diff options
Diffstat (limited to 'kernel/rcutorture.c')
-rw-r--r-- | kernel/rcutorture.c | 999 |
1 files changed, 0 insertions, 999 deletions
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c deleted file mode 100644 index 33acc424667e..000000000000 --- a/kernel/rcutorture.c +++ /dev/null @@ -1,999 +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> -#include <linux/slab.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; - int i; - - cpus_setall(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) - cpu_clear(rcu_idle_cpu, tmp_mask); - - set_cpus_allowed_ptr(current, &tmp_mask); - - if (reader_tasks) { - for (i = 0; i < nrealreaders; i++) - if (reader_tasks[i]) - set_cpus_allowed_ptr(reader_tasks[i], - &tmp_mask); - } - - if (fakewriter_tasks) { - for (i = 0; i < nfakewriters; i++) - if (fakewriter_tasks[i]) - set_cpus_allowed_ptr(fakewriter_tasks[i], - &tmp_mask); - } - - if (writer_task) - set_cpus_allowed_ptr(writer_task, &tmp_mask); - - if (stats_task) - set_cpus_allowed_ptr(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); |