torture: Increase stutter-end intensity
Currently, all stuttered kthreads block a jiffy at a time, which can
result in them starting at different times. (Note: This is not an
energy-efficiency problem unless you run torture tests in production,
in which case you have other problems!) This commit increases the
intensity of the restart event by causing kthreads to spin through the
last jiffy, restarting when they see the variable change.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
diff --git a/kernel/torture.c b/kernel/torture.c
index e5af6be..bc0ee38 100644
--- a/kernel/torture.c
+++ b/kernel/torture.c
@@ -533,7 +533,11 @@
while (ACCESS_ONCE(stutter_pause_test) ||
(torture_runnable && !ACCESS_ONCE(*torture_runnable))) {
if (stutter_pause_test)
- schedule_timeout_interruptible(1);
+ if (ACCESS_ONCE(stutter_pause_test) == 1)
+ schedule_timeout_interruptible(1);
+ else
+ while (ACCESS_ONCE(stutter_pause_test))
+ cond_resched();
else
schedule_timeout_interruptible(round_jiffies_relative(HZ));
torture_shutdown_absorb(title);
@@ -550,7 +554,11 @@
VERBOSE_TOROUT_STRING("torture_stutter task started");
do {
if (!torture_must_stop()) {
- schedule_timeout_interruptible(stutter);
+ if (stutter > 1) {
+ schedule_timeout_interruptible(stutter - 1);
+ ACCESS_ONCE(stutter_pause_test) = 2;
+ }
+ schedule_timeout_interruptible(1);
ACCESS_ONCE(stutter_pause_test) = 1;
}
if (!torture_must_stop())