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956 lines
25 KiB
956 lines
25 KiB
// SPDX-License-Identifier: GPL-2.0+ |
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/* |
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* Common functions for in-kernel torture tests. |
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* |
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* Copyright (C) IBM Corporation, 2014 |
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* |
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* Author: Paul E. McKenney <[email protected]> |
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* Based on kernel/rcu/torture.c. |
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*/ |
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#define pr_fmt(fmt) fmt |
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#include <linux/types.h> |
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#include <linux/kernel.h> |
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#include <linux/init.h> |
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#include <linux/module.h> |
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#include <linux/kthread.h> |
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#include <linux/err.h> |
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#include <linux/spinlock.h> |
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#include <linux/smp.h> |
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#include <linux/interrupt.h> |
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#include <linux/sched.h> |
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#include <linux/sched/clock.h> |
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#include <linux/atomic.h> |
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#include <linux/bitops.h> |
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#include <linux/completion.h> |
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#include <linux/moduleparam.h> |
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#include <linux/percpu.h> |
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#include <linux/notifier.h> |
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#include <linux/reboot.h> |
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#include <linux/freezer.h> |
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#include <linux/cpu.h> |
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#include <linux/delay.h> |
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#include <linux/stat.h> |
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#include <linux/slab.h> |
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#include <linux/trace_clock.h> |
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#include <linux/ktime.h> |
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#include <asm/byteorder.h> |
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#include <linux/torture.h> |
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#include "rcu/rcu.h" |
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MODULE_LICENSE("GPL"); |
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MODULE_AUTHOR("Paul E. McKenney <[email protected]>"); |
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static bool disable_onoff_at_boot; |
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module_param(disable_onoff_at_boot, bool, 0444); |
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static bool ftrace_dump_at_shutdown; |
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module_param(ftrace_dump_at_shutdown, bool, 0444); |
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static int verbose_sleep_frequency; |
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module_param(verbose_sleep_frequency, int, 0444); |
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static int verbose_sleep_duration = 1; |
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module_param(verbose_sleep_duration, int, 0444); |
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static char *torture_type; |
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static int verbose; |
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/* Mediate rmmod and system shutdown. Concurrent rmmod & shutdown illegal! */ |
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#define FULLSTOP_DONTSTOP 0 /* Normal operation. */ |
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#define FULLSTOP_SHUTDOWN 1 /* System shutdown with torture running. */ |
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#define FULLSTOP_RMMOD 2 /* Normal rmmod of torture. */ |
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static int fullstop = FULLSTOP_RMMOD; |
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static DEFINE_MUTEX(fullstop_mutex); |
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static atomic_t verbose_sleep_counter; |
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/* |
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* Sleep if needed from VERBOSE_TOROUT*(). |
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*/ |
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void verbose_torout_sleep(void) |
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{ |
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if (verbose_sleep_frequency > 0 && |
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verbose_sleep_duration > 0 && |
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!(atomic_inc_return(&verbose_sleep_counter) % verbose_sleep_frequency)) |
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schedule_timeout_uninterruptible(verbose_sleep_duration); |
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} |
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EXPORT_SYMBOL_GPL(verbose_torout_sleep); |
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/* |
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* Schedule a high-resolution-timer sleep in nanoseconds, with a 32-bit |
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* nanosecond random fuzz. This function and its friends desynchronize |
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* testing from the timer wheel. |
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*/ |
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int torture_hrtimeout_ns(ktime_t baset_ns, u32 fuzzt_ns, struct torture_random_state *trsp) |
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{ |
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ktime_t hto = baset_ns; |
