Date: Thu, 2 Oct 2008 06:12:36 -0700
From: Arjan van de Ven <arjan@infradead.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Jens Axboe <jens.axboe@oracle.com>, linux-kernel@vger.kernel.org,
       Alan Cox <alan@lxorguk.ukuu.org.uk>
Subject: Re: [PATCH] Give kjournald a IOPRIO_CLASS_RT io priority
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On Wed, 1 Oct 2008 23:55:01 -0700
> 
> I've forgotten where that code is now, but I don't think it was ever
> revisited.  It should be.
> 
> So.  Where are these atime updaters getting blocked?

my reproducer is sadly very simple (claws-mail is my mail client that uses maildir)

Process claws-mail (4896)                  Total: 2829.7 msec 
EXT3: Waiting for journal access                  2491.0 msec         88.4 % 
Writing back inodes				   160.9 msec          5.7 % 
synchronous write                                   78.8 msec          3.0 %

is an example of such a trace (this is with patch, without patch the numbers are about 3x bigger)

Waiting for journal access is "journal_get_write_access"
Writing back inodes is "writeback_inodes"
synchronous write is "do_sync_write"


-- 
Arjan van de Ven 	Intel Open Source Technology Centre
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