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![Paul E. McKenney](/assets/img/avatar_default.png)
When you do something like "t = kthread_run(...)", it is possible that the kthread will start running before the assignment to "t" happens. If the child kthread expects to find a pointer to its task_struct in "t", it will then be fatally disappointed. This commit therefore switches such cases to kthread_create() followed by wake_up_process(), guaranteeing that the assignment happens before the child kthread starts running. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2192 lines
62 KiB
C
2192 lines
62 KiB
C
/*
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* Read-Copy Update module-based torture test facility
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*
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* Copyright (C) IBM Corporation, 2005, 2006
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*
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* Authors: Paul E. McKenney <paulmck@us.ibm.com>
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* Josh Triplett <josh@freedesktop.org>
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*
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* See also: Documentation/RCU/torture.txt
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*/
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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/rcupdate.h>
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#include <linux/interrupt.h>
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#include <linux/sched.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/srcu.h>
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#include <linux/slab.h>
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#include <asm/byteorder.h>
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and Josh Triplett <josh@freedesktop.org>");
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static int nreaders = -1; /* # reader threads, defaults to 2*ncpus */
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static int nfakewriters = 4; /* # fake writer threads */
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static int stat_interval = 60; /* Interval between stats, in seconds. */
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/* Zero means "only at end of test". */
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static bool verbose; /* Print more debug info. */
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static bool test_no_idle_hz = true;
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/* Test RCU support for tickless idle CPUs. */
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static int shuffle_interval = 3; /* Interval between shuffles (in sec)*/
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static int stutter = 5; /* Start/stop testing interval (in sec) */
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static int irqreader = 1; /* RCU readers from irq (timers). */
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static int fqs_duration; /* Duration of bursts (us), 0 to disable. */
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static int fqs_holdoff; /* Hold time within burst (us). */
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static int fqs_stutter = 3; /* Wait time between bursts (s). */
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static int n_barrier_cbs; /* Number of callbacks to test RCU barriers. */
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static int onoff_interval; /* Wait time between CPU hotplugs, 0=disable. */
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static int onoff_holdoff; /* Seconds after boot before CPU hotplugs. */
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static int shutdown_secs; /* Shutdown time (s). <=0 for no shutdown. */
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static int stall_cpu; /* CPU-stall duration (s). 0 for no stall. */
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static int stall_cpu_holdoff = 10; /* Time to wait until stall (s). */
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static int test_boost = 1; /* Test RCU prio boost: 0=no, 1=maybe, 2=yes. */
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static int test_boost_interval = 7; /* Interval between boost tests, seconds. */
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static int test_boost_duration = 4; /* Duration of each boost test, seconds. */
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static char *torture_type = "rcu"; /* What RCU implementation to torture. */
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module_param(nreaders, int, 0444);
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MODULE_PARM_DESC(nreaders, "Number of RCU reader threads");
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module_param(nfakewriters, int, 0444);
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MODULE_PARM_DESC(nfakewriters, "Number of RCU fake writer threads");
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module_param(stat_interval, int, 0644);
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MODULE_PARM_DESC(stat_interval, "Number of seconds between stats printk()s");
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module_param(verbose, bool, 0444);
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MODULE_PARM_DESC(verbose, "Enable verbose debugging printk()s");
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module_param(test_no_idle_hz, bool, 0444);
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MODULE_PARM_DESC(test_no_idle_hz, "Test support for tickless idle CPUs");
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module_param(shuffle_interval, int, 0444);
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MODULE_PARM_DESC(shuffle_interval, "Number of seconds between shuffles");
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module_param(stutter, int, 0444);
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MODULE_PARM_DESC(stutter, "Number of seconds to run/halt test");
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module_param(irqreader, int, 0444);
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MODULE_PARM_DESC(irqreader, "Allow RCU readers from irq handlers");
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module_param(fqs_duration, int, 0444);
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MODULE_PARM_DESC(fqs_duration, "Duration of fqs bursts (us)");
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module_param(fqs_holdoff, int, 0444);
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MODULE_PARM_DESC(fqs_holdoff, "Holdoff time within fqs bursts (us)");
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module_param(fqs_stutter, int, 0444);
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MODULE_PARM_DESC(fqs_stutter, "Wait time between fqs bursts (s)");
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module_param(n_barrier_cbs, int, 0444);
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MODULE_PARM_DESC(n_barrier_cbs, "# of callbacks/kthreads for barrier testing");
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module_param(onoff_interval, int, 0444);
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MODULE_PARM_DESC(onoff_interval, "Time between CPU hotplugs (s), 0=disable");
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module_param(onoff_holdoff, int, 0444);
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MODULE_PARM_DESC(onoff_holdoff, "Time after boot before CPU hotplugs (s)");
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module_param(shutdown_secs, int, 0444);
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MODULE_PARM_DESC(shutdown_secs, "Shutdown time (s), zero to disable.");
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module_param(stall_cpu, int, 0444);
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MODULE_PARM_DESC(stall_cpu, "Stall duration (s), zero to disable.");
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module_param(stall_cpu_holdoff, int, 0444);
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MODULE_PARM_DESC(stall_cpu_holdoff, "Time to wait before starting stall (s).");
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module_param(test_boost, int, 0444);
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MODULE_PARM_DESC(test_boost, "Test RCU prio boost: 0=no, 1=maybe, 2=yes.");
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module_param(test_boost_interval, int, 0444);
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MODULE_PARM_DESC(test_boost_interval, "Interval between boost tests, seconds.");
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module_param(test_boost_duration, int, 0444);
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MODULE_PARM_DESC(test_boost_duration, "Duration of each boost test, seconds.");
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module_param(torture_type, charp, 0444);
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MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, srcu)");
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#define TORTURE_FLAG "-torture:"
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#define PRINTK_STRING(s) \
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do { pr_alert("%s" TORTURE_FLAG s "\n", torture_type); } while (0)
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#define VERBOSE_PRINTK_STRING(s) \
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do { if (verbose) pr_alert("%s" TORTURE_FLAG s "\n", torture_type); } while (0)
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#define VERBOSE_PRINTK_ERRSTRING(s) \
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do { if (verbose) pr_alert("%s" TORTURE_FLAG "!!! " s "\n", torture_type); } while (0)
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static char printk_buf[4096];
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static int nrealreaders;
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static struct task_struct *writer_task;
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static struct task_struct **fakewriter_tasks;
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static struct task_struct **reader_tasks;
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static struct task_struct *stats_task;
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static struct task_struct *shuffler_task;
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static struct task_struct *stutter_task;
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static struct task_struct *fqs_task;
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static struct task_struct *boost_tasks[NR_CPUS];
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static struct task_struct *shutdown_task;
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#ifdef CONFIG_HOTPLUG_CPU
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static struct task_struct *onoff_task;
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#endif /* #ifdef CONFIG_HOTPLUG_CPU */
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static struct task_struct *stall_task;
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static struct task_struct **barrier_cbs_tasks;
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static struct task_struct *barrier_task;
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#define RCU_TORTURE_PIPE_LEN 10
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struct rcu_torture {
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struct rcu_head rtort_rcu;
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int rtort_pipe_count;
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struct list_head rtort_free;
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int rtort_mbtest;
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};
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static LIST_HEAD(rcu_torture_freelist);
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static struct rcu_torture __rcu *rcu_torture_current;
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static unsigned long rcu_torture_current_version;
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static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN];
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static DEFINE_SPINLOCK(rcu_torture_lock);
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static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count) =
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{ 0 };
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static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch) =
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{ 0 };
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static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1];
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static atomic_t n_rcu_torture_alloc;
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static atomic_t n_rcu_torture_alloc_fail;
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static atomic_t n_rcu_torture_free;
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static atomic_t n_rcu_torture_mberror;
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static atomic_t n_rcu_torture_error;
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static long n_rcu_torture_barrier_error;
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static long n_rcu_torture_boost_ktrerror;
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static long n_rcu_torture_boost_rterror;
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static long n_rcu_torture_boost_failure;
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static long n_rcu_torture_boosts;
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static long n_rcu_torture_timers;
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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 long n_barrier_attempts;
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static long n_barrier_successes;
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static struct list_head rcu_torture_removed;
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static cpumask_var_t shuffle_tmp_mask;
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static int stutter_pause_test;
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#if defined(MODULE) || defined(CONFIG_RCU_TORTURE_TEST_RUNNABLE)
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#define RCUTORTURE_RUNNABLE_INIT 1
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#else
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#define RCUTORTURE_RUNNABLE_INIT 0
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#endif
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int rcutorture_runnable = RCUTORTURE_RUNNABLE_INIT;
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module_param(rcutorture_runnable, int, 0444);
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MODULE_PARM_DESC(rcutorture_runnable, "Start rcutorture at boot");
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#if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU)
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#define rcu_can_boost() 1
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#else /* #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */
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#define rcu_can_boost() 0
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#endif /* #else #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */
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static unsigned long shutdown_time; /* jiffies to system shutdown. */
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static unsigned long boost_starttime; /* jiffies of next boost test start. */
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DEFINE_MUTEX(boost_mutex); /* protect setting boost_starttime */
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/* and boost task create/destroy. */
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static atomic_t barrier_cbs_count; /* Barrier callbacks registered. */
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static bool barrier_phase; /* Test phase. */
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static atomic_t barrier_cbs_invoked; /* Barrier callbacks invoked. */
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static wait_queue_head_t *barrier_cbs_wq; /* Coordinate barrier testing. */
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static DECLARE_WAIT_QUEUE_HEAD(barrier_wq);
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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 rcutorture running. */
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#define FULLSTOP_RMMOD 2 /* Normal rmmod of rcutorture. */
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static int fullstop = FULLSTOP_RMMOD;
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/*
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* Protect fullstop transitions and spawning of kthreads.
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*/
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static DEFINE_MUTEX(fullstop_mutex);
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/* Forward reference. */
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static void rcu_torture_cleanup(void);
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/*
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* Detect and respond to a system shutdown.
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*/
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static int
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rcutorture_shutdown_notify(struct notifier_block *unused1,
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unsigned long unused2, void *unused3)
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{
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mutex_lock(&fullstop_mutex);
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if (fullstop == FULLSTOP_DONTSTOP)
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fullstop = FULLSTOP_SHUTDOWN;
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else
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pr_warn(/* but going down anyway, so... */
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"Concurrent 'rmmod rcutorture' and shutdown illegal!\n");
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mutex_unlock(&fullstop_mutex);
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return NOTIFY_DONE;
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}
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/*
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* Absorb kthreads into a kernel function that won't return, so that
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* they won't ever access module text or data again.
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*/
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static void rcutorture_shutdown_absorb(char *title)
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{
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if (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) {
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pr_notice(
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"rcutorture thread %s parking due to system shutdown\n",
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title);
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schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT);
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}
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}
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/*
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* Allocate an element from the rcu_tortures pool.
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*/
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static struct rcu_torture *
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rcu_torture_alloc(void)
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{
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struct list_head *p;
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spin_lock_bh(&rcu_torture_lock);
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if (list_empty(&rcu_torture_freelist)) {
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atomic_inc(&n_rcu_torture_alloc_fail);
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spin_unlock_bh(&rcu_torture_lock);
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return NULL;
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}
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atomic_inc(&n_rcu_torture_alloc);
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p = rcu_torture_freelist.next;
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list_del_init(p);
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spin_unlock_bh(&rcu_torture_lock);
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return container_of(p, struct rcu_torture, rtort_free);
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}
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/*
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* Free an element to the rcu_tortures pool.