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if (trsp) |
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hto += (torture_random(trsp) >> 3) % fuzzt_ns; |
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set_current_state(TASK_UNINTERRUPTIBLE); |
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return schedule_hrtimeout(&hto, HRTIMER_MODE_REL); |
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} |
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EXPORT_SYMBOL_GPL(torture_hrtimeout_ns); |
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/* |
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* Schedule a high-resolution-timer sleep in microseconds, with a 32-bit |
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* nanosecond (not microsecond!) random fuzz. |
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*/ |
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int torture_hrtimeout_us(u32 baset_us, u32 fuzzt_ns, struct torture_random_state *trsp) |
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{ |
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ktime_t baset_ns = baset_us * NSEC_PER_USEC; |
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return torture_hrtimeout_ns(baset_ns, fuzzt_ns, trsp); |
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} |
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EXPORT_SYMBOL_GPL(torture_hrtimeout_us); |
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/* |
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* Schedule a high-resolution-timer sleep in milliseconds, with a 32-bit |
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* microsecond (not millisecond!) random fuzz. |
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*/ |
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int torture_hrtimeout_ms(u32 baset_ms, u32 fuzzt_us, struct torture_random_state *trsp) |
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{ |
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ktime_t baset_ns = baset_ms * NSEC_PER_MSEC; |
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u32 fuzzt_ns; |
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if ((u32)~0U / NSEC_PER_USEC < fuzzt_us) |
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fuzzt_ns = (u32)~0U; |
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else |
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fuzzt_ns = fuzzt_us * NSEC_PER_USEC; |
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return torture_hrtimeout_ns(baset_ns, fuzzt_ns, trsp); |
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} |
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EXPORT_SYMBOL_GPL(torture_hrtimeout_ms); |
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/* |
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* Schedule a high-resolution-timer sleep in jiffies, with an |
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* implied one-jiffy random fuzz. This is intended to replace calls to |
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* schedule_timeout_interruptible() and friends. |
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*/ |
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int torture_hrtimeout_jiffies(u32 baset_j, struct torture_random_state *trsp) |
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{ |
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ktime_t baset_ns = jiffies_to_nsecs(baset_j); |
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return torture_hrtimeout_ns(baset_ns, jiffies_to_nsecs(1), trsp); |
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} |
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EXPORT_SYMBOL_GPL(torture_hrtimeout_jiffies); |
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/* |
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* Schedule a high-resolution-timer sleep in milliseconds, with a 32-bit |
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* millisecond (not second!) random fuzz. |
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*/ |
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int torture_hrtimeout_s(u32 baset_s, u32 fuzzt_ms, struct torture_random_state *trsp) |
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{ |
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ktime_t baset_ns = baset_s * NSEC_PER_SEC; |
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u32 fuzzt_ns; |
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if ((u32)~0U / NSEC_PER_MSEC < fuzzt_ms) |
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fuzzt_ns = (u32)~0U; |
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else |
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fuzzt_ns = fuzzt_ms * NSEC_PER_MSEC; |
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return torture_hrtimeout_ns(baset_ns, fuzzt_ns, trsp); |
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} |
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EXPORT_SYMBOL_GPL(torture_hrtimeout_s); |
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#ifdef CONFIG_HOTPLUG_CPU |
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/* |
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* Variables for online-offline handling. Only present if CPU hotplug |
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* is enabled, otherwise does nothing. |
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*/ |
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static struct task_struct *onoff_task; |
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static long onoff_holdoff; |
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static long onoff_interval; |
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static torture_ofl_func *onoff_f; |
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static long n_offline_attempts; |
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static long n_offline_successes; |
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static unsigned long sum_offline; |
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static int min_offline = -1; |
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static int max_offline; |
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static long n_online_attempts; |
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static long n_online_successes; |
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static unsigned long sum_online; |
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static int min_online = -1; |
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static int max_online; |
