From: Mel Gorman <mgorman@suse.de>
To: Zdenek Kabelac <zkabelac@redhat.com>
Cc: Seth Jennings <sjenning@linux.vnet.ibm.com>,
Jiri Slaby <jslaby@suse.cz>,
Valdis.Kletnieks@vt.edu, Jiri Slaby <jirislaby@gmail.com>,
linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Rik van Riel <riel@redhat.com>,
Robert Jennings <rcj@linux.vnet.ibm.com>
Subject: Re: kswapd0: excessive CPU usage
Date: Mon, 12 Nov 2012 13:31:39 +0000 [thread overview]
Message-ID: <20121112133139.GU8218@suse.de> (raw)
In-Reply-To: <50A0F5F0.6090400@redhat.com>
On Mon, Nov 12, 2012 at 02:13:20PM +0100, Zdenek Kabelac wrote:
> 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
>
Not all together. Test either 1+2 or 1+3. 1+2 is the safer choice but
does nothing about THP stalls. 1+3 is a riskier version but depends on
me being correct on what the root cause of the problem you see it.
If both 1+2 and 1+3 work for you, I'd choose 1+3 for merging. If you only
have the time to test one combination then it would be preferred that you
test the safe option of 1+2.
Thanks.
--
Mel Gorman
SUSE Labs
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next prev parent reply other threads:[~2012-11-12 13:31 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-11 8:52 kswapd0: wxcessive CPU usage Jiri Slaby
2012-10-11 13:44 ` Valdis.Kletnieks
2012-10-11 15:34 ` Jiri Slaby
2012-10-11 17:56 ` Valdis.Kletnieks
2012-10-11 17:59 ` Jiri Slaby
2012-10-11 18:19 ` Valdis.Kletnieks
2012-10-11 22:08 ` kswapd0: excessive " Jiri Slaby
2012-10-12 12:37 ` Jiri Slaby
2012-10-12 13:57 ` Mel Gorman
2012-10-15 9:54 ` Jiri Slaby
2012-10-15 11:09 ` Mel Gorman
2012-10-29 10:52 ` Thorsten Leemhuis
2012-10-30 19:18 ` Mel Gorman
2012-10-31 11:25 ` Thorsten Leemhuis
2012-10-31 15:04 ` Mel Gorman
2012-11-04 16:36 ` Rik van Riel
2012-11-02 10:44 ` Zdenek Kabelac
2012-11-02 10:53 ` Jiri Slaby
2012-11-02 19:45 ` Jiri Slaby
2012-11-04 11:26 ` Zdenek Kabelac
2012-11-05 14:24 ` [PATCH] Revert "mm: vmscan: scale number of pages reclaimed by reclaim/compaction based on failures" Mel Gorman
2012-11-06 10:15 ` Johannes Hirte
2012-11-09 8:36 ` Mel Gorman
2012-11-14 21:43 ` Johannes Hirte
2012-11-09 9:12 ` Mel Gorman
2012-11-09 4:22 ` kswapd0: excessive CPU usage Seth Jennings
2012-11-09 8:07 ` Zdenek Kabelac
2012-11-09 9:06 ` Mel Gorman
2012-11-11 9:13 ` Zdenek Kabelac
2012-11-12 11:37 ` [PATCH] Revert "mm: remove __GFP_NO_KSWAPD" Mel Gorman
2012-11-16 19:14 ` Josh Boyer
2012-11-16 19:51 ` Andrew Morton
2012-11-20 1:43 ` Valdis.Kletnieks
2012-11-16 20:06 ` Mel Gorman
2012-11-20 15:38 ` Josh Boyer
2012-11-20 16:13 ` Bruno Wolff III
2012-11-20 17:43 ` Thorsten Leemhuis
2012-11-23 15:20 ` Thorsten Leemhuis
2012-11-27 11:12 ` Mel Gorman
2012-11-21 15:08 ` Mel Gorman
2012-11-20 9:18 ` Glauber Costa
2012-11-20 20:18 ` Andrew Morton
2012-11-21 8:30 ` Glauber Costa
2012-11-12 12:19 ` kswapd0: excessive CPU usage Mel Gorman
2012-11-12 13:13 ` Zdenek Kabelac
2012-11-12 13:31 ` Mel Gorman [this message]
2012-11-12 14:50 ` Zdenek Kabelac
2012-11-18 19:00 ` Zdenek Kabelac
2012-11-18 19:07 ` Jiri Slaby
2012-11-09 8:40 ` Mel Gorman
2012-10-11 22:14 ` kswapd0: wxcessive " Andrew Morton
2012-10-11 22:26 ` Jiri Slaby
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