From: Paul E. McKenney Date: Tue, 4 Mar 2014 19:03:21 +0000 (-0800) Subject: torture: Increase stutter-end intensity X-Git-Url: http://drtracing.org/?a=commitdiff_plain;ds=sidebyside;h=ab7d45053f99f44f81a221eb5c9fbe253ee94524;p=deliverable%2Flinux.git 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 Reviewed-by: Josh Triplett --- diff --git a/kernel/torture.c b/kernel/torture.c index e5af6be2594d..bc0ee382b3c8 100644 --- a/kernel/torture.c +++ b/kernel/torture.c @@ -533,7 +533,11 @@ 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); + 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 @@ static int torture_stutter(void *arg) 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())