diff options
| -rw-r--r-- | Documentation/RCU/torture.txt | 15 | ||||
| -rw-r--r-- | kernel/rcutorture.c | 133 |
2 files changed, 138 insertions, 10 deletions
diff --git a/Documentation/RCU/torture.txt b/Documentation/RCU/torture.txt index a4948591607d..2174badd31e0 100644 --- a/Documentation/RCU/torture.txt +++ b/Documentation/RCU/torture.txt @@ -118,6 +118,21 @@ o "Free-Block Circulation": Shows the number of torture structures as it is only incremented if a torture structure's counter somehow gets incremented farther than it should. +Different implementations of RCU can provide implementation-specific +additional information. For example, SRCU provides the following: + + srcu-torture: rtc: f8cf46a8 ver: 355 tfle: 0 rta: 356 rtaf: 0 rtf: 346 rtmbe: 0 + srcu-torture: Reader Pipe: 559738 939 0 0 0 0 0 0 0 0 0 + srcu-torture: Reader Batch: 560434 243 0 0 0 0 0 0 0 0 + srcu-torture: Free-Block Circulation: 355 354 353 352 351 350 349 348 347 346 0 + srcu-torture: per-CPU(idx=1): 0(0,1) 1(0,1) 2(0,0) 3(0,1) + +The first four lines are similar to those for RCU. The last line shows +the per-CPU counter state. The numbers in parentheses are the values +of the "old" and "current" counters for the corresponding CPU. The +"idx" value maps the "old" and "current" values to the underlying array, +and is useful for debugging. + USAGE diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c index 23446e91cded..e34d22bf2293 100644 --- a/kernel/rcutorture.c +++ b/kernel/rcutorture.c @@ -44,6 +44,7 @@ #include <linux/delay.h> #include <linux/byteorder/swabb.h> #include <linux/stat.h> +#include <linux/srcu.h> MODULE_LICENSE("GPL"); @@ -53,7 +54,7 @@ static int stat_interval; /* Interval between stats, in seconds. */ 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. */ +static char *torture_type = "rcu"; /* What to torture: rcu, srcu. */ module_param(nreaders, int, 0); MODULE_PARM_DESC(nreaders, "Number of RCU reader threads"); @@ -66,7 +67,7 @@ MODULE_PARM_DESC(test_no_idle_hz, "Test support for tickless idle CPUs"); module_param(shuffle_interval, int, 0); MODULE_PARM_DESC(shuffle_interval, "Number of seconds between shuffles"); module_param(torture_type, charp, 0); -MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh)"); +MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, srcu)"); #define TORTURE_FLAG "-torture:" #define PRINTK_STRING(s) \ @@ -104,11 +105,11 @@ 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; -atomic_t n_rcu_torture_mberror; -atomic_t n_rcu_torture_error; +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; /* * Allocate an element from the rcu_tortures pool. @@ -180,6 +181,7 @@ 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); @@ -198,6 +200,18 @@ static int rcu_torture_read_lock(void) __acquires(RCU) 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(); @@ -239,6 +253,7 @@ 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, @@ -275,6 +290,7 @@ 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, @@ -282,8 +298,105 @@ static struct rcu_torture_ops rcu_bh_ops = { .name = "rcu_bh" }; +/* + * 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); +} + +static void srcu_torture_cleanup(void) +{ + synchronize_srcu(&srcu_ctl); + cleanup_srcu_struct(&srcu_ctl); +} + +static int srcu_torture_read_lock(void) +{ + 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) +{ + srcu_read_unlock(&srcu_ctl, idx); +} + +static int srcu_torture_completed(void) +{ + return srcu_batches_completed(&srcu_ctl); +} + +static void srcu_torture_deferred_free(struct rcu_torture *p) +{ + 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) +{ + 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 = srcu_torture_deferred_free, + .stats = srcu_torture_stats, + .name = "srcu" +}; + static struct rcu_torture_ops *torture_ops[] = - { &rcu_ops, &rcu_bh_ops, NULL }; + { &rcu_ops, &rcu_bh_ops, &srcu_ops, NULL }; /* * RCU torture writer kthread. Repeatedly substitutes a new structure @@ -359,7 +472,7 @@ rcu_torture_reader(void *arg) } if (p->rtort_mbtest == 0) atomic_inc(&n_rcu_torture_mberror); - udelay(rcu_random(&rand) & 0x7f); + cur_ops->readdelay(&rand); preempt_disable(); pipe_count = p->rtort_pipe_count; if (pipe_count > RCU_TORTURE_PIPE_LEN) { @@ -483,7 +596,7 @@ 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. */ -void rcu_torture_shuffle_tasks(void) +static void rcu_torture_shuffle_tasks(void) { cpumask_t tmp_mask = CPU_MASK_ALL; int i; |