[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit
Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/os/linux/linux-3.4.x/kernel/rcutorture.c b/ap/os/linux/linux-3.4.x/kernel/rcutorture.c
new file mode 100644
index 0000000..8de0030
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/kernel/rcutorture.c
@@ -0,0 +1,1921 @@
+/*
+ * Read-Copy Update module-based torture test facility
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Copyright (C) IBM Corporation, 2005, 2006
+ *
+ * Authors: Paul E. McKenney <paulmck@us.ibm.com>
+ * Josh Triplett <josh@freedesktop.org>
+ *
+ * See also: Documentation/RCU/torture.txt
+ */
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kthread.h>
+#include <linux/err.h>
+#include <linux/spinlock.h>
+#include <linux/smp.h>
+#include <linux/rcupdate.h>
+#include <linux/interrupt.h>
+#include <linux/sched.h>
+#include <linux/atomic.h>
+#include <linux/bitops.h>
+#include <linux/completion.h>
+#include <linux/moduleparam.h>
+#include <linux/percpu.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/freezer.h>
+#include <linux/cpu.h>
+#include <linux/delay.h>
+#include <linux/stat.h>
+#include <linux/srcu.h>
+#include <linux/slab.h>
+#include <asm/byteorder.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and "
+ "Josh Triplett <josh@freedesktop.org>");
+
+static int nreaders = -1; /* # reader threads, defaults to 2*ncpus */
+static int nfakewriters = 4; /* # fake writer threads */
+static int stat_interval; /* Interval between stats, in seconds. */
+ /* Defaults to "only at end of test". */
+static bool verbose; /* Print more debug info. */
+static bool test_no_idle_hz; /* Test RCU's support for tickless idle CPUs. */
+static int shuffle_interval = 3; /* Interval between shuffles (in sec)*/
+static int stutter = 5; /* Start/stop testing interval (in sec) */
+static int irqreader = 1; /* RCU readers from irq (timers). */
+static int fqs_duration; /* Duration of bursts (us), 0 to disable. */
+static int fqs_holdoff; /* Hold time within burst (us). */
+static int fqs_stutter = 3; /* Wait time between bursts (s). */
+static int onoff_interval; /* Wait time between CPU hotplugs, 0=disable. */
+static int onoff_holdoff; /* Seconds after boot before CPU hotplugs. */
+static int shutdown_secs; /* Shutdown time (s). <=0 for no shutdown. */
+static int stall_cpu; /* CPU-stall duration (s). 0 for no stall. */
+static int stall_cpu_holdoff = 10; /* Time to wait until stall (s). */
+static int test_boost = 1; /* Test RCU prio boost: 0=no, 1=maybe, 2=yes. */
+static int test_boost_interval = 7; /* Interval between boost tests, seconds. */
+static int test_boost_duration = 4; /* Duration of each boost test, seconds. */
+static char *torture_type = "rcu"; /* What RCU implementation to torture. */
+
+module_param(nreaders, int, 0444);
+MODULE_PARM_DESC(nreaders, "Number of RCU reader threads");
+module_param(nfakewriters, int, 0444);
+MODULE_PARM_DESC(nfakewriters, "Number of RCU fake writer threads");
+module_param(stat_interval, int, 0644);
+MODULE_PARM_DESC(stat_interval, "Number of seconds between stats printk()s");
+module_param(verbose, bool, 0444);
+MODULE_PARM_DESC(verbose, "Enable verbose debugging printk()s");
+module_param(test_no_idle_hz, bool, 0444);
+MODULE_PARM_DESC(test_no_idle_hz, "Test support for tickless idle CPUs");
+module_param(shuffle_interval, int, 0444);
+MODULE_PARM_DESC(shuffle_interval, "Number of seconds between shuffles");
+module_param(stutter, int, 0444);
+MODULE_PARM_DESC(stutter, "Number of seconds to run/halt test");
