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Date: Wed, 8 Apr 2009 11:25:41 -0400
From: Theodore Tso <tytso@mit.edu>
To: Jens Axboe <jens.axboe@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
       Linux Kernel Developers List <linux-kernel@vger.kernel.org>,
       Ext4 Developers List <linux-ext4@vger.kernel.org>, jack@suse.cz
Subject: Re: [PATCH 1/3] block_write_full_page: Use synchronous writes for
	WBC_SYNC_ALL writebacks
Message-ID: <20090408152541.GA14895@mit.edu>
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On Wed, Apr 08, 2009 at 07:58:54AM +0200, Jens Axboe wrote:
> 
> I'm not even sure what is documented about this sort of thing in biodoc,
> but it's actually somewhat outside the realm of block layer
> documentation. The block layer should document that you need to call
> unplug if you are going to be waiting for that IO. How the vm code does
> it is implementation detail mostly, the important thing is that it gets
> done :-)

Fair enough; I agree a lot of the problem is the page writeback
subsystem isn't well documented at all, and is crying out for a review
for possible refactorization and cleanup....

						- Ted
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