Commit-ID: 628edaa5062282b6e3d76c886fd2cbccae5cb87b
Gitweb: http://git.kernel.org/tip/628edaa5062282b6e3d76c886fd2cbccae5cb87b
Author: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
AuthorDate: Fri, 31 Jan 2014 11:57:43 -0800
Committer: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
CommitDate: Sun, 23 Feb 2014 09:02:54 -0800
rcutorture: Abstract stutter_wait()
Because stuttering the test load (stopping and restarting it) is useful
for non-RCU testing, this commit moves the load-stuttering functionality
to kernel/torture.c.
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
---
include/linux/torture.h | 7 +++-
kernel/rcu/rcutorture.c | 69 +++++++--------------------------------
kernel/torture.c | 87 ++++++++++++++++++++++++++++++++++++++++++++++++-
3 files changed, 104 insertions(+), 59 deletions(-)
diff --git a/include/linux/torture.h b/include/linux/torture.h
index 0259db3..203f127 100644
--- a/include/linux/torture.h
+++ b/include/linux/torture.h
@@ -75,8 +75,13 @@ int torture_shuffle_init(long shuffint);
/* Shutdown task absorption, for when the tasks cannot safely be killed. */
void torture_shutdown_absorb(const char *title);
+/* Task stuttering, which forces load/no-load transitions. */
+void stutter_wait(const char *title);
+int torture_stutter_init(int s);
+void torture_stutter_cleanup(void);
+
/* Initialization and cleanup. */
-void torture_init_begin(char *ttype, bool v);
+void torture_init_begin(char *ttype, bool v, int *runnable);
void torture_init_end(void);
bool torture_cleanup(void);
bool torture_must_stop(void);
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 9357c88..4329ad1 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -103,7 +103,6 @@ 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 *stutter_task;
static struct task_struct *fqs_task;
static struct task_struct *boost_tasks[NR_CPUS];
static struct task_struct *shutdown_task;
@@ -145,8 +144,6 @@ static long n_barrier_attempts;
static long n_barrier_successes;
static struct list_head rcu_torture_removed;
-static int stutter_pause_test;
-
#if defined(MODULE) || defined(CONFIG_RCU_TORTURE_TEST_RUNNABLE)
#define RCUTORTURE_RUNNABLE_INIT 1
#else
@@ -222,18 +219,6 @@ rcu_torture_free(struct rcu_torture *p)
spin_unlock_bh(&rcu_torture_lock);
}
-static void
-rcu_stutter_wait(const char *title)
-{
- while (stutter_pause_test || !rcutorture_runnable) {
- if (rcutorture_runnable)
- schedule_timeout_interruptible(1);
- else
- schedule_timeout_interruptible(round_jiffies_relative(HZ));
- torture_shutdown_absorb(title);
- }
-}
-
/*
* Operations vector for selecting different types of tests.
