* A memcg must be visible for expand_shrinker_info() |
|
* by the time the maps are allocated. So, we allocate maps |
|
* here, when for_each_mem_cgroup() can't skip it. |
|
*/ |
|
if (alloc_shrinker_info(memcg)) |
|
goto offline_kmem; |
|
|
|
/* Online state pins memcg ID, memcg ID pins CSS */ |
|
refcount_set(&memcg->id.ref, 1); |
|
css_get(css); |
|
|
|
if (unlikely(mem_cgroup_is_root(memcg))) |
|
queue_delayed_work(system_unbound_wq, &stats_flush_dwork, |
|
2UL*HZ); |
|
return 0; |
|
offline_kmem: |
|
memcg_offline_kmem(memcg); |
|
remove_id: |
|
mem_cgroup_id_remove(memcg); |
|
return -ENOMEM; |
|
} |
|
|
|
static void mem_cgroup_css_offline(struct cgroup_subsys_state *css) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
|
struct mem_cgroup_event *event, *tmp; |
|
|
|
/* |
|
* Unregister events and notify userspace. |
|
* Notify userspace about cgroup removing only after rmdir of cgroup |
|
* directory to avoid race between userspace and kernelspace. |
|
*/ |
|
spin_lock_irq(&memcg->event_list_lock); |
|
list_for_each_entry_safe(event, tmp, &memcg->event_list, list) { |
|
list_del_init(&event->list); |
|
schedule_work(&event->remove); |
|
} |
|
spin_unlock_irq(&memcg->event_list_lock); |
|
|
|
page_counter_set_min(&memcg->memory, 0); |
|
page_counter_set_low(&memcg->memory, 0); |
|
|
|
memcg_offline_kmem(memcg); |
|
reparent_shrinker_deferred(memcg); |
|
wb_memcg_offline(memcg); |
|
|
|
drain_all_stock(memcg); |
|
|
|
mem_cgroup_id_put(memcg); |
|
} |
|
|
|
static void mem_cgroup_css_released(struct cgroup_subsys_state *css) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
|
|
|
invalidate_reclaim_iterators(memcg); |
|
} |
|
|
|
static void mem_cgroup_css_free(struct cgroup_subsys_state *css) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
|
int __maybe_unused i; |
|
|
|
#ifdef CONFIG_CGROUP_WRITEBACK |
|
for (i = 0; i < MEMCG_CGWB_FRN_CNT; i++) |
|
wb_wait_for_completion(&memcg->cgwb_frn[i].done); |
|
#endif |
|
if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket) |
|
static_branch_dec(&memcg_sockets_enabled_key); |
|
|
|
if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && memcg->tcpmem_active) |
|
static_branch_dec(&memcg_sockets_enabled_key); |
|
|
|
vmpressure_cleanup(&memcg->vmpressure); |
|
cancel_work_sync(&memcg->high_work); |
|
mem_cgroup_remove_from_trees(memcg); |
|
free_shrinker_info(memcg); |
|
mem_cgroup_free(memcg); |
|
} |
|
|
|
/** |
|
* mem_cgroup_css_reset - reset the states of a mem_cgroup |
|
* @css: the target css |
|
* |
|
* Reset the states of the mem_cgroup associated with @css. This is |
|
* invoked when the userland requests disabling on the default hierarchy |
|
* but the memcg is pinned through dependency. The memcg should stop |
|
* applying policies and should revert to the vanilla state as it may be |
|
* made visible again. |
|
* |
|
* The current implementation only resets the essential configurations. |
|
* This needs to be expanded to cover all the visible parts. |
|
*/ |
|
static void mem_cgroup_css_reset(struct cgroup_subsys_state *css) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
|
|
|
page_counter_set_max(&memcg->memory, PAGE_COUNTER_MAX); |
|
page_counter_set_max(&memcg->swap, PAGE_COUNTER_MAX); |
|
page_counter_set_max(&memcg->kmem, PAGE_COUNTER_MAX); |
|
page_counter_set_max(&memcg->tcpmem, PAGE_COUNTER_MAX); |
|
page_counter_set_min(&memcg->memory, 0); |
|
page_counter_set_low(&memcg->memory, 0); |
|
page_counter_set_high(&memcg->memory, PAGE_COUNTER_MAX); |
|
memcg->soft_limit = PAGE_COUNTER_MAX; |
|
page_counter_set_high(&memcg->swap, PAGE_COUNTER_MAX); |
|
memcg_wb_domain_size_changed(memcg); |
|
} |
|
|
|
static void mem_cgroup_css_rstat_flush(struct cgroup_subsys_state *css, int cpu) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
|
struct mem_cgroup *parent = parent_mem_cgroup(memcg); |
|
struct memcg_vmstats_percpu *statc; |
|
long delta, v; |
|
int i, nid; |
|
|
|
statc = per_cpu_ptr(memcg->vmstats_percpu, cpu); |
|
|
|
for (i = 0; i < MEMCG_NR_STAT; i++) { |
|
/* |
|
* Collect the aggregated propagation counts of groups |
|
* below us. We're in a per-cpu loop here and this is |
|
* a global counter, so the first cycle will get them. |
|
*/ |
|
delta = memcg->vmstats->state_pending[i]; |
|
if (delta) |
|
memcg->vmstats->state_pending[i] = 0; |
|
|
|
/* Add CPU changes on this level since the last flush */ |
|
v = READ_ONCE(statc->state[i]); |
|
if (v != statc->state_prev[i]) { |
|
delta += v - statc->state_prev[i]; |
|
statc->state_prev[i] = v; |
|
} |
|
|
|
if (!delta) |
|
continue; |
|
|
|
/* Aggregate counts on this level and propagate upwards */ |
|
memcg->vmstats->state[i] += delta; |
|
if (parent) |
|
parent->vmstats->state_pending[i] += delta; |
|
} |
|
|
|
for (i = 0; i < NR_MEMCG_EVENTS; i++) { |
|
delta = memcg->vmstats->events_pending[i]; |
|
if (delta) |
|
memcg->vmstats->events_pending[i] = 0; |
|
|
|
v = READ_ONCE(statc->events[i]); |
|
if (v != statc->events_prev[i]) { |
|
delta += v - statc->events_prev[i]; |
|
statc->events_prev[i] = v; |
|
} |
|
|
|
if (!delta) |
|
continue; |
|
|
|
memcg->vmstats->events[i] += delta; |
|
if (parent) |
|
parent->vmstats->events_pending[i] += delta; |
|
} |
|
|
|
for_each_node_state(nid, N_MEMORY) { |
|
struct mem_cgroup_per_node *pn = memcg->nodeinfo[nid]; |
|
struct mem_cgroup_per_node *ppn = NULL; |
|
struct lruvec_stats_percpu *lstatc; |
|
|
|
if (parent) |
|
ppn = parent->nodeinfo[nid]; |
|
|
|
lstatc = per_cpu_ptr(pn->lruvec_stats_percpu, cpu); |
|
|
|
for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) { |
|
delta = pn->lruvec_stats.state_pending[i]; |
|
if (delta) |
|
pn->lruvec_stats.state_pending[i] = 0; |
|
|
|
v = READ_ONCE(lstatc->state[i]); |
|
if (v != lstatc->state_prev[i]) { |
|
delta += v - lstatc->state_prev[i]; |
|
lstatc->state_prev[i] = v; |
|
} |
|
|
|
if (!delta) |
|
continue; |
|
|
|
pn->lruvec_stats.state[i] += delta; |
|
if (ppn) |
|
ppn->lruvec_stats.state_pending[i] += delta; |
|
} |
|
} |
|
} |
|
|
|
#ifdef CONFIG_MMU |
|
/* Handlers for move charge at task migration. */ |
|
static int mem_cgroup_do_precharge(unsigned long count) |
|
{ |
|
int ret; |
|
|
|
/* Try a single bulk charge without reclaim first, kswapd may wake */ |
|
ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_DIRECT_RECLAIM, count); |
|
if (!ret) { |
|
mc.precharge += count; |
|
return ret; |
|
} |
|
|
|
/* Try charges one by one with reclaim, but do not retry */ |
|
while (count--) { |
|
ret = try_charge(mc.to, GFP_KERNEL | __GFP_NORETRY, 1); |
|
if (ret) |
|
return ret; |
|
mc.precharge++; |
|
cond_resched(); |
|
} |
|
return 0; |
|
} |
|
|
|
union mc_target { |
|
struct page *page; |
|
swp_entry_t ent; |
|
}; |
|
|
|
enum mc_target_type { |
|
MC_TARGET_NONE = 0, |
|
MC_TARGET_PAGE, |
|
MC_TARGET_SWAP, |
|
MC_TARGET_DEVICE, |
|
}; |
|
|
|
static struct page *mc_handle_present_pte(struct vm_area_struct *vma, |
|
unsigned long addr, pte_t ptent) |
|
{ |
|
struct page *page = vm_normal_page(vma, addr, ptent); |
|
|
|
if (!page || !page_mapped(page)) |
|
return NULL; |
|
if (PageAnon(page)) { |
|
if (!(mc.flags & MOVE_ANON)) |
|
return NULL; |
|
} else { |
|
if (!(mc.flags & MOVE_FILE)) |
|
return NULL; |
|
} |
|
if (!get_page_unless_zero(page)) |
|
return NULL; |
|
|
|
return page; |
|
} |
|
|
|
#if defined(CONFIG_SWAP) || defined(CONFIG_DEVICE_PRIVATE) |
|
static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, |
|
pte_t ptent, swp_entry_t *entry) |
|
{ |
|
struct page *page = NULL; |
|
swp_entry_t ent = pte_to_swp_entry(ptent); |
|
|
|
if (!(mc.flags & MOVE_ANON)) |
|
return NULL; |
|
|
|
/* |
|
* Handle device private pages that are not accessible by the CPU, but |
|
* stored as special swap entries in the page table. |
|
*/ |
|
if (is_device_private_entry(ent)) { |
|
page = pfn_swap_entry_to_page(ent); |
|
if (!get_page_unless_zero(page)) |
|
return NULL; |
|
return page; |
|
} |
|
|
|
if (non_swap_entry(ent)) |
|
return NULL; |
|
|
|
/* |
|
* Because swap_cache_get_folio() updates some statistics counter, |
|
* we call find_get_page() with swapper_space directly. |
|
*/ |
|
page = find_get_page(swap_address_space(ent), swp_offset(ent)); |
|
entry->val = ent.val; |
|
|
|
return page; |
|
} |
|
#else |
|
static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, |
|
pte_t ptent, swp_entry_t *entry) |
|
{ |
|
return NULL; |
|
} |
|
#endif |
|
|
|
static struct page *mc_handle_file_pte(struct vm_area_struct *vma, |
|
unsigned long addr, pte_t ptent) |
|
{ |
|
if (!vma->vm_file) /* anonymous vma */ |
|
return NULL; |
|
if (!(mc.flags & MOVE_FILE)) |
|
return NULL; |
|
|
