Re: [PATCH] sched/core: remove unnecessary unlikely() in push_xx_task

From: Frank Lee
Date: Thu Nov 08 2018 - 12:58:20 EST


Hi mingo:
What is your point of view?
--Yangtao

On Sun, Nov 4, 2018 at 1:26 AM Yangtao Li <tiny.windzz@xxxxxxxxx> wrote:
>
> WARN_ON() already contains an unlikely(), so it's not necessary to
> use WARN_ON(1).
>
> Signed-off-by: Yangtao Li <tiny.windzz@xxxxxxxxx>
> ---
> kernel/sched/deadline.c | 4 +---
> kernel/sched/rt.c | 4 +---
> 2 files changed, 2 insertions(+), 6 deletions(-)
>
> diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
> index 91e4202b0634..8b5d964d59c5 100644
> --- a/kernel/sched/deadline.c
> +++ b/kernel/sched/deadline.c
> @@ -2041,10 +2041,8 @@ static int push_dl_task(struct rq *rq)
> return 0;
>
> retry:
> - if (unlikely(next_task == rq->curr)) {
> - WARN_ON(1);
> + if (WARN_ON(next_task == rq->curr))
> return 0;
> - }
>
> /*
> * If next_task preempts rq->curr, and rq->curr
> diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
> index 2e2955a8cf8f..0efd58563c80 100644
> --- a/kernel/sched/rt.c
> +++ b/kernel/sched/rt.c
> @@ -1810,10 +1810,8 @@ static int push_rt_task(struct rq *rq)
> return 0;
>
> retry:
> - if (unlikely(next_task == rq->curr)) {
> - WARN_ON(1);
> + if (WARN_ON(next_task == rq->curr))
> return 0;
> - }
>
> /*
> * It's possible that the next_task slipped in of
> --
> 2.17.0
>