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Subject[PATCH 3/7] Move rcutorture to tests/
From: Ananth N Mavinakayanahalli <ananth@in.ibm.com>

Move the rcutorture infrastructure to tests/

Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
---
kernel/rcutorture.c | 995 ----------------------------------------------------
kernel/Makefile | 1
lib/Kconfig.debug | 13
tests/Kconfig | 13
tests/Makefile | 1
tests/rcutorture.c | 995 ++++++++++++++++++++++++++++++++++++++++++++++++++++
6 files changed, 1009 insertions(+), 1009 deletions(-)
Index: linux-2.6.24-rc6/kernel/Makefile
===================================================================
--- linux-2.6.24-rc6.orig/kernel/Makefile
+++ linux-2.6.24-rc6/kernel/Makefile
@@ -56,7 +56,6 @@ obj-$(CONFIG_DETECT_SOFTLOCKUP) += softl
obj-$(CONFIG_GENERIC_HARDIRQS) += irq/
obj-$(CONFIG_SECCOMP) += seccomp.o
obj-$(CONFIG_DEBUG_SYNCHRO_TEST) += synchro-test.o
-obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o
obj-$(CONFIG_CLASSIC_RCU) += rcuclassic.o
obj-$(CONFIG_PREEMPT_RCU) += rcupreempt.o
ifeq ($(CONFIG_PREEMPT_RCU),y)
Index: linux-2.6.24-rc6/kernel/rcutorture.c
===================================================================
--- linux-2.6.24-rc6.orig/kernel/rcutorture.c
+++ /dev/null
@@ -1,995 +0,0 @@
-/*
- * 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 <asm/atomic.h>
-#include <linux/bitops.h>
-#include <linux/completion.h>
-#include <linux/moduleparam.h>
-#include <linux/percpu.h>
-#include <linux/notifier.h>
-#include <linux/freezer.h>
-#include <linux/cpu.h>
-#include <linux/delay.h>
-#include <linux/byteorder/swabb.h>
-#include <linux/stat.h>
-#include <linux/srcu.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 int verbose; /* Print more debug info. */
-static int test_no_idle_hz; /* Test RCU's support for tickless idle CPUs. */
-static int shuffle_interval = 5; /* Interval between shuffles (in sec)*/
-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, 0444);
-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(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;
-
-#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 int fullstop = 0; /* stop generating callbacks at test end. */
-static LIST_HEAD(rcu_torture_freelist);
-static struct rcu_torture *rcu_torture_current = NULL;
-static long rcu_torture_current_version = 0;
-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 struct list_head rcu_torture_removed;
-
-/*
- * 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)cpu_clock(raw_smp_processor_id());
- rrsp->rrs_count = RCU_RANDOM_REFRESH;
- }
- rrsp->rrs_state = rrsp->rrs_state * RCU_RANDOM_MULT + RCU_RANDOM_ADD;
- return swahw32(rrsp->rrs_state);
-}
-
-/*
- * Operations vector for selecting different types of tests.