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*/
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static void
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rcu_torture_free(struct rcu_torture *p)
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{
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atomic_inc(&n_rcu_torture_free);
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spin_lock_bh(&rcu_torture_lock);
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list_add_tail(&p->rtort_free, &rcu_torture_freelist);
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spin_unlock_bh(&rcu_torture_lock);
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}
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struct rcu_random_state {
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unsigned long rrs_state;
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long rrs_count;
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};
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#define RCU_RANDOM_MULT 39916801 /* prime */
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#define RCU_RANDOM_ADD 479001701 /* prime */
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#define RCU_RANDOM_REFRESH 10000
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#define DEFINE_RCU_RANDOM(name) struct rcu_random_state name = { 0, 0 }
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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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static unsigned long
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rcu_random(struct rcu_random_state *rrsp)
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{
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if (--rrsp->rrs_count < 0) {
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rrsp->rrs_state += (unsigned long)local_clock();
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rrsp->rrs_count = RCU_RANDOM_REFRESH;
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}
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rrsp->rrs_state = rrsp->rrs_state * RCU_RANDOM_MULT + RCU_RANDOM_ADD;
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return swahw32(rrsp->rrs_state);
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}
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static void
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rcu_stutter_wait(char *title)
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{
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while (stutter_pause_test || !rcutorture_runnable) {
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if (rcutorture_runnable)
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schedule_timeout_interruptible(1);
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else
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schedule_timeout_interruptible(round_jiffies_relative(HZ));
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rcutorture_shutdown_absorb(title);
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}
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}
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/*
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* Operations vector for selecting different types of tests.
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*/
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struct rcu_torture_ops {
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void (*init)(void);
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void (*cleanup)(void);
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int (*readlock)(void);
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void (*read_delay)(struct rcu_random_state *rrsp);
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void (*readunlock)(int idx);
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int (*completed)(void);
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void (*deferred_free)(struct rcu_torture *p);
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void (*sync)(void);
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void (*call)(struct rcu_head *head, void (*func)(struct rcu_head *rcu));
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void (*cb_barrier)(void);
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void (*fqs)(void);
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int (*stats)(char *page);
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int irq_capable;
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int can_boost;
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char *name;
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};
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static struct rcu_torture_ops *cur_ops;
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/*
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* Definitions for rcu torture testing.
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*/
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static int rcu_torture_read_lock(void) __acquires(RCU)
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{
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rcu_read_lock();
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return 0;
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}
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static void rcu_read_delay(struct rcu_random_state *rrsp)
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{
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const unsigned long shortdelay_us = 200;
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const unsigned long longdelay_ms = 50;
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/* We want a short delay sometimes to make a reader delay the grace
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* period, and we want a long delay occasionally to trigger
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* force_quiescent_state. */
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if (!(rcu_random(rrsp) % (nrealreaders * 2000 * longdelay_ms)))
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mdelay(longdelay_ms);
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if (!(rcu_random(rrsp) % (nrealreaders * 2 * shortdelay_us)))
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udelay(shortdelay_us);
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#ifdef CONFIG_PREEMPT
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if (!preempt_count() && !(rcu_random(rrsp) % (nrealreaders * 20000)))
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preempt_schedule(); /* No QS if preempt_disable() in effect */
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#endif
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}
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static void rcu_torture_read_unlock(int idx) __releases(RCU)
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{
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rcu_read_unlock();
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}
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static int rcu_torture_completed(void)
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{
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return rcu_batches_completed();
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}
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static void
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rcu_torture_cb(struct rcu_head *p)
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{
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int i;
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struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu);
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if (fullstop != FULLSTOP_DONTSTOP) {
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/* Test is ending, just drop callbacks on the floor. */
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/* The next initialization will pick up the pieces. */
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return;
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}
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i = rp->rtort_pipe_count;
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if (i > RCU_TORTURE_PIPE_LEN)
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i = RCU_TORTURE_PIPE_LEN;
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atomic_inc(&rcu_torture_wcount[i]);
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if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) {
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rp->rtort_mbtest = 0;
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rcu_torture_free(rp);
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} else {
|
|
cur_ops->deferred_free(rp);
|
|
}
|
|
}
|
|
|
|
static int rcu_no_completed(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static void rcu_torture_deferred_free(struct rcu_torture *p)
|
|
{
|
|
call_rcu(&p->rtort_rcu, rcu_torture_cb);
|
|
}
|
|
|
|
static struct rcu_torture_ops rcu_ops = {
|
|
.init = NULL,
|
|
.cleanup = NULL,
|
|
.readlock = rcu_torture_read_lock,
|
|
.read_delay = rcu_read_delay,
|
|
.readunlock = rcu_torture_read_unlock,
|
|
.completed = rcu_torture_completed,
|
|
.deferred_free = rcu_torture_deferred_free,
|
|
.sync = synchronize_rcu,
|
|
.call = call_rcu,
|
|
.cb_barrier = rcu_barrier,
|
|
.fqs = rcu_force_quiescent_state,
|
|
.stats = NULL,
|
|
.irq_capable = 1,
|
|
.can_boost = rcu_can_boost(),
|
|
.name = "rcu"
|
|
};
|
|
|
|
static void rcu_sync_torture_deferred_free(struct rcu_torture *p)
|
|
{
|
|
int i;
|
|
struct rcu_torture *rp;
|
|
struct rcu_torture *rp1;
|
|
|
|
cur_ops->sync();
|
|
list_add(&p->rtort_free, &rcu_torture_removed);
|
|
list_for_each_entry_safe(rp, rp1, &rcu_torture_removed, rtort_free) {
|
|
i = rp->rtort_pipe_count;
|
|
if (i > RCU_TORTURE_PIPE_LEN)
|
|
i = RCU_TORTURE_PIPE_LEN;
|
|
atomic_inc(&rcu_torture_wcount[i]);
|
|
if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) {
|
|
rp->rtort_mbtest = 0;
|
|
list_del(&rp->rtort_free);
|
|
rcu_torture_free(rp);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void rcu_sync_torture_init(void)
|
|
{
|
|
INIT_LIST_HEAD(&rcu_torture_removed);
|
|
}
|
|
|
|
static struct rcu_torture_ops rcu_sync_ops = {
|
|
.init = rcu_sync_torture_init,
|
|
.cleanup = NULL,
|
|
.readlock = rcu_torture_read_lock,
|
|
.read_delay = rcu_read_delay,
|
|
.readunlock = rcu_torture_read_unlock,
|
|
.completed = rcu_torture_completed,
|
|
.deferred_free = rcu_sync_torture_deferred_free,
|
|
.sync = synchronize_rcu,
|
|
.call = NULL,
|
|
.cb_barrier = NULL,
|
|
.fqs = rcu_force_quiescent_state,
|
|
.stats = NULL,
|
|
.irq_capable = 1,
|
|
.can_boost = rcu_can_boost(),
|
|
.name = "rcu_sync"
|
|
};
|
|
|
|
static struct rcu_torture_ops rcu_expedited_ops = {
|
|
.init = rcu_sync_torture_init,
|
|
.cleanup = NULL,
|
|
.readlock = rcu_torture_read_lock,
|
|
.read_delay = rcu_read_delay, /* just reuse rcu's version. */
|
|
.readunlock = rcu_torture_read_unlock,
|
|
.completed = rcu_no_completed,
|
|
.deferred_free = rcu_sync_torture_deferred_free,
|
|
.sync = synchronize_rcu_expedited,
|
|
.call = NULL,
|
|
.cb_barrier = NULL,
|
|
.fqs = rcu_force_quiescent_state,
|
|
.stats = NULL,
|
|
.irq_capable = 1,
|
|
.can_boost = rcu_can_boost(),
|
|
.name = "rcu_expedited"
|
|
};
|
|
|
|
/*
|
|
* Definitions for rcu_bh torture testing.
|
|
*/
|
|
|
|
static int rcu_bh_torture_read_lock(void) __acquires(RCU_BH)
|
|
{
|
|
rcu_read_lock_bh();
|
|
return 0;
|
|
}
|
|
|
|
static void rcu_bh_torture_read_unlock(int idx) __releases(RCU_BH)
|
|
{
|
|
rcu_read_unlock_bh();
|
|
}
|
|
|
|
static int rcu_bh_torture_completed(void)
|
|
{
|
|
return rcu_batches_completed_bh();
|
|
}
|
|
|
|
static void rcu_bh_torture_deferred_free(struct rcu_torture *p)
|
|
{
|
|
call_rcu_bh(&p->rtort_rcu, rcu_torture_cb);
|
|
}
|
|
|
|
static struct rcu_torture_ops rcu_bh_ops = {
|
|
.init = NULL,
|
|
.cleanup = NULL,
|
|
.readlock = rcu_bh_torture_read_lock,
|
|
.read_delay = rcu_read_delay, /* just reuse rcu's version. */
|
|
.readunlock = rcu_bh_torture_read_unlock,
|
|
.completed = rcu_bh_torture_completed,
|
|
.deferred_free = rcu_bh_torture_deferred_free,
|
|
.sync = synchronize_rcu_bh,
|
|
.call = call_rcu_bh,
|
|
.cb_barrier = rcu_barrier_bh,
|
|
.fqs = rcu_bh_force_quiescent_state,
|
|
.stats = NULL,
|
|
.irq_capable = 1,
|
|
.name = "rcu_bh"
|
|
};
|
|
|
|
static struct rcu_torture_ops rcu_bh_sync_ops = {
|
|
.init = rcu_sync_torture_init,
|
|
.cleanup = NULL,
|
|
.readlock = rcu_bh_torture_read_lock,
|
|
.read_delay = rcu_read_delay, /* just reuse rcu's version. */
|
|
.readunlock = rcu_bh_torture_read_unlock,
|
|
.completed = rcu_bh_torture_completed,
|
|
.deferred_free = rcu_sync_torture_deferred_free,
|
|
.sync = synchronize_rcu_bh,
|
|
.call = NULL,
|
|
.cb_barrier = NULL,
|
|
.fqs = rcu_bh_force_quiescent_state,
|
|
.stats = NULL,
|
|
.irq_capable = 1,
|
|
.name = "rcu_bh_sync"
|
|
};
|
|
|
|
static struct rcu_torture_ops rcu_bh_expedited_ops = {
|
|
.init = rcu_sync_torture_init,
|
|
.cleanup = NULL,
|
|
.readlock = rcu_bh_torture_read_lock,
|
|
.read_delay = rcu_read_delay, /* just reuse rcu's version. */
|
|
.readunlock = rcu_bh_torture_read_unlock,
|
|
.completed = rcu_bh_torture_completed,
|
|
.deferred_free = rcu_sync_torture_deferred_free,
|
|
.sync = synchronize_rcu_bh_expedited,
|
|
.call = NULL,
|
|
.cb_barrier = NULL,
|
|
.fqs = rcu_bh_force_quiescent_state,
|
|
.stats = NULL,
|
|
.irq_capable = 1,
|
|
.name = "rcu_bh_expedited"
|
|
};
|
|
|
|
/*
|
|
* Definitions for srcu torture testing.
