X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Frcutorture.c;h=3245b40952c61548d835d3f19c9d06cf4d1aa9d1;hb=fe0bdec68b77020281dc814805edfe594ae89e0f;hp=dd413bf6a1d2e458a379c7f9d8e01d6a509f0d9b;hpb=a9022e9cb9e919e31d5bc15fcef5c7186740645e;p=safe%2Fjmp%2Flinux-2.6 diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c index dd413bf..3245b40 100644 --- a/kernel/rcutorture.c +++ b/kernel/rcutorture.c @@ -39,13 +39,14 @@ #include #include #include +#include #include #include -#include #include -#include #include #include +#include +#include MODULE_LICENSE("GPL"); MODULE_AUTHOR("Paul E. McKenney and " @@ -57,7 +58,9 @@ 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 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_param(nreaders, int, 0444); @@ -72,6 +75,10 @@ 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)"); @@ -91,6 +98,7 @@ 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 @@ -101,7 +109,6 @@ struct rcu_torture { 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; @@ -117,8 +124,42 @@ 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 = 0; static struct list_head rcu_torture_removed; +static int stutter_pause_test = 0; + +#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; + +#define FULLSTOP_SIGNALED 1 /* Bail due to signal. */ +#define FULLSTOP_CLEANUP 2 /* Orderly shutdown. */ +static int fullstop; /* stop generating callbacks at test end. */ +DEFINE_MUTEX(fullstop_mutex); /* protect fullstop transitions and */ + /* spawning of kthreads. */ + +/* + * Detect and respond to a signal-based shutdown. + */ +static int +rcutorture_shutdown_notify(struct notifier_block *unused1, + unsigned long unused2, void *unused3) +{ + if (fullstop) + return NOTIFY_DONE; + if (signal_pending(current)) { + mutex_lock(&fullstop_mutex); + if (!ACCESS_ONCE(fullstop)) + fullstop = FULLSTOP_SIGNALED; + mutex_unlock(&fullstop_mutex); + } + return NOTIFY_DONE; +} + /* * Allocate an element from the rcu_tortures pool. */ @@ -165,22 +206,31 @@ struct rcu_random_state { /* * Crude but fast random-number generator. Uses a linear congruential - * generator, with occasional help from get_random_bytes(). + * generator, with occasional help from cpu_clock(). */ static unsigned long rcu_random(struct rcu_random_state *rrsp) { - long refresh; - if (--rrsp->rrs_count < 0) { - get_random_bytes(&refresh, sizeof(refresh)); - rrsp->rrs_state += refresh; + 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(void) +{ + while ((stutter_pause_test || !rcutorture_runnable) && !fullstop) { + if (rcutorture_runnable) + schedule_timeout_interruptible(1); + else + schedule_timeout_interruptible(round_jiffies_relative(HZ)); + } +} + /* * Operations vector for selecting different types of tests. */ @@ -194,7 +244,9 @@ struct rcu_torture_ops { int (*completed)(void); void (*deferredfree)(struct rcu_torture *p); void (*sync)(void); + void (*cb_barrier)(void); int (*stats)(char *page); + int irqcapable; char *name; }; static struct rcu_torture_ops *cur_ops = NULL; @@ -267,7 +319,9 @@ static struct rcu_torture_ops rcu_ops = { .completed = rcu_torture_completed, .deferredfree = rcu_torture_deferred_free, .sync = synchronize_rcu, + .cb_barrier = rcu_barrier, .stats = NULL, + .irqcapable = 1, .name = "rcu" }; @@ -306,7 +360,9 @@ static struct rcu_torture_ops rcu_sync_ops = { .completed = rcu_torture_completed, .deferredfree = rcu_sync_torture_deferred_free, .sync = synchronize_rcu, + .cb_barrier = NULL, .stats = NULL, + .irqcapable = 1, .name = "rcu_sync" }; @@ -366,7 +422,9 @@ static struct rcu_torture_ops rcu_bh_ops = { .completed = rcu_bh_torture_completed, .deferredfree = rcu_bh_torture_deferred_free, .sync = rcu_bh_torture_synchronize, + .cb_barrier = rcu_barrier_bh, .stats = NULL, + .irqcapable = 1, .name = "rcu_bh" }; @@ -379,7 +437,9 @@ static struct rcu_torture_ops rcu_bh_sync_ops = { .completed = rcu_bh_torture_completed, .deferredfree = rcu_sync_torture_deferred_free, .sync = rcu_bh_torture_synchronize, + .cb_barrier = NULL, .stats = NULL, + .irqcapable = 1, .name = "rcu_bh_sync" }; @@ -460,6 +520,7 @@ static struct rcu_torture_ops srcu_ops = { .completed = srcu_torture_completed, .deferredfree = rcu_sync_torture_deferred_free, .sync = srcu_torture_synchronize, + .cb_barrier = NULL, .stats = srcu_torture_stats, .name = "srcu" }; @@ -484,6 +545,11 @@ static int sched_torture_completed(void) return 0; } +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(); @@ -496,12 +562,28 @@ static struct rcu_torture_ops sched_ops = { .readdelay = rcu_read_delay, /* just reuse rcu's version. */ .readunlock = sched_torture_read_unlock, .completed = sched_torture_completed, - .deferredfree = rcu_sync_torture_deferred_free, + .deferredfree = rcu_sched_torture_deferred_free, .sync = sched_torture_synchronize, + .cb_barrier = rcu_barrier_sched, .stats = NULL, + .irqcapable = 1, .name = "sched" }; +static struct rcu_torture_ops sched_ops_sync = { + .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, + .cb_barrier = NULL, + .stats = NULL, + .name = "sched_sync" +}; + /* * RCU torture writer kthread. Repeatedly substitutes a new structure * for that pointed to by rcu_torture_current, freeing the old structure @@ -539,9 +621,10 @@ rcu_torture_writer(void *arg) } rcu_torture_current_version++; oldbatch = cur_ops->completed(); + rcu_stutter_wait(); } while (!kthread_should_stop() && !fullstop); VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping"); - while (!kthread_should_stop()) + while (!kthread_should_stop() && fullstop != FULLSTOP_SIGNALED) schedule_timeout_uninterruptible(1); return 0; } @@ -562,15 +645,62 @@ rcu_torture_fakewriter(void *arg) schedule_timeout_uninterruptible(1 + rcu_random(&rand)%10); udelay(rcu_random(&rand) & 0x3ff); cur_ops->sync(); + rcu_stutter_wait(); } while (!kthread_should_stop() && !fullstop); VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task stopping"); - while (!kthread_should_stop()) + while (!kthread_should_stop() && fullstop != FULLSTOP_SIGNALED) 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->readdelay(&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; + } + ++__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); +} + +/* * 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 @@ -584,11 +714,18 @@ rcu_torture_reader(void *arg) 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->irqcapable) + setup_timer_on_stack(&t, rcu_torture_timer, 0); do { + if (irqreader && cur_ops->irqcapable) { + if (!timer_pending(&t)) + mod_timer(&t, 1); + } idx = cur_ops->readlock(); completed = cur_ops->completed(); p = rcu_dereference(rcu_torture_current); @@ -617,9 +754,12 @@ rcu_torture_reader(void *arg) preempt_enable(); cur_ops->readunlock(idx); schedule(); + rcu_stutter_wait(); } while (!kthread_should_stop() && !fullstop); VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping"); - while (!kthread_should_stop()) + if (irqreader && cur_ops->irqcapable) + del_timer_sync(&t); + while (!kthread_should_stop() && fullstop != FULLSTOP_SIGNALED) schedule_timeout_uninterruptible(1); return 0; } @@ -649,20 +789,22 @@ rcu_torture_printk(char *page) 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", + "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), - atomic_read(&n_rcu_torture_mberror)); + 