From: Mel Gorman <mgorman@suse.de>
To: Zheng Liu <gnehzuil.liu@gmail.com>
Cc: linux-ext4@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>, Jiri Slaby <jslaby@suse.cz>
Subject: Re: Excessive stall times on ext4 in 3.9-rc2
Date: Tue, 2 Apr 2013 16:15:58 +0100 [thread overview]
Message-ID: <20130402151558.GI32241@suse.de> (raw)
In-Reply-To: <515AF348.7060209@gmail.com>
On Tue, Apr 02, 2013 at 11:03:36PM +0800, Zheng Liu wrote:
> Hi Mel,
>
> Thanks for reporting it.
>
> On 04/02/2013 10:27 PM, Mel Gorman wrote:
> > I'm testing a page-reclaim-related series on my laptop that is partially
> > aimed at fixing long stalls when doing metadata-intensive operations on
> > low memory such as a git checkout. I've been running 3.9-rc2 with the
> > series applied but found that the interactive performance was awful even
> > when there was plenty of free memory.
> >
> > I activated a monitor from mmtests that logs when a process is stuck for
> > a long time in D state and found that there are a lot of stalls in ext4.
> > The report first states that processes have been stalled for a total of
> > 6498 seconds on IO which seems like a lot. Here is a breakdown of the
> > recorded events.
>
> In this merge window, we add a status tree as a extent cache. Meanwhile
> a es_cache shrinker is registered to try to reclaim from this cache when
> we are under a high memory pressure.
Ok.
> So I suspect that the root cause
> is this shrinker. Could you please tell me how to reproduce this
> problem? If I understand correctly, I can run mmtest to reproduce this
> problem, right?
>
This is normal desktop usage with some development thrown in, nothing
spectacular but nothing obviously reproducible either unfortuantely. I
just noticed that some git operations were taking abnormally long, mutt
was very slow opening mail, applications like mozilla were very slow to
launch etc. and dug a little further. I haven't checked if regression
tests under mmtests captured something similar yet.
--
Mel Gorman
SUSE Labs
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next prev parent reply other threads:[~2013-04-02 15:16 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-02 14:27 Excessive stall times on ext4 in 3.9-rc2 Mel Gorman
2013-04-02 15:00 ` Jiri Slaby
2013-04-02 15:03 ` Zheng Liu
2013-04-02 15:15 ` Mel Gorman [this message]
2013-04-02 15:06 ` Theodore Ts'o
2013-04-02 15:14 ` Theodore Ts'o
2013-04-02 18:19 ` Theodore Ts'o
2013-04-07 21:59 ` Frank Ch. Eigler
2013-04-08 8:36 ` Mel Gorman
2013-04-08 10:52 ` Frank Ch. Eigler
2013-04-08 11:01 ` Theodore Ts'o
2013-04-03 10:19 ` Mel Gorman
2013-04-03 12:05 ` Theodore Ts'o
2013-04-03 15:15 ` Mel Gorman
2013-04-05 22:18 ` Jiri Slaby
2013-04-05 23:16 ` Theodore Ts'o
2013-04-06 7:29 ` Jiri Slaby
2013-04-06 7:37 ` Jiri Slaby
2013-04-06 8:19 ` Jiri Slaby
2013-04-06 13:15 ` Theodore Ts'o
2013-04-10 10:56 ` Mel Gorman
2013-04-10 13:12 ` Theodore Ts'o
2013-04-11 17:04 ` Mel Gorman
2013-04-11 18:35 ` Theodore Ts'o
2013-04-11 21:33 ` Jan Kara
2013-04-12 2:57 ` Theodore Ts'o
2013-04-12 4:50 ` Dave Chinner
2013-04-12 15:19 ` Theodore Ts'o
2013-04-13 1:23 ` Dave Chinner
2013-04-22 14:38 ` Mel Gorman
2013-04-22 22:42 ` Jeff Moyer
2013-04-23 0:02 ` Theodore Ts'o
2013-04-23 9:31 ` Jan Kara
2013-04-23 14:01 ` Mel Gorman
2013-04-24 19:09 ` Jeff Moyer
2013-04-25 12:21 ` Mel Gorman
2013-04-12 9:47 ` Mel Gorman
2013-04-21 0:05 ` Theodore Ts'o
2013-04-21 0:07 ` [PATCH 1/3] ext4: mark all metadata I/O with REQ_META Theodore Ts'o
2013-04-21 0:07 ` [PATCH 2/3] buffer: add BH_Prio and BH_Meta flags Theodore Ts'o
2013-04-21 0:07 ` [PATCH 3/3] ext4: mark metadata blocks using bh flags Theodore Ts'o
2013-04-21 6:09 ` Jiri Slaby
2013-04-21 19:55 ` Theodore Ts'o
2013-04-21 20:48 ` [PATCH 3/3 -v2] " Theodore Ts'o
2013-04-22 12:06 ` [PATCH 1/3] ext4: mark all metadata I/O with REQ_META Zheng Liu
2013-04-23 15:33 ` Excessive stall times on ext4 in 3.9-rc2 Mel Gorman
2013-04-23 15:50 ` Theodore Ts'o
2013-04-23 16:13 ` Mel Gorman
2013-04-12 10:18 ` Tvrtko Ursulin
2013-04-12 9:45 ` Mel Gorman
2013-04-02 23:16 ` Theodore Ts'o
2013-04-03 15:22 ` Mel Gorman
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