|
|
*/
|
|
|
|
static struct srcu_struct srcu_ctl;
|
|
|
|
static void srcu_torture_init(void)
|
|
{
|
|
init_srcu_struct(&srcu_ctl);
|
|
rcu_sync_torture_init();
|
|
}
|
|
|
|
static void srcu_torture_cleanup(void)
|
|
{
|
|
synchronize_srcu(&srcu_ctl);
|
|
cleanup_srcu_struct(&srcu_ctl);
|
|
}
|
|
|
|
static int srcu_torture_read_lock(void) __acquires(&srcu_ctl)
|
|
{
|
|
return srcu_read_lock(&srcu_ctl);
|
|
}
|
|
|
|
static void srcu_read_delay(struct rcu_random_state *rrsp)
|
|
{
|
|
long delay;
|
|
const long uspertick = 1000000 / HZ;
|
|
const long longdelay = 10;
|
|
|
|
/* We want there to be long-running readers, but not all the time. */
|
|
|
|
delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay * uspertick);
|
|
if (!delay)
|
|
schedule_timeout_interruptible(longdelay);
|
|
else
|
|
rcu_read_delay(rrsp);
|
|
}
|
|
|
|
static void srcu_torture_read_unlock(int idx) __releases(&srcu_ctl)
|
|
{
|
|
srcu_read_unlock(&srcu_ctl, idx);
|
|
}
|
|
|
|
static int srcu_torture_completed(void)
|
|
{
|
|
return srcu_batches_completed(&srcu_ctl);
|
|
}
|
|
|
|
static void srcu_torture_deferred_free(struct rcu_torture *rp)
|
|
{
|
|
call_srcu(&srcu_ctl, &rp->rtort_rcu, rcu_torture_cb);
|
|
}
|
|
|
|
static void srcu_torture_synchronize(void)
|
|
{
|
|
synchronize_srcu(&srcu_ctl);
|
|
}
|
|
|
|
static void srcu_torture_call(struct rcu_head *head,
|
|
void (*func)(struct rcu_head *head))
|
|
{
|
|
call_srcu(&srcu_ctl, head, func);
|
|
}
|
|
|
|
static void srcu_torture_barrier(void)
|
|
{
|
|
srcu_barrier(&srcu_ctl);
|
|
}
|
|
|
|
static int srcu_torture_stats(char *page)
|
|
{
|
|
int cnt = 0;
|
|
int cpu;
|
|
int idx = srcu_ctl.completed & 0x1;
|
|
|
|
cnt += sprintf(&page[cnt], "%s%s per-CPU(idx=%d):",
|
|
torture_type, TORTURE_FLAG, idx);
|
|
for_each_possible_cpu(cpu) {
|
|
cnt += sprintf(&page[cnt], " %d(%lu,%lu)", cpu,
|
|
per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[!idx],
|
|
per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[idx]);
|
|
}
|
|
cnt += sprintf(&page[cnt], "\n");
|
|
return cnt;
|
|
}
|
|
|
|
static struct rcu_torture_ops srcu_ops = {
|
|
.init = srcu_torture_init,
|
|
.cleanup = srcu_torture_cleanup,
|
|
.readlock = srcu_torture_read_lock,
|
|
.read_delay = srcu_read_delay,
|
|
.readunlock = srcu_torture_read_unlock,
|
|
.completed = srcu_torture_completed,
|
|
.deferred_free = srcu_torture_deferred_free,
|
|
.sync = srcu_torture_synchronize,
|
|
.call = srcu_torture_call,
|
|
.cb_barrier = srcu_torture_barrier,
|
|
.stats = srcu_torture_stats,
|
|
.name = "srcu"
|
|
};
|
|
|
|
static struct rcu_torture_ops srcu_sync_ops = {
|
|
.init = srcu_torture_init,
|
|
.cleanup = srcu_torture_cleanup,
|
|
.readlock = srcu_torture_read_lock,
|
|
.read_delay = srcu_read_delay,
|
|
.readunlock = srcu_torture_read_unlock,
|
|
.completed = srcu_torture_completed,
|
|
.deferred_free = rcu_sync_torture_deferred_free,
|
|
.sync = srcu_torture_synchronize,
|
|
.call = NULL,
|
|
.cb_barrier = NULL,
|
|
.stats = srcu_torture_stats,
|
|
.name = "srcu_sync"
|
|
};
|
|
|
|
static int srcu_torture_read_lock_raw(void) __acquires(&srcu_ctl)
|
|
{
|
|
return srcu_read_lock_raw(&srcu_ctl);
|
|
}
|
|
|
|
static void srcu_torture_read_unlock_raw(int idx) __releases(&srcu_ctl)
|
|
{
|
|
srcu_read_unlock_raw(&srcu_ctl, idx);
|
|
}
|
|
|
|
static struct rcu_torture_ops srcu_raw_ops = {
|
|
.init = srcu_torture_init,
|
|
.cleanup = srcu_torture_cleanup,
|
|
.readlock = srcu_torture_read_lock_raw,
|
|
.read_delay = srcu_read_delay,
|
|
.readunlock = srcu_torture_read_unlock_raw,
|
|
.completed = srcu_torture_completed,
|
|
.deferred_free = srcu_torture_deferred_free,
|
|
.sync = srcu_torture_synchronize,
|
|
.call = NULL,
|
|
.cb_barrier = NULL,
|
|
.stats = srcu_torture_stats,
|
|
.name = "srcu_raw"
|
|
};
|
|
|
|
static struct rcu_torture_ops srcu_raw_sync_ops = {
|
|
.init = srcu_torture_init,
|
|
.cleanup = srcu_torture_cleanup,
|
|
.readlock = srcu_torture_read_lock_raw,
|
|
.read_delay = srcu_read_delay,
|
|
.readunlock = srcu_torture_read_unlock_raw,
|
|
.completed = srcu_torture_completed,
|
|
.deferred_free = rcu_sync_torture_deferred_free,
|
|
.sync = srcu_torture_synchronize,
|
|
.call = NULL,
|
|
.cb_barrier = NULL,
|
|
.stats = srcu_torture_stats,
|
|
.name = "srcu_raw_sync"
|
|
};
|
|
|
|
static void srcu_torture_synchronize_expedited(void)
|
|
{
|
|
synchronize_srcu_expedited(&srcu_ctl);
|
|
}
|
|
|
|
static struct rcu_torture_ops srcu_expedited_ops = {
|
|
.init = srcu_torture_init,
|
|
.cleanup = srcu_torture_cleanup,
|
|
.readlock = srcu_torture_read_lock,
|
|
.read_delay = srcu_read_delay,
|
|
.readunlock = srcu_torture_read_unlock,
|
|
.completed = srcu_torture_completed,
|
|
.deferred_free = rcu_sync_torture_deferred_free,
|
|
.sync = srcu_torture_synchronize_expedited,
|
|
.call = NULL,
|
|
.cb_barrier = NULL,
|
|
.stats = srcu_torture_stats,
|
|
.name = "srcu_expedited"
|
|
};
|
|
|
|
/*
|
|
* Definitions for sched torture testing.
|
|
*/
|
|
|
|
static int sched_torture_read_lock(void)
|
|
{
|
|
preempt_disable();
|
|
return 0;
|
|
}
|
|
|
|
static void sched_torture_read_unlock(int idx)
|
|
{
|
|
preempt_enable();
|
|
}
|
|
|
|
static void rcu_sched_torture_deferred_free(struct rcu_torture *p)
|
|
{
|
|
call_rcu_sched(&p->rtort_rcu, rcu_torture_cb);
|
|
}
|
|
|
|
static struct rcu_torture_ops sched_ops = {
|
|
.init = rcu_sync_torture_init,
|
|
.cleanup = NULL,
|
|
.readlock = sched_torture_read_lock,
|
|
.read_delay = rcu_read_delay, /* just reuse rcu's version. */
|
|
.readunlock = sched_torture_read_unlock,
|
|
.completed = rcu_no_completed,
|
|
.deferred_free = rcu_sched_torture_deferred_free,
|
|
.sync = synchronize_sched,
|
|
.cb_barrier = rcu_barrier_sched,
|
|
.fqs = rcu_sched_force_quiescent_state,
|
|
.stats = NULL,
|
|
.irq_capable = 1,
|
|
.name = "sched"
|
|
};
|
|
|
|
static struct rcu_torture_ops sched_sync_ops = {
|
|
.init = rcu_sync_torture_init,
|
|
.cleanup = NULL,
|
|
.readlock = sched_torture_read_lock,
|
|
.read_delay = rcu_read_delay, /* just reuse rcu's version. */
|
|
.readunlock = sched_torture_read_unlock,
|
|
.completed = rcu_no_completed,
|
|
.deferred_free = rcu_sync_torture_deferred_free,
|
|
.sync = synchronize_sched,
|
|
.cb_barrier = NULL,
|
|
.fqs = rcu_sched_force_quiescent_state,
|
|
.stats = NULL,
|
|
.name = "sched_sync"
|
|
};
|
|
|
|
static struct rcu_torture_ops sched_expedited_ops = {
|
|
.init = rcu_sync_torture_init,
|
|
.cleanup = NULL,
|
|
.readlock = sched_torture_read_lock,
|
|
.read_delay = rcu_read_delay, /* just reuse rcu's version. */
|
|
.readunlock = sched_torture_read_unlock,
|
|
.completed = rcu_no_completed,
|
|
.deferred_free = rcu_sync_torture_deferred_free,
|
|
.sync = synchronize_sched_expedited,
|
|
.cb_barrier = NULL,
|
|
.fqs = rcu_sched_force_quiescent_state,
|
|
.stats = NULL,
|
|
.irq_capable = 1,
|
|
.name = "sched_expedited"
|
|
};
|
|
|
|
/*
|
|
* RCU torture priority-boost testing. Runs one real-time thread per
|
|
* CPU for moderate bursts, repeatedly registering RCU callbacks and
|
|
* spinning waiting for them to be invoked. If a given callback takes
|
|
* too long to be invoked, we assume that priority inversion has occurred.
|
|
*/
|
|
|
|
struct rcu_boost_inflight {
|
|
struct rcu_head rcu;
|
|
int inflight;
|
|
};
|
|
|
|
static void rcu_torture_boost_cb(struct rcu_head *head)
|
|
{
|
|
struct rcu_boost_inflight *rbip =
|
|
container_of(head, struct rcu_boost_inflight, rcu);
|
|
|
|
smp_mb(); /* Ensure RCU-core accesses precede clearing ->inflight */
|
|
rbip->inflight = 0;
|
|
}
|
|
|
|
static int rcu_torture_boost(void *arg)
|
|
{
|
|
unsigned long call_rcu_time;
|
|
unsigned long endtime;
|
|
unsigned long oldstarttime;
|
|
struct rcu_boost_inflight rbi = { .inflight = 0 };
|
|
struct sched_param sp;
|
|
|
|
VERBOSE_PRINTK_STRING("rcu_torture_boost started");
|
|
|
|
/* Set real-time priority. */
|
|
sp.sched_priority = 1;
|
|
if (sched_setscheduler(current, SCHED_FIFO, &sp) < 0) {
|
|
VERBOSE_PRINTK_STRING("rcu_torture_boost RT prio failed!");
|
|
n_rcu_torture_boost_rterror++;
|
|
}
|
|
|
|
init_rcu_head_on_stack(&rbi.rcu);
|
|
/* Each pass through the following loop does one boost-test cycle. */
|
|
do {
|
|
/* Wait for the next test interval. */
|
|
oldstarttime = boost_starttime;
|
|
while (ULONG_CMP_LT(jiffies, oldstarttime)) {
|
|
schedule_timeout_uninterruptible(1);
|
|
rcu_stutter_wait("rcu_torture_boost");
|
|
if (kthread_should_stop() ||
|
|
fullstop != FULLSTOP_DONTSTOP)
|
|
goto checkwait;
|
|
}
|
|
|
|
/* Do one boost-test interval. */
|
|
endtime = oldstarttime + test_boost_duration * HZ;
|
|
call_rcu_time = jiffies;
|
|
while (ULONG_CMP_LT(jiffies, endtime)) {
|
|
/* If we don't have a callback in flight, post one. */
|
|
if (!rbi.inflight) {
|
|
smp_mb(); /* RCU core before ->inflight = 1. */
|
|
rbi.inflight = 1;
|
|
call_rcu(&rbi.rcu, rcu_torture_boost_cb);
|
|
if (jiffies - call_rcu_time >
|
|
test_boost_duration * HZ - HZ / 2) {
|
|
VERBOSE_PRINTK_STRING("rcu_torture_boost boosting failed");
|
|
n_rcu_torture_boost_failure++;
|
|
}
|
|
call_rcu_time = jiffies;
|
|
}
|
|
cond_resched();
|
|
rcu_stutter_wait("rcu_torture_boost");
|
|
if (kthread_should_stop() ||
|
|
fullstop != FULLSTOP_DONTSTOP)
|
|
goto checkwait;
|
|
}
|
|
|
|
/*
|
|
* Set the start time of the next test interval.
