Re: kswapd0: excessive CPU usage

Mel Gorman
2012-11-09T09:06:43Z

On Fri, Nov 09, 2012 at 09:07:45AM +0100, Zdenek Kabelac wrote:
> >fe2c2a106663130a5ab45cb0e3414b52df2fff0c is the first bad commit
> >commit fe2c2a106663130a5ab45cb0e3414b52df2fff0c
> >Author: Rik van Riel <riel@redhat.com>
> >Date: Wed Mar 21 16:33:51 2012 -0700
> >
> > vmscan: reclaim at order 0 when compaction is enabled
> >...
> >
> >This is plausible since the issue seems to be in the kswapd + compaction
> >realm. I've yet to figure out exactly what about this commit results in
> >kswapd spinning.
> >
> >I would be interested if someone can confirm this finding.
> >
> >--
> >Seth
> >
>
>
> On my system 3.7-rc4 the problem seems to be effectively solved by
> revert patch: https://lkml.org/lkml/2012/11/5/308
>

Ok, while there is still a question on whether it's enough I think it's
sensible to at least start with the obvious one.

Thanks very much.

--
Mel Gorman
SUSE Labs