Re: [PATCH] dm-bufio: fix sched in atomic context

[Sheng Yong <shengyong2021@xxxxxxxxx>]

On 7/15/25 01:17, Mikulas Patocka wrote:
> On Thu, 10 Jul 2025, Sheng Yong wrote:
>
> > From: Sheng Yong <shengyong1@xxxxxxxxxx>
[..]
> > diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
> > index ec84ba5e93e5..caf6ae9a8b52 100644
> > --- a/drivers/md/dm-bufio.c
> > +++ b/drivers/md/dm-bufio.c
> > @@ -2742,7 +2742,9 @@ static unsigned long __evict_a_few(unsigned long nr_buffers)
> >   		__make_buffer_clean(b);
> >   		__free_buffer_wake(b);
> >   
> > +		dm_bufio_unlock(c);
> >   		cond_resched();
> > +		dm_bufio_lock(c);
> >   	}
> >   
> >   	dm_bufio_unlock(c);
> > --
> > 2.43.0
>
> Hi
>
> I accepted this patch. I changed it to:
>
> -               cond_resched();
> +               if (need_resched()) {
> +                       dm_bufio_unlock(c);
> +                       cond_resched();
> +                       dm_bufio_lock(c);
> +               }
>          }
>
>          dm_bufio_unlock(c);
>
> so that we are not hammering on the dm bufio lock when scheduling is not
> needed.

Hi, Mikulas,

Thank you for the update. It looks good to me.

thanks,
Yong
> Mikulas