|
|
* Yes, this is vulnerable to long delays, but such
|
|
* delays simply cause a false negative for the next
|
|
* interval. Besides, we are running at RT priority,
|
|
* so delays should be relatively rare.
|
|
*/
|
|
while (oldstarttime == boost_starttime &&
|
|
!kthread_should_stop()) {
|
|
if (mutex_trylock(&boost_mutex)) {
|
|
boost_starttime = jiffies +
|
|
test_boost_interval * HZ;
|
|
n_rcu_torture_boosts++;
|
|
mutex_unlock(&boost_mutex);
|
|
break;
|
|
}
|
|
schedule_timeout_uninterruptible(1);
|
|
}
|
|
|
|
/* Go do the stutter. */
|
|
checkwait: rcu_stutter_wait("rcu_torture_boost");
|
|
} while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP);
|
|
|
|
/* Clean up and exit. */
|
|
VERBOSE_PRINTK_STRING("rcu_torture_boost task stopping");
|
|
rcutorture_shutdown_absorb("rcu_torture_boost");
|
|
while (!kthread_should_stop() || rbi.inflight)
|
|
schedule_timeout_uninterruptible(1);
|
|
smp_mb(); /* order accesses to ->inflight before stack-frame death. */
|
|
destroy_rcu_head_on_stack(&rbi.rcu);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* RCU torture force-quiescent-state kthread. Repeatedly induces
|
|
* bursts of calls to force_quiescent_state(), increasing the probability
|
|
* of occurrence of some important types of race conditions.
|
|
*/
|
|
static int
|
|
rcu_torture_fqs(void *arg)
|
|
{
|
|
unsigned long fqs_resume_time;
|
|
int fqs_burst_remaining;
|
|
|
|
VERBOSE_PRINTK_STRING("rcu_torture_fqs task started");
|
|
do {
|
|
fqs_resume_time = jiffies + fqs_stutter * HZ;
|
|
while (ULONG_CMP_LT(jiffies, fqs_resume_time) &&
|
|
!kthread_should_stop()) {
|
|
schedule_timeout_interruptible(1);
|
|
}
|
|
fqs_burst_remaining = fqs_duration;
|
|
while (fqs_burst_remaining > 0 &&
|
|
!kthread_should_stop()) {
|
|
cur_ops->fqs();
|
|
udelay(fqs_holdoff);
|
|
fqs_burst_remaining -= fqs_holdoff;
|
|
}
|
|
rcu_stutter_wait("rcu_torture_fqs");
|
|
} while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP);
|
|
VERBOSE_PRINTK_STRING("rcu_torture_fqs task stopping");
|
|
rcutorture_shutdown_absorb("rcu_torture_fqs");
|
|
while (!kthread_should_stop())
|
|
schedule_timeout_uninterruptible(1);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* RCU torture writer kthread. Repeatedly substitutes a new structure
|
|
* for that pointed to by rcu_torture_current, freeing the old structure
|
|
* after a series of grace periods (the "pipeline").
|
|
*/
|
|
static int
|
|
rcu_torture_writer(void *arg)
|
|
{
|
|
int i;
|
|
long oldbatch = rcu_batches_completed();
|
|
struct rcu_torture *rp;
|
|
struct rcu_torture *old_rp;
|
|
static DEFINE_RCU_RANDOM(rand);
|
|
|
|
VERBOSE_PRINTK_STRING("rcu_torture_writer task started");
|
|
set_user_nice(current, 19);
|
|
|
|
do {
|
|
schedule_timeout_uninterruptible(1);
|
|
rp = rcu_torture_alloc();
|
|
if (rp == NULL)
|
|
continue;
|
|
rp->rtort_pipe_count = 0;
|
|
udelay(rcu_random(&rand) & 0x3ff);
|
|
old_rp = rcu_dereference_check(rcu_torture_current,
|
|
current == writer_task);
|
|
rp->rtort_mbtest = 1;
|
|
rcu_assign_pointer(rcu_torture_current, rp);
|
|
smp_wmb(); /* Mods to old_rp must follow rcu_assign_pointer() */
|
|
if (old_rp) {
|
|
i = old_rp->rtort_pipe_count;
|
|
if (i > RCU_TORTURE_PIPE_LEN)
|
|
i = RCU_TORTURE_PIPE_LEN;
|
|
atomic_inc(&rcu_torture_wcount[i]);
|
|
old_rp->rtort_pipe_count++;
|
|
cur_ops->deferred_free(old_rp);
|
|
}
|
|
rcutorture_record_progress(++rcu_torture_current_version);
|
|
oldbatch = cur_ops->completed();
|
|
rcu_stutter_wait("rcu_torture_writer");
|
|
} while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP);
|
|
VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping");
|
|
rcutorture_shutdown_absorb("rcu_torture_writer");
|
|
while (!kthread_should_stop())
|
|
schedule_timeout_uninterruptible(1);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* RCU torture fake writer kthread. Repeatedly calls sync, with a random
|
|
* delay between calls.
|
|
*/
|
|
static int
|
|
rcu_torture_fakewriter(void *arg)
|
|
{
|
|
DEFINE_RCU_RANDOM(rand);
|
|
|
|
VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task started");
|
|
set_user_nice(current, 19);
|
|
|
|
do {
|
|
schedule_timeout_uninterruptible(1 + rcu_random(&rand)%10);
|
|
udelay(rcu_random(&rand) & 0x3ff);
|
|
if (cur_ops->cb_barrier != NULL &&
|
|
rcu_random(&rand) % (nfakewriters * 8) == 0)
|
|
cur_ops->cb_barrier();
|
|
else
|
|
cur_ops->sync();
|
|
rcu_stutter_wait("rcu_torture_fakewriter");
|
|
} while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP);
|
|
|
|
VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task stopping");
|
|
rcutorture_shutdown_absorb("rcu_torture_fakewriter");
|
|
while (!kthread_should_stop())
|
|
schedule_timeout_uninterruptible(1);
|
|
return 0;
|
|
}
|
|
|
|
void rcutorture_trace_dump(void)
|
|
{
|
|
static atomic_t beenhere = ATOMIC_INIT(0);
|
|
|
|
if (atomic_read(&beenhere))
|
|
return;
|
|
if (atomic_xchg(&beenhere, 1) != 0)
|
|
return;
|
|
do_trace_rcu_torture_read(cur_ops->name, (struct rcu_head *)~0UL);
|
|
ftrace_dump(DUMP_ALL);
|
|
}
|
|
|
|
/*
|
|
* RCU torture reader from timer handler. Dereferences rcu_torture_current,
|
|
* incrementing the corresponding element of the pipeline array. The
|
|
* counter in the element should never be greater than 1, otherwise, the
|
|
* RCU implementation is broken.
|
|
*/
|
|
static void rcu_torture_timer(unsigned long unused)
|
|
{
|
|
int idx;
|
|
int completed;
|
|
static DEFINE_RCU_RANDOM(rand);
|
|
static DEFINE_SPINLOCK(rand_lock);
|
|
struct rcu_torture *p;
|
|
int pipe_count;
|
|
|
|
idx = cur_ops->readlock();
|
|
completed = cur_ops->completed();
|
|
p = rcu_dereference_check(rcu_torture_current,
|
|
rcu_read_lock_bh_held() ||
|
|
rcu_read_lock_sched_held() ||
|
|
srcu_read_lock_held(&srcu_ctl));
|
|
if (p == NULL) {
|
|
/* Leave because rcu_torture_writer is not yet underway */
|
|
cur_ops->readunlock(idx);
|
|
return;
|
|
}
|
|
do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu);
|
|
if (p->rtort_mbtest == 0)
|
|
atomic_inc(&n_rcu_torture_mberror);
|
|
spin_lock(&rand_lock);
|
|
cur_ops->read_delay(&rand);
|
|
n_rcu_torture_timers++;
|
|
spin_unlock(&rand_lock);
|
|
preempt_disable();
|
|
pipe_count = p->rtort_pipe_count;
|
|
if (pipe_count > RCU_TORTURE_PIPE_LEN) {
|
|
/* Should not happen, but... */
|
|
pipe_count = RCU_TORTURE_PIPE_LEN;
|
|
}
|
|
if (pipe_count > 1)
|
|
rcutorture_trace_dump();
|
|
__this_cpu_inc(rcu_torture_count[pipe_count]);
|
|
completed = cur_ops->completed() - completed;
|
|
if (completed > RCU_TORTURE_PIPE_LEN) {
|
|
/* Should not happen, but... */
|
|
completed = RCU_TORTURE_PIPE_LEN;
|
|
}
|
|
__this_cpu_inc(rcu_torture_batch[completed]);
|
|
preempt_enable();
|
|
cur_ops->readunlock(idx);
|
|
}
|
|
|
|
/*
|
|
* RCU torture reader kthread. Repeatedly dereferences rcu_torture_current,
|
|
* incrementing the corresponding element of the pipeline array. The
|
|
* counter in the element should never be greater than 1, otherwise, the
|
|
* RCU implementation is broken.
