From: Jeff Moyer <jmoyer@redhat.com>
To: tytso@mit.edu
Cc: linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org,
       jens.axboe@oracle.com, esandeen@redhat.com
Subject: Re: [patch/rft] jbd2: tag journal writes as metadata I/O
References: <x49iq8b9ep5.fsf@segfault.boston.devel.redhat.com>
	<20100405175205.GA4681@thunk.org>
	<x49hbnpkaqw.fsf@segfault.boston.devel.redhat.com>
	<20100405194803.GC23670@thunk.org>
Date: Mon, 05 Apr 2010 16:34:36 -0400
In-Reply-To: <20100405194803.GC23670@thunk.org> (tytso@mit.edu's message of
	"Mon, 5 Apr 2010 15:48:03 -0400")
Message-ID: <x49zl1hiqoz.fsf@segfault.boston.devel.redhat.com>
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tytso@mit.edu writes:

> On Mon, Apr 05, 2010 at 02:36:07PM -0400, Jeff Moyer wrote:
>> >
>> > What benchmark were you using to test small file writes?  This looks
>> > good to me as well, but we might want to do some extra benchmarking
>> > just to be sure we're not accidentally introducing a performance
>> > regression.
>> 
>> iozone showed regressions for write and re-write in runs that include
>> fsync timings for small files (<8MB).  Here's the command line used for
>> testing:
>> 
>> iozone -az -n 4k -g 2048m -y 1k -q 1m -e
>
> iozone is showing performance regressions or performance improvements?
> I thought the point of this patch was to improve iozone benchmarks?

Sorry, Ted, what I meant to say was that iozone showed differences
between deadline and cfq, where cfq's performance was much worse than
deadline's.

Thanks!
Jeff
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