+module_param(irqreader, int, 0444);
+MODULE_PARM_DESC(irqreader, "Allow RCU readers from irq handlers");
+module_param(fqs_duration, int, 0444);
+MODULE_PARM_DESC(fqs_duration, "Duration of fqs bursts (us)");
+module_param(fqs_holdoff, int, 0444);
+MODULE_PARM_DESC(fqs_holdoff, "Holdoff time within fqs bursts (us)");
+module_param(fqs_stutter, int, 0444);
+MODULE_PARM_DESC(fqs_stutter, "Wait time between fqs bursts (s)");
+module_param(onoff_interval, int, 0444);
+MODULE_PARM_DESC(onoff_interval, "Time between CPU hotplugs (s), 0=disable");
+module_param(onoff_holdoff, int, 0444);
+MODULE_PARM_DESC(onoff_holdoff, "Time after boot before CPU hotplugs (s)");
+module_param(shutdown_secs, int, 0444);
+MODULE_PARM_DESC(shutdown_secs, "Shutdown time (s), zero to disable.");
+module_param(stall_cpu, int, 0444);
+MODULE_PARM_DESC(stall_cpu, "Stall duration (s), zero to disable.");
+module_param(stall_cpu_holdoff, int, 0444);
+MODULE_PARM_DESC(stall_cpu_holdoff, "Time to wait before starting stall (s).");
+module_param(test_boost, int, 0444);
+MODULE_PARM_DESC(test_boost, "Test RCU prio boost: 0=no, 1=maybe, 2=yes.");
+module_param(test_boost_interval, int, 0444);
+MODULE_PARM_DESC(test_boost_interval, "Interval between boost tests, seconds.");
+module_param(test_boost_duration, int, 0444);
+MODULE_PARM_DESC(test_boost_duration, "Duration of each boost test, seconds.");
+module_param(torture_type, charp, 0444);
+MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, srcu)");
+
+#define TORTURE_FLAG "-torture:"
+#define PRINTK_STRING(s) \
+ do { printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0)
+#define VERBOSE_PRINTK_STRING(s) \
+ do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0)
+#define VERBOSE_PRINTK_ERRSTRING(s) \
+ do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG "!!! " s "\n", torture_type); } while (0)
+
+static char printk_buf[4096];
+
+static int nrealreaders;
+static struct task_struct *writer_task;
+static struct task_struct **fakewriter_tasks;
+static struct task_struct **reader_tasks;
+static struct task_struct *stats_task;
+static struct task_struct *shuffler_task;
+static struct task_struct *stutter_task;
+static struct task_struct *fqs_task;
+static struct task_struct *boost_tasks[NR_CPUS];
+static struct task_struct *shutdown_task;
+#ifdef CONFIG_HOTPLUG_CPU
+static struct task_struct *onoff_task;
+#endif /* #ifdef CONFIG_HOTPLUG_CPU */
+static struct task_struct *stall_task;
+
+#define RCU_TORTURE_PIPE_LEN 10
+
+struct rcu_torture {
+ struct rcu_head rtort_rcu;
+ int rtort_pipe_count;
+ struct list_head rtort_free;
+ int rtort_mbtest;
+};
+
+static LIST_HEAD(rcu_torture_freelist);
+static struct rcu_torture __rcu *rcu_torture_current;
+static unsigned long rcu_torture_current_version;
+static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN];
+static DEFINE_SPINLOCK(rcu_torture_lock);
+static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count) =
+ { 0 };
+static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch) =
+ { 0 };
+static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1];
+static atomic_t n_rcu_torture_alloc;
+static atomic_t n_rcu_torture_alloc_fail;
+static atomic_t n_rcu_torture_free;
+static atomic_t n_rcu_torture_mberror;
+static atomic_t n_rcu_torture_error;
+static long n_rcu_torture_boost_ktrerror;
+static long n_rcu_torture_boost_rterror;
+static long n_rcu_torture_boost_failure;
+static long n_rcu_torture_boosts;
+static long n_rcu_torture_timers;
+static long n_offline_attempts;
+static long n_offline_successes;