- */
-
-struct rcu_torture_ops {
- void (*init)(void);
- void (*cleanup)(void);
- int (*readlock)(void);
- void (*readdelay)(struct rcu_random_state *rrsp);
- void (*readunlock)(int idx);
- int (*completed)(void);
- void (*deferredfree)(struct rcu_torture *p);
- void (*sync)(void);
- int (*stats)(char *page);
- char *name;
-};
-static struct rcu_torture_ops *cur_ops = NULL;
-
-/*
- * 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)
-{
- long delay;
- const long longdelay = 200;
-
- /* We want there to be long-running readers, but not all the time. */
-
- delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay);
- if (!delay)
- udelay(longdelay);
-}
-
-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) {
- /* 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->deferredfree(rp);
-}
-
-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,
- .readdelay = rcu_read_delay,
- .readunlock = rcu_torture_read_unlock,
- .completed = rcu_torture_completed,
- .deferredfree = rcu_torture_deferred_free,
- .sync = synchronize_rcu,
- .stats = NULL,
- .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,
- .readdelay = rcu_read_delay,
- .readunlock = rcu_torture_read_unlock,
- .completed = rcu_torture_completed,
- .deferredfree = rcu_sync_torture_deferred_free,
- .sync = synchronize_rcu,
- .stats = NULL,
- .name = "rcu_sync"
-};
-
-/*
- * 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);
-}
-
-struct rcu_bh_torture_synchronize {
- struct rcu_head head;
- struct completion completion;
-};
-
-static void rcu_bh_torture_wakeme_after_cb(struct rcu_head *head)
-{
- struct rcu_bh_torture_synchronize *rcu;
-
- rcu = container_of(head, struct rcu_bh_torture_synchronize, head);
- complete(&rcu->completion);
-}
-
-static void rcu_bh_torture_synchronize(void)
-{
- struct rcu_bh_torture_synchronize rcu;
-
- init_completion(&rcu.completion);
- call_rcu_bh(&rcu.head, rcu_bh_torture_wakeme_after_cb);
- wait_for_completion(&rcu.completion);
-}
-
-static struct rcu_torture_ops rcu_bh_ops = {
- .init = NULL,
- .cleanup = NULL,
- .readlock = rcu_bh_torture_read_lock,
- .readdelay = rcu_read_delay, /* just reuse rcu's version. */
- .readunlock = rcu_bh_torture_read_unlock,
- .completed = rcu_bh_torture_completed,
- .deferredfree = rcu_bh_torture_deferred_free,
- .sync = rcu_bh_torture_synchronize,
- .stats = NULL,
- .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,
- .readdelay = rcu_read_delay, /* just reuse rcu's version. */
- .readunlock = rcu_bh_torture_read_unlock,
- .completed = rcu_bh_torture_completed,
- .deferredfree = rcu_sync_torture_deferred_free,
- .sync = rcu_bh_torture_synchronize,
- .stats = NULL,
- .name = "rcu_bh_sync"
-};
-
-/*
- * 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);
-}
-
-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,
- .readdelay = srcu_read_delay,
- .readunlock = srcu_torture_read_unlock,
- .completed = srcu_torture_completed,
- .deferredfree = rcu_sync_torture_deferred_free,
- .sync = srcu_torture_synchronize,
- .stats = srcu_torture_stats,
- .name = "srcu"
-};
-
-/*
- * 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 int sched_torture_completed(void)
-{
- return 0;
-}
-
-static void sched_torture_synchronize(void)
-{
- synchronize_sched();
-}
-
-static struct rcu_torture_ops sched_ops = {
- .init = rcu_sync_torture_init,
- .cleanup = NULL,
- .readlock = sched_torture_read_lock,
- .readdelay = rcu_read_delay, /* just reuse rcu's version. */
- .readunlock = sched_torture_read_unlock,
- .completed = sched_torture_completed,
- .deferredfree = rcu_sync_torture_deferred_free,
- .sync = sched_torture_synchronize,
- .stats = NULL,
- .name = "sched"
-};
-
-/*
- * 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);
- if ((rp = rcu_torture_alloc()) == NULL)
- continue;
- rp->rtort_pipe_count = 0;
- udelay(rcu_random(&rand) & 0x3ff);
- old_rp = rcu_torture_current;
- rp->rtort_mbtest = 1;
- rcu_assign_pointer(rcu_torture_current, rp);
- smp_wmb();
- 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->deferredfree(old_rp);
- }
- rcu_torture_current_version++;
- oldbatch = cur_ops->completed();
- } while (!kthread_should_stop() && !fullstop);
- VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping");
- 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();
- } while (!kthread_should_stop() && !fullstop);
-
- VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task stopping");
- while (!kthread_should_stop())
- schedule_timeout_uninterruptible(1);
- return 0;
-}
-
-/*
- * 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;
-
- VERBOSE_PRINTK_STRING("rcu_torture_reader task started");
- set_user_nice(current, 19);
-
- do {
- idx = cur_ops->readlock();
- completed = cur_ops->completed();
- p = rcu_dereference(rcu_torture_current);
- if (p == NULL) {
- /* Wait for rcu_torture_writer to get underway */
- cur_ops->readunlock(idx);
- schedule_timeout_interruptible(HZ);
- continue;
- }
- if (p->rtort_mbtest == 0)
- atomic_inc(&n_rcu_torture_mberror);
- cur_ops->readdelay(&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;
- }
- ++__get_cpu_var(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;
- }
- ++__get_cpu_var(rcu_torture_batch)[completed];
- preempt_enable();
- cur_ops->readunlock(idx);
- schedule();
- } while (!kthread_should_stop() && !fullstop);
- VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping");
- 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: %ld tfle: %d rta: %d rtaf: %d rtf: %d "
- "rtmbe: %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),
- atomic_read(&n_rcu_torture_mberror));
- if (atomic_read(&n_rcu_torture_mberror) != 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);
- }
- 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();
- } 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)
-{
- cpumask_t tmp_mask = CPU_MASK_ALL;
- int i;
-
- 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)
- cpu_clear(rcu_idle_cpu, tmp_mask);
-
- set_cpus_allowed(current, tmp_mask);
-
- if (reader_tasks) {
- for (i = 0; i < nrealreaders; i++)
- if (reader_tasks[i])
- set_cpus_allowed(reader_tasks[i], tmp_mask);
- }
-
- if (fakewriter_tasks) {
- for (i = 0; i < nfakewriters; i++)
- if (fakewriter_tasks[i])
- set_cpus_allowed(fakewriter_tasks[i], tmp_mask);
- }
-
- if (writer_task)
- set_cpus_allowed(writer_task, tmp_mask);
-
- if (stats_task)
- set_cpus_allowed(stats_task, 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();
- } while (!kthread_should_stop());
- VERBOSE_PRINTK_STRING("rcu_torture_shuffle task stopping");
- return 0;
-}
-
-static inline void
-rcu_torture_print_module_parms(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\n",
- torture_type, tag, nrealreaders, nfakewriters,
- stat_interval, verbose, test_no_idle_hz, shuffle_interval);
-}
-
-static void
-rcu_torture_cleanup(void)
-{
- int i;
-
- fullstop = 1;
- if (shuffler_task) {
- VERBOSE_PRINTK_STRING("Stopping rcu_torture_shuffle task");
- kthread_stop(shuffler_task);
- }
- 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;
-
- /* Wait for all RCU callbacks to fire. */
- rcu_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("End of test: FAILURE");
- else
- rcu_torture_print_module_parms("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_bh_ops, &rcu_bh_sync_ops,
- &srcu_ops, &sched_ops, };
-
- /* 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 "rcutorture: invalid torture type: \"%s\"\n",
- torture_type);
- return (-EINVAL);
- }
- 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("Start of test");
- fullstop = 0;
-
- /* 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);
- 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;
- /* Create the shuffler thread */
- shuffler_task = kthread_run(rcu_torture_shuffle, NULL,
- "rcu_torture_shuffle");
- if (IS_ERR(shuffler_task)) {
- firsterr = PTR_ERR(shuffler_task);
- VERBOSE_PRINTK_ERRSTRING("Failed to create shuffler");
- shuffler_task = NULL;
- goto unwind;
- }
- }
- return 0;
-
-unwind:
- rcu_torture_cleanup();
- return firsterr;
-}
-
-module_init(rcu_torture_init);
-module_exit(rcu_torture_cleanup);
Index: linux-2.6.24-rc6/lib/Kconfig.debug
===================================================================
--- linux-2.6.24-rc6.orig/lib/Kconfig.debug
+++ linux-2.6.24-rc6/lib/Kconfig.debug
@@ -487,19 +487,6 @@ config DEBUG_SYNCHRO_TEST

See Documentation/synchro-test.txt.

-config RCU_TORTURE_TEST
- tristate "torture tests for RCU"
- depends on DEBUG_KERNEL
- depends on m
- default n
- help
- This option provides a kernel module that runs torture tests
- on the RCU infrastructure. The kernel module may be built
- after the fact on the running kernel to be tested, if desired.
