From: Jiri Slaby <jslaby@suse.cz>
Subject: Re: Excessive stall times on ext4 in 3.9-rc2
Date: Tue, 02 Apr 2013 17:00:12 +0200
Message-ID: <515AF27C.2060206@suse.cz>
References: <20130402142717.GH32241@suse.de>
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Cc: LKML <linux-kernel@vger.kernel.org>, Linux-MM <linux-mm@kvack.org>
To: Mel Gorman <mgorman@suse.de>, linux-ext4@vger.kernel.org
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On 04/02/2013 04:27 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.

Just a note that I am indeed using ext4 on the affected machine for all
filesystems I have except for an efi partition...

-- 
js
suse labs

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