Re: [PATCH] mm/vmscan: make do_shrink_slab more robust.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hello,

On Mon, Nov 27, 2017 at 09:37:30AM +0800, Jiang Biao wrote:
> When running ltp stress test for 7*24 hours, the kernel occasionally
> complains the following warning continuously,
> 
> mb_cache_shrink_scan+0x0/0x3f0 negative objects to delete
> nr=-9222526086287711848
> mb_cache_shrink_scan+0x0/0x3f0 negative objects to delete
> nr=-9222420761333860545
> mb_cache_shrink_scan+0x0/0x3f0 negative objects to delete
> nr=-9222287677544280360
> ...
> 
> The tracing result shows the freeable(mb_cache_shrink_scan returns)
> is -1, which causes the continuous accumulation and overflow of
> total_scan.

Good catch.

> 
> This patch make do_shrink_slab more robust when
> shrinker->count_objects return negative freeable.

Shrinker.h says count_objects should return 0 if there are no
freeable objects, not -1.

So if something returns -1, changing it with returning 0 would
be more proper fix.

Thanks.


> 
> Signed-off-by: Jiang Biao <jiang.biao2@xxxxxxxxxx>
> ---
>  mm/vmscan.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index eb2f031..3ea28f0 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -323,7 +323,7 @@ static unsigned long do_shrink_slab(struct shrink_control *shrinkctl,
>  	long scanned = 0, next_deferred;
>  
>  	freeable = shrinker->count_objects(shrinker, shrinkctl);
> -	if (freeable == 0)
> +	if (freeable <= 0)
>  		return 0;
>  
>  	/*
> -- 
> 2.7.4
> 
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@xxxxxxxxx.  For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>



[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Bugtraq]     [Linux OMAP]     [Linux MIPS]     [eCos]     [Asterisk Internet PBX]     [Linux API]
  Powered by Linux