|
/* page is moved even if it's not RSS of this task(page-faulted). */ |
|
/* shmem/tmpfs may report page out on swap: account for that too. */ |
|
return find_get_incore_page(vma->vm_file->f_mapping, |
|
linear_page_index(vma, addr)); |
|
} |
|
|
|
/** |
|
* mem_cgroup_move_account - move account of the page |
|
* @page: the page |
|
* @compound: charge the page as compound or small page |
|
* @from: mem_cgroup which the page is moved from. |
|
* @to: mem_cgroup which the page is moved to. @from != @to. |
|
* |
|
* The caller must make sure the page is not on LRU (isolate_page() is useful.) |
|
* |
|
* This function doesn't do "charge" to new cgroup and doesn't do "uncharge" |
|
* from old cgroup. |
|
*/ |
|
static int mem_cgroup_move_account(struct page *page, |
|
bool compound, |
|
struct mem_cgroup *from, |
|
struct mem_cgroup *to) |
|
{ |
|
struct folio *folio = page_folio(page); |
|
struct lruvec *from_vec, *to_vec; |
|
struct pglist_data *pgdat; |
|
unsigned int nr_pages = compound ? folio_nr_pages(folio) : 1; |
|
int nid, ret; |
|
|
|
VM_BUG_ON(from == to); |
|
VM_BUG_ON_FOLIO(folio_test_lru(folio), folio); |
|
VM_BUG_ON(compound && !folio_test_large(folio)); |
|
|
|
/* |
|
* Prevent mem_cgroup_migrate() from looking at |
|
* page's memory cgroup of its source page while we change it. |
|
*/ |
|
ret = -EBUSY; |
|
if (!folio_trylock(folio)) |
|
goto out; |
|
|
|
ret = -EINVAL; |
|
if (folio_memcg(folio) != from) |
|
goto out_unlock; |
|
|
|
pgdat = folio_pgdat(folio); |
|
from_vec = mem_cgroup_lruvec(from, pgdat); |
|
to_vec = mem_cgroup_lruvec(to, pgdat); |
|
|
|
folio_memcg_lock(folio); |
|
|
|
if (folio_test_anon(folio)) { |
|
if (folio_mapped(folio)) { |
|
__mod_lruvec_state(from_vec, NR_ANON_MAPPED, -nr_pages); |
|
__mod_lruvec_state(to_vec, NR_ANON_MAPPED, nr_pages); |
|
if (folio_test_transhuge(folio)) { |
|
__mod_lruvec_state(from_vec, NR_ANON_THPS, |
|
-nr_pages); |
|
__mod_lruvec_state(to_vec, NR_ANON_THPS, |
|
nr_pages); |
|
} |
|
} |
|
} else { |
|
__mod_lruvec_state(from_vec, NR_FILE_PAGES, -nr_pages); |
|
__mod_lruvec_state(to_vec, NR_FILE_PAGES, nr_pages); |
|
|
|
if (folio_test_swapbacked(folio)) { |
|
__mod_lruvec_state(from_vec, NR_SHMEM, -nr_pages); |
|
__mod_lruvec_state(to_vec, NR_SHMEM, nr_pages); |
|
} |
|
|
|
if (folio_mapped(folio)) { |
|
__mod_lruvec_state(from_vec, NR_FILE_MAPPED, -nr_pages); |
|
__mod_lruvec_state(to_vec, NR_FILE_MAPPED, nr_pages); |
|
} |
|
|
|
if (folio_test_dirty(folio)) { |
|
struct address_space *mapping = folio_mapping(folio); |
|
|
|
if (mapping_can_writeback(mapping)) { |
|
__mod_lruvec_state(from_vec, NR_FILE_DIRTY, |
|
-nr_pages); |
|
__mod_lruvec_state(to_vec, NR_FILE_DIRTY, |
|
nr_pages); |
|
} |
|
} |
|
} |
|
|
|
if (folio_test_writeback(folio)) { |
|
__mod_lruvec_state(from_vec, NR_WRITEBACK, -nr_pages); |
|
__mod_lruvec_state(to_vec, NR_WRITEBACK, nr_pages); |
|
} |
|
|
|
/* |
|
* All state has been migrated, let's switch to the new memcg. |
|
* |
|
* It is safe to change page's memcg here because the page |
|
* is referenced, charged, isolated, and locked: we can't race |
|
* with (un)charging, migration, LRU putback, or anything else |
|
* that would rely on a stable page's memory cgroup. |
|
* |
|
* Note that lock_page_memcg is a memcg lock, not a page lock, |
|
* to save space. As soon as we switch page's memory cgroup to a |
|
* new memcg that isn't locked, the above state can change |
|
* concurrently again. Make sure we're truly done with it. |
|
*/ |
|
smp_mb(); |
|
|
|
css_get(&to->css); |
|
css_put(&from->css); |
|
|
|
folio->memcg_data = (unsigned long)to; |
|
|
|
__folio_memcg_unlock(from); |
|
|
|
ret = 0; |
|
nid = folio_nid(folio); |
|
|
|
local_irq_disable(); |
|
mem_cgroup_charge_statistics(to, nr_pages); |
|
memcg_check_events(to, nid); |
|
mem_cgroup_charge_statistics(from, -nr_pages); |
|
memcg_check_events(from, nid); |
|
local_irq_enable(); |
|
out_unlock: |
|
folio_unlock(folio); |
|
out: |
|
return ret; |
|
} |
|
|
|
/** |
|
* get_mctgt_type - get target type of moving charge |
|
* @vma: the vma the pte to be checked belongs |
|
* @addr: the address corresponding to the pte to be checked |
|
* @ptent: the pte to be checked |
|
* @target: the pointer the target page or swap ent will be stored(can be NULL) |
|
* |
|
* Returns |
|
* 0(MC_TARGET_NONE): if the pte is not a target for move charge. |
|
* 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for |
|
* move charge. if @target is not NULL, the page is stored in target->page |
|
* with extra refcnt got(Callers should handle it). |
|
* 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a |
|
* target for charge migration. if @target is not NULL, the entry is stored |
|
* in target->ent. |
|
* 3(MC_TARGET_DEVICE): like MC_TARGET_PAGE but page is device memory and |
|
* thus not on the lru. |
|
* For now we such page is charge like a regular page would be as for all |
|
* intent and purposes it is just special memory taking the place of a |
|
* regular page. |
|
* |
|
* See Documentations/vm/hmm.txt and include/linux/hmm.h |
|
* |
|
* Called with pte lock held. |
|
*/ |
|
|
|
static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma, |
|
unsigned long addr, pte_t ptent, union mc_target *target) |
|
{ |
|
struct page *page = NULL; |
|
enum mc_target_type ret = MC_TARGET_NONE; |
|
swp_entry_t ent = { .val = 0 }; |
|
|
|
if (pte_present(ptent)) |
|
page = mc_handle_present_pte(vma, addr, ptent); |
|
else if (pte_none_mostly(ptent)) |
|
/* |
|
* PTE markers should be treated as a none pte here, separated |
|
* from other swap handling below. |
|
*/ |
|
page = mc_handle_file_pte(vma, addr, ptent); |
|
else if (is_swap_pte(ptent)) |
|
page = mc_handle_swap_pte(vma, ptent, &ent); |
|
|
|
if (!page && !ent.val) |
|
return ret; |
|
if (page) { |
|
/* |
|
* Do only loose check w/o serialization. |
|
* mem_cgroup_move_account() checks the page is valid or |
|
* not under LRU exclusion. |
|
*/ |
|
if (page_memcg(page) == mc.from) { |
|
ret = MC_TARGET_PAGE; |
|
if (is_device_private_page(page) || |
|
is_device_coherent_page(page)) |
|
ret = MC_TARGET_DEVICE; |
|
if (target) |
|
target->page = page; |
|
} |
|
if (!ret || !target) |
|
put_page(page); |
|
} |
|
/* |
|
* There is a swap entry and a page doesn't exist or isn't charged. |
|
* But we cannot move a tail-page in a THP. |
|
*/ |
|
if (ent.val && !ret && (!page || !PageTransCompound(page)) && |
|
mem_cgroup_id(mc.from) == lookup_swap_cgroup_id(ent)) { |
|
ret = MC_TARGET_SWAP; |
|
if (target) |
|
target->ent = ent; |
|
} |
|
return ret; |
|
} |
|
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE |
|
/* |
|
* We don't consider PMD mapped swapping or file mapped pages because THP does |
|
* not support them for now. |
|
* Caller should make sure that pmd_trans_huge(pmd) is true. |
|
*/ |
|
static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, |
|
unsigned long addr, pmd_t pmd, union mc_target *target) |
|
{ |
|
struct page *page = NULL; |
|
enum mc_target_type ret = MC_TARGET_NONE; |
|
|
|
if (unlikely(is_swap_pmd(pmd))) { |
|
VM_BUG_ON(thp_migration_supported() && |
|
!is_pmd_migration_entry(pmd)); |
|
return ret; |
|
} |
|
page = pmd_page(pmd); |
|
VM_BUG_ON_PAGE(!page || !PageHead(page), page); |
|
if (!(mc.flags & MOVE_ANON)) |
|
return ret; |
|
if (page_memcg(page) == mc.from) { |
|
ret = MC_TARGET_PAGE; |
|
if (target) { |
|
get_page(page); |
|
target->page = page; |
|
} |
|
} |
|
return ret; |
|
} |
|
#else |
|
static inline enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, |
|
unsigned long addr, pmd_t pmd, union mc_target *target) |
|
{ |
|
return MC_TARGET_NONE; |
|
} |
|
#endif |
|
|
|
static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd, |
|
unsigned long addr, unsigned long end, |
|
struct mm_walk *walk) |
|
{ |
|
struct vm_area_struct *vma = walk->vma; |
|
pte_t *pte; |
|
spinlock_t *ptl; |
|
|
|
ptl = pmd_trans_huge_lock(pmd, vma); |
|
if (ptl) { |
|
/* |
|
* Note their can not be MC_TARGET_DEVICE for now as we do not |
|
* support transparent huge page with MEMORY_DEVICE_PRIVATE but |
|
* this might change. |
|
*/ |
|
if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE) |
|
mc.precharge += HPAGE_PMD_NR; |
|
spin_unlock(ptl); |
|
return 0; |
|
} |
|
|
|
if (pmd_trans_unstable(pmd)) |
|
return 0; |
|
pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); |
|
for (; addr != end; pte++, addr += PAGE_SIZE) |
|
if (get_mctgt_type(vma, addr, *pte, NULL)) |
|
mc.precharge++; /* increment precharge temporarily */ |
|
pte_unmap_unlock(pte - 1, ptl); |
|
cond_resched(); |
|
|
|
return 0; |
|
} |
|
|
|
