From mboxrd@z Thu Jan  1 00:00:00 1970
From: Wu Fengguang <fengguang.wu@intel.com>
Subject: Re: [PATCH 00/45] some writeback experiments
Date: Wed, 7 Oct 2009 22:45:02 +0800
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References: <20091007073818.318088777@intel.com> <20091007142632.GM17883@mit.edu>
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To: Theodore Tso <tytso@mit.edu>,
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	Christoph Hellwig <hch@infradead.org>,
	Dave Chinner <david@fromorbit.com>,
	Chris Mason <chris.mason@oracle.co
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On Wed, Oct 07, 2009 at 10:26:32PM +0800, Theodore Ts'o wrote:
> On Wed, Oct 07, 2009 at 03:38:18PM +0800, Wu Fengguang wrote:
> > 
> > The estimated writeback bandwidth is about 1/2 the real throughput
> > for ext2/3/4 and btrfs; noticeable bigger than real throughput for NFS; and
> > cannot be estimated at all for XFS.  Very interesting..
> 
> Can you expand on what you mean here?  Estimated write bandwidth of
> what?  And what are you comparing it against?
 
Please refer to [PATCH 21/45] writeback: estimate bdi write bandwidth
and patch 22, I have some numbers there :)

> I'm having trouble understanding your note (which I'm guessing you
> write fairly late at night?  :-)

Sorry - I wrote that when I got tired on debugging ;)

Thanks,
Fengguang