|
|
*/
|
|
static int
|
|
rcu_torture_reader(void *arg)
|
|
{
|
|
int completed;
|
|
int idx;
|
|
DEFINE_RCU_RANDOM(rand);
|
|
struct rcu_torture *p;
|
|
int pipe_count;
|
|
struct timer_list t;
|
|
|
|
VERBOSE_PRINTK_STRING("rcu_torture_reader task started");
|
|
set_user_nice(current, 19);
|
|
if (irqreader && cur_ops->irq_capable)
|
|
setup_timer_on_stack(&t, rcu_torture_timer, 0);
|
|
|
|
do {
|
|
if (irqreader && cur_ops->irq_capable) {
|
|
if (!timer_pending(&t))
|
|
mod_timer(&t, jiffies + 1);
|
|
}
|
|
idx = cur_ops->readlock();
|
|
completed = cur_ops->completed();
|
|
p = rcu_dereference_check(rcu_torture_current,
|
|
rcu_read_lock_bh_held() ||
|
|
rcu_read_lock_sched_held() ||
|
|
srcu_read_lock_held(&srcu_ctl));
|
|
if (p == NULL) {
|
|
/* Wait for rcu_torture_writer to get underway */
|
|
cur_ops->readunlock(idx);
|
|
schedule_timeout_interruptible(HZ);
|
|
continue;
|
|
}
|
|
do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu);
|
|
if (p->rtort_mbtest == 0)
|
|
atomic_inc(&n_rcu_torture_mberror);
|
|
cur_ops->read_delay(&rand);
|
|
preempt_disable();
|
|
pipe_count = p->rtort_pipe_count;
|
|
if (pipe_count > RCU_TORTURE_PIPE_LEN) {
|
|
/* Should not happen, but... */
|
|
pipe_count = RCU_TORTURE_PIPE_LEN;
|
|
}
|
|
if (pipe_count > 1)
|
|
rcutorture_trace_dump();
|
|
__this_cpu_inc(rcu_torture_count[pipe_count]);
|
|
completed = cur_ops->completed() - completed;
|
|
if (completed > RCU_TORTURE_PIPE_LEN) {
|
|
/* Should not happen, but... */
|
|
completed = RCU_TORTURE_PIPE_LEN;
|
|
}
|
|
__this_cpu_inc(rcu_torture_batch[completed]);
|
|
preempt_enable();
|
|
cur_ops->readunlock(idx);
|
|
schedule();
|
|
rcu_stutter_wait("rcu_torture_reader");
|
|
} while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP);
|
|
VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping");
|
|
rcutorture_shutdown_absorb("rcu_torture_reader");
|
|
if (irqreader && cur_ops->irq_capable)
|
|
del_timer_sync(&t);
|
|
while (!kthread_should_stop())
|
|
schedule_timeout_uninterruptible(1);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Create an RCU-torture statistics message in the specified buffer.
|
|
*/
|
|
static int
|
|
rcu_torture_printk(char *page)
|
|
{
|
|
int cnt = 0;
|
|
int cpu;
|
|
int i;
|
|
long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
|
|
long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
|
|
pipesummary[i] += per_cpu(rcu_torture_count, cpu)[i];
|
|
batchsummary[i] += per_cpu(rcu_torture_batch, cpu)[i];
|
|
}
|
|
}
|
|
for (i = RCU_TORTURE_PIPE_LEN - 1; i >= 0; i--) {
|
|
if (pipesummary[i] != 0)
|
|
break;
|
|
}
|
|
cnt += sprintf(&page[cnt], "%s%s ", torture_type, TORTURE_FLAG);
|
|
cnt += sprintf(&page[cnt],
|
|
"rtc: %p ver: %lu tfle: %d rta: %d rtaf: %d rtf: %d ",
|
|
rcu_torture_current,
|
|
rcu_torture_current_version,
|
|
list_empty(&rcu_torture_freelist),
|
|
atomic_read(&n_rcu_torture_alloc),
|
|
atomic_read(&n_rcu_torture_alloc_fail),
|
|
atomic_read(&n_rcu_torture_free));
|
|
cnt += sprintf(&page[cnt], "rtmbe: %d rtbke: %ld rtbre: %ld ",
|
|
atomic_read(&n_rcu_torture_mberror),
|
|
n_rcu_torture_boost_ktrerror,
|
|
n_rcu_torture_boost_rterror);
|
|
cnt += sprintf(&page[cnt], "rtbf: %ld rtb: %ld nt: %ld ",
|
|
n_rcu_torture_boost_failure,
|
|
n_rcu_torture_boosts,
|
|
n_rcu_torture_timers);
|
|
cnt += sprintf(&page[cnt],
|
|
"onoff: %ld/%ld:%ld/%ld %d,%d:%d,%d %lu:%lu (HZ=%d) ",
|
|
n_online_successes, n_online_attempts,
|
|
n_offline_successes, n_offline_attempts,
|
|
min_online, max_online,
|
|
min_offline, max_offline,
|
|
sum_online, sum_offline, HZ);
|
|
cnt += sprintf(&page[cnt], "barrier: %ld/%ld:%ld",
|
|
n_barrier_successes,
|
|
n_barrier_attempts,
|
|
n_rcu_torture_barrier_error);
|
|
cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG);
|
|
if (atomic_read(&n_rcu_torture_mberror) != 0 ||
|
|
n_rcu_torture_barrier_error != 0 ||
|
|
n_rcu_torture_boost_ktrerror != 0 ||
|
|
n_rcu_torture_boost_rterror != 0 ||
|
|
n_rcu_torture_boost_failure != 0 ||
|
|
i > 1) {
|
|
cnt += sprintf(&page[cnt], "!!! ");
|
|
atomic_inc(&n_rcu_torture_error);
|
|
WARN_ON_ONCE(1);
|
|
}
|
|
cnt += sprintf(&page[cnt], "Reader Pipe: ");
|
|
for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
|
|
cnt += sprintf(&page[cnt], " %ld", pipesummary[i]);
|
|
cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG);
|
|
cnt += sprintf(&page[cnt], "Reader Batch: ");
|
|
for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
|
|
cnt += sprintf(&page[cnt], " %ld", batchsummary[i]);
|
|
cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG);
|
|
cnt += sprintf(&page[cnt], "Free-Block Circulation: ");
|
|
for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
|
|
cnt += sprintf(&page[cnt], " %d",
|
|
atomic_read(&rcu_torture_wcount[i]));
|
|
}
|
|
cnt += sprintf(&page[cnt], "\n");
|
|
if (cur_ops->stats)
|
|
cnt += cur_ops->stats(&page[cnt]);
|
|
return cnt;
|
|
}
|
|
|
|
/*
|
|
* Print torture statistics. Caller must ensure that there is only
|
|
* one call to this function at a given time!!! This is normally
|
|
* accomplished by relying on the module system to only have one copy
|
|
* of the module loaded, and then by giving the rcu_torture_stats
|
|
* kthread full control (or the init/cleanup functions when rcu_torture_stats
|
|
* thread is not running).
|
|
*/
|
|
static void
|
|
rcu_torture_stats_print(void)
|
|
{
|
|
int cnt;
|
|
|
|
cnt = rcu_torture_printk(printk_buf);
|
|
pr_alert("%s", printk_buf);
|
|
}
|
|
|
|
/*
|
|
* Periodically prints torture statistics, if periodic statistics printing
|
|
* was specified via the stat_interval module parameter.
|
|
*
|
|
* No need to worry about fullstop here, since this one doesn't reference
|
|
* volatile state or register callbacks.
|
|
*/
|
|
static int
|
|
rcu_torture_stats(void *arg)
|
|
{
|
|
VERBOSE_PRINTK_STRING("rcu_torture_stats task started");
|
|
do {
|
|
schedule_timeout_interruptible(stat_interval * HZ);
|
|
rcu_torture_stats_print();
|
|
rcutorture_shutdown_absorb("rcu_torture_stats");
|
|
} while (!kthread_should_stop());
|
|
VERBOSE_PRINTK_STRING("rcu_torture_stats task stopping");
|
|
return 0;
|
|
}
|
|
|
|
static int rcu_idle_cpu; /* Force all torture tasks off this CPU */
|
|
|
|
/* Shuffle tasks such that we allow @rcu_idle_cpu to become idle. A special case
|
|
* is when @rcu_idle_cpu = -1, when we allow the tasks to run on all CPUs.
|
|
*/
|
|
static void rcu_torture_shuffle_tasks(void)
|
|
{
|
|
int i;
|
|
|
|
cpumask_setall(shuffle_tmp_mask);
|
|
get_online_cpus();
|
|
|
|
/* No point in shuffling if there is only one online CPU (ex: UP) */
|
|
if (num_online_cpus() == 1) {
|
|
put_online_cpus();
|
|
return;
|
|
}
|
|
|
|
if (rcu_idle_cpu != -1)
|
|
cpumask_clear_cpu(rcu_idle_cpu, shuffle_tmp_mask);
|
|
|
|
set_cpus_allowed_ptr(current, shuffle_tmp_mask);
|
|
|
|
if (reader_tasks) {
|
|
for (i = 0; i < nrealreaders; i++)
|
|
if (reader_tasks[i])
|
|
set_cpus_allowed_ptr(reader_tasks[i],
|
|
shuffle_tmp_mask);
|
|
}
|
|
|
|
if (fakewriter_tasks) {
|
|
for (i = 0; i < nfakewriters; i++)
|
|
if (fakewriter_tasks[i])
|
|
set_cpus_allowed_ptr(fakewriter_tasks[i],
|
|
shuffle_tmp_mask);
|
|
}
|
|
|
|
if (writer_task)
|
|
set_cpus_allowed_ptr(writer_task, shuffle_tmp_mask);
|
|
|
|
if (stats_task)
|
|
set_cpus_allowed_ptr(stats_task, shuffle_tmp_mask);
|
|
|
|
if (rcu_idle_cpu == -1)
|
|
rcu_idle_cpu = num_online_cpus() - 1;
|
|
else
|
|
rcu_idle_cpu--;
|
|
|
|
put_online_cpus();
|
|
}
|
|
|
|
/* 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
|
|
rcu_torture_shuffle(void *arg)
|
|
{
|
|
VERBOSE_PRINTK_STRING("rcu_torture_shuffle task started");
|
|
do {
|
|
schedule_timeout_interruptible(shuffle_interval * HZ);
|
|
rcu_torture_shuffle_tasks();
|
|
rcutorture_shutdown_absorb("rcu_torture_shuffle");
|
|
} while (!kthread_should_stop());
|
|
VERBOSE_PRINTK_STRING("rcu_torture_shuffle task stopping");
|
|
return 0;
|
|
}
|
|
|
|
/* Cause the rcutorture test to "stutter", starting and stopping all
|
|
* threads periodically.