static const struct mm_walk_ops precharge_walk_ops = { |
|
.pmd_entry = mem_cgroup_count_precharge_pte_range, |
|
}; |
|
|
|
static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm) |
|
{ |
|
unsigned long precharge; |
|
|
|
mmap_read_lock(mm); |
|
walk_page_range(mm, 0, ULONG_MAX, &precharge_walk_ops, NULL); |
|
mmap_read_unlock(mm); |
|
|
|
precharge = mc.precharge; |
|
mc.precharge = 0; |
|
|
|
return precharge; |
|
} |
|
|
|
static int mem_cgroup_precharge_mc(struct mm_struct *mm) |
|
{ |
|
unsigned long precharge = mem_cgroup_count_precharge(mm); |
|
|
|
VM_BUG_ON(mc.moving_task); |
|
mc.moving_task = current; |
|
return mem_cgroup_do_precharge(precharge); |
|
} |
|
|
|
/* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */ |
|
static void __mem_cgroup_clear_mc(void) |
|
{ |
|
struct mem_cgroup *from = mc.from; |
|
struct mem_cgroup *to = mc.to; |
|
|
|
/* we must uncharge all the leftover precharges from mc.to */ |
|
if (mc.precharge) { |
|
cancel_charge(mc.to, mc.precharge); |
|
mc.precharge = 0; |
|
} |
|
/* |
|
* we didn't uncharge from mc.from at mem_cgroup_move_account(), so |
|
* we must uncharge here. |
|
*/ |
|
if (mc.moved_charge) { |
|
cancel_charge(mc.from, mc.moved_charge); |
|
mc.moved_charge = 0; |
|
} |
|
/* we must fixup refcnts and charges */ |
|
if (mc.moved_swap) { |
|
/* uncharge swap account from the old cgroup */ |
|
if (!mem_cgroup_is_root(mc.from)) |
|
page_counter_uncharge(&mc.from->memsw, mc.moved_swap); |
|
|
|
mem_cgroup_id_put_many(mc.from, mc.moved_swap); |
|
|
|
/* |
|
* we charged both to->memory and to->memsw, so we |
|
* should uncharge to->memory. |
|
*/ |
|
if (!mem_cgroup_is_root(mc.to)) |
|
page_counter_uncharge(&mc.to->memory, mc.moved_swap); |
|
|
|
mc.moved_swap = 0; |
|
} |
|
memcg_oom_recover(from); |
|
memcg_oom_recover(to); |
|
wake_up_all(&mc.waitq); |
|
} |
|
|
|
static void mem_cgroup_clear_mc(void) |
|
{ |
|
struct mm_struct *mm = mc.mm; |
|
|
|
/* |
|
* we must clear moving_task before waking up waiters at the end of |
|
* task migration. |
|
*/ |
|
mc.moving_task = NULL; |
|
__mem_cgroup_clear_mc(); |
|
spin_lock(&mc.lock); |
|
mc.from = NULL; |
|
mc.to = NULL; |
|
mc.mm = NULL; |
|
spin_unlock(&mc.lock); |
|
|
|
mmput(mm); |
|
} |
|
|
|
static int mem_cgroup_can_attach(struct cgroup_taskset *tset) |
|
{ |
|
struct cgroup_subsys_state *css; |
|
struct mem_cgroup *memcg = NULL; /* unneeded init to make gcc happy */ |
|
struct mem_cgroup *from; |
|
struct task_struct *leader, *p; |
|
struct mm_struct *mm; |
|
unsigned long move_flags; |
|
int ret = 0; |
|
|
|
/* charge immigration isn't supported on the default hierarchy */ |
|
if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) |
|
return 0; |
|
|
|
/* |
|
* Multi-process migrations only happen on the default hierarchy |
|
* where charge immigration is not used. Perform charge |
|
* immigration if @tset contains a leader and whine if there are |
|
* multiple. |
|
*/ |
|
p = NULL; |
|
cgroup_taskset_for_each_leader(leader, css, tset) { |
|
WARN_ON_ONCE(p); |
|
p = leader; |
|
memcg = mem_cgroup_from_css(css); |
|
} |
|
if (!p) |
|
return 0; |
|
|
|
/* |
|
* We are now committed to this value whatever it is. Changes in this |
|
* tunable will only affect upcoming migrations, not the current one. |
|
* So we need to save it, and keep it going. |
|
*/ |
|
move_flags = READ_ONCE(memcg->move_charge_at_immigrate); |
|
if (!move_flags) |
|
return 0; |
|
|
|
from = mem_cgroup_from_task(p); |
|
|
|
VM_BUG_ON(from == memcg); |
|
|
|
mm = get_task_mm(p); |
|
if (!mm) |
|
return 0; |
|
/* We move charges only when we move a owner of the mm */ |
|
if (mm->owner == p) { |
|
VM_BUG_ON(mc.from); |
|
VM_BUG_ON(mc.to); |
|
VM_BUG_ON(mc.precharge); |
|
VM_BUG_ON(mc.moved_charge); |
|
VM_BUG_ON(mc.moved_swap); |
|
|
|
spin_lock(&mc.lock); |
|
mc.mm = mm; |
|
mc.from = from; |
|
mc.to = memcg; |
|
mc.flags = move_flags; |
|
spin_unlock(&mc.lock); |
|
/* We set mc.moving_task later */ |
|
|
|
ret = mem_cgroup_precharge_mc(mm); |
|
if (ret) |
|
mem_cgroup_clear_mc(); |
|
} else { |
|
mmput(mm); |
|
} |
|
return ret; |
|
} |
|
|
|
static void mem_cgroup_cancel_attach(struct cgroup_taskset *tset) |
|
{ |
|
if (mc.to) |
|
mem_cgroup_clear_mc(); |
|
} |
|
|
|
static int mem_cgroup_move_charge_pte_range(pmd_t *pmd, |
|
unsigned long addr, unsigned long end, |
|
struct mm_walk *walk) |
|
{ |
|
int ret = 0; |
|
struct vm_area_struct *vma = walk->vma; |
|
pte_t *pte; |
|
spinlock_t *ptl; |
|
enum mc_target_type target_type; |
|
union mc_target target; |
|
struct page *page; |
|
|
|
ptl = pmd_trans_huge_lock(pmd, vma); |
|
if (ptl) { |
|
if (mc.precharge < HPAGE_PMD_NR) { |
|
spin_unlock(ptl); |
|
return 0; |
|
} |
|
target_type = get_mctgt_type_thp(vma, addr, *pmd, &target); |
|
if (target_type == MC_TARGET_PAGE) { |
|
page = target.page; |
|
if (!isolate_lru_page(page)) { |
|
if (!mem_cgroup_move_account(page, true, |
|
mc.from, mc.to)) { |
|
mc.precharge -= HPAGE_PMD_NR; |
|
mc.moved_charge += HPAGE_PMD_NR; |
|
} |
|
putback_lru_page(page); |
|
} |
|
put_page(page); |
|
} else if (target_type == MC_TARGET_DEVICE) { |
|
page = target.page; |
|
if (!mem_cgroup_move_account(page, true, |
|
mc.from, mc.to)) { |
|
mc.precharge -= HPAGE_PMD_NR; |
|
mc.moved_charge += HPAGE_PMD_NR; |
|
} |
|
put_page(page); |
|
} |
|
spin_unlock(ptl); |
|
return 0; |
|
} |
|
|
|
if (pmd_trans_unstable(pmd)) |
|
return 0; |
|
retry: |
|
pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); |
|
for (; addr != end; addr += PAGE_SIZE) { |
|
pte_t ptent = *(pte++); |
|
bool device = false; |
|
swp_entry_t ent; |
|
|
|
if (!mc.precharge) |
|
break; |
|
|
|
switch (get_mctgt_type(vma, addr, ptent, &target)) { |
|
case MC_TARGET_DEVICE: |
|
device = true; |
|
fallthrough; |
|
case MC_TARGET_PAGE: |
|
page = target.page; |
|
/* |
|
* We can have a part of the split pmd here. Moving it |
|
* can be done but it would be too convoluted so simply |
|
* ignore such a partial THP and keep it in original |
|
* memcg. There should be somebody mapping the head. |
|
*/ |
|
if (PageTransCompound(page)) |
|
goto put; |
|
if (!device && isolate_lru_page(page)) |
|
goto put; |
|
if (!mem_cgroup_move_account(page, false, |
|
mc.from, mc.to)) { |
|
mc.precharge--; |
|
/* we uncharge from mc.from later. */ |
|
mc.moved_charge++; |
|
} |
|
if (!device) |
|
putback_lru_page(page); |
|
put: /* get_mctgt_type() gets the page */ |
|
put_page(page); |
|
break; |
|
case MC_TARGET_SWAP: |
|
ent = target.ent; |
|
if (!mem_cgroup_move_swap_account(ent, mc.from, mc.to)) { |
|
mc.precharge--; |
|
mem_cgroup_id_get_many(mc.to, 1); |
|
/* we fixup other refcnts and charges later. */ |
|
mc.moved_swap++; |
|
} |
|
break; |
|
default: |
|
break; |
|
} |
|
} |
|
pte_unmap_unlock(pte - 1, ptl); |
|
cond_resched(); |
|
|
|
if (addr != end) { |
|
/* |
|
* We have consumed all precharges we got in can_attach(). |
|
* We try charge one by one, but don't do any additional |
|
* charges to mc.to if we have failed in charge once in attach() |
|
* phase. |
|
*/ |
|
ret = mem_cgroup_do_precharge(1); |
|
if (!ret) |
|
goto retry; |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
static const struct mm_walk_ops charge_walk_ops = { |
|
.pmd_entry = mem_cgroup_move_charge_pte_range, |
|
}; |
|
|
|
static void mem_cgroup_move_charge(void) |
|
{ |
|
lru_add_drain_all(); |
|
/* |
|
* Signal lock_page_memcg() to take the memcg's move_lock |
|
* while we're moving its pages to another memcg. Then wait |
|
* for already started RCU-only updates to finish. |
|
*/ |
|
atomic_inc(&mc.from->moving_account); |
|
synchronize_rcu(); |
|
retry: |
|
if (unlikely(!mmap_read_trylock(mc.mm))) { |
|
/* |
|
* Someone who are holding the mmap_lock might be waiting in |
|
* waitq. So we cancel all extra charges, wake up all waiters, |
|
* and retry. Because we cancel precharges, we might not be able |
|
* to move enough charges, but moving charge is a best-effort |
|
* feature anyway, so it wouldn't be a big problem. |
|
*/ |
|
__mem_cgroup_clear_mc(); |
|
cond_resched(); |
|
goto retry; |
|
} |
|
/* |
|
* When we have consumed all precharges and failed in doing |
|
* additional charge, the page walk just aborts. |
|
*/ |
|
walk_page_range(mc.mm, 0, ULONG_MAX, &charge_walk_ops, NULL); |
|
mmap_read_unlock(mc.mm); |
|
atomic_dec(&mc.from->moving_account); |
|
} |
|
|
|
static void mem_cgroup_move_task(void) |
|
{ |
|
if (mc.to) { |
|
mem_cgroup_move_charge(); |
|
mem_cgroup_clear_mc(); |
|
} |
|
} |
|
#else /* !CONFIG_MMU */ |
|
static int mem_cgroup_can_attach(struct cgroup_taskset *tset) |
|
{ |
|
return 0; |
|
} |
|