-
- Say M if you want the RCU torture tests to build as a module.
- Say N if you are unsure.
-
config LKDTM
tristate "Linux Kernel Dump Test Tool Module"
depends on DEBUG_KERNEL
Index: linux-2.6.24-rc6/tests/Kconfig
===================================================================
--- linux-2.6.24-rc6.orig/tests/Kconfig
+++ linux-2.6.24-rc6/tests/Kconfig
@@ -18,5 +18,18 @@ config DEBUG_LOCKING_API_SELFTESTS
The following locking APIs are covered: spinlocks, rwlocks,
mutexes and rwsems.

+config RCU_TORTURE_TEST
+ tristate "torture tests for RCU"
+ depends on DEBUG_KERNEL
+ depends on m
+ default n
+ help
+ This option provides a kernel module that runs torture tests
+ on the RCU infrastructure. The kernel module may be built
+ after the fact on the running kernel to be tested, if desired.
+
+ Say M if you want the RCU torture tests to build as a module.
+ Say N if you are unsure.
+
endif # KERNEL_TESTS

Index: linux-2.6.24-rc6/tests/Makefile
===================================================================
--- linux-2.6.24-rc6.orig/tests/Makefile
+++ linux-2.6.24-rc6/tests/Makefile
@@ -3,3 +3,4 @@
#

obj-$(CONFIG_DEBUG_LOCKING_API_SELFTESTS) += locking-selftest.o
+obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o
Index: linux-2.6.24-rc6/tests/rcutorture.c
===================================================================
--- /dev/null
+++ linux-2.6.24-rc6/tests/rcutorture.c
@@ -0,0 +1,995 @@
+/*
+ * 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 <asm/atomic.h>
+#include <linux/bitops.h>
+#include <linux/completion.h>
+#include <linux/moduleparam.h>
+#include <linux/percpu.h>
+#include <linux/notifier.h>
+#include <linux/freezer.h>
+#include <linux/cpu.h>
+#include <linux/delay.h>
+#include <linux/byteorder/swabb.h>
+#include <linux/stat.h>
+#include <linux/srcu.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 int verbose; /* Print more debug info. */
+static int test_no_idle_hz; /* Test RCU's support for tickless idle CPUs. */
+static int shuffle_interval = 5; /* Interval between shuffles (in sec)*/
+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, 0444);
+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(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;
+
+#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 int fullstop = 0; /* stop generating callbacks at test end. */
+static LIST_HEAD(rcu_torture_freelist);
+static struct rcu_torture *rcu_torture_current = NULL;
+static long rcu_torture_current_version = 0;
+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 struct list_head rcu_torture_removed;
+
+/*
+ * 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)cpu_clock(raw_smp_processor_id());
+ rrsp->rrs_count = RCU_RANDOM_REFRESH;
+ }
+ rrsp->rrs_state = rrsp->rrs_state * RCU_RANDOM_MULT + RCU_RANDOM_ADD;
+ return swahw32(rrsp->rrs_state);
+}
+
+/*
+ * Operations vector for selecting different types of tests.