|
|
*/
|
|
static int
|
|
rcu_torture_stutter(void *arg)
|
|
{
|
|
VERBOSE_PRINTK_STRING("rcu_torture_stutter task started");
|
|
do {
|
|
schedule_timeout_interruptible(stutter * HZ);
|
|
stutter_pause_test = 1;
|
|
if (!kthread_should_stop())
|
|
schedule_timeout_interruptible(stutter * HZ);
|
|
stutter_pause_test = 0;
|
|
rcutorture_shutdown_absorb("rcu_torture_stutter");
|
|
} while (!kthread_should_stop());
|
|
VERBOSE_PRINTK_STRING("rcu_torture_stutter task stopping");
|
|
return 0;
|
|
}
|
|
|
|
static inline void
|
|
rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, char *tag)
|
|
{
|
|
pr_alert("%s" TORTURE_FLAG
|
|
"--- %s: nreaders=%d nfakewriters=%d "
|
|
"stat_interval=%d verbose=%d test_no_idle_hz=%d "
|
|
"shuffle_interval=%d stutter=%d irqreader=%d "
|
|
"fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d "
|
|
"test_boost=%d/%d test_boost_interval=%d "
|
|
"test_boost_duration=%d shutdown_secs=%d "
|
|
"onoff_interval=%d onoff_holdoff=%d\n",
|
|
torture_type, tag, nrealreaders, nfakewriters,
|
|
stat_interval, verbose, test_no_idle_hz, shuffle_interval,
|
|
stutter, irqreader, fqs_duration, fqs_holdoff, fqs_stutter,
|
|
test_boost, cur_ops->can_boost,
|
|
test_boost_interval, test_boost_duration, shutdown_secs,
|
|
onoff_interval, onoff_holdoff);
|
|
}
|
|
|
|
static struct notifier_block rcutorture_shutdown_nb = {
|
|
.notifier_call = rcutorture_shutdown_notify,
|
|
};
|
|
|
|
static void rcutorture_booster_cleanup(int cpu)
|
|
{
|
|
struct task_struct *t;
|
|
|
|
if (boost_tasks[cpu] == NULL)
|
|
return;
|
|
mutex_lock(&boost_mutex);
|
|
VERBOSE_PRINTK_STRING("Stopping rcu_torture_boost task");
|
|
t = boost_tasks[cpu];
|
|
boost_tasks[cpu] = NULL;
|
|
mutex_unlock(&boost_mutex);
|
|
|
|
/* This must be outside of the mutex, otherwise deadlock! */
|
|
kthread_stop(t);
|
|
boost_tasks[cpu] = NULL;
|
|
}
|
|
|
|
static int rcutorture_booster_init(int cpu)
|
|
{
|
|
int retval;
|
|
|
|
if (boost_tasks[cpu] != NULL)
|
|
return 0; /* Already created, nothing more to do. */
|
|
|
|
/* Don't allow time recalculation while creating a new task. */
|
|
mutex_lock(&boost_mutex);
|
|
VERBOSE_PRINTK_STRING("Creating rcu_torture_boost task");
|
|
boost_tasks[cpu] = kthread_create_on_node(rcu_torture_boost, NULL,
|
|
cpu_to_node(cpu),
|
|
"rcu_torture_boost");
|
|
if (IS_ERR(boost_tasks[cpu])) {
|
|
retval = PTR_ERR(boost_tasks[cpu]);
|
|
VERBOSE_PRINTK_STRING("rcu_torture_boost task create failed");
|
|
n_rcu_torture_boost_ktrerror++;
|
|
boost_tasks[cpu] = NULL;
|
|
mutex_unlock(&boost_mutex);
|
|
return retval;
|
|
}
|
|
kthread_bind(boost_tasks[cpu], cpu);
|
|
wake_up_process(boost_tasks[cpu]);
|
|
mutex_unlock(&boost_mutex);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Cause the rcutorture test to shutdown the system after the test has
|
|
* run for the time specified by the shutdown_secs module parameter.
|
|
*/
|
|
static int
|
|
rcu_torture_shutdown(void *arg)
|
|
{
|
|
long delta;
|
|
unsigned long jiffies_snap;
|
|
|
|
VERBOSE_PRINTK_STRING("rcu_torture_shutdown task started");
|
|
jiffies_snap = ACCESS_ONCE(jiffies);
|
|
while (ULONG_CMP_LT(jiffies_snap, shutdown_time) &&
|
|
!kthread_should_stop()) {
|
|
delta = shutdown_time - jiffies_snap;
|
|
if (verbose)
|
|
pr_alert("%s" TORTURE_FLAG
|
|
"rcu_torture_shutdown task: %lu jiffies remaining\n",
|
|
torture_type, delta);
|
|
schedule_timeout_interruptible(delta);
|
|
jiffies_snap = ACCESS_ONCE(jiffies);
|
|
}
|
|
if (kthread_should_stop()) {
|
|
VERBOSE_PRINTK_STRING("rcu_torture_shutdown task stopping");
|
|
return 0;
|
|
}
|
|
|
|
/* OK, shut down the system. */
|
|
|
|
VERBOSE_PRINTK_STRING("rcu_torture_shutdown task shutting down system");
|
|
shutdown_task = NULL; /* Avoid self-kill deadlock. */
|
|
rcu_torture_cleanup(); /* Get the success/failure message. */
|
|
kernel_power_off(); /* Shut down the system. */
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
|
|
/*
|
|
* Execute random CPU-hotplug operations at the interval specified
|
|
* by the onoff_interval.
|
|
*/
|
|
static int __cpuinit
|
|
rcu_torture_onoff(void *arg)
|
|
{
|
|
int cpu;
|
|
unsigned long delta;
|
|
int maxcpu = -1;
|
|
DEFINE_RCU_RANDOM(rand);
|
|
unsigned long starttime;
|
|
|
|
VERBOSE_PRINTK_STRING("rcu_torture_onoff task started");
|
|
for_each_online_cpu(cpu)
|
|
maxcpu = cpu;
|
|
WARN_ON(maxcpu < 0);
|
|
if (onoff_holdoff > 0) {
|
|
VERBOSE_PRINTK_STRING("rcu_torture_onoff begin holdoff");
|
|
schedule_timeout_interruptible(onoff_holdoff * HZ);
|
|
VERBOSE_PRINTK_STRING("rcu_torture_onoff end holdoff");
|
|
}
|
|
while (!kthread_should_stop()) {
|
|
cpu = (rcu_random(&rand) >> 4) % (maxcpu + 1);
|
|
if (cpu_online(cpu) && cpu_is_hotpluggable(cpu)) {
|
|
if (verbose)
|
|
pr_alert("%s" TORTURE_FLAG
|
|
"rcu_torture_onoff task: offlining %d\n",
|
|
torture_type, cpu);
|
|
starttime = jiffies;
|
|
n_offline_attempts++;
|
|
if (cpu_down(cpu) == 0) {
|
|
if (verbose)
|
|
pr_alert("%s" TORTURE_FLAG
|
|
"rcu_torture_onoff task: offlined %d\n",
|
|
torture_type, cpu);
|
|
n_offline_successes++;
|
|
delta = jiffies - starttime;
|
|
sum_offline += delta;
|
|
if (min_offline < 0) {
|
|
min_offline = delta;
|
|
max_offline = delta;
|
|
}
|
|
if (min_offline > delta)
|
|
min_offline = delta;
|
|
if (max_offline < delta)
|
|
max_offline = delta;
|
|
}
|
|
} else if (cpu_is_hotpluggable(cpu)) {
|
|
if (verbose)
|
|
pr_alert("%s" TORTURE_FLAG
|
|
"rcu_torture_onoff task: onlining %d\n",
|
|
torture_type, cpu);
|
|
starttime = jiffies;
|
|
n_online_attempts++;
|
|
if (cpu_up(cpu) == 0) {
|
|
if (verbose)
|
|
pr_alert("%s" TORTURE_FLAG
|
|
"rcu_torture_onoff task: onlined %d\n",
|
|
torture_type, cpu);
|
|
n_online_successes++;
|
|
delta = jiffies - starttime;
|
|
sum_online += delta;
|
|
if (min_online < 0) {
|
|
min_online = delta;
|
|
max_online = delta;
|
|
}
|
|
if (min_online > delta)
|
|
min_online = delta;
|
|
if (max_online < delta)
|
|
max_online = delta;
|
|
}
|
|
}
|
|
schedule_timeout_interruptible(onoff_interval * HZ);
|
|
}
|
|
VERBOSE_PRINTK_STRING("rcu_torture_onoff task stopping");
|
|
return 0;
|
|
}
|
|
|
|
static int __cpuinit
|
|
rcu_torture_onoff_init(void)
|
|
{
|
|
int ret;
|
|
|
|
if (onoff_interval <= 0)
|
|
return 0;
|
|
onoff_task = kthread_run(rcu_torture_onoff, NULL, "rcu_torture_onoff");
|
|
if (IS_ERR(onoff_task)) {
|
|
ret = PTR_ERR(onoff_task);
|
|
onoff_task = NULL;
|
|
return ret;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void rcu_torture_onoff_cleanup(void)
|
|
{
|
|
if (onoff_task == NULL)
|
|
return;
|
|
VERBOSE_PRINTK_STRING("Stopping rcu_torture_onoff task");
|
|
kthread_stop(onoff_task);
|
|
onoff_task = NULL;
|
|
}
|
|
|
|
#else /* #ifdef CONFIG_HOTPLUG_CPU */
|
|
|
|
static int
|
|
rcu_torture_onoff_init(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static void rcu_torture_onoff_cleanup(void)
|
|
{
|
|
}
|
|
|
|
#endif /* #else #ifdef CONFIG_HOTPLUG_CPU */
|
|
|
|
/*
|
|
* CPU-stall kthread. It waits as specified by stall_cpu_holdoff, then
|
|
* induces a CPU stall for the time specified by stall_cpu.