static void mem_cgroup_cancel_attach(struct cgroup_taskset *tset) |
|
{ |
|
} |
|
static void mem_cgroup_move_task(void) |
|
{ |
|
} |
|
#endif |
|
|
|
#ifdef CONFIG_LRU_GEN |
|
static void mem_cgroup_attach(struct cgroup_taskset *tset) |
|
{ |
|
struct task_struct *task; |
|
struct cgroup_subsys_state *css; |
|
|
|
/* find the first leader if there is any */ |
|
cgroup_taskset_for_each_leader(task, css, tset) |
|
break; |
|
|
|
if (!task) |
|
return; |
|
|
|
task_lock(task); |
|
if (task->mm && READ_ONCE(task->mm->owner) == task) |
|
lru_gen_migrate_mm(task->mm); |
|
task_unlock(task); |
|
} |
|
#else |
|
static void mem_cgroup_attach(struct cgroup_taskset *tset) |
|
{ |
|
} |
|
#endif /* CONFIG_LRU_GEN */ |
|
|
|
static int seq_puts_memcg_tunable(struct seq_file *m, unsigned long value) |
|
{ |
|
if (value == PAGE_COUNTER_MAX) |
|
seq_puts(m, "max\n"); |
|
else |
|
seq_printf(m, "%llu\n", (u64)value * PAGE_SIZE); |
|
|
|
return 0; |
|
} |
|
|
|
static u64 memory_current_read(struct cgroup_subsys_state *css, |
|
struct cftype *cft) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
|
|
|
return (u64)page_counter_read(&memcg->memory) * PAGE_SIZE; |
|
} |
|
|
|
static u64 memory_peak_read(struct cgroup_subsys_state *css, |
|
struct cftype *cft) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
|
|
|
return (u64)memcg->memory.watermark * PAGE_SIZE; |
|
} |
|
|
|
static int memory_min_show(struct seq_file *m, void *v) |
|
{ |
|
return seq_puts_memcg_tunable(m, |
|
READ_ONCE(mem_cgroup_from_seq(m)->memory.min)); |
|
} |
|
|
|
static ssize_t memory_min_write(struct kernfs_open_file *of, |
|
char *buf, size_t nbytes, loff_t off) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); |
|
unsigned long min; |
|
int err; |
|
|
|
buf = strstrip(buf); |
|
err = page_counter_memparse(buf, "max", &min); |
|
if (err) |
|
return err; |
|
|
|
page_counter_set_min(&memcg->memory, min); |
|
|
|
return nbytes; |
|
} |
|
|
|
static int memory_low_show(struct seq_file *m, void *v) |
|
{ |
|
return seq_puts_memcg_tunable(m, |
|
READ_ONCE(mem_cgroup_from_seq(m)->memory.low)); |
|
} |
|
|
|
static ssize_t memory_low_write(struct kernfs_open_file *of, |
|
char *buf, size_t nbytes, loff_t off) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); |
|
unsigned long low; |
|
int err; |
|
|
|
buf = strstrip(buf); |
|
err = page_counter_memparse(buf, "max", &low); |
|
if (err) |
|
return err; |
|
|
|
page_counter_set_low(&memcg->memory, low); |
|
|
|
return nbytes; |
|
} |
|
|
|
static int memory_high_show(struct seq_file *m, void *v) |
|
{ |
|
return seq_puts_memcg_tunable(m, |
|
READ_ONCE(mem_cgroup_from_seq(m)->memory.high)); |
|
} |
|
|
|
static ssize_t memory_high_write(struct kernfs_open_file *of, |
|
char *buf, size_t nbytes, loff_t off) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); |
|
unsigned int nr_retries = MAX_RECLAIM_RETRIES; |
|
bool drained = false; |
|
unsigned long high; |
|
int err; |
|
|
|
buf = strstrip(buf); |
|
err = page_counter_memparse(buf, "max", &high); |
|
if (err) |
|
return err; |
|
|
|
page_counter_set_high(&memcg->memory, high); |
|
|
|
for (;;) { |
|
unsigned long nr_pages = page_counter_read(&memcg->memory); |
|
unsigned long reclaimed; |
|
|
|
if (nr_pages <= high) |
|
break; |
|
|
|
if (signal_pending(current)) |
|
break; |
|
|
|
if (!drained) { |
|
drain_all_stock(memcg); |
|
drained = true; |
|
continue; |
|
} |
|
|
|
reclaimed = try_to_free_mem_cgroup_pages(memcg, nr_pages - high, |
|
GFP_KERNEL, MEMCG_RECLAIM_MAY_SWAP); |
|
|
|
if (!reclaimed && !nr_retries--) |
|
break; |
|
} |
|
|
|
memcg_wb_domain_size_changed(memcg); |
|
return nbytes; |
|
} |
|
|
|
static int memory_max_show(struct seq_file *m, void *v) |
|
{ |
|
return seq_puts_memcg_tunable(m, |
|
READ_ONCE(mem_cgroup_from_seq(m)->memory.max)); |
|
} |
|
|
|
static ssize_t memory_max_write(struct kernfs_open_file *of, |
|
char *buf, size_t nbytes, loff_t off) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); |
|
unsigned int nr_reclaims = MAX_RECLAIM_RETRIES; |
|
bool drained = false; |
|
unsigned long max; |
|
int err; |
|
|
|
buf = strstrip(buf); |
|
err = page_counter_memparse(buf, "max", &max); |
|
if (err) |
|
return err; |
|
|
|
xchg(&memcg->memory.max, max); |
|
|
|
for (;;) { |
|
unsigned long nr_pages = page_counter_read(&memcg->memory); |
|
|
|
if (nr_pages <= max) |
|
break; |
|
|
|
if (signal_pending(current)) |
|
break; |
|
|
|
if (!drained) { |
|
drain_all_stock(memcg); |
|
drained = true; |
|
continue; |
|
} |
|
|
|
if (nr_reclaims) { |
|
if (!try_to_free_mem_cgroup_pages(memcg, nr_pages - max, |
|
GFP_KERNEL, MEMCG_RECLAIM_MAY_SWAP)) |
|
nr_reclaims--; |
|
continue; |
|
} |
|
|
|
memcg_memory_event(memcg, MEMCG_OOM); |
|
if (!mem_cgroup_out_of_memory(memcg, GFP_KERNEL, 0)) |
|
break; |
|
} |
|
|
|
memcg_wb_domain_size_changed(memcg); |
|
return nbytes; |
|
} |
|
|
|
static void __memory_events_show(struct seq_file *m, atomic_long_t *events) |
|
{ |
|
seq_printf(m, "low %lu\n", atomic_long_read(&events[MEMCG_LOW])); |
|
seq_printf(m, "high %lu\n", atomic_long_read(&events[MEMCG_HIGH])); |
|
seq_printf(m, "max %lu\n", atomic_long_read(&events[MEMCG_MAX])); |
|
seq_printf(m, "oom %lu\n", atomic_long_read(&events[MEMCG_OOM])); |
|
seq_printf(m, "oom_kill %lu\n", |
|
atomic_long_read(&events[MEMCG_OOM_KILL])); |
|
seq_printf(m, "oom_group_kill %lu\n", |
|
atomic_long_read(&events[MEMCG_OOM_GROUP_KILL])); |
|
} |
|
|
|
static int memory_events_show(struct seq_file *m, void *v) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_seq(m); |
|
|
|
__memory_events_show(m, memcg->memory_events); |
|
return 0; |
|
} |
|
|
|
static int memory_events_local_show(struct seq_file *m, void *v) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_seq(m); |
|
|
|
__memory_events_show(m, memcg->memory_events_local); |
|
return 0; |
|
} |
|
|
|
static int memory_stat_show(struct seq_file *m, void *v) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_seq(m); |
|
char *buf = kmalloc(PAGE_SIZE, GFP_KERNEL); |
|
|
|
if (!buf) |
|
return -ENOMEM; |
|
memory_stat_format(memcg, buf, PAGE_SIZE); |
|
seq_puts(m, buf); |
|
kfree(buf); |
|
return 0; |
|
} |
|
|
|
#ifdef CONFIG_NUMA |
|
static inline unsigned long lruvec_page_state_output(struct lruvec *lruvec, |
|
int item) |
|
{ |
|
return lruvec_page_state(lruvec, item) * memcg_page_state_unit(item); |
|
} |
|
|
|
static int memory_numa_stat_show(struct seq_file *m, void *v) |
|
{ |
|
int i; |
|
struct mem_cgroup *memcg = mem_cgroup_from_seq(m); |
|
|
|
mem_cgroup_flush_stats(); |
|
|
|
for (i = 0; i < ARRAY_SIZE(memory_stats); i++) { |
|
int nid; |
|
|
|
if (memory_stats[i].idx >= NR_VM_NODE_STAT_ITEMS) |
|
continue; |
|
|
|
seq_printf(m, "%s", memory_stats[i].name); |
|
for_each_node_state(nid, N_MEMORY) { |
|
u64 size; |
|
struct lruvec *lruvec; |
|
|
|
lruvec = mem_cgroup_lruvec(memcg, NODE_DATA(nid)); |
|
size = lruvec_page_state_output(lruvec, |
|
memory_stats[i].idx); |
|
seq_printf(m, " N%d=%llu", nid, size); |
|
} |
|
seq_putc(m, '\n'); |
|
} |
|
|
|
return 0; |
|
} |
|
#endif |
|
|
|
static int memory_oom_group_show(struct seq_file *m, void *v) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_seq(m); |
|
|
|
seq_printf(m, "%d\n", memcg->oom_group); |
|
|
|
return 0; |
|
} |
|
|
|
static ssize_t memory_oom_group_write(struct kernfs_open_file *of, |
|
char *buf, size_t nbytes, loff_t off) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); |
|
int ret, oom_group; |
|
|
|
buf = strstrip(buf); |
|
if (!buf) |
|
return -EINVAL; |
|
|
|
ret = kstrtoint(buf, 0, &oom_group); |
|
if (ret) |
|
return ret; |
|
|
|
if (oom_group != 0 && oom_group != 1) |
|
return -EINVAL; |
|
|
|
memcg->oom_group = oom_group; |
|
|
|
return nbytes; |
|
} |
|
|
|
static ssize_t memory_reclaim(struct kernfs_open_file *of, char *buf, |
|
size_t nbytes, loff_t off) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); |
|
unsigned int nr_retries = MAX_RECLAIM_RETRIES; |
|
unsigned long nr_to_reclaim, nr_reclaimed = 0; |
|
unsigned int reclaim_options; |
|
int err; |
|
|
|
buf = strstrip(buf); |
|
err = page_counter_memparse(buf, "", &nr_to_reclaim); |
|
if (err) |
|
return err; |
|
|
|
reclaim_options = MEMCG_RECLAIM_MAY_SWAP | MEMCG_RECLAIM_PROACTIVE; |
|
while (nr_reclaimed < nr_to_reclaim) { |
|
unsigned long reclaimed; |
|
|
|
if (signal_pending(current)) |
|
return -EINTR; |
|
|
|
/* |
|
* This is the final attempt, drain percpu lru caches in the |
|
* hope of introducing more evictable pages for |
|
* try_to_free_mem_cgroup_pages(). |
|
*/ |
|
if (!nr_retries) |
|
lru_add_drain_all(); |
|
|
|
reclaimed = try_to_free_mem_cgroup_pages(memcg, |
