Commit-ID: ab7d45053f99f44f81a221eb5c9fbe253ee94524
Gitweb: http://git.kernel.org/tip/ab7d45053f99f44f81a221eb5c9fbe253ee94524
Author: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
AuthorDate: Tue, 4 Mar 2014 11:03:21 -0800
Committer: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
CommitDate: Wed, 14 May 2014 09:46:02 -0700
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@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
---
kernel/torture.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
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 @@ 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())
--
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