X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Frcutorture.c;h=9bb52177af02a3e20aa347e3b65c0a236caa1922;hb=7acd72eb85f1c7a15e8b5eb554994949241737f1;hp=9b58f1eff3ca8990d29f4e4f9b9ad52a621babd4;hpb=a241ec65aeac3d69a08a7b153cccbdb7ea35063f;p=safe%2Fjmp%2Flinux-2.6 diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c index 9b58f1e..9bb5217 100644 --- a/kernel/rcutorture.c +++ b/kernel/rcutorture.c @@ -1,5 +1,5 @@ /* - * Read-Copy Update /proc-based torture test facility + * 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 @@ -15,9 +15,10 @@ * 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 + * Copyright (C) IBM Corporation, 2005, 2006 * * Authors: Paul E. McKenney + * Josh Triplett * * See also: Documentation/RCU/torture.txt */ @@ -34,45 +35,70 @@ #include #include #include -#include #include #include #include #include -#include +#include +#include #include -#include #include -#include #include +#include +#include +#include MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Paul E. McKenney and " + "Josh Triplett "); -static int nreaders = -1; /* # reader threads, defaults to 4*ncpus */ -static int stat_interval = 0; /* Interval between stats, in seconds. */ +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 = 0; /* Print more debug info. */ +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 = 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 char *torture_type = "rcu"; /* What RCU implementation to torture. */ -MODULE_PARM(nreaders, "i"); +module_param(nreaders, int, 0444); MODULE_PARM_DESC(nreaders, "Number of RCU reader threads"); -MODULE_PARM(stat_interval, "i"); +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_PARM(verbose, "i"); +module_param(verbose, bool, 0444); MODULE_PARM_DESC(verbose, "Enable verbose debugging printk()s"); -#define TORTURE_FLAG "rcutorture: " +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(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 TORTURE_FLAG s "\n"); } while (0) + do { printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0) #define VERBOSE_PRINTK_STRING(s) \ - do { if (verbose) printk(KERN_ALERT TORTURE_FLAG s "\n"); } while (0) + 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 TORTURE_FLAG "!!! " s "\n"); } while (0) + 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; #define RCU_TORTURE_PIPE_LEN 10 @@ -80,12 +106,12 @@ 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_torture_current; +static 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) = @@ -93,28 +119,82 @@ static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count) = 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]; -atomic_t n_rcu_torture_alloc; -atomic_t n_rcu_torture_alloc_fail; -atomic_t n_rcu_torture_free; +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_timers; +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; + +/* 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; +DEFINE_MUTEX(fullstop_mutex); /* Protect fullstop transitions and spawning */ + /* of kthreads. */ + +/* + * 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. */ -struct rcu_torture * +static struct rcu_torture * rcu_torture_alloc(void) { struct list_head *p; - spin_lock(&rcu_torture_lock); + spin_lock_bh(&rcu_torture_lock); if (list_empty(&rcu_torture_freelist)) { atomic_inc(&n_rcu_torture_alloc_fail); - spin_unlock(&rcu_torture_lock); + 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(&rcu_torture_lock); + spin_unlock_bh(&rcu_torture_lock); return container_of(p, struct rcu_torture, rtort_free); } @@ -125,9 +205,104 @@ static void rcu_torture_free(struct rcu_torture *p) { atomic_inc(&n_rcu_torture_free); - spin_lock(&rcu_torture_lock); + spin_lock_bh(&rcu_torture_lock); list_add_tail(&p->rtort_free, &rcu_torture_freelist); - spin_unlock(&rcu_torture_lock); + 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); +} + +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); + int (*stats)(char *page); + int irq_capable; + 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); +} + +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 @@ -136,7 +311,7 @@ rcu_torture_cb(struct rcu_head *p) int i; struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu); - if (fullstop) { + if (fullstop != FULLSTOP_DONTSTOP) { /* Test is ending, just drop callbacks on the floor. */ /* The next initialization