From: Dave Olien <dmo@osdl.org>
To: rwhron@earthlink.net, piggin@cyberone.com.au
Cc: linux-kernel@vger.kernel.org, akpm@osdl.org
Subject: Re: [BENCHMARK] I/O regression after 2.6.0-test5
Date: Mon, 27 Oct 2003 15:49:11 -0800 [thread overview]
Message-ID: <20031027234911.GA31491@osdl.org> (raw)
In-Reply-To: <20031026103829.GA6549@rushmore>
[-- Attachment #1: Type: text/plain, Size: 1418 bytes --]
On Sun, Oct 26, 2003 at 05:38:29AM -0500, rwhron@earthlink.net wrote:
> 2.6.0-test8-mm1 doesn't have the AIM7 database regression
> that 2.6.0-test8 has. The AIM7 fileserver and shared
> workloads regression between test5-mm2 and test8-mm1 is
> about 18%. Mainline regression was about 38% between test5
> and test8 on AIM7 fileserver and shared workloads.
>
Yes, I've noticed this as well. This has been the pattern since
test5. Every mainline release (test6, test7, test8, AND test9)
has a large regression in as-iosched vs deadline scheduler performance.
The regression is considerably smaller when the mm[1-4] patches are
applied. See the attachment for a collection of data points, collected
running REAIM, an updated version of AIM7.
In the mm[1-4] broken-out patches lists, there is an O_SYNC-SPEEDUP-2.patch
that has been in all of the mm[1-4] patches since test5. The comments at
the head of that patch says this patch reduces the blocking of writers on i_sem.
This patch probably allows more writer concurrency. This benefits
only O_SYNC writes. Reaim does O_SYNC writes. My guess this patch
is what reduces the as-iosched regression for mm[1-4] patched kernels.
I imagine the O_SYNC-SPEEDUP is unlikely to get into any more TEST kernels.
But maybe it gives a hint is to what's going on with as-iosched.
Letting in more concurrent writers seems to reduce as-iosched's peformance
regression.
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Some data points (marked with XXX) haven't been collected yet.
This data has been collected on the Scalable Test Platform (STP)
8-way machines at OSDL.
REAIM is an updated version of AIM7. Information on REAIM and
performance data collected on 2, 4, and 8 way machines can be found at
http://developer.osdl.org/cliffw/
Hardware details of the STP 8-way machine are at the bottom of this page.
More details on each test run can be viewed by construcing a URL from the
STP ID #. For example, the first entry in the table can be seen at URL
http://khack.osdl.org/279446
Maximum Jobs Per Minute
Kernel Version IO Scheduler STP ID # Peak Load Quick Convergence
2.6.0-test5 Deadline 279446 8950 8542
As-iosched 279444 8785 8489
mm1 Deadline 279560 8303 7998
As-iosched 279558 8401 7935
mm2 Deadline 279929 8309 8063
As-iosched 281948 8224 7741
mm3 Deadline 281859 8438 8064
As-iosched 281813 8207 7879
mm4 Deadline 281814 8222 7991
As-iosched 281815 8417 7963
2.6.0-test6 Deadline 281816 8302 7949 ****
As-iosched 281817 6934 6945
mm1 Deadline 281864 8375 7930
As-iosched 281863 8163 7923
mm2 Deadline 281948 8224 7741
As-iosched 281865 8309 7616
mm3 Deadline 281868 8280 8022
As-iosched 281867 8348 8017
mm4 Deadline 281870 8512 7868
As-iosched 281869 8307 7749
2.6.0-test7 Deadline 281231 8413 8002 ****
As-iosched 282095 6957 6790
mm1 Deadline 281548 8567 8033
As-iosched 282181 8346 7755
2.6.0-test8 Deadline 281671 8294 8020 ****
As-iosched 281669 7018 6926
mm1 Deadline 282183 8326 7997
As-iosched 282182 8347 XXX
2.6.0-test9 Deadline XXXX XXXX
As-iosched 282310 6868 6045 ****
next prev parent reply other threads:[~2003-10-27 23:49 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-10-26 10:38 [BENCHMARK] I/O regression after 2.6.0-test5 rwhron
2003-10-27 23:49 ` Dave Olien [this message]
-- strict thread matches above, loose matches on Subject: below --
2003-10-29 0:38 rwhron
2003-10-27 23:33 John Hawkes
2003-10-24 23:43 rwhron
2003-10-24 12:46 rwhron
2003-10-24 0:10 rwhron
2003-10-21 13:05 rwhron
2003-10-21 15:57 ` Nick Piggin
2003-10-21 21:07 ` venom
2003-10-22 9:54 ` Nick Piggin
2003-10-22 18:30 ` Dave Olien
2003-10-22 19:08 ` Dave Olien
2003-10-23 2:24 ` Nick Piggin
2003-10-23 3:48 ` Nick Piggin
2003-10-23 20:35 ` Dave Olien
2003-10-23 23:07 ` Nick Piggin
2003-10-20 0:37 rwhron
2003-10-20 1:35 ` Nick Piggin
2003-10-20 4:52 ` Andrew Morton
2003-10-20 8:12 ` Nick Piggin
2003-10-20 4:51 ` Dave Olien
2003-10-20 7:55 ` venom
2003-10-21 4:49 ` Nick Piggin
2003-10-24 13:52 ` Magnus Andersson
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