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-rw-r--r--kernel/rcutorture.c109
1 files changed, 104 insertions, 5 deletions
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index 43d6d4f9ef0..e0450210ce4 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
*/
@@ -47,9 +48,11 @@
#include <linux/srcu.h>
MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com>");
+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. */
@@ -59,6 +62,8 @@ static char *torture_type = "rcu"; /* What to torture: rcu, rcu_bh, srcu. */
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;
@@ -186,6 +192,7 @@ 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;
};
@@ -258,6 +265,7 @@ 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"
};
@@ -287,6 +295,28 @@ 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,
@@ -295,6 +325,7 @@ 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"
};
@@ -367,6 +398,11 @@ static void srcu_torture_deferred_free(struct rcu_torture *p)
}
}
+static void srcu_torture_synchronize(void)
+{
+ synchronize_srcu(&srcu_ctl);
+}
+
static int srcu_torture_stats(char *page)
{
int cnt = 0;
@@ -392,6 +428,7 @@ static struct rcu_torture_ops srcu_ops = {
.readunlock = srcu_torture_read_unlock,
.completed = srcu_torture_completed,
.deferredfree = srcu_torture_deferred_free,
+ .sync = srcu_torture_synchronize,
.stats = srcu_torture_stats,
.name = "srcu"
};
@@ -444,6 +481,30 @@ 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
@@ -621,6 +682,12 @@ 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 +721,12 @@ 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 +761,19 @@ 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 +861,24 @@ 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) {
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-12-29 18:35:08 +0000