Re: [PATCH] Give kjournald a IOPRIO_CLASS_RT io priority

From: Arjan van de Ven
Date: Thu Oct 02 2008 - 09:13:11 EST


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"


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Arjan van de Ven Intel Open Source Technology Centre
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