*/
@@ -571,7 +556,7 @@ static int rcu_torture_boost(void *arg)
oldstarttime = boost_starttime;
while (ULONG_CMP_LT(jiffies, oldstarttime)) {
schedule_timeout_interruptible(oldstarttime - jiffies);
- rcu_stutter_wait("rcu_torture_boost");
+ stutter_wait("rcu_torture_boost");
if (torture_must_stop())
goto checkwait;
}
@@ -593,7 +578,7 @@ static int rcu_torture_boost(void *arg)
call_rcu_time = jiffies;
}
cond_resched();
- rcu_stutter_wait("rcu_torture_boost");
+ stutter_wait("rcu_torture_boost");
if (torture_must_stop())
goto checkwait;
}
@@ -618,7 +603,7 @@ static int rcu_torture_boost(void *arg)
}
/* Go do the stutter. */
-checkwait: rcu_stutter_wait("rcu_torture_boost");
+checkwait: stutter_wait("rcu_torture_boost");
} while (!torture_must_stop());
/* Clean up and exit. */
@@ -656,7 +641,7 @@ rcu_torture_fqs(void *arg)
udelay(fqs_holdoff);
fqs_burst_remaining -= fqs_holdoff;
}
- rcu_stutter_wait("rcu_torture_fqs");
+ stutter_wait("rcu_torture_fqs");
} while (!torture_must_stop());
VERBOSE_TOROUT_STRING("rcu_torture_fqs task stopping");
torture_shutdown_absorb("rcu_torture_fqs");
@@ -728,7 +713,7 @@ rcu_torture_writer(void *arg)
}
}
rcutorture_record_progress(++rcu_torture_current_version);
- rcu_stutter_wait("rcu_torture_writer");
+ stutter_wait("rcu_torture_writer");
} while (!torture_must_stop());
VERBOSE_TOROUT_STRING("rcu_torture_writer task stopping");
torture_shutdown_absorb("rcu_torture_writer");
@@ -765,7 +750,7 @@ rcu_torture_fakewriter(void *arg)
} else {
cur_ops->exp_sync();
}
- rcu_stutter_wait("rcu_torture_fakewriter");
+ stutter_wait("rcu_torture_fakewriter");
} while (!torture_must_stop());
VERBOSE_TOROUT_STRING("rcu_torture_fakewriter task stopping");
@@ -910,7 +895,7 @@ rcu_torture_reader(void *arg)
preempt_enable();
cur_ops->readunlock(idx);
schedule();
- rcu_stutter_wait("rcu_torture_reader");
+ stutter_wait("rcu_torture_reader");
} while (!torture_must_stop());
VERBOSE_TOROUT_STRING("rcu_torture_reader task stopping");
torture_shutdown_absorb("rcu_torture_reader");
@@ -1034,25 +1019,6 @@ rcu_torture_stats(void *arg)
return 0;
}
-/* Cause the rcutorture test to "stutter", starting and stopping all
- * threads periodically.
- */
-static int
-rcu_torture_stutter(void *arg)
-{
- VERBOSE_TOROUT_STRING("rcu_torture_stutter task started");
- do {
- schedule_timeout_interruptible(stutter * HZ);
- stutter_pause_test = 1;
- if (!kthread_should_stop())
- schedule_timeout_interruptible(stutter * HZ);
- stutter_pause_test = 0;
- torture_shutdown_absorb("rcu_torture_stutter");
- } while (!kthread_should_stop());
- VERBOSE_TOROUT_STRING("rcu_torture_stutter task stopping");
- return 0;
-}
-
static inline void
rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag)
{
@@ -1403,11 +1369,7 @@ rcu_torture_cleanup(void)
rcu_torture_barrier_cleanup();
rcu_torture_stall_cleanup();
- if (stutter_task) {
- VERBOSE_TOROUT_STRING("Stopping rcu_torture_stutter task");
- kthread_stop(stutter_task);
- }
- stutter_task = NULL;
+ torture_stutter_cleanup();
if (writer_task) {
VERBOSE_TOROUT_STRING("Stopping rcu_torture_writer task");
@@ -1548,7 +1510,7 @@ rcu_torture_init(void)
&rcu_ops, &rcu_bh_ops, &srcu_ops, &sched_ops,
};
- torture_init_begin(torture_type, verbose);
+ torture_init_begin(torture_type, verbose, &rcutorture_runnable);
/* Process args and tell the world that the torturer is on the job. */
for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
@@ -1682,21 +1644,14 @@ rcu_torture_init(void)
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_TOROUT_ERRSTRING("Failed to create stutter");
- stutter_task = NULL;
+ firsterr = torture_stutter_init(stutter * HZ);
+ if (firsterr)
goto unwind;
- }
- torture_shuffle_task_register(stutter_task);
}
if (fqs_duration < 0)
fqs_duration = 0;
if (fqs_duration) {
- /* Create the stutter thread */
+ /* Create the fqs thread */
fqs_task = kthread_run(rcu_torture_fqs, NULL,
"rcu_torture_fqs");
if (IS_ERR(fqs_task)) {
diff --git a/kernel/torture.c b/kernel/torture.c
index d51de30..b30c2ee 100644
--- a/kernel/torture.c
+++ b/kernel/torture.c
@@ -58,6 +58,7 @@ static bool verbose;
#define FULLSTOP_RMMOD 2 /* Normal rmmod of torture. */
static int fullstop = FULLSTOP_RMMOD;
static DEFINE_MUTEX(fullstop_mutex);
+static int *torture_runnable;
#ifdef CONFIG_HOTPLUG_CPU
@@ -453,16 +454,100 @@ static struct notifier_block torture_shutdown_nb = {
};
/*
+ * Variables for stuttering, which means to periodically pause and
+ * restart testing in order to catch bugs that appear when load is
+ * suddenly applied to or removed from the system.
