[PATCH] sched_ext: Remove dead code in scx_set_task_state default case

fangqiurong@kylinos.cn posted 1 patch 2 months, 1 week ago
kernel/sched/ext.c | 1 -
1 file changed, 1 deletion(-)
[PATCH] sched_ext: Remove dead code in scx_set_task_state default case
Posted by fangqiurong@kylinos.cn 2 months, 1 week ago
From: fangqiurong <fangqiurong@kylinos.cn>

The 'warn = true' assignment before 'return' in the default case is
dead code - WARN_ONCE is never reached when returning early. Remove it.

Signed-off-by: fangqiurong <fangqiurong@kylinos.cn>
---
 kernel/sched/ext.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index e8384b5f1b0f..4aaa7bf1faa6 100644
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -2934,7 +2934,6 @@ static void scx_set_task_state(struct task_struct *p, enum scx_task_state state)
 		warn = prev_state != SCX_TASK_READY;
 		break;
 	default:
-		warn = true;
 		return;
 	}
 
-- 
2.25.1
Re: [PATCH] sched_ext: Remove dead code in scx_set_task_state default case
Posted by Cheng-Yang Chou 2 months, 1 week ago
Hi fangqiurong,

On Wed, Apr 08, 2026 at 11:20:25AM +0800, fangqiurong@kylinos.cn wrote:
> From: fangqiurong <fangqiurong@kylinos.cn>
> 
> The 'warn = true' assignment before 'return' in the default case is
> dead code - WARN_ONCE is never reached when returning early. Remove it.
> 
> Signed-off-by: fangqiurong <fangqiurong@kylinos.cn>
> ---
>  kernel/sched/ext.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
> index e8384b5f1b0f..4aaa7bf1faa6 100644
> --- a/kernel/sched/ext.c
> +++ b/kernel/sched/ext.c
> @@ -2934,7 +2934,6 @@ static void scx_set_task_state(struct task_struct *p, enum scx_task_state state)
>  		warn = prev_state != SCX_TASK_READY;
>  		break;
>  	default:
> -		warn = true;
>  		return;
>  	}
>  
> -- 
> 2.25.1
> 

Thanks for spotting this, but it's already fixed in b905ee77d5f5:

 https://lore.kernel.org/all/20260402170025.1387202-1-smariotti@disroot.org/

You can probably use Tejun's branch for future contribution:

 git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext.git

-- 
Thanks,
Cheng-Yang