sched: monitor clock underflows in /proc/sched_debug
We monitor clock overflows, let's also monitor clock underflows.
Signed-off-by: Guillaume Chazarain <guichaz@yahoo.fr>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/sched.c b/kernel/sched.c
index 3995d167..4d3a5a7 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -465,7 +465,7 @@
u64 clock, prev_clock_raw;
s64 clock_max_delta;
- unsigned int clock_warps, clock_overflows;
+ unsigned int clock_warps, clock_overflows, clock_underflows;
u64 idle_clock;
unsigned int clock_deep_idle_events;
u64 tick_timestamp;
@@ -3736,8 +3736,10 @@
/*
* Let rq->clock advance by at least TICK_NSEC:
*/
- if (unlikely(rq->clock < next_tick))
+ if (unlikely(rq->clock < next_tick)) {
rq->clock = next_tick;
+ rq->clock_underflows++;
+ }
rq->tick_timestamp = rq->clock;
update_cpu_load(rq);
curr->sched_class->task_tick(rq, curr, 0);
