Re: kswapd0: excessive CPU usage

Zdenek Kabelac
2012-11-12T13:13:36Z

Dne 12.11.2012 13:19, Mel Gorman napsal(a):
> On Sun, Nov 11, 2012 at 10:13:14AM +0100, Zdenek Kabelac wrote:
>> Hmm, so it's just took longer to hit the problem and observe kswapd0
>> spinning on my CPU again - it's not as endless like before - but
>> still it easily eats minutes - it helps to turn off Firefox or TB
>> (memory hungry apps) so kswapd0 stops soon - and restart those apps
>> again.
>> (And I still have like >1GB of cached memory)
>>
>
> I posted a "safe" patch that I believe explains why you are seeing what
> you are seeing. It does mean that there will still be some stalls due to
> THP because kswapd is not helping and it's avoiding the problem rather
> than trying to deal with it.
>
> Hence, I'm also going to post this patch even though I have not tested
> it myself. If you find it fixes the problem then it would be a
> preferable patch to the revert. It still is the case that the
> balance_pgdat() logic is in sort need of a rethink as it's pretty
> twisted right now.
>

Should I apply them all together for 3.7-rc5 ?

1) https://lkml.org/lkml/2012/11/5/308
2) https://lkml.org/lkml/2012/11/12/113
3) https://lkml.org/lkml/2012/11/12/151

Zdenek