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static int torture_online_cpus = NR_CPUS; |
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/* |
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* Some torture testing leverages confusion as to the number of online |
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* CPUs. This function returns the torture-testing view of this number, |
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* which allows torture tests to load-balance appropriately. |
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*/ |
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int torture_num_online_cpus(void) |
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{ |
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return READ_ONCE(torture_online_cpus); |
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} |
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EXPORT_SYMBOL_GPL(torture_num_online_cpus); |
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/* |
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* Attempt to take a CPU offline. Return false if the CPU is already |
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* offline or if it is not subject to CPU-hotplug operations. The |
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* caller can detect other failures by looking at the statistics. |
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*/ |
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bool torture_offline(int cpu, long *n_offl_attempts, long *n_offl_successes, |
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unsigned long *sum_offl, int *min_offl, int *max_offl) |
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{ |
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unsigned long delta; |
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int ret; |
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char *s; |
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unsigned long starttime; |
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if (!cpu_online(cpu) || !cpu_is_hotpluggable(cpu)) |
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return false; |
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if (num_online_cpus() <= 1) |
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return false; /* Can't offline the last CPU. */ |
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if (verbose > 1) |
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pr_alert("%s" TORTURE_FLAG |
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"torture_onoff task: offlining %d\n", |
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torture_type, cpu); |
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starttime = jiffies; |
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(*n_offl_attempts)++; |
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ret = remove_cpu(cpu); |
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if (ret) { |
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s = ""; |
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if (!rcu_inkernel_boot_has_ended() && ret == -EBUSY) { |
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// PCI probe frequently disables hotplug during boot. |
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(*n_offl_attempts)--; |
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s = " (-EBUSY forgiven during boot)"; |
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} |
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if (verbose) |
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pr_alert("%s" TORTURE_FLAG |
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"torture_onoff task: offline %d failed%s: errno %d\n", |
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torture_type, cpu, s, ret); |
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} else { |
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if (verbose > 1) |
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pr_alert("%s" TORTURE_FLAG |
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"torture_onoff task: offlined %d\n", |
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torture_type, cpu); |
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if (onoff_f) |
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onoff_f(); |
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(*n_offl_successes)++; |
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delta = jiffies - starttime; |
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*sum_offl += delta; |
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if (*min_offl < 0) { |
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*min_offl = delta; |
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*max_offl = delta; |
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} |
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if (*min_offl > delta) |
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*min_offl = delta; |
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if (*max_offl < delta) |
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*max_offl = delta; |
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WRITE_ONCE(torture_online_cpus, torture_online_cpus - 1); |
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WARN_ON_ONCE(torture_online_cpus <= 0); |
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} |
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return true; |
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} |
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EXPORT_SYMBOL_GPL(torture_offline); |
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/* |
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* Attempt to bring a CPU online. Return false if the CPU is already |
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* online or if it is not subject to CPU-hotplug operations. The |
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* caller can detect other failures by looking at the statistics. |
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*/ |
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bool torture_online(int cpu, long *n_onl_attempts, long *n_onl_successes, |
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unsigned long *sum_onl, int *min_onl, int *max_onl) |
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{ |
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unsigned long delta; |
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int ret; |
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char *s; |
