Re: [PATCH] mm: terminate shrink_slab loop if signal is pending

[Sergey Senozhatsky]

On (12/06/17 11:20), Suren Baghdasaryan wrote:
> Slab shrinkers can be quite time consuming and when signal
> is pending they can delay handling of the signal. If fatal
> signal is pending there is no point in shrinking that process
> since it will be killed anyway. This change checks for pending
> fatal signals inside shrink_slab loop and if one is detected
> terminates this loop early.
> 
> Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
> ---
>  mm/vmscan.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index c02c850ea349..69296528ff33 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -486,6 +486,13 @@ static unsigned long shrink_slab(gfp_t gfp_mask, int nid,
>  			.memcg = memcg,
>  		};
>  
> +		/*
> +		 * We are about to die and free our memory.
> +		 * Stop shrinking which might delay signal handling.
> +		 */
> +		if (unlikely(fatal_signal_pending(current))

-               if (unlikely(fatal_signal_pending(current))
+               if (unlikely(fatal_signal_pending(current)))

	-ss