will pick up the pieces. */ return; @@ -145,41 +320,341 @@ rcu_torture_cb(struct rcu_head *p) 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) + if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) { + rp->rtort_mbtest = 0; rcu_torture_free(rp); - else - call_rcu(p, rcu_torture_cb); + } else + cur_ops->deferred_free(rp); } -struct rcu_random_state { - unsigned long rrs_state; - unsigned long rrs_count; +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, + .stats = NULL, + .irq_capable = 1, + .name = "rcu" }; -#define RCU_RANDOM_MULT 39916801 /* prime */ -#define RCU_RANDOM_ADD 479001701 /* prime */ -#define RCU_RANDOM_REFRESH 10000 +static void rcu_sync_torture_deferred_free(struct rcu_torture *p) +{ + int i; + struct rcu_torture *rp; + struct rcu_torture *rp1; -#define DEFINE_RCU_RANDOM(name) struct rcu_random_state name = { 0, 0 } + 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, + .stats = NULL, + .irq_capable = 1, + .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, + .stats = NULL, + .irq_capable = 1, + .name = "rcu_expedited" +}; /* - * Crude but fast random-number generator. Uses a linear congruential - * generator, with occasional help from get_random_bytes(). + * Definitions for rcu_bh torture testing. */ -static long -rcu_random(struct rcu_random_state *rrsp) + +static int rcu_bh_torture_read_lock(void) __acquires(RCU_BH) { - long refresh; + rcu_read_lock_bh(); + return 0; +} - if (--rrsp->rrs_count < 0) { - get_random_bytes(&refresh, sizeof(refresh)); - rrsp->rrs_state += refresh; - rrsp->rrs_count = RCU_RANDOM_REFRESH; +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, + .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 = rcu_bh_torture_synchronize, + .cb_barrier = rcu_barrier_bh, + .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 = rcu_bh_torture_synchronize, + .cb_barrier = NULL, + .stats = NULL, + .irq_capable = 1, + .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]); } - rrsp->rrs_state = rrsp->rrs_state * RCU_RANDOM_MULT + RCU_RANDOM_ADD; - return swahw32(rrsp->rrs_state); + 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 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 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, + .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 = sched_torture_synchronize, + .cb_barrier = rcu_barrier_sched, + .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 = sched_torture_synchronize, + .cb_barrier = NULL, + .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, + .stats = rcu_expedited_torture_stats, + .irq_capable = 1, + .name = "sched_expedited" +}; + /* * RCU torture writer kthread. Repeatedly substitutes a new structure * for that pointed to by rcu_torture_current, freeing the old structure @@ -195,35 +670,111 @@ rcu_torture_writer(void *arg) static DEFINE_RCU_RANDOM(rand); VERBOSE_PRINTK_STRING("rcu_torture_writer task started"); + set_user_nice(current, 19); + do { schedule_timeout_uninterruptible(1); - if (rcu_batches_completed() == oldbatch) - continue; - if ((rp = rcu_torture_alloc()) == NULL) + rp = rcu_torture_alloc(); + if (rp == 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 != NULL) { + 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++; - call_rcu(&old_rp->rtort_rcu, rcu_torture_cb); + cur_ops->deferred_free(old_rp); } rcu_torture_current_version++; - oldbatch = rcu_batches_completed(); - } while (!kthread_should_stop() && !fullstop); + 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; +} + +/* + * 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(rcu_torture_current); + if (p == NULL) { + /* Leave because rcu_torture_writer is not yet underway */ + cur_ops->readunlock(idx); + return; + } + 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; + } + __this_cpu_inc(per_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; + } + __this_cpu_inc(per_cpu_var(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 @@ -233,40 +784,56 @@ 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 { - rcu_read_lock(); - completed = rcu_batches_completed(); + if (irqreader && cur_ops->irq_capable) { + if (!timer_pending(&t)) + mod_timer(&t, 1); + } + 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 */ - rcu_read_unlock(); + cur_ops->readunlock(idx); schedule_timeout_interruptible(HZ); continue; } - udelay(rcu_random(&rand) & 