+ */
+
+struct rcu_torture_ops {
+ void (*init)(void);
+ void (*cleanup)(void);
+ int (*readlock)(void);
+ void (*readdelay)(struct rcu_random_state *rrsp);
+ void (*readunlock)(int idx);
+ int (*completed)(void);
+ void (*deferredfree)(struct rcu_torture *p);
+ void (*sync)(void);
+ int (*stats)(char *page);
+ char *name;
+};
+static struct rcu_torture_ops *cur_ops = NULL;
+
+/*
+ * 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)
+{
+ long delay;
+ const long longdelay = 200;
+
+ /* We want there to be long-running readers, but not all the time. */
+
+ delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay);
+ if (!delay)
+ udelay(longdelay);
+}
+
+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) {
+ /* 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->deferredfree(rp);
+}
+
+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,
+ .readdelay = rcu_read_delay,
+ .readunlock = rcu_torture_read_unlock,
+ .completed = rcu_torture_completed,
+ .deferredfree = rcu_torture_deferred_free,
+ .sync = synchronize_rcu,
+ .stats = NULL,
+ .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,
+ .readdelay = rcu_read_delay,
+ .readunlock = rcu_torture_read_unlock,
+ .completed = rcu_torture_completed,
+ .deferredfree = rcu_sync_torture_deferred_free,
+ .sync = synchronize_rcu,
+ .stats = NULL,
+ .name = "rcu_sync"
+};
+
+/*
+ * 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);
+}
+
+struct rcu_bh_torture_synchronize {
+ struct rcu_head head;
+ struct completion completion;
+};
+
+static void rcu_bh_torture_wakeme_after_cb(struct rcu_head *head)
+{
+ struct rcu_bh_torture_synchronize *rcu;
+
+ rcu = container_of(head, struct rcu_bh_torture_synchronize, head);
+ complete(&rcu->completion);
+}
+
+static void rcu_bh_torture_synchronize(void)
+{
+ struct rcu_bh_torture_synchronize rcu;
+
+ init_completion(&rcu.completion);
+ call_rcu_bh(&rcu.head, rcu_bh_torture_wakeme_after_cb);
+ wait_for_completion(&rcu.completion);
+}
+
+static struct rcu_torture_ops rcu_bh_ops = {
+ .init = NULL,
+ .cleanup = NULL,
+ .readlock = rcu_bh_torture_read_lock,
+ .readdelay = rcu_read_delay, /* just reuse rcu's version. */
+ .readunlock = rcu_bh_torture_read_unlock,
+ .completed = rcu_bh_torture_completed,
+ .deferredfree = rcu_bh_torture_deferred_free,
+ .sync = rcu_bh_torture_synchronize,
+ .stats = NULL,
+ .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,
+ .readdelay = rcu_read_delay, /* just reuse rcu's version. */
+ .readunlock = rcu_bh_torture_read_unlock,
+ .completed = rcu_bh_torture_completed,
+ .deferredfree = rcu_sync_torture_deferred_free,
+ .sync = rcu_bh_torture_synchronize,
+ .stats = NULL,
+ .name = "rcu_bh_sync"
+};
+
+/*
+ * 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);
+}
+
+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,
+ .readdelay = srcu_read_delay,
+ .readunlock = srcu_torture_read_unlock,
+ .completed = srcu_torture_completed,
+ .deferredfree = rcu_sync_torture_deferred_free,
+ .sync = srcu_torture_synchronize,
+ .stats = srcu_torture_stats,
+ .name = "srcu"
+};
+
+/*
+ * 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 int sched_torture_completed(void)
+{
+ return 0;
+}
+
+static void sched_torture_synchronize(void)
+{
+ synchronize_sched();
+}
+
+static struct rcu_torture_ops sched_ops = {
+ .init = rcu_sync_torture_init,
+ .cleanup = NULL,
+ .readlock = sched_torture_read_lock,
+ .readdelay = rcu_read_delay, /* just reuse rcu's version. */
+ .readunlock = sched_torture_read_unlock,
+ .completed = sched_torture_completed,
+ .deferredfree = rcu_sync_torture_deferred_free,
+ .sync = sched_torture_synchronize,
+ .stats = NULL,
+ .name = "sched"
+};
+
+/*
+ * 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);
+ if ((rp = rcu_torture_alloc()) == NULL)
+ continue;
+ rp->rtort_pipe_count = 0;
+ udelay(rcu_random(&rand) & 0x3ff);
+ old_rp = rcu_torture_current;
+ rp->rtort_mbtest = 1;
+ rcu_assign_pointer(rcu_torture_current, rp);
+ smp_wmb();
+ 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->deferredfree(old_rp);
+ }
+ rcu_torture_current_version++;