|
|
*/
|
|
static int __cpuinit rcu_torture_stall(void *args)
|
|
{
|
|
unsigned long stop_at;
|
|
|
|
VERBOSE_PRINTK_STRING("rcu_torture_stall task started");
|
|
if (stall_cpu_holdoff > 0) {
|
|
VERBOSE_PRINTK_STRING("rcu_torture_stall begin holdoff");
|
|
schedule_timeout_interruptible(stall_cpu_holdoff * HZ);
|
|
VERBOSE_PRINTK_STRING("rcu_torture_stall end holdoff");
|
|
}
|
|
if (!kthread_should_stop()) {
|
|
stop_at = get_seconds() + stall_cpu;
|
|
/* RCU CPU stall is expected behavior in following code. */
|
|
pr_alert("rcu_torture_stall start.\n");
|
|
rcu_read_lock();
|
|
preempt_disable();
|
|
while (ULONG_CMP_LT(get_seconds(), stop_at))
|
|
continue; /* Induce RCU CPU stall warning. */
|
|
preempt_enable();
|
|
rcu_read_unlock();
|
|
pr_alert("rcu_torture_stall end.\n");
|
|
}
|
|
rcutorture_shutdown_absorb("rcu_torture_stall");
|
|
while (!kthread_should_stop())
|
|
schedule_timeout_interruptible(10 * HZ);
|
|
return 0;
|
|
}
|
|
|
|
/* Spawn CPU-stall kthread, if stall_cpu specified. */
|
|
static int __init rcu_torture_stall_init(void)
|
|
{
|
|
int ret;
|
|
|
|
if (stall_cpu <= 0)
|
|
return 0;
|
|
stall_task = kthread_run(rcu_torture_stall, NULL, "rcu_torture_stall");
|
|
if (IS_ERR(stall_task)) {
|
|
ret = PTR_ERR(stall_task);
|
|
stall_task = NULL;
|
|
return ret;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* Clean up after the CPU-stall kthread, if one was spawned. */
|
|
static void rcu_torture_stall_cleanup(void)
|
|
{
|
|
if (stall_task == NULL)
|
|
return;
|
|
VERBOSE_PRINTK_STRING("Stopping rcu_torture_stall_task.");
|
|
kthread_stop(stall_task);
|
|
stall_task = NULL;
|
|
}
|
|
|
|
/* Callback function for RCU barrier testing. */
|
|
void rcu_torture_barrier_cbf(struct rcu_head *rcu)
|
|
{
|
|
atomic_inc(&barrier_cbs_invoked);
|
|
}
|
|
|
|
/* kthread function to register callbacks used to test RCU barriers. */
|
|
static int rcu_torture_barrier_cbs(void *arg)
|
|
{
|
|
long myid = (long)arg;
|
|
bool lastphase = 0;
|
|
struct rcu_head rcu;
|
|
|
|
init_rcu_head_on_stack(&rcu);
|
|
VERBOSE_PRINTK_STRING("rcu_torture_barrier_cbs task started");
|
|
set_user_nice(current, 19);
|
|
do {
|
|
wait_event(barrier_cbs_wq[myid],
|
|
barrier_phase != lastphase ||
|
|
kthread_should_stop() ||
|
|
fullstop != FULLSTOP_DONTSTOP);
|
|
lastphase = barrier_phase;
|
|
smp_mb(); /* ensure barrier_phase load before ->call(). */
|
|
if (kthread_should_stop() || fullstop != FULLSTOP_DONTSTOP)
|
|
break;
|
|
cur_ops->call(&rcu, rcu_torture_barrier_cbf);
|
|
if (atomic_dec_and_test(&barrier_cbs_count))
|
|
wake_up(&barrier_wq);
|
|
} while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP);
|
|
VERBOSE_PRINTK_STRING("rcu_torture_barrier_cbs task stopping");
|
|
rcutorture_shutdown_absorb("rcu_torture_barrier_cbs");
|
|
while (!kthread_should_stop())
|
|
schedule_timeout_interruptible(1);
|
|
cur_ops->cb_barrier();
|
|
destroy_rcu_head_on_stack(&rcu);
|
|
return 0;
|
|
}
|
|
|
|
/* kthread function to drive and coordinate RCU barrier testing. */
|
|
static int rcu_torture_barrier(void *arg)
|
|
{
|
|
int i;
|
|
|
|
VERBOSE_PRINTK_STRING("rcu_torture_barrier task starting");
|
|
do {
|
|
atomic_set(&barrier_cbs_invoked, 0);
|
|
atomic_set(&barrier_cbs_count, n_barrier_cbs);
|
|
smp_mb(); /* Ensure barrier_phase after prior assignments. */
|
|
barrier_phase = !barrier_phase;
|
|
for (i = 0; i < n_barrier_cbs; i++)
|
|
wake_up(&barrier_cbs_wq[i]);
|
|
wait_event(barrier_wq,
|
|
atomic_read(&barrier_cbs_count) == 0 ||
|
|
kthread_should_stop() ||
|
|
fullstop != FULLSTOP_DONTSTOP);
|
|
if (kthread_should_stop() || fullstop != FULLSTOP_DONTSTOP)
|
|
break;
|
|
n_barrier_attempts++;
|
|
cur_ops->cb_barrier();
|
|
if (atomic_read(&barrier_cbs_invoked) != n_barrier_cbs) {
|
|
n_rcu_torture_barrier_error++;
|
|
WARN_ON_ONCE(1);
|
|
}
|
|
n_barrier_successes++;
|
|
schedule_timeout_interruptible(HZ / 10);
|
|
} while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP);
|
|
VERBOSE_PRINTK_STRING("rcu_torture_barrier task stopping");
|
|
rcutorture_shutdown_absorb("rcu_torture_barrier");
|
|
while (!kthread_should_stop())
|
|
schedule_timeout_interruptible(1);
|
|
return 0;
|
|
}
|
|
|
|
/* Initialize RCU barrier testing. */
|
|
static int rcu_torture_barrier_init(void)
|
|
{
|
|
int i;
|
|
int ret;
|
|
|
|
if (n_barrier_cbs == 0)
|
|
return 0;
|
|
if (cur_ops->call == NULL || cur_ops->cb_barrier == NULL) {
|
|
pr_alert("%s" TORTURE_FLAG
|
|
" Call or barrier ops missing for %s,\n",
|
|
torture_type, cur_ops->name);
|
|
pr_alert("%s" TORTURE_FLAG
|
|
" RCU barrier testing omitted from run.\n",
|
|
torture_type);
|
|
return 0;
|
|
}
|
|
atomic_set(&barrier_cbs_count, 0);
|
|
atomic_set(&barrier_cbs_invoked, 0);
|
|
barrier_cbs_tasks =
|
|
kzalloc(n_barrier_cbs * sizeof(barrier_cbs_tasks[0]),
|
|
GFP_KERNEL);
|
|
barrier_cbs_wq =
|
|
kzalloc(n_barrier_cbs * sizeof(barrier_cbs_wq[0]),
|
|
GFP_KERNEL);
|
|
if (barrier_cbs_tasks == NULL || barrier_cbs_wq == 0)
|
|
return -ENOMEM;
|
|
for (i = 0; i < n_barrier_cbs; i++) {
|
|
init_waitqueue_head(&barrier_cbs_wq[i]);
|
|
barrier_cbs_tasks[i] = kthread_run(rcu_torture_barrier_cbs,
|
|
(void *)(long)i,
|
|
"rcu_torture_barrier_cbs");
|
|
if (IS_ERR(barrier_cbs_tasks[i])) {
|
|
ret = PTR_ERR(barrier_cbs_tasks[i]);
|
|
VERBOSE_PRINTK_ERRSTRING("Failed to create rcu_torture_barrier_cbs");
|
|
barrier_cbs_tasks[i] = NULL;
|
|
return ret;
|
|
}
|
|
}
|
|
barrier_task = kthread_run(rcu_torture_barrier, NULL,
|
|
"rcu_torture_barrier");
|
|
if (IS_ERR(barrier_task)) {
|
|
ret = PTR_ERR(barrier_task);
|
|
VERBOSE_PRINTK_ERRSTRING("Failed to create rcu_torture_barrier");
|
|
barrier_task = NULL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* Clean up after RCU barrier testing. */
|
|
static void rcu_torture_barrier_cleanup(void)
|
|
{
|
|
int i;
|
|
|
|
if (barrier_task != NULL) {
|
|
VERBOSE_PRINTK_STRING("Stopping rcu_torture_barrier task");
|
|
kthread_stop(barrier_task);
|
|
barrier_task = NULL;
|
|
}
|
|
if (barrier_cbs_tasks != NULL) {
|
|
for (i = 0; i < n_barrier_cbs; i++) {
|
|
if (barrier_cbs_tasks[i] != NULL) {
|
|
VERBOSE_PRINTK_STRING("Stopping rcu_torture_barrier_cbs task");
|
|
kthread_stop(barrier_cbs_tasks[i]);
|
|
barrier_cbs_tasks[i] = NULL;
|
|
}
|
|
}
|
|
kfree(barrier_cbs_tasks);
|
|
barrier_cbs_tasks = NULL;
|
|
}
|
|
if (barrier_cbs_wq != NULL) {
|
|
kfree(barrier_cbs_wq);
|
|
barrier_cbs_wq = NULL;
|
|
}
|
|
}
|
|
|
|
static int rcutorture_cpu_notify(struct notifier_block *self,
|
|
unsigned long action, void *hcpu)
|
|
{
|
|
long cpu = (long)hcpu;
|
|
|
|
switch (action) {
|
|
case CPU_ONLINE:
|
|
case CPU_DOWN_FAILED:
|
|
(void)rcutorture_booster_init(cpu);
|
|
break;
|
|
case CPU_DOWN_PREPARE:
|
|
rcutorture_booster_cleanup(cpu);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
static struct notifier_block rcutorture_cpu_nb = {
|
|
.notifier_call = rcutorture_cpu_notify,
|
|
};
|
|
|
|
static void
|
|
rcu_torture_cleanup(void)
|
|
{
|
|
int i;
|
|
|
|
mutex_lock(&fullstop_mutex);
|
|
rcutorture_record_test_transition();
|
|
if (fullstop == FULLSTOP_SHUTDOWN) {
|
|
pr_warn(/* but going down anyway, so... */
|
|
"Concurrent 'rmmod rcutorture' and shutdown illegal!\n");
|
|
mutex_unlock(&fullstop_mutex);
|
|
schedule_timeout_uninterruptible(10);
|
|
if (cur_ops->cb_barrier != NULL)
|
|
cur_ops->cb_barrier();
|
|
return;
|
|
}
|
|
fullstop = FULLSTOP_RMMOD;
|
|
mutex_unlock(&fullstop_mutex);
|
|
unregister_reboot_notifier(&rcutorture_shutdown_nb);
|
|
rcu_torture_barrier_cleanup();
|
|
rcu_torture_stall_cleanup();
|
|
if (stutter_task) {
|
|
VERBOSE_PRINTK_STRING("Stopping rcu_torture_stutter task");
|
|
kthread_stop(stutter_task);
|
|
}
|
|
stutter_task = NULL;
|
|
if (shuffler_task) {
|
|
VERBOSE_PRINTK_STRING("Stopping rcu_torture_shuffle task");
|
|
kthread_stop(shuffler_task);
|
|
free_cpumask_var(shuffle_tmp_mask);
|
|
}
|
|
shuffler_task = NULL;
|
|
|
|
if (writer_task) {
|
|
VERBOSE_PRINTK_STRING("Stopping rcu_torture_writer task");
|
|
kthread_stop(writer_task);
|
|
}
|
|
writer_task = NULL;
|
|
|
|
if (reader_tasks) {
|
|
for (i = 0; i < nrealreaders; i++) {
|
|
if (reader_tasks[i]) {
|
|
VERBOSE_PRINTK_STRING(
|
|
"Stopping rcu_torture_reader task");
|
|
kthread_stop(reader_tasks[i]);
|
|
}
|
|
reader_tasks[i] = NULL;
|
|
}
|
|
kfree(reader_tasks);
|
|
reader_tasks = NULL;
|
|
}
|
|
rcu_torture_current = NULL;
|
|
|
|
if (fakewriter_tasks) {
|
|
for (i = 0; i < nfakewriters; i++) {
|
|
if (fakewriter_tasks[i]) {
|
|
VERBOSE_PRINTK_STRING(
|
|
"Stopping rcu_torture_fakewriter task");
|
|
kthread_stop(fakewriter_tasks[i]);
|
|
}
|
|
fakewriter_tasks[i] = NULL;
|
|
}
|
|
kfree(fakewriter_tasks);
|
|
fakewriter_tasks = NULL;
|
|
}
|
|
|
|
if (stats_task) {
|
|