|
nr_to_reclaim - nr_reclaimed, |
|
GFP_KERNEL, reclaim_options); |
|
|
|
if (!reclaimed && !nr_retries--) |
|
return -EAGAIN; |
|
|
|
nr_reclaimed += reclaimed; |
|
} |
|
|
|
return nbytes; |
|
} |
|
|
|
static struct cftype memory_files[] = { |
|
{ |
|
.name = "current", |
|
.flags = CFTYPE_NOT_ON_ROOT, |
|
.read_u64 = memory_current_read, |
|
}, |
|
{ |
|
.name = "peak", |
|
.flags = CFTYPE_NOT_ON_ROOT, |
|
.read_u64 = memory_peak_read, |
|
}, |
|
{ |
|
.name = "min", |
|
.flags = CFTYPE_NOT_ON_ROOT, |
|
.seq_show = memory_min_show, |
|
.write = memory_min_write, |
|
}, |
|
{ |
|
.name = "low", |
|
.flags = CFTYPE_NOT_ON_ROOT, |
|
.seq_show = memory_low_show, |
|
.write = memory_low_write, |
|
}, |
|
{ |
|
.name = "high", |
|
.flags = CFTYPE_NOT_ON_ROOT, |
|
.seq_show = memory_high_show, |
|
.write = memory_high_write, |
|
}, |
|
{ |
|
.name = "max", |
|
.flags = CFTYPE_NOT_ON_ROOT, |
|
.seq_show = memory_max_show, |
|
.write = memory_max_write, |
|
}, |
|
{ |
|
.name = "events", |
|
.flags = CFTYPE_NOT_ON_ROOT, |
|
.file_offset = offsetof(struct mem_cgroup, events_file), |
|
.seq_show = memory_events_show, |
|
}, |
|
{ |
|
.name = "events.local", |
|
.flags = CFTYPE_NOT_ON_ROOT, |
|
.file_offset = offsetof(struct mem_cgroup, events_local_file), |
|
.seq_show = memory_events_local_show, |
|
}, |
|
{ |
|
.name = "stat", |
|
.seq_show = memory_stat_show, |
|
}, |
|
#ifdef CONFIG_NUMA |
|
{ |
|
.name = "numa_stat", |
|
.seq_show = memory_numa_stat_show, |
|
}, |
|
#endif |
|
{ |
|
.name = "oom.group", |
|
.flags = CFTYPE_NOT_ON_ROOT | CFTYPE_NS_DELEGATABLE, |
|
.seq_show = memory_oom_group_show, |
|
.write = memory_oom_group_write, |
|
}, |
|
{ |
|
.name = "reclaim", |
|
.flags = CFTYPE_NS_DELEGATABLE, |
|
.write = memory_reclaim, |
|
}, |
|
{ } /* terminate */ |
|
}; |
|
|
|
struct cgroup_subsys memory_cgrp_subsys = { |
|
.css_alloc = mem_cgroup_css_alloc, |
|
.css_online = mem_cgroup_css_online, |
|
.css_offline = mem_cgroup_css_offline, |
|
.css_released = mem_cgroup_css_released, |
|
.css_free = mem_cgroup_css_free, |
|
.css_reset = mem_cgroup_css_reset, |
|
.css_rstat_flush = mem_cgroup_css_rstat_flush, |
|
.can_attach = mem_cgroup_can_attach, |
|
.attach = mem_cgroup_attach, |
|
.cancel_attach = mem_cgroup_cancel_attach, |
|
.post_attach = mem_cgroup_move_task, |
|
.dfl_cftypes = memory_files, |
|
.legacy_cftypes = mem_cgroup_legacy_files, |
|
.early_init = 0, |
|
}; |
|
|
|
/* |
|
* This function calculates an individual cgroup's effective |
|
* protection which is derived from its own memory.min/low, its |
|
* parent's and siblings' settings, as well as the actual memory |
|
* distribution in the tree. |
|
* |
|
* The following rules apply to the effective protection values: |
|
* |
|
* 1. At the first level of reclaim, effective protection is equal to |
|
* the declared protection in memory.min and memory.low. |
|
* |
|
* 2. To enable safe delegation of the protection configuration, at |
|
* subsequent levels the effective protection is capped to the |
|
* parent's effective protection. |
|
* |
|
* 3. To make complex and dynamic subtrees easier to configure, the |
|
* user is allowed to overcommit the declared protection at a given |
|
* level. If that is the case, the parent's effective protection is |
|
* distributed to the children in proportion to how much protection |
|
* they have declared and how much of it they are utilizing. |
|
* |
|
* This makes distribution proportional, but also work-conserving: |
|
* if one cgroup claims much more protection than it uses memory, |
|
* the unused remainder is available to its siblings. |
|
* |
|
* 4. Conversely, when the declared protection is undercommitted at a |
|
* given level, the distribution of the larger parental protection |
|
* budget is NOT proportional. A cgroup's protection from a sibling |
|
* is capped to its own memory.min/low setting. |
|
* |
|
* 5. However, to allow protecting recursive subtrees from each other |
|
* without having to declare each individual cgroup's fixed share |
|
* of the ancestor's claim to protection, any unutilized - |
|
* "floating" - protection from up the tree is distributed in |
|
* proportion to each cgroup's *usage*. This makes the protection |
|
* neutral wrt sibling cgroups and lets them compete freely over |
|
* the shared parental protection budget, but it protects the |
|
* subtree as a whole from neighboring subtrees. |
|
* |
|
* Note that 4. and 5. are not in conflict: 4. is about protecting |
|
* against immediate siblings whereas 5. is about protecting against |
|
* neighboring subtrees. |
|
*/ |
|
static unsigned long effective_protection(unsigned long usage, |
|
unsigned long parent_usage, |
|
unsigned long setting, |
|
unsigned long parent_effective, |
|
unsigned long siblings_protected) |
|
{ |
|
unsigned long protected; |
|
unsigned long ep; |
|
|
|
protected = min(usage, setting); |
|
/* |
|
* If all cgroups at this level combined claim and use more |
|
* protection then what the parent affords them, distribute |
|
* shares in proportion to utilization. |
|
* |
|
* We are using actual utilization rather than the statically |
|
* claimed protection in order to be work-conserving: claimed |
|
* but unused protection is available to siblings that would |
|
* otherwise get a smaller chunk than what they claimed. |
|
*/ |
|
if (siblings_protected > parent_effective) |
|
return protected * parent_effective / siblings_protected; |
|
|
|
/* |
|
* Ok, utilized protection of all children is within what the |
|
* parent affords them, so we know whatever this child claims |
|
* and utilizes is effectively protected. |
|
* |
|
* If there is unprotected usage beyond this value, reclaim |
|
* will apply pressure in proportion to that amount. |
|
* |
|
* If there is unutilized protection, the cgroup will be fully |
|
* shielded from reclaim, but we do return a smaller value for |
|
* protection than what the group could enjoy in theory. This |
|
* is okay. With the overcommit distribution above, effective |
|
* protection is always dependent on how memory is actually |
|
* consumed among the siblings anyway. |
|
*/ |
|
ep = protected; |
|
|
|
/* |
|
* If the children aren't claiming (all of) the protection |
|
* afforded to them by the parent, distribute the remainder in |
|
* proportion to the (unprotected) memory of each cgroup. That |
|
* way, cgroups that aren't explicitly prioritized wrt each |
|
* other compete freely over the allowance, but they are |
|
* collectively protected from neighboring trees. |
|
* |
|
* We're using unprotected memory for the weight so that if |
|
* some cgroups DO claim explicit protection, we don't protect |
|
* the same bytes twice. |
|
* |
|
* Check both usage and parent_usage against the respective |
|
* protected values. One should imply the other, but they |
|
* aren't read atomically - make sure the division is sane. |
|
*/ |
|
if (!(cgrp_dfl_root.flags & CGRP_ROOT_MEMORY_RECURSIVE_PROT)) |
|
return ep; |
|
if (parent_effective > siblings_protected && |
|
parent_usage > siblings_protected && |
|
usage > protected) { |
|
unsigned long unclaimed; |
|
|
|
unclaimed = parent_effective - siblings_protected; |
|
unclaimed *= usage - protected; |
|
unclaimed /= parent_usage - siblings_protected; |
|
|
|
ep += unclaimed; |
|
} |
|
|
|
return ep; |
|
} |
|
|
|
/** |
|
* mem_cgroup_calculate_protection - check if memory consumption is in the normal range |
|
* @root: the top ancestor of the sub-tree being checked |
|
* @memcg: the memory cgroup to check |
|
* |
|
* WARNING: This function is not stateless! It can only be used as part |
|
* of a top-down tree iteration, not for isolated queries. |
|
*/ |
|
void mem_cgroup_calculate_protection(struct mem_cgroup *root, |
|
struct mem_cgroup *memcg) |
|
{ |
|
unsigned long usage, parent_usage; |
|
struct mem_cgroup *parent; |
|
|
|
if (mem_cgroup_disabled()) |
|
return; |
|
|
|
if (!root) |
|
root = root_mem_cgroup; |
|
|
|
/* |
|
* Effective values of the reclaim targets are ignored so they |
|
* can be stale. Have a look at mem_cgroup_protection for more |
|
* details. |
|
* TODO: calculation should be more robust so that we do not need |
|
* that special casing. |
|
*/ |
|
if (memcg == root) |
|
return; |
|
|
|
usage = page_counter_read(&memcg->memory); |
|
if (!usage) |
|
return; |
|
|
|
parent = parent_mem_cgroup(memcg); |
|
|
|
if (parent == root) { |
|
memcg->memory.emin = READ_ONCE(memcg->memory.min); |
|
memcg->memory.elow = READ_ONCE(memcg->memory.low); |
|
return; |
|
} |
|
|
|
parent_usage = page_counter_read(&parent->memory); |
|
|
