diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2016-10-03 16:53:49 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-03-16 09:46:21 +0100 |
| commit | 26ae58d23b94a075ae724fd18783a3773131cfbc (patch) | |
| tree | 2838d38cfafb54b10b97cbe9e39cb3cf0d90115e /kernel/sched | |
| parent | 3e777f9909483b603946685d88acfae89f31b07b (diff) | |
sched/core: Add WARNING for multiple update_rq_clock() calls
Now that we have no missing calls, add a warning to find multiple
calls.
By having only a single update_rq_clock() call per rq-lock section,
the section appears 'atomic' wrt time.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched')
| -rw-r--r-- | kernel/sched/core.c | 3 | ||||
| -rw-r--r-- | kernel/sched/features.h | 7 |
2 files changed, 10 insertions, 0 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 3b31fc05a0f1..1bd15d0d0307 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -233,8 +233,11 @@ void update_rq_clock(struct rq *rq) return; #ifdef CONFIG_SCHED_DEBUG + if (sched_feat(WARN_DOUBLE_CLOCK)) + SCHED_WARN_ON(rq->clock_update_flags & RQCF_UPDATED); rq->clock_update_flags |= RQCF_UPDATED; #endif + delta = sched_clock_cpu(cpu_of(rq)) - rq->clock; if (delta < 0) return; diff --git a/kernel/sched/features.h b/kernel/sched/features.h index 1b3c8189b286..11192e0cb122 100644 --- a/kernel/sched/features.h +++ b/kernel/sched/features.h @@ -56,6 +56,13 @@ SCHED_FEAT(TTWU_QUEUE, true) */ SCHED_FEAT(SIS_AVG_CPU, false) +/* + * Issue a WARN when we do multiple update_rq_clock() calls + * in a single rq->lock section. Default disabled because the + * annotations are not complete. + */ +SCHED_FEAT(WARN_DOUBLE_CLOCK, false) + #ifdef HAVE_RT_PUSH_IPI /* * In order to avoid a thundering herd attack of CPUs that are |