+static long n_online_attempts;
+static long n_online_successes;
+static struct list_head rcu_torture_removed;
+static cpumask_var_t shuffle_tmp_mask;
+
+static int stutter_pause_test;
+
+#if defined(MODULE) || defined(CONFIG_RCU_TORTURE_TEST_RUNNABLE)
+#define RCUTORTURE_RUNNABLE_INIT 1
+#else
+#define RCUTORTURE_RUNNABLE_INIT 0
+#endif
+int rcutorture_runnable = RCUTORTURE_RUNNABLE_INIT;
+module_param(rcutorture_runnable, int, 0444);
+MODULE_PARM_DESC(rcutorture_runnable, "Start rcutorture at boot");
+
+#if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU)
+#define rcu_can_boost() 1
+#else /* #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */
+#define rcu_can_boost() 0
+#endif /* #else #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */
+
+static unsigned long shutdown_time; /* jiffies to system shutdown. */
+static unsigned long boost_starttime; /* jiffies of next boost test start. */
+DEFINE_MUTEX(boost_mutex); /* protect setting boost_starttime */
+ /* and boost task create/destroy. */
+
+/* Mediate rmmod and system shutdown. Concurrent rmmod & shutdown illegal! */
+
+#define FULLSTOP_DONTSTOP 0 /* Normal operation. */
+#define FULLSTOP_SHUTDOWN 1 /* System shutdown with rcutorture running. */
+#define FULLSTOP_RMMOD 2 /* Normal rmmod of rcutorture. */
+static int fullstop = FULLSTOP_RMMOD;
+/*
+ * Protect fullstop transitions and spawning of kthreads.
+ */
+static DEFINE_MUTEX(fullstop_mutex);
+
+/* Forward reference. */
+static void rcu_torture_cleanup(void);
+
+/*
+ * Detect and respond to a system shutdown.
+ */
+static int
+rcutorture_shutdown_notify(struct notifier_block *unused1,
+ unsigned long unused2, void *unused3)
+{
+ mutex_lock(&fullstop_mutex);
+ if (fullstop == FULLSTOP_DONTSTOP)
+ fullstop = FULLSTOP_SHUTDOWN;
+ else
+ printk(KERN_WARNING /* but going down anyway, so... */
+ "Concurrent 'rmmod rcutorture' and shutdown illegal!\n");
+ mutex_unlock(&fullstop_mutex);
+ return NOTIFY_DONE;
+}
+
+/*
+ * Absorb kthreads into a kernel function that won't return, so that
+ * they won't ever access module text or data again.
+ */
+static void rcutorture_shutdown_absorb(char *title)
+{
+ if (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) {
+ printk(KERN_NOTICE
+ "rcutorture thread %s parking due to system shutdown\n",
+ title);
+ schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT);
+ }
+}
+
+/*
+ * Allocate an element from the rcu_tortures pool.
+ */
+static struct rcu_torture *
+rcu_torture_alloc(void)
+{
+ struct list_head *p;
+
+ spin_lock_bh(&rcu_torture_lock);
+ if (list_empty(&rcu_torture_freelist)) {
+ atomic_inc(&n_rcu_torture_alloc_fail);
+ spin_unlock_bh(&rcu_torture_lock);
+ return NULL;
+ }
+ atomic_inc(&n_rcu_torture_alloc);
+ p = rcu_torture_freelist.next;
+ list_del_init(p);
+ spin_unlock_bh(&rcu_torture_lock);
+ return container_of(p, struct rcu_torture, rtort_free);
+}
+
+/*
+ * Free an element to the rcu_tortures pool.
+ */
+static void
+rcu_torture_free(struct rcu_torture *p)
+{
+ atomic_inc(&n_rcu_torture_free);
+ spin_lock_bh(&rcu_torture_lock);
+ list_add_tail(&p->rtort_free, &rcu_torture_freelist);
+ spin_unlock_bh(&rcu_torture_lock);
+}
+
+struct rcu_random_state {
+ unsigned long rrs_state;
+ long rrs_count;
+};
+
+#define RCU_RANDOM_MULT 39916801 /* prime */
+#define RCU_RANDOM_ADD 479001701 /* prime */
+#define RCU_RANDOM_REFRESH 10000
+
+#define DEFINE_RCU_RANDOM(name) struct rcu_random_state name = { 0, 0 }
+
+/*
+ * Crude but fast random-number generator. Uses a linear congruential
+ * generator, with occasional help from cpu_clock().
