From mboxrd@z Thu Jan  1 00:00:00 1970
From: bgamari@gmail.com (Ben Gamari)
Date: Tue, 20 Jan 2009 15:22:12 -0500
Subject: [ltt-dev] [RFC PATCH] block: Fix bio merge induced high I/O
	latency
In-Reply-To: <20090120073709.GC30821@kernel.dk>
References: <20090117004439.GA11492@Krystal> <20090117162657.GA31965@Krystal>
	<20090117190437.GZ30821@kernel.dk> <20090118211234.GA4913@Krystal>
	<20090119182654.GT30821@kernel.dk> <20090120021055.GA6990@Krystal>
	<20090120073709.GC30821@kernel.dk>
Message-ID: <720e76b80901201222m72ae2e98l972c81ef5886a12e@mail.gmail.com>

On Tue, Jan 20, 2009 at 2:37 AM, Jens Axboe <jens.axboe at oracle.com> wrote:
> On Mon, Jan 19 2009, Mathieu Desnoyers wrote:
>> * Jens Axboe (jens.axboe at oracle.com) wrote:
>> Yes, ideally I should re-run those directly on the disk partitions.
>
> At least for comparison.
>

I just completed my own set of benchmarks using the fio job file
Mathieu provided. This was on a 2.5 inch 7200 RPM SATA partition
formatted as ext3. As you can see, I tested all of the available
schedulers with both queuing enabled and disabled. I'll test the Jens'
patch soon. Would a blktrace of the fio run help? Let me know if
there's any other benchmarking or profiling that could be done.
Thanks,

- Ben


			mint		maxt
==========================================================
queue_depth=31:
anticipatory		35 msec		11036 msec
cfq			37 msec		3350 msec
deadline		36 msec		18144 msec
noop			39 msec		41512 msec

==========================================================
queue_depth=1:
anticipatory		45 msec		9561 msec
cfq			28 msec		3974 msec
deadline		47 msec		16802 msec
noop			35 msec		38173 msec