VERBOSE_PRINTK_STRING("Stopping rcu_torture_stats task");
|
|
kthread_stop(stats_task);
|
|
}
|
|
stats_task = NULL;
|
|
|
|
if (fqs_task) {
|
|
VERBOSE_PRINTK_STRING("Stopping rcu_torture_fqs task");
|
|
kthread_stop(fqs_task);
|
|
}
|
|
fqs_task = NULL;
|
|
if ((test_boost == 1 && cur_ops->can_boost) ||
|
|
test_boost == 2) {
|
|
unregister_cpu_notifier(&rcutorture_cpu_nb);
|
|
for_each_possible_cpu(i)
|
|
rcutorture_booster_cleanup(i);
|
|
}
|
|
if (shutdown_task != NULL) {
|
|
VERBOSE_PRINTK_STRING("Stopping rcu_torture_shutdown task");
|
|
kthread_stop(shutdown_task);
|
|
}
|
|
shutdown_task = NULL;
|
|
rcu_torture_onoff_cleanup();
|
|
|
|
/* Wait for all RCU callbacks to fire. */
|
|
|
|
if (cur_ops->cb_barrier != NULL)
|
|
cur_ops->cb_barrier();
|
|
|
|
rcu_torture_stats_print(); /* -After- the stats thread is stopped! */
|
|
|
|
if (cur_ops->cleanup)
|
|
cur_ops->cleanup();
|
|
if (atomic_read(&n_rcu_torture_error) || n_rcu_torture_barrier_error)
|
|
rcu_torture_print_module_parms(cur_ops, "End of test: FAILURE");
|
|
else if (n_online_successes != n_online_attempts ||
|
|
n_offline_successes != n_offline_attempts)
|
|
rcu_torture_print_module_parms(cur_ops,
|
|
"End of test: RCU_HOTPLUG");
|
|
else
|
|
rcu_torture_print_module_parms(cur_ops, "End of test: SUCCESS");
|
|
}
|
|
|
|
static int __init
|
|
rcu_torture_init(void)
|
|
{
|
|
int i;
|
|
int cpu;
|
|
int firsterr = 0;
|
|
int retval;
|
|
static struct rcu_torture_ops *torture_ops[] =
|
|
{ &rcu_ops, &rcu_sync_ops, &rcu_expedited_ops,
|
|
&rcu_bh_ops, &rcu_bh_sync_ops, &rcu_bh_expedited_ops,
|
|
&srcu_ops, &srcu_sync_ops, &srcu_expedited_ops,
|
|
&srcu_raw_ops, &srcu_raw_sync_ops,
|
|
&sched_ops, &sched_sync_ops, &sched_expedited_ops, };
|
|
|
|
mutex_lock(&fullstop_mutex);
|
|
|
|
/* Process args and tell the world that the torturer is on the job. */
|
|
for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
|
|
cur_ops = torture_ops[i];
|
|
if (strcmp(torture_type, cur_ops->name) == 0)
|
|
break;
|
|
}
|
|
if (i == ARRAY_SIZE(torture_ops)) {
|
|
pr_alert("rcu-torture: invalid torture type: \"%s\"\n",
|
|
torture_type);
|
|
pr_alert("rcu-torture types:");
|
|
for (i = 0; i < ARRAY_SIZE(torture_ops); i++)
|
|
pr_alert(" %s", torture_ops[i]->name);
|
|
pr_alert("\n");
|
|
mutex_unlock(&fullstop_mutex);
|
|
return -EINVAL;
|
|
}
|
|
if (cur_ops->fqs == NULL && fqs_duration != 0) {
|
|
pr_alert("rcu-torture: ->fqs NULL and non-zero fqs_duration, fqs disabled.\n");
|
|
fqs_duration = 0;
|
|
}
|
|
if (cur_ops->init)
|
|
cur_ops->init(); /* no "goto unwind" prior to this point!!! */
|
|
|
|
if (nreaders >= 0)
|
|
nrealreaders = nreaders;
|
|
else
|
|
nrealreaders = 2 * num_online_cpus();
|
|
rcu_torture_print_module_parms(cur_ops, "Start of test");
|
|
fullstop = FULLSTOP_DONTSTOP;
|
|
|
|
/* Set up the freelist. */
|
|
|
|
INIT_LIST_HEAD(&rcu_torture_freelist);
|
|
for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) {
|
|
rcu_tortures[i].rtort_mbtest = 0;
|
|
list_add_tail(&rcu_tortures[i].rtort_free,
|
|
&rcu_torture_freelist);
|
|
}
|
|
|
|
/* Initialize the statistics so that each run gets its own numbers. */
|
|
|
|
rcu_torture_current = NULL;
|
|
rcu_torture_current_version = 0;
|
|
atomic_set(&n_rcu_torture_alloc, 0);
|
|
atomic_set(&n_rcu_torture_alloc_fail, 0);
|
|
atomic_set(&n_rcu_torture_free, 0);
|
|
atomic_set(&n_rcu_torture_mberror, 0);
|
|
atomic_set(&n_rcu_torture_error, 0);
|
|
n_rcu_torture_barrier_error = 0;
|
|
n_rcu_torture_boost_ktrerror = 0;
|
|
n_rcu_torture_boost_rterror = 0;
|
|
n_rcu_torture_boost_failure = 0;
|
|
n_rcu_torture_boosts = 0;
|
|
for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
|
|
atomic_set(&rcu_torture_wcount[i], 0);
|
|
for_each_possible_cpu(cpu) {
|
|
for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
|
|
per_cpu(rcu_torture_count, cpu)[i] = 0;
|
|
per_cpu(rcu_torture_batch, cpu)[i] = 0;
|
|
}
|
|
}
|
|
|
|
/* Start up the kthreads. */
|
|
|
|
VERBOSE_PRINTK_STRING("Creating rcu_torture_writer task");
|
|
writer_task = kthread_create(rcu_torture_writer, NULL,
|
|
"rcu_torture_writer");
|
|
if (IS_ERR(writer_task)) {
|
|
firsterr = PTR_ERR(writer_task);
|
|
VERBOSE_PRINTK_ERRSTRING("Failed to create writer");
|
|
writer_task = NULL;
|
|
goto unwind;
|
|
}
|
|
wake_up_process(writer_task);
|
|
fakewriter_tasks = kzalloc(nfakewriters * sizeof(fakewriter_tasks[0]),
|
|
GFP_KERNEL);
|
|
if (fakewriter_tasks == NULL) {
|
|
VERBOSE_PRINTK_ERRSTRING("out of memory");
|
|
firsterr = -ENOMEM;
|
|
goto unwind;
|
|
}
|
|
for (i = 0; i < nfakewriters; i++) {
|
|
VERBOSE_PRINTK_STRING("Creating rcu_torture_fakewriter task");
|
|
fakewriter_tasks[i] = kthread_run(rcu_torture_fakewriter, NULL,
|
|
"rcu_torture_fakewriter");
|
|
if (IS_ERR(fakewriter_tasks[i])) {
|
|
firsterr = PTR_ERR(fakewriter_tasks[i]);
|
|
VERBOSE_PRINTK_ERRSTRING("Failed to create fakewriter");
|
|
fakewriter_tasks[i] = NULL;
|
|
goto unwind;
|
|
}
|
|
}
|
|
reader_tasks = kzalloc(nrealreaders * sizeof(reader_tasks[0]),
|
|
GFP_KERNEL);
|
|
if (reader_tasks == NULL) {
|
|
VERBOSE_PRINTK_ERRSTRING("out of memory");
|
|
firsterr = -ENOMEM;
|
|
goto unwind;
|
|
}
|
|
for (i = 0; i < nrealreaders; i++) {
|
|
VERBOSE_PRINTK_STRING("Creating rcu_torture_reader task");
|
|
reader_tasks[i] = kthread_run(rcu_torture_reader, NULL,
|
|
"rcu_torture_reader");
|
|
if (IS_ERR(reader_tasks[i])) {
|
|
firsterr = PTR_ERR(reader_tasks[i]);
|
|
VERBOSE_PRINTK_ERRSTRING("Failed to create reader");
|
|
reader_tasks[i] = NULL;
|
|
goto unwind;
|
|
}
|
|
}
|
|
if (stat_interval > 0) {
|
|
VERBOSE_PRINTK_STRING("Creating rcu_torture_stats task");
|
|
stats_task = kthread_run(rcu_torture_stats, NULL,
|
|
"rcu_torture_stats");
|
|
if (IS_ERR(stats_task)) {
|
|
firsterr = PTR_ERR(stats_task);
|
|
VERBOSE_PRINTK_ERRSTRING("Failed to create stats");
|
|
stats_task = NULL;
|
|
goto unwind;
|
|
}
|
|
}
|
|
if (test_no_idle_hz) {
|
|
rcu_idle_cpu = num_online_cpus() - 1;
|
|
|
|
if (!alloc_cpumask_var(&shuffle_tmp_mask, GFP_KERNEL)) {
|
|
firsterr = -ENOMEM;
|
|
VERBOSE_PRINTK_ERRSTRING("Failed to alloc mask");
|
|
goto unwind;
|
|
}
|
|
|
|
/* Create the shuffler thread */
|
|
shuffler_task = kthread_run(rcu_torture_shuffle, NULL,
|
|
"rcu_torture_shuffle");
|
|
if (IS_ERR(shuffler_task)) {
|
|
free_cpumask_var(shuffle_tmp_mask);
|
|
firsterr = PTR_ERR(shuffler_task);
|
|
VERBOSE_PRINTK_ERRSTRING("Failed to create shuffler");
|
|
shuffler_task = NULL;
|
|
goto unwind;
|
|
}
|
|
}
|
|
if (stutter < 0)
|
|
stutter = 0;
|
|
if (stutter) {
|
|
/* Create the stutter thread */
|
|
stutter_task = kthread_run(rcu_torture_stutter, NULL,
|
|
"rcu_torture_stutter");
|
|
if (IS_ERR(stutter_task)) {
|
|
firsterr = PTR_ERR(stutter_task);
|
|
VERBOSE_PRINTK_ERRSTRING("Failed to create stutter");
|
|
stutter_task = NULL;
|
|
goto unwind;
|
|
}
|
|
}
|
|
if (fqs_duration < 0)
|
|
fqs_duration = 0;
|
|
if (fqs_duration) {
|
|
/* Create the stutter thread */
|
|
fqs_task = kthread_run(rcu_torture_fqs, NULL,
|
|
"rcu_torture_fqs");
|
|
if (IS_ERR(fqs_task)) {
|
|
firsterr = PTR_ERR(fqs_task);
|
|
VERBOSE_PRINTK_ERRSTRING("Failed to create fqs");
|
|
fqs_task = NULL;
|
|
goto unwind;
|
|
}
|
|
}
|
|
if (test_boost_interval < 1)
|
|
test_boost_interval = 1;
|
|
if (test_boost_duration < 2)
|
|
test_boost_duration = 2;
|
|
if ((test_boost == 1 && cur_ops->can_boost) ||
|
|
test_boost == 2) {
|
|
|
|
boost_starttime = jiffies + test_boost_interval * HZ;
|
|
register_cpu_notifier(&rcutorture_cpu_nb);
|
|
for_each_possible_cpu(i) {
|
|
if (cpu_is_offline(i))
|
|
continue; /* Heuristic: CPU can go offline. */
|
|
retval = rcutorture_booster_init(i);
|
|
if (retval < 0) {
|
|
firsterr = retval;
|
|
goto unwind;
|
|
}
|
|
}
|
|
}
|
|
if (shutdown_secs > 0) {
|
|
shutdown_time = jiffies + shutdown_secs * HZ;
|
|
shutdown_task = kthread_create(rcu_torture_shutdown, NULL,
|
|
"rcu_torture_shutdown");
|
|
if (IS_ERR(shutdown_task)) {
|
|
firsterr = PTR_ERR(shutdown_task);
|
|
VERBOSE_PRINTK_ERRSTRING("Failed to create shutdown");
|
|
shutdown_task = NULL;
|
|
goto unwind;
|
|
}
|
|
wake_up_process(shutdown_task);
|
|
}
|
|
i = rcu_torture_onoff_init();
|
|
if (i != 0) {
|
|
firsterr = i;
|
|
goto unwind;
|
|
}
|
|
register_reboot_notifier(&rcutorture_shutdown_nb);
|
|
i = rcu_torture_stall_init();
|
|
if (i != 0) {
|
|
firsterr = i;
|
|
goto unwind;
|
|
}
|
|
retval = rcu_torture_barrier_init();
|
|
if (retval != 0) {
|
|
firsterr = retval;
|
|
goto unwind;
|
|
}
|
|
rcutorture_record_test_transition();
|
|
mutex_unlock(&fullstop_mutex);
|
|
return 0;
|
|
|
|
unwind:
|
|
mutex_unlock(&fullstop_mutex);
|
|
rcu_torture_cleanup();
|
|
return firsterr;
|
|
}
|
|
|
|
module_init(rcu_torture_init);
|
|
module_exit(rcu_torture_cleanup);
|