+ */
+static unsigned long
+rcu_random(struct rcu_random_state *rrsp)
+{
+ if (--rrsp->rrs_count < 0) {
+ rrsp->rrs_state += (unsigned long)local_clock();
+ rrsp->rrs_count = RCU_RANDOM_REFRESH;
+ }
+ rrsp->rrs_state = rrsp->rrs_state * RCU_RANDOM_MULT + RCU_RANDOM_ADD;
+ return swahw32(rrsp->rrs_state);
+}
+
+static void
+rcu_stutter_wait(char *title)
+{
+ while (stutter_pause_test || !rcutorture_runnable) {
+ if (rcutorture_runnable)
+ schedule_timeout_interruptible(1);
+ else
+ schedule_timeout_interruptible(round_jiffies_relative(HZ));
+ rcutorture_shutdown_absorb(title);
+ }
+}
+
+/*
+ * Operations vector for selecting different types of tests.
+ */
+
+struct rcu_torture_ops {
+ void (*init)(void);
+ void (*cleanup)(void);
+ int (*readlock)(void);
+ void (*read_delay)(struct rcu_random_state *rrsp);
+ void (*readunlock)(int idx);
+ int (*completed)(void);
+ void (*deferred_free)(struct rcu_torture *p);
+ void (*sync)(void);
+ void (*cb_barrier)(void);
+ void (*fqs)(void);
+ int (*stats)(char *page);
+ int irq_capable;
+ int can_boost;
+ char *name;
+};
+
+static struct rcu_torture_ops *cur_ops;
+
+/*
+ * Definitions for rcu torture testing.
+ */
+
+static int rcu_torture_read_lock(void) __acquires(RCU)
+{
+ rcu_read_lock();
+ return 0;
+}
+
+static void rcu_read_delay(struct rcu_random_state *rrsp)
+{
+ const unsigned long shortdelay_us = 200;
+ const unsigned long longdelay_ms = 50;
+
+ /* We want a short delay sometimes to make a reader delay the grace
+ * period, and we want a long delay occasionally to trigger
+ * force_quiescent_state. */
+
+ if (!(rcu_random(rrsp) % (nrealreaders * 2000 * longdelay_ms)))
+ mdelay(longdelay_ms);
+ if (!(rcu_random(rrsp) % (nrealreaders * 2 * shortdelay_us)))
+ udelay(shortdelay_us);
+#ifdef CONFIG_PREEMPT
+ if (!preempt_count() && !(rcu_random(rrsp) % (nrealreaders * 20000)))
+ preempt_schedule(); /* No QS if preempt_disable() in effect */
+#endif
+}
+
+static void rcu_torture_read_unlock(int idx) __releases(RCU)
+{
+ rcu_read_unlock();
+}
+
+static int rcu_torture_completed(void)
+{
+ return rcu_batches_completed();
+}
+
+static void
+rcu_torture_cb(struct rcu_head *p)
+{
+ int i;
+ struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu);
+
+ if (fullstop != FULLSTOP_DONTSTOP) {
+ /* Test is ending, just drop callbacks on the floor. */
+ /* The next initialization will pick up the pieces. */
+ return;
+ }
+ 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;
+ rcu_torture_free(rp);
+ } 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,
+ .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,
+ .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,
+ .cb_barrier = NULL,
+ .fqs = rcu_force_quiescent_state,
+ .stats = NULL,
+ .irq_capable = 1,
+ .can_boost = rcu_can_boost(),
+ .name = "rcu_expedited"
+};
+
+#ifndef CONFIG_PREEMPT_RT_FULL
+/*
+ * 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,
+ .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,
+ .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,
+ .cb_barrier = NULL,
+ .fqs = rcu_bh_force_quiescent_state,
+ .stats = NULL,
+ .irq_capable = 1,
+ .name = "rcu_bh_expedited"
+};
+
+#else
+static struct rcu_torture_ops rcu_bh_ops = {
+ .ttype = INVALID_RCU_FLAVOR,
+};
+#endif
+
+/*
+ * 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_synchronize(void)
+{
+ synchronize_srcu(&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(%d,%d)", 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 = rcu_sync_torture_deferred_free,
+ .sync = srcu_torture_synchronize,
+ .cb_barrier = NULL,
+ .stats = srcu_torture_stats,
+ .name = "srcu"
+};
+
+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 = rcu_sync_torture_deferred_free,
+ .sync = srcu_torture_synchronize,
