Re: [PATCH] mm: Fix kswapd livelock on single core, no preempt kernel

[Mike Waychison]

On Wed, Dec 14, 2011 at 4:20 AM, Mel Gorman <mgorman@xxxxxxx> wrote:
> On Tue, Dec 13, 2011 at 08:36:43PM -0800, Mike Waychison wrote:
>> FYI, this was seen with a 2.6.39-based kernel with no-numa, no-memcg
>> and swap-enabled.
>>
>
> If this is 2.6.39, can you try applying the commit
> [f06590bd: mm: vmscan: correctly check if reclaimer should schedule during shrink_slab]
>
> There have been a few fixes around kswapd hogging the CPU since 2.6.39.

In this particular case, I didn't see any problem acquiring
shrinker_rwsem (the shrinkers should up in the cpu profile I
gathered).  I think this patch would fix my issue though as it happens
to drop in a cond_resched() into the path.  It isn't obvious that this
cond_resched() really belongs in shrink_slab() though.  Thanks :)

>
> --
> Mel Gorman
> SUSE Labs
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