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-rw-r--r--kernel/rcutorture.c317
1 files changed, 300 insertions, 17 deletions
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index 23446e9..e2bda18 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 <paulmck@us.ibm.com>
+ * Josh Triplett <josh@freedesktop.org>
*
* See also: Documentation/RCU/torture.txt
*/
@@ -44,19 +45,25 @@
#include <linux/delay.h>
#include <linux/byteorder/swabb.h>
#include <linux/stat.h>
+#include <linux/srcu.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 to torture. */
+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);
@@ -66,7 +73,7 @@ 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) \
@@ -80,6 +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;
@@ -104,11 +112,12 @@ 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;
+static struct list_head rcu_torture_removed;
/*
* Allocate an element from the rcu_tortures pool.
@@ -145,7 +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 */
@@ -158,7 +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;
@@ -180,9 +189,11 @@ 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;
};
@@ -198,6 +209,18 @@ 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();
@@ -239,13 +262,54 @@ 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.
*/
@@ -271,19 +335,176 @@ 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)
+{
+ 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_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"
+};
+
static struct rcu_torture_ops *torture_ops[] =
- { &rcu_ops, &rcu_bh_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
@@ -330,6 +551,30 @@ rcu_torture_writer(void *arg)
}
/*
+ * 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
@@ -359,7 +604,7 @@ 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 +728,7 @@ 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;
@@ -507,6 +752,12 @@ 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);
@@ -540,11 +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
@@ -579,6 +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);
@@ -666,7 +931,25 @@ 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");
generated by cgit v0.10.2 at 2024-11-12 11:18:34 (GMT)