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>
diff --git a/kernel/sched/features.h b/kernel/sched/features.h
index 1b3c818..11192e0 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
