diff options
| author | Joonwoo Park <joonwoop@codeaurora.org> | 2014-12-16 14:44:09 -0800 |
|---|---|---|
| committer | David Keitel <dkeitel@codeaurora.org> | 2016-03-23 20:01:23 -0700 |
| commit | a4ca8c9b561213652950165170730375bbafbb98 (patch) | |
| tree | 51825334ec1a80dce58997ec22df40c70c262424 | |
| parent | 790d5d8a4ad4309dfc44ca217fe073b1e51200c1 (diff) | |
sched: take account of irq preemption when calculating irqload delta
If irq raises while sched_irqload() is calculating irqload delta,
sched_account_irqtime() can update rq's irqload_ts which can be greater
than the jiffies stored in sched_irqload()'s context so delta can be
negative. This negative delta means there was recent irq occurence.
So remove improper BUG_ON().
CRs-fixed: 771894
Change-Id: I5bb01b50ec84c14bf9f26dd9c95de82ec2cd19b5
Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>
| -rw-r--r-- | kernel/sched/sched.h | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 2307b7cea12c..898e24e9f63d 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1039,7 +1039,12 @@ static inline u64 sched_irqload(int cpu) s64 delta; delta = get_jiffies_64() - rq->irqload_ts; - BUG_ON(delta < 0); + /* + * Current context can be preempted by irq and rq->irqload_ts can be + * updated by irq context so that delta can be negative. + * But this is okay and we can safely return as this means there + * was recent irq occurrence. + */ if (delta < SCHED_HIGH_IRQ_TIMEOUT) return rq->avg_irqload; |