Re: [PATCH] sched_ext: Remove redundant rcu_read_lock/unlock() in sysrq_handle_sched_ext_reset()

[Andrea Righi <arighi@nvidia.com>]

Hi Zqiang,

On Thu, Apr 30, 2026 at 04:45:43PM +0800, Zqiang wrote:
> The sysrq_handle_sched_ext_reset() callback has already been
> executed in the rcu read critical section within __handle_sysrq(),
> this commit therefore remove redundant rcu_read_lock/unlock() in
> the sysrq_handle_sched_ext_reset().
> 
> Signed-off-by: Zqiang <qiang.zhang@linux.dev>

Looks good to me.

Reviewed-by: Andrea Righi <arighi@nvidia.com>

Thanks,
-Andrea

> ---
>  kernel/sched/ext.c | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
> index 45a2668284bc..0f3e9d088151 100644
> --- a/kernel/sched/ext.c
> +++ b/kernel/sched/ext.c
> @@ -7953,13 +7953,11 @@ static void sysrq_handle_sched_ext_reset(u8 key)
>  {
>  	struct scx_sched *sch;
>  
> -	rcu_read_lock();
>  	sch = rcu_dereference(scx_root);
>  	if (likely(sch))
>  		scx_disable(sch, SCX_EXIT_SYSRQ);
>  	else
>  		pr_info("sched_ext: BPF schedulers not loaded\n");
> -	rcu_read_unlock();
>  }
>  
>  static const struct sysrq_key_op sysrq_sched_ext_reset_op = {
> -- 
> 2.17.1
>