From: Mel Gorman <mgorman@suse.de>
To: Thorsten Leemhuis <fedora@leemhuis.info>
Cc: 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>
Subject: Re: kswapd0: excessive CPU usage
Date: Wed, 31 Oct 2012 15:04:38 +0000 [thread overview]
Message-ID: <20121031150438.GK3888@suse.de> (raw)
In-Reply-To: <50910A99.5050707@leemhuis.info>
On Wed, Oct 31, 2012 at 12:25:13PM +0100, Thorsten Leemhuis wrote:
> On 30.10.2012 20:18, Mel Gorman wrote:
> >On Mon, Oct 29, 2012 at 11:52:03AM +0100, Thorsten Leemhuis wrote:
> >>On 15.10.2012 13:09, Mel Gorman wrote:
> >>>On Mon, Oct 15, 2012 at 11:54:13AM +0200, Jiri Slaby wrote:
> >>>>On 10/12/2012 03:57 PM, Mel Gorman wrote:
> >>>>>mm: vmscan: scale number of pages reclaimed by reclaim/compaction only in direct reclaim
> >>>>>Jiri Slaby reported the following:
> >[...]
> >>>>Yes, applying this instead of the revert fixes the issue as well.
> >>Just wondering, is there a reason why this patch wasn't applied to
> >>mainline? Did it simply fall through the cracks? Or am I missing
> >>something?
> >It's because a problem was reported related to the patch (off-list,
> >whoops). I'm waiting to hear if a second patch fixes the problem or not.
>
> Anything in particular I should look out for while testing?
>
Excessive reclaim, high CPU usage by kswapd, processes getting stick in
isolate_migratepages or isolate_freepages.
> >>I'm asking because I think I stil see the issue on
> >>3.7-rc2-git-checkout-from-friday. Seems Fedora rawhide users are
> >>hitting it, too:
> >>https://bugzilla.redhat.com/show_bug.cgi?id=866988
> >I like the steps to reproduce.
>
> One of those cases where the bugzilla bug template was not very
> helpful or where it was not used as intended (you decide) :-)
>
It wins at entertainment value if nothing else :)
> >Is step 3 profit?
>
> Yes, but psst, don't tell anyone; step 4 (world domination! for
> real!) is also hidden to keep that part of the big plan a secret for
> now ;-)
>
No doubt it's the default private comment #1 !
> >>Or are we seeing something different which just looks similar? I can
> >>test the patch if it needs further testing, but from the discussion
> >>I got the impression that everything is clear and the patch ready
> >>for merging.
> >It could be the same issue. Can you test with the "mm: vmscan: scale
> >number of pages reclaimed by reclaim/compaction only in direct reclaim"
> >patch and the following on top please?
>
> Built a vanilla mainline kernel with those two patches and installed
> it on the machine where I was seeing problems high kswapd0 load on
> 3.7-rc3. Ran it an hour yesterday and a few hours today; seems the
> patches fix the issue for me as kswapd behaves:
>
> $ LC_ALL=C ps -aux | grep 'kswapd'
> root 62 0.0 0.0 0 0 ? S Oct30 0:05 [kswapd0]
>
> So everything is looking fine again so far thx to the two patches
> -- hopefully it stays that way even after hitting "send" in my
> mailer in a few seconds.
>
Ok, great. Keep an eye on it please. If Jiri Slaby reports similar
success then I'll collapse the two patches together and resend to
Andrew.
Thanks.
--
Mel Gorman
SUSE Labs
next prev parent reply other threads:[~2012-10-31 15:04 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 [this message]
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
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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