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unsigned long starttime; |
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if (cpu_online(cpu) || !cpu_is_hotpluggable(cpu)) |
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return false; |
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if (verbose > 1) |
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pr_alert("%s" TORTURE_FLAG |
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"torture_onoff task: onlining %d\n", |
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torture_type, cpu); |
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starttime = jiffies; |
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(*n_onl_attempts)++; |
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ret = add_cpu(cpu); |
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if (ret) { |
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s = ""; |
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if (!rcu_inkernel_boot_has_ended() && ret == -EBUSY) { |
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// PCI probe frequently disables hotplug during boot. |
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(*n_onl_attempts)--; |
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s = " (-EBUSY forgiven during boot)"; |
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} |
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if (verbose) |
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pr_alert("%s" TORTURE_FLAG |
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"torture_onoff task: online %d failed%s: errno %d\n", |
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torture_type, cpu, s, ret); |
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} else { |
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if (verbose > 1) |
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pr_alert("%s" TORTURE_FLAG |
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"torture_onoff task: onlined %d\n", |
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torture_type, cpu); |
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(*n_onl_successes)++; |
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delta = jiffies - starttime; |
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*sum_onl += delta; |
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if (*min_onl < 0) { |
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*min_onl = delta; |
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*max_onl = delta; |
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} |
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if (*min_onl > delta) |
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*min_onl = delta; |
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if (*max_onl < delta) |
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*max_onl = delta; |
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WRITE_ONCE(torture_online_cpus, torture_online_cpus + 1); |
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} |
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return true; |
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} |
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EXPORT_SYMBOL_GPL(torture_online); |
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/* |
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* Get everything online at the beginning and ends of tests. |
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*/ |
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static void torture_online_all(char *phase) |
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{ |
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int cpu; |
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int ret; |
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for_each_possible_cpu(cpu) { |
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if (cpu_online(cpu)) |
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continue; |
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ret = add_cpu(cpu); |
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if (ret && verbose) { |
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pr_alert("%s" TORTURE_FLAG |
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"%s: %s online %d: errno %d\n", |
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__func__, phase, torture_type, cpu, ret); |
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} |
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} |
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} |
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/* |
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* Execute random CPU-hotplug operations at the interval specified |
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* by the onoff_interval. |
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*/ |
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static int |
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torture_onoff(void *arg) |
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{ |
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int cpu; |
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int maxcpu = -1; |
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DEFINE_TORTURE_RANDOM(rand); |
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VERBOSE_TOROUT_STRING("torture_onoff task started"); |
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for_each_online_cpu(cpu) |
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maxcpu = cpu; |
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WARN_ON(maxcpu < 0); |
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torture_online_all("Initial"); |
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if (maxcpu == 0) { |
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VERBOSE_TOROUT_STRING("Only one CPU, so CPU-hotplug testing is disabled"); |
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goto stop; |
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} |
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if (onoff_holdoff > 0) { |
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VERBOSE_TOROUT_STRING("torture_onoff begin holdoff"); |
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schedule_timeout_interruptible(onoff_holdoff); |
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VERBOSE_TOROUT_STRING("torture_onoff end holdoff"); |
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} |
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while (!torture_must_stop()) { |