|
WRITE_ONCE(memcg->memory.emin, effective_protection(usage, parent_usage, |
|
READ_ONCE(memcg->memory.min), |
|
READ_ONCE(parent->memory.emin), |
|
atomic_long_read(&parent->memory.children_min_usage))); |
|
|
|
WRITE_ONCE(memcg->memory.elow, effective_protection(usage, parent_usage, |
|
READ_ONCE(memcg->memory.low), |
|
READ_ONCE(parent->memory.elow), |
|
atomic_long_read(&parent->memory.children_low_usage))); |
|
} |
|
|
|
static int charge_memcg(struct folio *folio, struct mem_cgroup *memcg, |
|
gfp_t gfp) |
|
{ |
|
long nr_pages = folio_nr_pages(folio); |
|
int ret; |
|
|
|
ret = try_charge(memcg, gfp, nr_pages); |
|
if (ret) |
|
goto out; |
|
|
|
css_get(&memcg->css); |
|
commit_charge(folio, memcg); |
|
|
|
local_irq_disable(); |
|
mem_cgroup_charge_statistics(memcg, nr_pages); |
|
memcg_check_events(memcg, folio_nid(folio)); |
|
local_irq_enable(); |
|
out: |
|
return ret; |
|
} |
|
|
|
int __mem_cgroup_charge(struct folio *folio, struct mm_struct *mm, gfp_t gfp) |
|
{ |
|
struct mem_cgroup *memcg; |
|
int ret; |
|
|
|
memcg = get_mem_cgroup_from_mm(mm); |
|
ret = charge_memcg(folio, memcg, gfp); |
|
css_put(&memcg->css); |
|
|
|
return ret; |
|
} |
|
|
|
/** |
|
* mem_cgroup_swapin_charge_folio - Charge a newly allocated folio for swapin. |
|
* @folio: folio to charge. |
|
* @mm: mm context of the victim |
|
* @gfp: reclaim mode |
|
* @entry: swap entry for which the folio is allocated |
|
* |
|
* This function charges a folio allocated for swapin. Please call this before |
|
* adding the folio to the swapcache. |
|
* |
|
* Returns 0 on success. Otherwise, an error code is returned. |
|
*/ |
|
int mem_cgroup_swapin_charge_folio(struct folio *folio, struct mm_struct *mm, |
|
gfp_t gfp, swp_entry_t entry) |
|
{ |
|
struct mem_cgroup *memcg; |
|
unsigned short id; |
|
int ret; |
|
|
|
if (mem_cgroup_disabled()) |
|
return 0; |
|
|
|
id = lookup_swap_cgroup_id(entry); |
|
rcu_read_lock(); |
|
memcg = mem_cgroup_from_id(id); |
|
if (!memcg || !css_tryget_online(&memcg->css)) |
|
memcg = get_mem_cgroup_from_mm(mm); |
|
rcu_read_unlock(); |
|
|
|
ret = charge_memcg(folio, memcg, gfp); |
|
|
|
css_put(&memcg->css); |
|
return ret; |
|
} |
|
|
|
/* |
|
* mem_cgroup_swapin_uncharge_swap - uncharge swap slot |
|
* @entry: swap entry for which the page is charged |
|
* |
|
* Call this function after successfully adding the charged page to swapcache. |
|
* |
|
* Note: This function assumes the page for which swap slot is being uncharged |
|
* is order 0 page. |
|
*/ |
|
void mem_cgroup_swapin_uncharge_swap(swp_entry_t entry) |
|
{ |
|
/* |
|
* Cgroup1's unified memory+swap counter has been charged with the |
|
* new swapcache page, finish the transfer by uncharging the swap |
|
* slot. The swap slot would also get uncharged when it dies, but |
|
* it can stick around indefinitely and we'd count the page twice |
|
* the entire time. |
|
* |
|
* Cgroup2 has separate resource counters for memory and swap, |
|
* so this is a non-issue here. Memory and swap charge lifetimes |
|
* correspond 1:1 to page and swap slot lifetimes: we charge the |
|
* page to memory here, and uncharge swap when the slot is freed. |
|
*/ |
|
if (!mem_cgroup_disabled() && do_memsw_account()) { |
|
/* |
|
* The swap entry might not get freed for a long time, |
|
* let's not wait for it. The page already received a |
|
* memory+swap charge, drop the swap entry duplicate. |
|
*/ |
|
mem_cgroup_uncharge_swap(entry, 1); |
|
} |
|
} |
|
|
|
struct uncharge_gather { |
|
struct mem_cgroup *memcg; |
|
unsigned long nr_memory; |
|
unsigned long pgpgout; |
|
unsigned long nr_kmem; |
|
int nid; |
|
}; |
|
|
|
static inline void uncharge_gather_clear(struct uncharge_gather *ug) |
|
{ |
|
memset(ug, 0, sizeof(*ug)); |
|
} |
|
|
|
static void uncharge_batch(const struct uncharge_gather *ug) |
|
{ |
|
unsigned long flags; |
|
|
|
if (ug->nr_memory) { |
|
page_counter_uncharge(&ug->memcg->memory, ug->nr_memory); |
|
if (do_memsw_account()) |
|
page_counter_uncharge(&ug->memcg->memsw, ug->nr_memory); |
|
if (ug->nr_kmem) |
|
memcg_account_kmem(ug->memcg, -ug->nr_kmem); |
|
memcg_oom_recover(ug->memcg); |
|
} |
|
|
|
local_irq_save(flags); |
|
__count_memcg_events(ug->memcg, PGPGOUT, ug->pgpgout); |
|
__this_cpu_add(ug->memcg->vmstats_percpu->nr_page_events, ug->nr_memory); |
|
memcg_check_events(ug->memcg, ug->nid); |
|
local_irq_restore(flags); |
|
|
|
/* drop reference from uncharge_folio */ |
|
css_put(&ug->memcg->css); |
|
} |
|
|
|
static void uncharge_folio(struct folio *folio, struct uncharge_gather *ug) |
|
{ |
|
long nr_pages; |
|
struct mem_cgroup *memcg; |
|
struct obj_cgroup *objcg; |
|
|
|
VM_BUG_ON_FOLIO(folio_test_lru(folio), folio); |
|
|
|
/* |
|
* Nobody should be changing or seriously looking at |
|
* folio memcg or objcg at this point, we have fully |
|
* exclusive access to the folio. |
|
*/ |
|
if (folio_memcg_kmem(folio)) { |
|
objcg = __folio_objcg(folio); |
|
/* |
|
* This get matches the put at the end of the function and |
|
* kmem pages do not hold memcg references anymore. |
|
*/ |
|
memcg = get_mem_cgroup_from_objcg(objcg); |
|
} else { |
|
memcg = __folio_memcg(folio); |
|
} |
|
|
|
if (!memcg) |
|
return; |
|
|
|
if (ug->memcg != memcg) { |
|
if (ug->memcg) { |
|
uncharge_batch(ug); |
|
uncharge_gather_clear(ug); |
|
} |
|
ug->memcg = memcg; |
|
ug->nid = folio_nid(folio); |
|
|
|
/* pairs with css_put in uncharge_batch */ |
|
css_get(&memcg->css); |
|
} |
|
|
|
nr_pages = folio_nr_pages(folio); |
|
|
|
if (folio_memcg_kmem(folio)) { |
|
ug->nr_memory += nr_pages; |
|
ug->nr_kmem += nr_pages; |
|
|
|
folio->memcg_data = 0; |
|
obj_cgroup_put(objcg); |
|
} else { |
|
/* LRU pages aren't accounted at the root level */ |
|
if (!mem_cgroup_is_root(memcg)) |
|
ug->nr_memory += nr_pages; |
|
ug->pgpgout++; |
|
|
|
folio->memcg_data = 0; |
|
} |
|
|
|
css_put(&memcg->css); |
|
} |
|
|
|
void __mem_cgroup_uncharge(struct folio *folio) |
|
{ |
|
struct uncharge_gather ug; |
|
|
|
/* Don't touch folio->lru of any random page, pre-check: */ |
|
if (!folio_memcg(folio)) |
|
return; |
|
|
|
uncharge_gather_clear(&ug); |
|
uncharge_folio(folio, &ug); |
|
uncharge_batch(&ug); |
|
} |
|
|
|
/** |
|
* __mem_cgroup_uncharge_list - uncharge a list of page |
|
* @page_list: list of pages to uncharge |
|
* |
|
* Uncharge a list of pages previously charged with |
|
* __mem_cgroup_charge(). |
|
*/ |
|
void __mem_cgroup_uncharge_list(struct list_head *page_list) |
|
{ |
|
struct uncharge_gather ug; |
|
struct folio *folio; |
|
|
|
uncharge_gather_clear(&ug); |
|
list_for_each_entry(folio, page_list, lru) |
|
uncharge_folio(folio, &ug); |
|
if (ug.memcg) |
|
uncharge_batch(&ug); |
|
} |
|
|
|
/** |
|
* mem_cgroup_migrate - Charge a folio's replacement. |
|
* @old: Currently circulating folio. |
|
* @new: Replacement folio. |
|
* |
|
* Charge @new as a replacement folio for @old. @old will |
|
* be uncharged upon free. |
|
* |
|
* Both folios must be locked, @new->mapping must be set up. |
|
*/ |
|
void mem_cgroup_migrate(struct folio *old, struct folio *new) |
|
{ |
|
struct mem_cgroup *memcg; |
|
long nr_pages = folio_nr_pages(new); |
|
unsigned long flags; |
|
|
|
VM_BUG_ON_FOLIO(!folio_test_locked(old), old); |
|
VM_BUG_ON_FOLIO(!folio_test_locked(new), new); |
|
VM_BUG_ON_FOLIO(folio_test_anon(old) != folio_test_anon(new), new); |
|
VM_BUG_ON_FOLIO(folio_nr_pages(old) != nr_pages, new); |
|
|
|
if (mem_cgroup_disabled()) |
|
return; |
|
|
|
/* Page cache replacement: new folio already charged? */ |
|
if (folio_memcg(new)) |
|
return; |
|
|
|
memcg = folio_memcg(old); |
|
VM_WARN_ON_ONCE_FOLIO(!memcg, old); |
|
if (!memcg) |
|
return; |
|
|
|
/* Force-charge the new page. The old one will be freed soon */ |
|
if (!mem_cgroup_is_root(memcg)) { |
|
page_counter_charge(&memcg->memory, nr_pages); |
|
if (do_memsw_account()) |
|
page_counter_charge(&memcg->memsw, nr_pages); |
|
} |
|
|
|
css_get(&memcg->css); |
|
commit_charge(new, memcg); |
|
|
|
local_irq_save(flags); |
|
mem_cgroup_charge_statistics(memcg, nr_pages); |
|
memcg_check_events(memcg, folio_nid(new)); |
|
local_irq_restore(flags); |
|
} |
|
|
|
DEFINE_STATIC_KEY_FALSE(memcg_sockets_enabled_key); |
|
EXPORT_SYMBOL(memcg_sockets_enabled_key); |
|
|
|
void mem_cgroup_sk_alloc(struct sock *sk) |
|
{ |
|
struct mem_cgroup *memcg; |
|
|
|
if (!mem_cgroup_sockets_enabled) |
|
return; |
|
|
|
/* Do not associate the sock with unrelated interrupted task's memcg. */ |
|
if (!in_task()) |
|
return; |
|
|
|
rcu_read_lock(); |
|
memcg = mem_cgroup_from_task(current); |
|
if (memcg == root_mem_cgroup) |
|
goto out; |
|
