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

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

[Yangtao Li]

WARN_ON() already contains an unlikely(), so it's not necessary to
use WARN_ON(1).

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
---
 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

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

[Frank Lee]

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

On Sun, Nov 4, 2018 at 1:26 AM Yangtao Li <tiny.windzz@gmail.com> wrote:
>
> WARN_ON() already contains an unlikely(), so it's not necessary to
> use WARN_ON(1).
>
> Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
> ---
>  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
>

[tip:sched/core] sched/core: Remove unnecessary unlikely() in push_*_task()

[tip-bot for Yangtao Li]

Commit-ID:  9ebc6053814d37b9de8cc291fba28f30a729c929
Gitweb:     https://git.kernel.org/tip/9ebc6053814d37b9de8cc291fba28f30a729c929
Author:     Yangtao Li <tiny.windzz@gmail.com>
AuthorDate: Sat, 3 Nov 2018 13:26:02 -0400
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 11 Dec 2018 15:16:57 +0100

sched/core: Remove unnecessary unlikely() in push_*_task()

WARN_ON() already contains an unlikely(), so it's not necessary to
use WARN_ON(1).

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
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>
Link: http://lkml.kernel.org/r/20181103172602.1917-1-tiny.windzz@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 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 b32bc1f7cd14..fb8b7b5d745d 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -2042,10 +2042,8 @@ 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 9aa3287ce301..e4f398ad9e73 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -1813,10 +1813,8 @@ 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