0x7f); + 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; } - ++__get_cpu_var(rcu_torture_count)[pipe_count]; - completed = rcu_batches_completed() - completed; + __this_cpu_inc(per_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]; + __this_cpu_inc(per_cpu_var(rcu_torture_batch)[completed]); preempt_enable(); - rcu_read_unlock(); + cur_ops->readunlock(idx); schedule(); - } while (!kthread_should_stop() && !fullstop); + 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; @@ -284,7 +851,7 @@ rcu_torture_printk(char *page) long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; - for_each_cpu(cpu) { + 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]; @@ -294,32 +861,42 @@ rcu_torture_printk(char *page) if (pipesummary[i] != 0) break; } - cnt += sprintf(&page[cnt], "rcutorture: "); + 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", + "rtc: %p ver: %ld tfle: %d rta: %d rtaf: %d rtf: %d " + "rtmbe: %d nt: %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)); - cnt += sprintf(&page[cnt], "\nrcutorture: "); - if (i > 1) + atomic_read(&n_rcu_torture_free), + atomic_read(&n_rcu_torture_mberror), + n_rcu_torture_timers); + 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); + 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], "\nrcutorture: "); + 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; i++) + for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) cnt += sprintf(&page[cnt], " %ld", batchsummary[i]); - cnt += sprintf(&page[cnt], "\nrcutorture: "); + 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; } @@ -354,26 +931,154 @@ rcu_torture_stats(void *arg) 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(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\n", + torture_type, tag, nrealreaders, nfakewriters, + stat_interval, verbose, test_no_idle_hz, shuffle_interval, + stutter, irqreader); +} + +static struct notifier_block rcutorture_nb = { + .notifier_call = rcutorture_shutdown_notify, +}; + static void rcu_torture_cleanup(void) { int i; - fullstop = 1; - if (writer_task != NULL) { + mutex_lock(&fullstop_mutex); + 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_nb); + 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 != NULL) { + if (reader_tasks) { for (i = 0; i < nrealreaders; i++) { - if (reader_tasks[i] != NULL) { + if (reader_tasks[i]) { VERBOSE_PRINTK_STRING( "Stopping rcu_torture_reader task"); kthread_stop(reader_tasks[i]); @@ -385,7 +1090,20 @@ rcu_torture_cleanup(void) } rcu_torture_current = NULL; - if (stats_task != 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); } @@ -393,34 +1111,64 @@ rcu_torture_cleanup(void) /* Wait for all RCU callbacks to fire. */ - for (i = 0; i < RCU_TORTURE_PIPE_LEN; i++) - synchronize_rcu(); + if (cur_ops->cb_barrier != NULL) + cur_ops->cb_barrier(); + rcu_torture_stats_print(); /* -After- the stats thread is stopped! */ - PRINTK_STRING("--- End of test"); + + 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 +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, + &srcu_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->init) + cur_ops->init(); /* no "goto unwind" prior to this point!!! */ if (nreaders >= 0) nrealreaders = nreaders; else nrealreaders = 2 * num_online_cpus(); - printk(KERN_ALERT TORTURE_FLAG - "--- Start of test: nreaders=%d stat_interval=%d verbose=%d\n", - nrealreaders, stat_interval, verbose); - fullstop = 0; + rcu_torture_print_module_parms("Start of test"); + fullstop = FULLSTOP_DONTSTOP; /* Set up the freelist. */ INIT_LIST_HEAD(&rcu_torture_freelist); - for (i = 0; i < sizeof(rcu_tortures) / sizeof(rcu_tortures[0]); i++) { + 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); } @@ -432,9 +1180,11 @@ rcu_torture_init(void) 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_cpu(cpu) { + 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; @@ -452,7 +1202,25 @@ rcu_torture_init(void) writer_task = NULL; goto unwind; } - reader_tasks = kmalloc(nrealreaders * sizeof(reader_tasks[0]), + 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"); @@ -481,9 +1249,45 @@ rcu_torture_init(void) 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; + } + } + register_reboot_notifier(&rcutorture_nb); + mutex_unlock(&fullstop_mutex); return 0; unwind: + mutex_unlock(&fullstop_mutex); rcu_torture_cleanup(); return firsterr; }