X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=kernel%2Frcutorture.c;h=c52f981ea0086e569b37c5195cf291c6be55d446;hb=2b2842146cb4105877c2be51d3857ec61ebd4ff9;hp=42e7f01e8003af785a335bc9c12f7adab34d9a97;hpb=2860aaba4dc87fa43c08724434b87a8650f3bff5;p=linux-2.6 diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c index 42e7f01e80..c52f981ea0 100644 --- a/kernel/rcutorture.c +++ b/kernel/rcutorture.c @@ -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 */ @@ -47,18 +48,22 @@ #include MODULE_LICENSE("GPL"); -MODULE_AUTHOR("Paul E. McKenney "); +MODULE_AUTHOR("Paul E. McKenney and " + "Josh Triplett "); 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 to torture: rcu, rcu_bh, srcu. */ +static char *torture_type = "rcu"; /* What RCU implementation to torture. */ module_param(nreaders, int, 0); MODULE_PARM_DESC(nreaders, "Number of RCU reader threads"); +module_param(nfakewriters, int, 0); +MODULE_PARM_DESC(nfakewriters, "Number of RCU fake writer threads"); module_param(stat_interval, int, 0); MODULE_PARM_DESC(stat_interval, "Number of seconds between stats printk()s"); module_param(verbose, bool, 0); @@ -82,6 +87,7 @@ 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; @@ -111,6 +117,7 @@ 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. @@ -147,7 +154,7 @@ rcu_torture_free(struct rcu_torture *p) struct rcu_random_state { unsigned long rrs_state; - unsigned long rrs_count; + long rrs_count; }; #define RCU_RANDOM_MULT 39916801 /* prime */ @@ -160,7 +167,7 @@ struct rcu_random_state { * Crude but fast random-number generator. Uses a linear congruential * generator, with occasional help from get_random_bytes(). */ -static long +static unsigned long rcu_random(struct rcu_random_state *rrsp) { long refresh; @@ -186,6 +193,7 @@ struct rcu_torture_ops { void (*readunlock)(int idx); int (*completed)(void); void (*deferredfree)(struct rcu_torture *p); + void (*sync)(void); int (*stats)(char *page); char *name; }; @@ -258,10 +266,50 @@ static struct rcu_torture_ops rcu_ops = { .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. */ @@ -287,6 +335,28 @@ 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, @@ -295,21 +365,34 @@ static struct rcu_torture_ops rcu_bh_ops = { .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 struct list_head srcu_removed; static void srcu_torture_init(void) { init_srcu_struct(&srcu_ctl); - INIT_LIST_HEAD(&srcu_removed); + rcu_sync_torture_init(); } static void srcu_torture_cleanup(void) @@ -318,7 +401,7 @@ static void srcu_torture_cleanup(void) cleanup_srcu_struct(&srcu_ctl); } -static int srcu_torture_read_lock(void) +static int srcu_torture_read_lock(void) __acquires(&srcu_ctl) { return srcu_read_lock(&srcu_ctl); } @@ -336,7 +419,7 @@ static void srcu_read_delay(struct rcu_random_state *rrsp) schedule_timeout_interruptible(longdelay); } -static void srcu_torture_read_unlock(int idx) +static void srcu_torture_read_unlock(int idx) __releases(&srcu_ctl) { srcu_read_unlock(&srcu_ctl, idx); } @@ -346,25 +429,9 @@ static int srcu_torture_completed(void) return srcu_batches_completed(&srcu_ctl); } -static void srcu_torture_deferred_free(struct rcu_torture *p) +static void srcu_torture_synchronize(void) { - int i; - struct rcu_torture *rp; - struct rcu_torture *rp1; - synchronize_srcu(&srcu_ctl); - list_add(&p->rtort_free, &srcu_removed); - list_for_each_entry_safe(rp, rp1, &srcu_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 int srcu_torture_stats(char *page) @@ -391,13 +458,53 @@ static struct rcu_torture_ops srcu_ops = { .readdelay = srcu_read_delay, .readunlock = srcu_torture_read_unlock, .completed = srcu_torture_completed, - .deferredfree = srcu_torture_deferred_free, + .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" +}; + static struct rcu_torture_ops *torture_ops[] = - { &rcu_ops, &rcu_bh_ops, &srcu_ops, NULL }; + { &rcu_ops, &rcu_sync_ops, &rcu_bh_ops, &rcu_bh_sync_ops, &srcu_ops, + &sched_ops, NULL }; /* * RCU torture writer kthread. Repeatedly substitutes a new structure @@ -443,6 +550,30 @@ rcu_torture_writer(void *arg) 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 @@ -621,6 +752,12 @@ static void rcu_torture_shuffle_tasks(void) set_cpus_allowed(reader_tasks[i], tmp_mask); } + if (fakewriter_tasks != NULL) { + 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); @@ -654,11 +791,12 @@ rcu_torture_shuffle(void *arg) static inline void rcu_torture_print_module_parms(char *tag) { - printk(KERN_ALERT "%s" TORTURE_FLAG "--- %s: nreaders=%d " + 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, stat_interval, verbose, - test_no_idle_hz, shuffle_interval); + torture_type, tag, nrealreaders, nfakewriters, + stat_interval, verbose, test_no_idle_hz, shuffle_interval); } static void @@ -693,6 +831,19 @@ rcu_torture_cleanup(void) } rcu_torture_current = NULL; + if (fakewriter_tasks != NULL) { + for (i = 0; i < nfakewriters; i++) { + if (fakewriter_tasks[i] != NULL) { + 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 != NULL) { VERBOSE_PRINTK_STRING("Stopping rcu_torture_stats task"); kthread_stop(stats_task); @@ -780,6 +931,24 @@ rcu_torture_init(void) 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) {