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if (disable_onoff_at_boot && !rcu_inkernel_boot_has_ended()) { |
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schedule_timeout_interruptible(HZ / 10); |
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continue; |
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} |
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cpu = (torture_random(&rand) >> 4) % (maxcpu + 1); |
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if (!torture_offline(cpu, |
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&n_offline_attempts, &n_offline_successes, |
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&sum_offline, &min_offline, &max_offline)) |
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torture_online(cpu, |
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&n_online_attempts, &n_online_successes, |
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&sum_online, &min_online, &max_online); |
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schedule_timeout_interruptible(onoff_interval); |
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} |
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stop: |
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torture_kthread_stopping("torture_onoff"); |
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torture_online_all("Final"); |
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return 0; |
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} |
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#endif /* #ifdef CONFIG_HOTPLUG_CPU */ |
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/* |
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* Initiate online-offline handling. |
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*/ |
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int torture_onoff_init(long ooholdoff, long oointerval, torture_ofl_func *f) |
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{ |
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#ifdef CONFIG_HOTPLUG_CPU |
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onoff_holdoff = ooholdoff; |
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onoff_interval = oointerval; |
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onoff_f = f; |
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if (onoff_interval <= 0) |
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return 0; |
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return torture_create_kthread(torture_onoff, NULL, onoff_task); |
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#else /* #ifdef CONFIG_HOTPLUG_CPU */ |
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return 0; |
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#endif /* #else #ifdef CONFIG_HOTPLUG_CPU */ |
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} |
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EXPORT_SYMBOL_GPL(torture_onoff_init); |
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/* |
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* Clean up after online/offline testing. |
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*/ |
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static void torture_onoff_cleanup(void) |
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{ |
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#ifdef CONFIG_HOTPLUG_CPU |
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if (onoff_task == NULL) |
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return; |
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VERBOSE_TOROUT_STRING("Stopping torture_onoff task"); |
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kthread_stop(onoff_task); |
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onoff_task = NULL; |
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#endif /* #ifdef CONFIG_HOTPLUG_CPU */ |
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} |
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/* |
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* Print online/offline testing statistics. |
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*/ |
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void torture_onoff_stats(void) |
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{ |
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#ifdef CONFIG_HOTPLUG_CPU |
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pr_cont("onoff: %ld/%ld:%ld/%ld %d,%d:%d,%d %lu:%lu (HZ=%d) ", |
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n_online_successes, n_online_attempts, |
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n_offline_successes, n_offline_attempts, |
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min_online, max_online, |
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min_offline, max_offline, |
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sum_online, sum_offline, HZ); |
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#endif /* #ifdef CONFIG_HOTPLUG_CPU */ |
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} |
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EXPORT_SYMBOL_GPL(torture_onoff_stats); |
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/* |
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* Were all the online/offline operations successful? |
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*/ |
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bool torture_onoff_failures(void) |
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{ |
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#ifdef CONFIG_HOTPLUG_CPU |
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return n_online_successes != n_online_attempts || |
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n_offline_successes != n_offline_attempts; |
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#else /* #ifdef CONFIG_HOTPLUG_CPU */ |
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return false; |
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#endif /* #else #ifdef CONFIG_HOTPLUG_CPU */ |
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} |
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EXPORT_SYMBOL_GPL(torture_onoff_failures); |
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#define TORTURE_RANDOM_MULT 39916801 /* prime */ |
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#define TORTURE_RANDOM_ADD 479001701 /* prime */ |
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#define TORTURE_RANDOM_REFRESH 10000 |
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/* |