if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && !memcg->tcpmem_active) |
|
goto out; |
|
if (css_tryget(&memcg->css)) |
|
sk->sk_memcg = memcg; |
|
out: |
|
rcu_read_unlock(); |
|
} |
|
|
|
void mem_cgroup_sk_free(struct sock *sk) |
|
{ |
|
if (sk->sk_memcg) |
|
css_put(&sk->sk_memcg->css); |
|
} |
|
|
|
/** |
|
* mem_cgroup_charge_skmem - charge socket memory |
|
* @memcg: memcg to charge |
|
* @nr_pages: number of pages to charge |
|
* @gfp_mask: reclaim mode |
|
* |
|
* Charges @nr_pages to @memcg. Returns %true if the charge fit within |
|
* @memcg's configured limit, %false if it doesn't. |
|
*/ |
|
bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages, |
|
gfp_t gfp_mask) |
|
{ |
|
if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) { |
|
struct page_counter *fail; |
|
|
|
if (page_counter_try_charge(&memcg->tcpmem, nr_pages, &fail)) { |
|
memcg->tcpmem_pressure = 0; |
|
return true; |
|
} |
|
memcg->tcpmem_pressure = 1; |
|
if (gfp_mask & __GFP_NOFAIL) { |
|
page_counter_charge(&memcg->tcpmem, nr_pages); |
|
return true; |
|
} |
|
return false; |
|
} |
|
|
|
if (try_charge(memcg, gfp_mask, nr_pages) == 0) { |
|
mod_memcg_state(memcg, MEMCG_SOCK, nr_pages); |
|
return true; |
|
} |
|
|
|
return false; |
|
} |
|
|
|
/** |
|
* mem_cgroup_uncharge_skmem - uncharge socket memory |
|
* @memcg: memcg to uncharge |
|
* @nr_pages: number of pages to uncharge |
|
*/ |
|
void mem_cgroup_uncharge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages) |
|
{ |
|
if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) { |
|
page_counter_uncharge(&memcg->tcpmem, nr_pages); |
|
return; |
|
} |
|
|
|
mod_memcg_state(memcg, MEMCG_SOCK, -nr_pages); |
|
|
|
refill_stock(memcg, nr_pages); |
|
} |
|
|
|
static int __init cgroup_memory(char *s) |
|
{ |
|
char *token; |
|
|
|
while ((token = strsep(&s, ",")) != NULL) { |
|
if (!*token) |
|
continue; |
|
if (!strcmp(token, "nosocket")) |
|
cgroup_memory_nosocket = true; |
|
if (!strcmp(token, "nokmem")) |
|
cgroup_memory_nokmem = true; |
|
} |
|
return 1; |
|
} |
|
__setup("cgroup.memory=", cgroup_memory); |
|
|
|
/* |
|
* subsys_initcall() for memory controller. |
|
* |
|
* Some parts like memcg_hotplug_cpu_dead() have to be initialized from this |
|
* context because of lock dependencies (cgroup_lock -> cpu hotplug) but |
|
* basically everything that doesn't depend on a specific mem_cgroup structure |
|
* should be initialized from here. |
|
*/ |
|
static int __init mem_cgroup_init(void) |
|
{ |
|
int cpu, node; |
|
|
|
/* |
|
* Currently s32 type (can refer to struct batched_lruvec_stat) is |
|
* used for per-memcg-per-cpu caching of per-node statistics. In order |
|
* to work fine, we should make sure that the overfill threshold can't |
|
* exceed S32_MAX / PAGE_SIZE. |
|
*/ |
|
BUILD_BUG_ON(MEMCG_CHARGE_BATCH > S32_MAX / PAGE_SIZE); |
|
|
|
cpuhp_setup_state_nocalls(CPUHP_MM_MEMCQ_DEAD, "mm/memctrl:dead", NULL, |
|
memcg_hotplug_cpu_dead); |
|
|
|
for_each_possible_cpu(cpu) |
|
INIT_WORK(&per_cpu_ptr(&memcg_stock, cpu)->work, |
|
drain_local_stock); |
|
|
|
for_each_node(node) { |
|
struct mem_cgroup_tree_per_node *rtpn; |
|
|
|
rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, |
|
node_online(node) ? node : NUMA_NO_NODE); |
|
|
|
rtpn->rb_root = RB_ROOT; |
|
rtpn->rb_rightmost = NULL; |
|
spin_lock_init(&rtpn->lock); |
|
soft_limit_tree.rb_tree_per_node[node] = rtpn; |
|
} |
|
|
|
return 0; |
|
} |
|
subsys_initcall(mem_cgroup_init); |
|
|
|
#ifdef CONFIG_SWAP |
|
static struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg) |
|
{ |
|
while (!refcount_inc_not_zero(&memcg->id.ref)) { |
|
/* |
|
* The root cgroup cannot be destroyed, so it's refcount must |
|
* always be >= 1. |
|
*/ |
|
if (WARN_ON_ONCE(memcg == root_mem_cgroup)) { |
|
VM_BUG_ON(1); |
|
break; |
|
} |
|
memcg = parent_mem_cgroup(memcg); |
|
if (!memcg) |
|
memcg = root_mem_cgroup; |
|
} |
|
return memcg; |
|
} |
|
|
|
/** |
|
* mem_cgroup_swapout - transfer a memsw charge to swap |
|
* @folio: folio whose memsw charge to transfer |
|
* @entry: swap entry to move the charge to |
|
* |
|
* Transfer the memsw charge of @folio to @entry. |
|
*/ |
|
void mem_cgroup_swapout(struct folio *folio, swp_entry_t entry) |
|
{ |
|
struct mem_cgroup *memcg, *swap_memcg; |
|
unsigned int nr_entries; |
|
unsigned short oldid; |
|
|
|
VM_BUG_ON_FOLIO(folio_test_lru(folio), folio); |
|
VM_BUG_ON_FOLIO(folio_ref_count(folio), folio); |
|
|
|
if (mem_cgroup_disabled()) |
|
return; |
|
|
|
if (!do_memsw_account()) |
|
return; |
|
|
|
memcg = folio_memcg(folio); |
|
|
|
VM_WARN_ON_ONCE_FOLIO(!memcg, folio); |
|
if (!memcg) |
|
return; |
|
|
|
/* |
|
* In case the memcg owning these pages has been offlined and doesn't |
|
* have an ID allocated to it anymore, charge the closest online |
|
* ancestor for the swap instead and transfer the memory+swap charge. |
|
*/ |
|
swap_memcg = mem_cgroup_id_get_online(memcg); |
|
nr_entries = folio_nr_pages(folio); |
|
/* Get references for the tail pages, too */ |
|
if (nr_entries > 1) |
|
mem_cgroup_id_get_many(swap_memcg, nr_entries - 1); |
|
oldid = swap_cgroup_record(entry, mem_cgroup_id(swap_memcg), |
|
nr_entries); |
|
VM_BUG_ON_FOLIO(oldid, folio); |
|
mod_memcg_state(swap_memcg, MEMCG_SWAP, nr_entries); |
|
|
|
folio->memcg_data = 0; |
|
|
|
if (!mem_cgroup_is_root(memcg)) |
|
page_counter_uncharge(&memcg->memory, nr_entries); |
|
|
|
if (memcg != swap_memcg) { |
|
if (!mem_cgroup_is_root(swap_memcg)) |
|
page_counter_charge(&swap_memcg->memsw, nr_entries); |
|
page_counter_uncharge(&memcg->memsw, nr_entries); |
|
} |
|
|
|
/* |
|
* Interrupts should be disabled here because the caller holds the |
|
* i_pages lock which is taken with interrupts-off. It is |
|
* important here to have the interrupts disabled because it is the |
|
* only synchronisation we have for updating the per-CPU variables. |
|
*/ |
|
memcg_stats_lock(); |
|
mem_cgroup_charge_statistics(memcg, -nr_entries); |
|
memcg_stats_unlock(); |
|
memcg_check_events(memcg, folio_nid(folio)); |
|
|
|
css_put(&memcg->css); |
|
} |
|
|
|
/** |
|
* __mem_cgroup_try_charge_swap - try charging swap space for a folio |
|
* @folio: folio being added to swap |
|
* @entry: swap entry to charge |
|
* |
|
* Try to charge @folio's memcg for the swap space at @entry. |
|
* |
|
* Returns 0 on success, -ENOMEM on failure. |
|
*/ |
|
int __mem_cgroup_try_charge_swap(struct folio *folio, swp_entry_t entry) |
|
{ |
|
unsigned int nr_pages = folio_nr_pages(folio); |
|
struct page_counter *counter; |
|
struct mem_cgroup *memcg; |
|
unsigned short oldid; |
|
|
|
if (do_memsw_account()) |
|
return 0; |
|
|
|
memcg = folio_memcg(folio); |
|
|
|
VM_WARN_ON_ONCE_FOLIO(!memcg, folio); |
|
if (!memcg) |
|
return 0; |
|
|
|
if (!entry.val) { |
|
memcg_memory_event(memcg, MEMCG_SWAP_FAIL); |
|
return 0; |
|
} |
|
|
|
memcg = mem_cgroup_id_get_online(memcg); |
|
|
|
if (!mem_cgroup_is_root(memcg) && |
|
!page_counter_try_charge(&memcg->swap, nr_pages, &counter)) { |
|
memcg_memory_event(memcg, MEMCG_SWAP_MAX); |
|
memcg_memory_event(memcg, MEMCG_SWAP_FAIL); |
|
mem_cgroup_id_put(memcg); |
|
return -ENOMEM; |
|
} |
|
|
|
/* Get references for the tail pages, too */ |
|
if (nr_pages > 1) |
|
mem_cgroup_id_get_many(memcg, nr_pages - 1); |
|
oldid = swap_cgroup_record(entry, mem_cgroup_id(memcg), nr_pages); |
|
VM_BUG_ON_FOLIO(oldid, folio); |
|
mod_memcg_state(memcg, MEMCG_SWAP, nr_pages); |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* __mem_cgroup_uncharge_swap - uncharge swap space |
|
* @entry: swap entry to uncharge |
|
* @nr_pages: the amount of swap space to uncharge |
|
*/ |
|
void __mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages) |
|
{ |
|
struct mem_cgroup *memcg; |
|
unsigned short id; |
|
|
|
if (mem_cgroup_disabled()) |
|
return; |
|
|
|
id = swap_cgroup_record(entry, 0, nr_pages); |
|
rcu_read_lock(); |
|
memcg = mem_cgroup_from_id(id); |
|
if (memcg) { |
|
if (!mem_cgroup_is_root(memcg)) { |
|
if (do_memsw_account()) |
|
page_counter_uncharge(&memcg->memsw, nr_pages); |
|
else |
|
page_counter_uncharge(&memcg->swap, nr_pages); |
|
} |
|
mod_memcg_state(memcg, MEMCG_SWAP, -nr_pages); |
|
mem_cgroup_id_put_many(memcg, nr_pages); |
|
} |
|
rcu_read_unlock(); |
|
} |
|
|
|
long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg) |
|
{ |
|
long nr_swap_pages = get_nr_swap_pages(); |
|
|
|
if (mem_cgroup_disabled() || do_memsw_account()) |
|
return nr_swap_pages; |
|
for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg)) |
|
nr_swap_pages = min_t(long, nr_swap_pages, |
|
READ_ONCE(memcg->swap.max) - |
|
