On Fri, Oct 09, 2020 at 05:25:30PM +0800, qianjun.ker...@gmail.com wrote:
> From: jun qian <qianjun.ker...@gmail.com>
>
> When the sched_schedstat changes from 0 to 1, some sched se maybe
> already in the runqueue, the se->statistics.wait_start will be 0.
> So it will let the (rq_of(cfs_rq)) - se->statistics.wait_start)
> wrong. We need to avoid this scenario.
>
> Signed-off-by: jun qian <qianjun.ker...@gmail.com>
> Signed-off-by: Yafang Shao <laoar.s...@gmail.com>
This SoB chain isn't valid. Did Yafang's tag need to a reviewed-by or
something?
> ---
> kernel/sched/fair.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 1a68a05..6f8ca0c 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -906,6 +906,15 @@ static void update_curr_fair(struct rq *rq)
> if (!schedstat_enabled())
> return;
>
> + /*
> + * When the sched_schedstat changes from 0 to 1, some sched se
> + * maybe already in the runqueue, the se->statistics.wait_start
> + * will be 0.So it will let the delta wrong. We need to avoid this
> + * scenario.
> + */
> + if (unlikely(!schedstat_val(se->statistics.wait_start)))
> + return;
> +
> delta = rq_clock(rq_of(cfs_rq)) -
> schedstat_val(se->statistics.wait_start);
>
> if (entity_is_task(se)) {
> --
> 1.8.3.1
>