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* Crude but fast random-number generator. Uses a linear congruential |
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* generator, with occasional help from cpu_clock(). |
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*/ |
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unsigned long |
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torture_random(struct torture_random_state *trsp) |
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{ |
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if (--trsp->trs_count < 0) { |
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trsp->trs_state += (unsigned long)local_clock(); |
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trsp->trs_count = TORTURE_RANDOM_REFRESH; |
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} |
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trsp->trs_state = trsp->trs_state * TORTURE_RANDOM_MULT + |
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TORTURE_RANDOM_ADD; |
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return swahw32(trsp->trs_state); |
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} |
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EXPORT_SYMBOL_GPL(torture_random); |
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/* |
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* Variables for shuffling. The idea is to ensure that each CPU stays |
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* idle for an extended period to test interactions with dyntick idle, |
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* as well as interactions with any per-CPU variables. |
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*/ |
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struct shuffle_task { |
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struct list_head st_l; |
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struct task_struct *st_t; |
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}; |
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static long shuffle_interval; /* In jiffies. */ |
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static struct task_struct *shuffler_task; |
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static cpumask_var_t shuffle_tmp_mask; |
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static int shuffle_idle_cpu; /* Force all torture tasks off this CPU */ |
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static struct list_head shuffle_task_list = LIST_HEAD_INIT(shuffle_task_list); |
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static DEFINE_MUTEX(shuffle_task_mutex); |
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/* |
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* Register a task to be shuffled. If there is no memory, just splat |
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* and don't bother registering. |
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*/ |
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void torture_shuffle_task_register(struct task_struct *tp) |
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{ |
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struct shuffle_task *stp; |
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if (WARN_ON_ONCE(tp == NULL)) |
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return; |
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stp = kmalloc(sizeof(*stp), GFP_KERNEL); |
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if (WARN_ON_ONCE(stp == NULL)) |
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return; |
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stp->st_t = tp; |
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mutex_lock(&shuffle_task_mutex); |
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list_add(&stp->st_l, &shuffle_task_list); |
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mutex_unlock(&shuffle_task_mutex); |
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} |
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EXPORT_SYMBOL_GPL(torture_shuffle_task_register); |
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/* |
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* Unregister all tasks, for example, at the end of the torture run. |
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*/ |
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static void torture_shuffle_task_unregister_all(void) |
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{ |
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struct shuffle_task *stp; |
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struct shuffle_task *p; |
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mutex_lock(&shuffle_task_mutex); |
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list_for_each_entry_safe(stp, p, &shuffle_task_list, st_l) { |
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list_del(&stp->st_l); |
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kfree(stp); |
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} |
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mutex_unlock(&shuffle_task_mutex); |
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} |
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/* Shuffle tasks such that we allow shuffle_idle_cpu to become idle. |
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* A special case is when shuffle_idle_cpu = -1, in which case we allow |
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* the tasks to run on all CPUs. |
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*/ |
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static void torture_shuffle_tasks(void) |
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{ |
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struct shuffle_task *stp; |
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cpumask_setall(shuffle_tmp_mask); |
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cpus_read_lock(); |
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/* No point in shuffling if there is only one online CPU (ex: UP) */ |
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if (num_online_cpus() == 1) { |
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cpus_read_unlock(); |
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return; |
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} |
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/* Advance to the next CPU. Upon overflow, don't idle any CPUs. */ |
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shuffle_idle_cpu = cpumask_next(shuffle_idle_cpu, shuffle_tmp_mask); |