+ .cb_barrier = NULL,
+ .stats = srcu_torture_stats,
+ .name = "srcu_raw"
+};
+
+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,
+ .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);
+ 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 "
+ "rtmbe: %d rtbke: %ld rtbre: %ld "
+ "rtbf: %ld rtb: %ld nt: %ld "
+ "onoff: %ld/%ld:%ld/%ld",
+ 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),
+ atomic_read(&n_rcu_torture_mberror),
+ n_rcu_torture_boost_ktrerror,
+ n_rcu_torture_boost_rterror,
+ n_rcu_torture_boost_failure,
+ n_rcu_torture_boosts,
+ n_rcu_torture_timers,
+ n_online_successes,
+ n_online_attempts,
+ n_offline_successes,
+ n_offline_attempts);
+ if (atomic_read(&n_rcu_torture_mberror) != 0 ||
+ n_rcu_torture_boost_ktrerror != 0 ||
+ n_rcu_torture_boost_rterror != 0 ||
+ n_rcu_torture_boost_failure != 0)
+ cnt += sprintf(&page[cnt], " !!!");
+ cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG);
+ if (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);
+ printk(KERN_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)
+{
+ printk(KERN_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);
+}
+
+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)
+ printk(KERN_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;
+ int maxcpu = -1;
+ DEFINE_RCU_RANDOM(rand);
+
+ 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)
+ printk(KERN_ALERT "%s" TORTURE_FLAG
+ "rcu_torture_onoff task: offlining %d\n",
+ torture_type, cpu);
+ n_offline_attempts++;
+ if (cpu_down(cpu) == 0) {
+ if (verbose)
+ printk(KERN_ALERT "%s" TORTURE_FLAG
+ "rcu_torture_onoff task: "
+ "offlined %d\n",
+ torture_type, cpu);
+ n_offline_successes++;
+ }
+ } else if (cpu_is_hotpluggable(cpu)) {
+ if (verbose)
+ printk(KERN_ALERT "%s" TORTURE_FLAG
+ "rcu_torture_onoff task: onlining %d\n",
+ torture_type, cpu);
+ n_online_attempts++;
+ if (cpu_up(cpu) == 0) {
+ if (verbose)
+ printk(KERN_ALERT "%s" TORTURE_FLAG
+ "rcu_torture_onoff task: "
+ "onlined %d\n",
+ torture_type, cpu);
+ n_online_successes++;
+ }
+ }
+ 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);
+}
+
+#else /* #ifdef CONFIG_HOTPLUG_CPU */
+
+static void
+rcu_torture_onoff_init(void)
+{
+}
+
+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. */
+ printk(KERN_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();
+ printk(KERN_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);
+}
+
+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) {
+ printk(KERN_WARNING /* 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_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);
+ }
+ 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))
+ 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;
+ 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_raw_ops, &srcu_expedited_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)) {
+ printk(KERN_ALERT "rcu-torture: invalid torture type: \"%s\"\n",
+ torture_type);
+ printk(KERN_ALERT "rcu-torture types:");
+ for (i = 0; i < ARRAY_SIZE(torture_ops); i++)
+ printk(KERN_ALERT " %s", torture_ops[i]->name);
+ printk(KERN_ALERT "\n");
+ mutex_unlock(&fullstop_mutex);
+ return -EINVAL;
+ }
+ if (cur_ops->fqs == NULL && fqs_duration != 0) {
+ printk(KERN_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_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_run(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;
+ }
+ 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) {
+ int retval;
+
+ 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_run(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;
+ }
+ }
+ rcu_torture_onoff_init();
+ register_reboot_notifier(&rcutorture_shutdown_nb);
+ rcu_torture_stall_init();
+ 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);