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++) @@ -714,7 +856,7 @@ rcu_torture_stats(void *arg) do { schedule_timeout_interruptible(stat_interval * HZ); rcu_torture_stats_print(); - } while (!kthread_should_stop()); + } while (!kthread_should_stop() && !fullstop); VERBOSE_PRINTK_STRING("rcu_torture_stats task stopping"); return 0; } @@ -726,46 +868,52 @@ static int rcu_idle_cpu; /* Force all torture tasks off this CPU */ */ static void rcu_torture_shuffle_tasks(void) { - cpumask_t tmp_mask = CPU_MASK_ALL; + cpumask_var_t tmp_mask; int i; - lock_cpu_hotplug(); + if (!alloc_cpumask_var(&tmp_mask, GFP_KERNEL)) + BUG(); + + cpumask_setall(tmp_mask); + get_online_cpus(); /* No point in shuffling if there is only one online CPU (ex: UP) */ - if (num_online_cpus() == 1) { - unlock_cpu_hotplug(); - return; - } + if (num_online_cpus() == 1) + goto out; if (rcu_idle_cpu != -1) - cpu_clear(rcu_idle_cpu, tmp_mask); + cpumask_clear_cpu(rcu_idle_cpu, tmp_mask); - set_cpus_allowed(current, 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(reader_tasks[i], tmp_mask); + 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(fakewriter_tasks[i], tmp_mask); + set_cpus_allowed_ptr(fakewriter_tasks[i], + tmp_mask); } if (writer_task) - set_cpus_allowed(writer_task, tmp_mask); + set_cpus_allowed_ptr(writer_task, tmp_mask); if (stats_task) - set_cpus_allowed(stats_task, tmp_mask); + set_cpus_allowed_ptr(stats_task, tmp_mask); if (rcu_idle_cpu == -1) rcu_idle_cpu = num_online_cpus() - 1; else rcu_idle_cpu--; - unlock_cpu_hotplug(); +out: + put_online_cpus(); + free_cpumask_var(tmp_mask); } /* Shuffle tasks across CPUs, with the intent of allowing each CPU in the @@ -779,28 +927,67 @@ rcu_torture_shuffle(void *arg) do { schedule_timeout_interruptible(shuffle_interval * HZ); rcu_torture_shuffle_tasks(); - } while (!kthread_should_stop()); + } while (!kthread_should_stop() && !fullstop); 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() && !fullstop) + schedule_timeout_interruptible(stutter * HZ); + stutter_pause_test = 0; + } while (!kthread_should_stop() && !fullstop); + 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\n", + "shuffle_interval=%d stutter=%d irqreader=%d\n", torture_type, tag, nrealreaders, nfakewriters, - stat_interval, verbose, test_no_idle_hz, shuffle_interval); + 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; + mutex_lock(&fullstop_mutex); + if (!fullstop) { + /* If being signaled, let it happen, then exit. */ + mutex_unlock(&fullstop_mutex); + schedule_timeout_interruptible(10 * HZ); + if (cur_ops->cb_barrier != NULL) + cur_ops->cb_barrier(); + return; + } + fullstop = FULLSTOP_CLEANUP; + 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); @@ -847,7 +1034,9 @@ rcu_torture_cleanup(void) stats_task = NULL; /* Wait for all RCU callbacks to fire. */ - rcu_barrier(); + + if (cur_ops->cb_barrier != NULL) + cur_ops->cb_barrier(); rcu_torture_stats_print(); /* -After- the stats thread is stopped! */ @@ -867,7 +1056,9 @@ rcu_torture_init(void) 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, }; + &srcu_ops, &sched_ops, &sched_ops_sync, }; + + 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++) { @@ -878,6 +1069,7 @@ rcu_torture_init(void) if (i == ARRAY_SIZE(torture_ops)) { printk(KERN_ALERT "rcutorture: invalid torture type: \"%s\"\n", torture_type); + mutex_unlock(&fullstop_mutex); return (-EINVAL); } if (cur_ops->init) @@ -987,9 +1179,25 @@ rcu_torture_init(void) 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; }