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if (shuffle_idle_cpu >= nr_cpu_ids) |
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shuffle_idle_cpu = -1; |
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else |
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cpumask_clear_cpu(shuffle_idle_cpu, shuffle_tmp_mask); |
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mutex_lock(&shuffle_task_mutex); |
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list_for_each_entry(stp, &shuffle_task_list, st_l) |
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set_cpus_allowed_ptr(stp->st_t, shuffle_tmp_mask); |
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mutex_unlock(&shuffle_task_mutex); |
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cpus_read_unlock(); |
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} |
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|
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/* Shuffle tasks across CPUs, with the intent of allowing each CPU in the |
|
* system to become idle at a time and cut off its timer ticks. This is meant |
|
* to test the support for such tickless idle CPU in RCU. |
|
*/ |
|
static int torture_shuffle(void *arg) |
|
{ |
|
VERBOSE_TOROUT_STRING("torture_shuffle task started"); |
|
do { |
|
schedule_timeout_interruptible(shuffle_interval); |
|
torture_shuffle_tasks(); |
|
torture_shutdown_absorb("torture_shuffle"); |
|
} while (!torture_must_stop()); |
|
torture_kthread_stopping("torture_shuffle"); |
|
return 0; |
|
} |
|
|
|
/* |
|
* Start the shuffler, with shuffint in jiffies. |
|
*/ |
|
int torture_shuffle_init(long shuffint) |
|
{ |
|
shuffle_interval = shuffint; |
|
|
|
shuffle_idle_cpu = -1; |
|
|
|
if (!alloc_cpumask_var(&shuffle_tmp_mask, GFP_KERNEL)) { |
|
VERBOSE_TOROUT_ERRSTRING("Failed to alloc mask"); |
|
return -ENOMEM; |
|
} |
|
|
|
/* Create the shuffler thread */ |
|
return torture_create_kthread(torture_shuffle, NULL, shuffler_task); |
|
} |
|
EXPORT_SYMBOL_GPL(torture_shuffle_init); |
|
|
|
/* |
|
* Stop the shuffling. |
|
*/ |
|
static void torture_shuffle_cleanup(void) |
|
{ |
|
torture_shuffle_task_unregister_all(); |
|
if (shuffler_task) { |
|
VERBOSE_TOROUT_STRING("Stopping torture_shuffle task"); |
|
kthread_stop(shuffler_task); |
|
free_cpumask_var(shuffle_tmp_mask); |
|
} |
|
shuffler_task = NULL; |
|
} |
|
|
|
/* |
|
* Variables for auto-shutdown. This allows "lights out" torture runs |
|
* to be fully scripted. |
|
*/ |
|
static struct task_struct *shutdown_task; |
|
static ktime_t shutdown_time; /* time to system shutdown. */ |
|
static void (*torture_shutdown_hook)(void); |
|
|
|
/* |
|
* Absorb kthreads into a kernel function that won't return, so that |
|
* they won't ever access module text or data again. |
|
*/ |
|
void torture_shutdown_absorb(const char *title) |
|
{ |
|
while (READ_ONCE(fullstop) == FULLSTOP_SHUTDOWN) { |
|
pr_notice("torture thread %s parking due to system shutdown\n", |
|
title); |
|
schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT); |
|
} |
|
} |
|
EXPORT_SYMBOL_GPL(torture_shutdown_absorb); |
|
|
|
/* |
|
* Cause the torture test to shutdown the system after the test has |
|
* run for the time specified by the shutdown_secs parameter. |
|
*/ |
|
static int torture_shutdown(void *arg) |
|
{ |
|
ktime_t ktime_snap; |
|
|
|
VERBOSE_TOROUT_STRING("torture_shutdown task started"); |
|
ktime_snap = ktime_get(); |
|
while (ktime_before(ktime_snap, shutdown_time) && |
|
!torture_must_stop()) { |
|
if (verbose) |
|
pr_alert("%s" TORTURE_FLAG |
|
"torture_shutdown task: %llu ms remaining\n", |
|
torture_type, |
|
ktime_ms_delta(shutdown_time, ktime_snap)); |
|
set_current_state(TASK_INTERRUPTIBLE); |
|
schedule_hrtimeout(&shutdown_time, HRTIMER_MODE_ABS); |
|
ktime_snap = ktime_get(); |
|
} |
|
if (torture_must_stop()) { |
|
torture_kthread_stopping("torture_shutdown"); |
|
return 0; |
|
} |
|
|
|
/* OK, shut down the system. */ |
|
|
|
VERBOSE_TOROUT_STRING("torture_shutdown task shutting down system"); |
|
shutdown_task = NULL; /* Avoid self-kill deadlock. */ |
|
if (torture_shutdown_hook) |
|
torture_shutdown_hook(); |
|
else |
|
VERBOSE_TOROUT_STRING("No torture_shutdown_hook(), skipping."); |
|
if (ftrace_dump_at_shutdown) |
|
rcu_ftrace_dump(DUMP_ALL); |
|
kernel_power_off(); /* Shut down the system. */ |
|
return 0; |
|
} |
|
|
|
/* |
|
* Start up the shutdown task. |
|
*/ |
|
int torture_shutdown_init(int ssecs, void (*cleanup)(void)) |
|
{ |
|
torture_shutdown_hook = cleanup; |
|
if (ssecs > 0) { |
|
shutdown_time = ktime_add(ktime_get(), ktime_set(ssecs, 0)); |
|
return torture_create_kthread(torture_shutdown, NULL, |
|
shutdown_task); |
|
} |
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(torture_shutdown_init); |
|
|
|
/* |
|
* Detect and respond to a system shutdown. |
|
*/ |
|
static int torture_shutdown_notify(struct notifier_block *unused1, |
|
unsigned long unused2, void *unused3) |
|
{ |
|
mutex_lock(&fullstop_mutex); |
|
if (READ_ONCE(fullstop) == FULLSTOP_DONTSTOP) { |
|
VERBOSE_TOROUT_STRING("Unscheduled system shutdown detected"); |
|
WRITE_ONCE(fullstop, FULLSTOP_SHUTDOWN); |
|
} else { |
|
pr_warn("Concurrent rmmod and shutdown illegal!\n"); |
|
} |
|
mutex_unlock(&fullstop_mutex); |
|
return NOTIFY_DONE; |
|
} |
|
|
|
static struct notifier_block torture_shutdown_nb = { |
|
.notifier_call = torture_shutdown_notify, |
|
}; |
|
|
|
/* |
|
* Shut down the shutdown task. Say what??? Heh! This can happen if |
|
* the torture module gets an rmmod before the shutdown time arrives. ;-) |
|
*/ |
|
static void torture_shutdown_cleanup(void) |
|
{ |
|
unregister_reboot_notifier(&torture_shutdown_nb); |
|
if (shutdown_task != NULL) { |
|
VERBOSE_TOROUT_STRING("Stopping torture_shutdown task"); |
|
kthread_stop(shutdown_task); |
|
} |
|
shutdown_task = NULL; |
|
} |
|
|
|
/* |
|
* Variables for stuttering, which means to periodically pause and |
|
* restart testing in order to catch bugs that appear when load is |
|
* suddenly applied to or removed from the system. |
|
*/ |
|
static struct task_struct *stutter_task; |
|
static int stutter_pause_test; |
|
static int stutter; |
|
static int stutter_gap; |
|
|
|
/* |
|
* Block until the stutter interval ends. This must be called periodically |
|
* by all running kthreads that need to be subject to stuttering. |
|
*/ |
|
bool stutter_wait(const char *title) |
|
{ |
|
unsigned int i = 0; |
|
bool ret = false; |
|
int spt; |
|
|
|
cond_resched_tasks_rcu_qs(); |
|
spt = READ_ONCE(stutter_pause_test); |
|
for (; spt; spt = READ_ONCE(stutter_pause_test)) { |
|
if (!ret) { |
|
sched_set_normal(current, MAX_NICE); |