+ oldbatch = cur_ops->completed();
+ } while (!kthread_should_stop() && !fullstop);
+ VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping");
+ 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();
+ } while (!kthread_should_stop() && !fullstop);
+
+ VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task stopping");
+ while (!kthread_should_stop())
+ schedule_timeout_uninterruptible(1);
+ return 0;
+}
+
+/*
+ * 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;
+
+ VERBOSE_PRINTK_STRING("rcu_torture_reader task started");
+ set_user_nice(current, 19);
+
+ do {
+ idx = cur_ops->readlock();
+ completed = cur_ops->completed();
+ p = rcu_dereference(rcu_torture_current);
+ if (p == NULL) {
+ /* Wait for rcu_torture_writer to get underway */
+ cur_ops->readunlock(idx);
+ schedule_timeout_interruptible(HZ);
+ continue;
+ }
+ if (p->rtort_mbtest == 0)
+ atomic_inc(&n_rcu_torture_mberror);
+ cur_ops->readdelay(&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;
+ }
+ ++__get_cpu_var(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;
+ }
+ ++__get_cpu_var(rcu_torture_batch)[completed];
+ preempt_enable();
+ cur_ops->readunlock(idx);
+ schedule();
+ } while (!kthread_should_stop() && !fullstop);
+ VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping");
+ 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: %ld tfle: %d rta: %d rtaf: %d rtf: %d "
+ "rtmbe: %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),
+ atomic_read(&n_rcu_torture_mberror));
+ if (atomic_read(&n_rcu_torture_mberror) != 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);
+ }
+ 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();
+ } 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)
+{
+ cpumask_t tmp_mask = CPU_MASK_ALL;
+ int i;
+
+ 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)
+ cpu_clear(rcu_idle_cpu, tmp_mask);
+
+ set_cpus_allowed(current, tmp_mask);
+
+ if (reader_tasks) {
+ for (i = 0; i < nrealreaders; i++)
+ if (reader_tasks[i])
+ set_cpus_allowed(reader_tasks[i], tmp_mask);
+ }
+
+ if (fakewriter_tasks) {
+ for (i = 0; i < nfakewriters; i++)
+ if (fakewriter_tasks[i])
+ set_cpus_allowed(fakewriter_tasks[i], tmp_mask);
+ }
+
+ if (writer_task)
+ set_cpus_allowed(writer_task, tmp_mask);
+
+ if (stats_task)
+ set_cpus_allowed(stats_task, 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();
+ } while (!kthread_should_stop());
+ VERBOSE_PRINTK_STRING("rcu_torture_shuffle task stopping");
+ return 0;
+}
+
+static inline void
+rcu_torture_print_module_parms(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\n",
+ torture_type, tag, nrealreaders, nfakewriters,
+ stat_interval, verbose, test_no_idle_hz, shuffle_interval);
+}
+
+static void
+rcu_torture_cleanup(void)
+{
+ int i;
+
+ fullstop = 1;
+ if (shuffler_task) {
+ VERBOSE_PRINTK_STRING("Stopping rcu_torture_shuffle task");
+ kthread_stop(shuffler_task);
+ }
+ 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;
+
+ /* Wait for all RCU callbacks to fire. */
+ rcu_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("End of test: FAILURE");
+ else
+ rcu_torture_print_module_parms("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_bh_ops, &rcu_bh_sync_ops,
+ &srcu_ops, &sched_ops, };
+
+ /* 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 "rcutorture: invalid torture type: \"%s\"\n",
+ torture_type);
+ return (-EINVAL);
+ }
+ 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("Start of test");
+ fullstop = 0;
+
+ /* 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);
+ 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;
+ /* Create the shuffler thread */
+ shuffler_task = kthread_run(rcu_torture_shuffle, NULL,
+ "rcu_torture_shuffle");
+ if (IS_ERR(shuffler_task)) {
+ firsterr = PTR_ERR(shuffler_task);
+ VERBOSE_PRINTK_ERRSTRING("Failed to create shuffler");
+ shuffler_task = NULL;
+ goto unwind;
+ }
+ }
+ return 0;
+
+unwind:
+ rcu_torture_cleanup();
+ return firsterr;
+}
+
+module_init(rcu_torture_init);
+module_exit(rcu_torture_cleanup);

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