From mboxrd@z Thu Jan  1 00:00:00 1970
From: Werner Almesberger <werner@almesberger.net>
Subject: Re: Reviewing ext3 improvement patches (delalloc, mballoc, extents)
Date: Mon, 14 Mar 2005 21:28:52 -0300
Message-ID: <20050314212852.O12802@almesberger.net>
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Cc: Suparna Bhattacharya <suparna@in.ibm.com>,
	Mingming Cao <cmm@us.ibm.com>, Badari Pulavarty <pbadari@us.ibm.com>,
	ext2-devel <ext2-devel@lists.sourceforge.net>,
	linux-fsdevel@vger.kernel.org, abiss-general@lists.sourceforge.net
To: Alex Tomas <alex@clusterfs.com>
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In-Reply-To: <m364zuxi9z.fsf@bzzz.home.net>; from alex@clusterfs.com on Mon, Mar 14, 2005 at 08:13:28PM +0300
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Alex Tomas wrote:
> you can drop PG_locked right as you set PG_writeback, I think

Hmm, not sure. mpage_writepage never calls writepage with PG_writeback,
only with PG_locked. Also, mpage_writepage calls get_block with
PG_locked, so the allocation, which may take a while, holds the lock.

This situation is admittedly a bit annoying: on the one hand, "sync"
should write all dirty data. On the other hand, if a random user
typing "sync" can break performance guarantees, these guarantees
aren't very valuable.

- Werner

-- 
  _________________________________________________________________________
 / Werner Almesberger, Buenos Aires, Argentina     werner@almesberger.net /
/_http://www.almesberger.net/____________________________________________/


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