page_counter_read(&memcg->swap)); |
|
return nr_swap_pages; |
|
} |
|
|
|
bool mem_cgroup_swap_full(struct folio *folio) |
|
{ |
|
struct mem_cgroup *memcg; |
|
|
|
VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio); |
|
|
|
if (vm_swap_full()) |
|
return true; |
|
if (do_memsw_account()) |
|
return false; |
|
|
|
memcg = folio_memcg(folio); |
|
if (!memcg) |
|
return false; |
|
|
|
for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg)) { |
|
unsigned long usage = page_counter_read(&memcg->swap); |
|
|
|
if (usage * 2 >= READ_ONCE(memcg->swap.high) || |
|
usage * 2 >= READ_ONCE(memcg->swap.max)) |
|
return true; |
|
} |
|
|
|
return false; |
|
} |
|
|
|
static int __init setup_swap_account(char *s) |
|
{ |
|
pr_warn_once("The swapaccount= commandline option is deprecated. " |
|
"Please report your usecase to [email protected] if you " |
|
"depend on this functionality.\n"); |
|
return 1; |
|
} |
|
__setup("swapaccount=", setup_swap_account); |
|
|
|
static u64 swap_current_read(struct cgroup_subsys_state *css, |
|
struct cftype *cft) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
|
|
|
return (u64)page_counter_read(&memcg->swap) * PAGE_SIZE; |
|
} |
|
|
|
static int swap_high_show(struct seq_file *m, void *v) |
|
{ |
|
return seq_puts_memcg_tunable(m, |
|
READ_ONCE(mem_cgroup_from_seq(m)->swap.high)); |
|
} |
|
|
|
static ssize_t swap_high_write(struct kernfs_open_file *of, |
|
char *buf, size_t nbytes, loff_t off) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); |
|
unsigned long high; |
|
int err; |
|
|
|
buf = strstrip(buf); |
|
err = page_counter_memparse(buf, "max", &high); |
|
if (err) |
|
return err; |
|
|
|
page_counter_set_high(&memcg->swap, high); |
|
|
|
return nbytes; |
|
} |
|
|
|
static int swap_max_show(struct seq_file *m, void *v) |
|
{ |
|
return seq_puts_memcg_tunable(m, |
|
READ_ONCE(mem_cgroup_from_seq(m)->swap.max)); |
|
} |
|
|
|
static ssize_t swap_max_write(struct kernfs_open_file *of, |
|
char *buf, size_t nbytes, loff_t off) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); |
|
unsigned long max; |
|
int err; |
|
|
|
buf = strstrip(buf); |
|
err = page_counter_memparse(buf, "max", &max); |
|
if (err) |
|
return err; |
|
|
|
xchg(&memcg->swap.max, max); |
|
|
|
return nbytes; |
|
} |
|
|
|
static int swap_events_show(struct seq_file *m, void *v) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_seq(m); |
|
|
|
seq_printf(m, "high %lu\n", |
|
atomic_long_read(&memcg->memory_events[MEMCG_SWAP_HIGH])); |
|
seq_printf(m, "max %lu\n", |
|
atomic_long_read(&memcg->memory_events[MEMCG_SWAP_MAX])); |
|
seq_printf(m, "fail %lu\n", |
|
atomic_long_read(&memcg->memory_events[MEMCG_SWAP_FAIL])); |
|
|
|
return 0; |
|
} |
|
|
|
static struct cftype swap_files[] = { |
|
{ |
|
.name = "swap.current", |
|
.flags = CFTYPE_NOT_ON_ROOT, |
|
.read_u64 = swap_current_read, |
|
}, |
|
{ |
|
.name = "swap.high", |
|
.flags = CFTYPE_NOT_ON_ROOT, |
|
.seq_show = swap_high_show, |
|
.write = swap_high_write, |
|
}, |
|
{ |
|
.name = "swap.max", |
|
.flags = CFTYPE_NOT_ON_ROOT, |
|
.seq_show = swap_max_show, |
|
.write = swap_max_write, |
|
}, |
|
{ |
|
.name = "swap.events", |
|
.flags = CFTYPE_NOT_ON_ROOT, |
|
.file_offset = offsetof(struct mem_cgroup, swap_events_file), |
|
.seq_show = swap_events_show, |
|
}, |
|
{ } /* terminate */ |
|
}; |
|
|
|
static struct cftype memsw_files[] = { |
|
{ |
|
.name = "memsw.usage_in_bytes", |
|
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE), |
|
.read_u64 = mem_cgroup_read_u64, |
|
}, |
|
{ |
|
.name = "memsw.max_usage_in_bytes", |
|
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE), |
|
.write = mem_cgroup_reset, |
|
.read_u64 = mem_cgroup_read_u64, |
|
}, |
|
{ |
|
.name = "memsw.limit_in_bytes", |
|
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT), |
|
.write = mem_cgroup_write, |
|
.read_u64 = mem_cgroup_read_u64, |
|
}, |
|
{ |
|
.name = "memsw.failcnt", |
|
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT), |
|
.write = mem_cgroup_reset, |
|
.read_u64 = mem_cgroup_read_u64, |
|
}, |
|
{ }, /* terminate */ |
|
}; |
|
|
|
#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP) |
|
/** |
|
* obj_cgroup_may_zswap - check if this cgroup can zswap |
|
* @objcg: the object cgroup |
|
* |
|
* Check if the hierarchical zswap limit has been reached. |
|
* |
|
* This doesn't check for specific headroom, and it is not atomic |
|
* either. But with zswap, the size of the allocation is only known |
|
* once compression has occured, and this optimistic pre-check avoids |
|
* spending cycles on compression when there is already no room left |
|
* or zswap is disabled altogether somewhere in the hierarchy. |
|
*/ |
|
bool obj_cgroup_may_zswap(struct obj_cgroup *objcg) |
|
{ |
|
struct mem_cgroup *memcg, *original_memcg; |
|
bool ret = true; |
|
|
|
if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) |
|
return true; |
|
|
|
original_memcg = get_mem_cgroup_from_objcg(objcg); |
|
for (memcg = original_memcg; memcg != root_mem_cgroup; |
|
memcg = parent_mem_cgroup(memcg)) { |
|
unsigned long max = READ_ONCE(memcg->zswap_max); |
|
unsigned long pages; |
|
|
|
if (max == PAGE_COUNTER_MAX) |
|
continue; |
|
if (max == 0) { |
|
ret = false; |
|
break; |
|
} |
|
|
|
cgroup_rstat_flush(memcg->css.cgroup); |
|
pages = memcg_page_state(memcg, MEMCG_ZSWAP_B) / PAGE_SIZE; |
|
if (pages < max) |
|
continue; |
|
ret = false; |
|
break; |
|
} |
|
mem_cgroup_put(original_memcg); |
|
return ret; |
|
} |
|
|
|
/** |
|
* obj_cgroup_charge_zswap - charge compression backend memory |
|
* @objcg: the object cgroup |
|
* @size: size of compressed object |
|
* |
|
* This forces the charge after obj_cgroup_may_swap() allowed |
|
* compression and storage in zwap for this cgroup to go ahead. |
|
*/ |
|
void obj_cgroup_charge_zswap(struct obj_cgroup *objcg, size_t size) |
|
{ |
|
struct mem_cgroup *memcg; |
|
|
|
if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) |
|
return; |
|
|
|
VM_WARN_ON_ONCE(!(current->flags & PF_MEMALLOC)); |
|
|
|
/* PF_MEMALLOC context, charging must succeed */ |
|
if (obj_cgroup_charge(objcg, GFP_KERNEL, size)) |
|
VM_WARN_ON_ONCE(1); |
|
|
|
rcu_read_lock(); |
|
memcg = obj_cgroup_memcg(objcg); |
|
mod_memcg_state(memcg, MEMCG_ZSWAP_B, size); |
|
mod_memcg_state(memcg, MEMCG_ZSWAPPED, 1); |
|
rcu_read_unlock(); |
|
} |
|
|
|
/** |
|
* obj_cgroup_uncharge_zswap - uncharge compression backend memory |
|
* @objcg: the object cgroup |
|
* @size: size of compressed object |
|
* |
|
* Uncharges zswap memory on page in. |
|
*/ |
|
void obj_cgroup_uncharge_zswap(struct obj_cgroup *objcg, size_t size) |
|
{ |
|
struct mem_cgroup *memcg; |
|
|
|
if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) |
|
return; |
|
|
|
obj_cgroup_uncharge(objcg, size); |
|
|
|
rcu_read_lock(); |
|
memcg = obj_cgroup_memcg(objcg); |
|
mod_memcg_state(memcg, MEMCG_ZSWAP_B, -size); |
|
mod_memcg_state(memcg, MEMCG_ZSWAPPED, -1); |
|
rcu_read_unlock(); |
|
} |
|
|
|
static u64 zswap_current_read(struct cgroup_subsys_state *css, |
|
struct cftype *cft) |
|
{ |
|
cgroup_rstat_flush(css->cgroup); |
|
return memcg_page_state(mem_cgroup_from_css(css), MEMCG_ZSWAP_B); |
|
} |
|
|
|
static int zswap_max_show(struct seq_file *m, void *v) |
|
{ |
|
return seq_puts_memcg_tunable(m, |
|
READ_ONCE(mem_cgroup_from_seq(m)->zswap_max)); |
|
} |
|
|
|
static ssize_t zswap_max_write(struct kernfs_open_file *of, |
|
char *buf, size_t nbytes, loff_t off) |
|
{ |
|
struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); |
|
unsigned long max; |
|
int err; |
|
|
|
buf = strstrip(buf); |
|
err = page_counter_memparse(buf, "max", &max); |
|
if (err) |
|
return err; |
|
|
|
xchg(&memcg->zswap_max, max); |
|
|
|
return nbytes; |
|
} |
|
|
|
static struct cftype zswap_files[] = { |
|
{ |
|
.name = "zswap.current", |
|
.flags = CFTYPE_NOT_ON_ROOT, |
|
.read_u64 = zswap_current_read, |
|
}, |
|
{ |
|
.name = "zswap.max", |
|
.flags = CFTYPE_NOT_ON_ROOT, |
|
.seq_show = zswap_max_show, |
|
.write = zswap_max_write, |
|
}, |
|
{ } /* terminate */ |
|
}; |
|
#endif /* CONFIG_MEMCG_KMEM && CONFIG_ZSWAP */ |
|
|
|
static int __init mem_cgroup_swap_init(void) |
|
{ |
|
if (mem_cgroup_disabled()) |
|
return 0; |
|
|
|
WARN_ON(cgroup_add_dfl_cftypes(&memory_cgrp_subsys, swap_files)); |
|
WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys, memsw_files)); |
|
#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP) |
|
WARN_ON(cgroup_add_dfl_cftypes(&memory_cgrp_subsys, zswap_files)); |
|
#endif |
|
return 0; |
|
} |
|
subsys_initcall(mem_cgroup_swap_init); |
|
|
|
#endif /* CONFIG_SWAP */
|
|
|