+ */
+static struct task_struct *stutter_task;
+static int stutter_pause_test;
+static int stutter;
+
+/*
+ * Block until the stutter interval ends. This must be called periodically
+ * by all running kthreads that need to be subject to stuttering.
+ */
+void stutter_wait(const char *title)
+{
+ while (ACCESS_ONCE(stutter_pause_test) ||
+ (torture_runnable && !ACCESS_ONCE(*torture_runnable))) {
+ if (stutter_pause_test)
+ schedule_timeout_interruptible(1);
+ else
+ schedule_timeout_interruptible(round_jiffies_relative(HZ));
+ torture_shutdown_absorb(title);
+ }
+}
+EXPORT_SYMBOL_GPL(stutter_wait);
+
+/*
+ * Cause the torture test to "stutter", starting and stopping all
+ * threads periodically.
+ */
+static int torture_stutter(void *arg)
+{
+ VERBOSE_TOROUT_STRING("torture_stutter task started");
+ do {
+ if (!torture_must_stop()) {
+ schedule_timeout_interruptible(stutter);
+ ACCESS_ONCE(stutter_pause_test) = 1;
+ }
+ if (!torture_must_stop())
+ schedule_timeout_interruptible(stutter);
+ ACCESS_ONCE(stutter_pause_test) = 0;
+ torture_shutdown_absorb("torture_stutter");
+ } while (!torture_must_stop());
+ VERBOSE_TOROUT_STRING("torture_stutter task stopping");
+ return 0;
+}
+
+/*
+ * Initialize and kick off the torture_stutter kthread.
+ */
+int torture_stutter_init(int s)
+{
+ int ret;
+
+ stutter = s;
+ stutter_task = kthread_run(torture_stutter, NULL, "torture_stutter");
+ if (IS_ERR(stutter_task)) {
+ ret = PTR_ERR(stutter_task);
+ VERBOSE_TOROUT_ERRSTRING("Failed to create stutter");
+ stutter_task = NULL;
+ return ret;
+ }
+ torture_shuffle_task_register(stutter_task);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(torture_stutter_init);
+
+/*
+ * Cleanup after the torture_stutter kthread.
+ */
+void torture_stutter_cleanup(void)
+{
+ if (!stutter_task)
+ return;
+ VERBOSE_TOROUT_STRING("Stopping torture_stutter task");
+ kthread_stop(stutter_task);
+ stutter_task = NULL;
+}
+EXPORT_SYMBOL_GPL(torture_stutter_cleanup);
+
+/*
* Initialize torture module. Please note that this is -not- invoked via
* the usual module_init() mechanism, but rather by an explicit call from
* the client torture module. This call must be paired with a later
* torture_init_end().
+ *
+ * The runnable parameter points to a flag that controls whether or not
+ * the test is currently runnable. If there is no such flag, pass in NULL.
*/
-void __init torture_init_begin(char *ttype, bool v)
+void __init torture_init_begin(char *ttype, bool v, int *runnable)
{
mutex_lock(&fullstop_mutex);
torture_type = ttype;
verbose = v;
+ torture_runnable = runnable;
fullstop = FULLSTOP_DONTSTOP;
}
--
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