|
ret = true; |
|
} |
|
if (spt == 1) { |
|
schedule_timeout_interruptible(1); |
|
} else if (spt == 2) { |
|
while (READ_ONCE(stutter_pause_test)) { |
|
if (!(i++ & 0xffff)) |
|
torture_hrtimeout_us(10, 0, NULL); |
|
cond_resched(); |
|
} |
|
} else { |
|
schedule_timeout_interruptible(round_jiffies_relative(HZ)); |
|
} |
|
torture_shutdown_absorb(title); |
|
} |
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(stutter_wait); |
|
|
|
/* |
|
* Cause the torture test to "stutter", starting and stopping all |
|
* threads periodically. |
|
*/ |
|
static int torture_stutter(void *arg) |
|
{ |
|
DEFINE_TORTURE_RANDOM(rand); |
|
int wtime; |
|
|
|
VERBOSE_TOROUT_STRING("torture_stutter task started"); |
|
do { |
|
if (!torture_must_stop() && stutter > 1) { |
|
wtime = stutter; |
|
if (stutter > 2) { |
|
WRITE_ONCE(stutter_pause_test, 1); |
|
wtime = stutter - 3; |
|
torture_hrtimeout_jiffies(wtime, &rand); |
|
wtime = 2; |
|
} |
|
WRITE_ONCE(stutter_pause_test, 2); |
|
torture_hrtimeout_jiffies(wtime, NULL); |
|
} |
|
WRITE_ONCE(stutter_pause_test, 0); |
|
if (!torture_must_stop()) |
|
torture_hrtimeout_jiffies(stutter_gap, NULL); |
|
torture_shutdown_absorb("torture_stutter"); |
|
} while (!torture_must_stop()); |
|
torture_kthread_stopping("torture_stutter"); |
|
return 0; |
|
} |
|
|
|
/* |
|
* Initialize and kick off the torture_stutter kthread. |
|
*/ |
|
int torture_stutter_init(const int s, const int sgap) |
|
{ |
|
stutter = s; |
|
stutter_gap = sgap; |
|
return torture_create_kthread(torture_stutter, NULL, stutter_task); |
|
} |
|
EXPORT_SYMBOL_GPL(torture_stutter_init); |
|
|
|
/* |
|
* Cleanup after the torture_stutter kthread. |
|
*/ |
|
static void torture_stutter_cleanup(void) |
|
{ |
|
if (!stutter_task) |
|
return; |
|
VERBOSE_TOROUT_STRING("Stopping torture_stutter task"); |
|
kthread_stop(stutter_task); |
|
stutter_task = NULL; |
|
} |
|
|
|
/* |
|
* Initialize torture module. Please note that this is -not- invoked via |
|
* the usual module_init() mechanism, but rather by an explicit call from |
|
* the client torture module. This call must be paired with a later |
|
* torture_init_end(). |
|
* |
|
* The runnable parameter points to a flag that controls whether or not |
|
* the test is currently runnable. If there is no such flag, pass in NULL. |
|
*/ |
|
bool torture_init_begin(char *ttype, int v) |
|
{ |
|
mutex_lock(&fullstop_mutex); |
|
if (torture_type != NULL) { |
|
pr_alert("%s: Refusing %s init: %s running.\n", |
|
__func__, ttype, torture_type); |
|
pr_alert("%s: One torture test at a time!\n", __func__); |
|
mutex_unlock(&fullstop_mutex); |
|
return false; |
|
} |
|
torture_type = ttype; |
|
verbose = v; |
|
fullstop = FULLSTOP_DONTSTOP; |
|
return true; |
|
} |
|
EXPORT_SYMBOL_GPL(torture_init_begin); |
|
|
|
/* |
|
* Tell the torture module that initialization is complete. |
|
*/ |
|
void torture_init_end(void) |
|
{ |
|
mutex_unlock(&fullstop_mutex); |
|
register_reboot_notifier(&torture_shutdown_nb); |
|
} |
|
EXPORT_SYMBOL_GPL(torture_init_end); |
|
|
|
/* |
|
* Clean up torture module. Please note that this is -not- invoked via |
|
* the usual module_exit() mechanism, but rather by an explicit call from |
|
* the client torture module. Returns true if a race with system shutdown |
|
* is detected, otherwise, all kthreads started by functions in this file |
|
* will be shut down. |
|
* |
|
* This must be called before the caller starts shutting down its own |
|
* kthreads. |
|
* |
|
* Both torture_cleanup_begin() and torture_cleanup_end() must be paired, |
|
* in order to correctly perform the cleanup. They are separated because |
|
* threads can still need to reference the torture_type type, thus nullify |
|
* only after completing all other relevant calls. |
|
*/ |
|
bool torture_cleanup_begin(void) |
|
{ |
|
mutex_lock(&fullstop_mutex); |
|
if (READ_ONCE(fullstop) == FULLSTOP_SHUTDOWN) { |
|
pr_warn("Concurrent rmmod and shutdown illegal!\n"); |
|
mutex_unlock(&fullstop_mutex); |
|
schedule_timeout_uninterruptible(10); |
|
return true; |
|
} |
|
WRITE_ONCE(fullstop, FULLSTOP_RMMOD); |
|
mutex_unlock(&fullstop_mutex); |
|
torture_shutdown_cleanup(); |
|
torture_shuffle_cleanup(); |
|
torture_stutter_cleanup(); |
|
torture_onoff_cleanup(); |
|
return false; |
|
} |
|
EXPORT_SYMBOL_GPL(torture_cleanup_begin); |
|
|
|
void torture_cleanup_end(void) |
|
{ |
|
mutex_lock(&fullstop_mutex); |
|
torture_type = NULL; |
|
mutex_unlock(&fullstop_mutex); |
|
} |
|
EXPORT_SYMBOL_GPL(torture_cleanup_end); |
|
|
|
/* |
|
* Is it time for the current torture test to stop? |
|
*/ |
|
bool torture_must_stop(void) |
|
{ |
|
return torture_must_stop_irq() || kthread_should_stop(); |
|
} |
|
EXPORT_SYMBOL_GPL(torture_must_stop); |
|
|
|
/* |
|
* Is it time for the current torture test to stop? This is the irq-safe |
|
* version, hence no check for kthread_should_stop(). |
|
*/ |
|
bool torture_must_stop_irq(void) |
|
{ |
|
return READ_ONCE(fullstop) != FULLSTOP_DONTSTOP; |
|
} |
|
EXPORT_SYMBOL_GPL(torture_must_stop_irq); |
|
|
|
/* |
|
* Each kthread must wait for kthread_should_stop() before returning from |
|
* its top-level function, otherwise segfaults ensue. This function |
|
* prints a "stopping" message and waits for kthread_should_stop(), and |
|
* should be called from all torture kthreads immediately prior to |
|
* returning. |
|
*/ |
|
void torture_kthread_stopping(char *title) |
|
{ |
|
char buf[128]; |
|
|
|
snprintf(buf, sizeof(buf), "Stopping %s", title); |
|
VERBOSE_TOROUT_STRING(buf); |
|
while (!kthread_should_stop()) { |
|
torture_shutdown_absorb(title); |
|
schedule_timeout_uninterruptible(1); |
|
} |
|
} |
|
EXPORT_SYMBOL_GPL(torture_kthread_stopping); |
|
|
|
/* |
|
* Create a generic torture kthread that is immediately runnable. If you |
|
* need the kthread to be stopped so that you can do something to it before |
|
* it starts, you will need to open-code your own. |
|
*/ |
|
int _torture_create_kthread(int (*fn)(void *arg), void *arg, char *s, char *m, |
|
char *f, struct task_struct **tp) |
|
{ |
|
int ret = 0; |
|
|
|
VERBOSE_TOROUT_STRING(m); |
|
*tp = kthread_run(fn, arg, "%s", s); |
|
if (IS_ERR(*tp)) { |
|
ret = PTR_ERR(*tp); |
|
VERBOSE_TOROUT_ERRSTRING(f); |
|
*tp = NULL; |
|
} |
|
torture_shuffle_task_register(*tp); |
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(_torture_create_kthread); |
|
|
|
/* |
|
* Stop a generic kthread, emitting a message. |
|
*/ |
|
void _torture_stop_kthread(char *m, struct task_struct **tp) |
|
{ |
|
if (*tp == NULL) |
|
return; |
|
VERBOSE_TOROUT_STRING(m); |
|
kthread_stop(*tp); |
|
*tp = NULL; |
|
} |
|
EXPORT_SYMBOL_GPL(_torture_stop_kthread);
|
|
|