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| author | Paul E. McKenney <paulmck@kernel.org> | 2020-09-02 21:08:41 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2020-11-06 17:13:49 -0800 |
| commit | fda5ba9ed254727ac5761b81455d8e93c78eba4a (patch) | |
| tree | f8aabe3c3114b0ed1a35a528edb8925e87671d55 /kernel/torture.c | |
| parent | 19012b786ecccb29a9fa20c4ec0a67e2cdfbc010 (diff) | |
| download | lwn-fda5ba9ed254727ac5761b81455d8e93c78eba4a.tar.gz lwn-fda5ba9ed254727ac5761b81455d8e93c78eba4a.zip | |
torture: Make torture_stutter() use hrtimer
The torture_stutter() function uses schedule_timeout_interruptible()
to time the stutter duration, but this can miss race conditions due to
its being time-synchronized with everything else that is based on the
timer wheels. This commit therefore converts torture_stutter() to use
the high-resolution timers via schedule_hrtimeout(), and also to fuzz
the stutter interval. While in the area, this commit also limits the
spin-loop portion of the stutter_wait() function's wait loop to two
jiffies, down from about one second.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/torture.c')
| -rw-r--r-- | kernel/torture.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/kernel/torture.c b/kernel/torture.c index be09377af6bc..56ff02bf444f 100644 --- a/kernel/torture.c +++ b/kernel/torture.c @@ -641,20 +641,27 @@ EXPORT_SYMBOL_GPL(stutter_wait); */ static int torture_stutter(void *arg) { + ktime_t delay; + DEFINE_TORTURE_RANDOM(rand); int wtime; VERBOSE_TOROUT_STRING("torture_stutter task started"); do { if (!torture_must_stop() && stutter > 1) { wtime = stutter; - if (stutter > HZ + 1) { + if (stutter > 2) { WRITE_ONCE(stutter_pause_test, 1); - wtime = stutter - HZ - 1; - schedule_timeout_interruptible(wtime); - wtime = HZ + 1; + wtime = stutter - 3; + delay = ktime_divns(NSEC_PER_SEC * wtime, HZ); + delay += (torture_random(&rand) >> 3) % NSEC_PER_MSEC; + set_current_state(TASK_INTERRUPTIBLE); + schedule_hrtimeout(&delay, HRTIMER_MODE_REL); + wtime = 2; } WRITE_ONCE(stutter_pause_test, 2); - schedule_timeout_interruptible(wtime); + delay = ktime_divns(NSEC_PER_SEC * wtime, HZ); + set_current_state(TASK_INTERRUPTIBLE); + schedule_hrtimeout(&delay, HRTIMER_MODE_REL); } WRITE_ONCE(stutter_pause_test, 0); if (!torture_must_stop()) |