From: Andrew Morton <akpm@zip.com.au>
To: Lincoln Dale <ltd@cisco.com>
Cc: Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: O_DIRECT performance impact on 2.4.18 (was: Re: [PATCH] 2.5.14IDE 56)
Date: Fri, 10 May 2002 00:15:19 -0700 [thread overview]
Message-ID: <3CDB7387.F309D519@zip.com.au> (raw)
In-Reply-To: <3CDAC4EB.FC4FE5CF@zip.com.au> <5.1.0.14.2.20020510155122.02d97910@mira-sjcm-3.cisco.com>
Lincoln Dale wrote:
>
> At 11:50 AM 9/05/2002 -0700, Andrew Morton wrote:
> > > /dev/md0 raid-0 with O_DIRECT: 91847kbyte/sec (2781usec
> > > /dev/md0
> > raid-0: 129455kbyte/sec (1978usec
> > > /dev/md0 raid-0 with O_NOCOPY: 195868kbyte/sec (1297usec
> >
> >hmm. Why is O_DIRECT always the slowest? (and it would presumably do
> >even worse with an 8k transfer size).
>
> i just reproduced the test to validate the data. i'm using 8kbyte blocks here.
> on kernel is 2.4.18, O_DIRECT is still the slowest.
8k would rather disadvantage O_DIRECT. It can't do readahead and it
can't to write-behind. It'll be forced to do tons of tiny I/Os.
> ...
>
> the biggest difference here is bounce_end_io_read in O_DIRECT.
Well hopefully that will be gone in 2.4.20, for many popular
controllers.
Not sure why it bit you here. It could be that the page allocator
just happened to give you highmem pages for the O_DIRECT test.
Turning off highmem may make the test more repeatable.
> given there's still lots of idle-time, i'll file up lockmeter on here and
> see if theres any gremlins there.
lockmeter will go off the dial. All those copies happen at
interrupt time, inside the global io_request_lock. It's horrid.
Try it with the block-highmem patch:
http://www.kernel.org/pub/linux/kernel/people/andrea/kernels/v2.4/2.4.19pre1aa1/00_block-highmem-all-18b-4.gz
-
next prev parent reply other threads:[~2002-05-10 7:12 UTC|newest]
Thread overview: 220+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-05-06 3:53 Linux-2.5.14 Linus Torvalds
2002-05-06 6:30 ` Linux-2.5.14 Daniel Pittman
2002-05-06 6:51 ` Linux-2.5.14 Andrew Morton
2002-05-06 15:13 ` Linux-2.5.14 Linus Torvalds
2002-05-07 4:28 ` Linux-2.5.14 Daniel Pittman
2002-05-09 3:53 ` Linux-2.5.14 Daniel Pittman
2002-05-09 4:34 ` Linux-2.5.14 Andrew Morton
2002-05-09 6:02 ` Linux-2.5.14 Daniel Pittman
2002-05-06 6:47 ` Linux-2.5.14 bert hubert
2002-05-06 7:07 ` Linux-2.5.14 Andrew Morton
2002-05-06 14:00 ` Linux-2.5.14 Rik van Riel
2002-05-06 9:09 ` [PATCH] 2.5.14 IDE 55 Martin Dalecki
2002-05-06 17:48 ` David Lang
2002-05-06 22:40 ` Roman Zippel
2002-05-07 10:10 ` Martin Dalecki
2002-05-07 11:31 ` Roman Zippel
2002-05-07 10:31 ` Martin Dalecki
2002-05-07 10:34 ` Martin Dalecki
2002-05-07 11:48 ` Roman Zippel
2002-05-07 11:19 ` Martin Dalecki
2002-05-07 12:35 ` Roman Zippel
2002-05-07 12:36 ` Andrey Panin
2002-05-07 11:32 ` Martin Dalecki
2002-05-07 12:38 ` Dave Jones
2002-05-07 0:03 ` Roman Zippel
2002-05-07 10:12 ` Martin Dalecki
2002-05-07 11:39 ` Roman Zippel
2002-05-07 10:40 ` Martin Dalecki
2002-05-07 12:42 ` Roman Zippel
2002-05-07 11:22 ` [PATCH] 2.5.14 IDE 56 Martin Dalecki
2002-05-07 14:02 ` Padraig Brady
2002-05-07 13:15 ` Martin Dalecki
2002-05-07 14:30 ` Padraig Brady
2002-05-07 15:08 ` Anton Altaparmakov
2002-05-07 15:36 ` Linus Torvalds
2002-05-07 16:20 ` Jan Harkes
2002-05-07 15:26 ` Martin Dalecki
2002-05-07 21:36 ` Jan Harkes
2002-05-08 0:25 ` Guest section DW
2002-05-08 3:03 ` Jan Harkes
2002-05-08 9:03 ` Martin Dalecki
2002-05-08 12:10 ` Alan Cox
2002-05-08 10:51 ` Martin Dalecki
2002-05-07 16:29 ` Padraig Brady
2002-05-07 16:51 ` Linus Torvalds
2002-05-07 18:29 ` Kai Henningsen
2002-05-08 7:48 ` Juan Quintela
2002-05-08 16:54 ` Linus Torvalds
2002-05-07 17:08 ` Alan Cox
2002-05-07 17:00 ` Linus Torvalds
2002-05-07 17:19 ` benh
2002-05-07 17:24 ` Linus Torvalds
2002-05-07 17:30 ` benh
2002-05-10 1:45 ` Mike Fedyk
2002-05-07 17:43 ` Richard Gooch
2002-05-07 18:05 ` Linus Torvalds
2002-05-07 18:26 ` Alan Cox
2002-05-07 18:16 ` Linus Torvalds
2002-05-07 18:40 ` Richard Gooch
2002-05-07 18:46 ` Linus Torvalds
2002-05-07 23:54 ` Roman Zippel
2002-05-08 6:57 ` Kai Henningsen
2002-05-08 9:37 ` Ian Molton
2002-05-09 13:58 ` Pavel Machek
2002-05-08 8:21 ` Martin Dalecki
2002-05-07 17:27 ` Jauder Ho
2002-05-08 8:13 ` Martin Dalecki
2002-05-07 18:29 ` Patrick Mochel
2002-05-07 18:02 ` Greg KH
2002-05-07 18:44 ` Richard Gooch
2002-05-07 18:44 ` Patrick Mochel
2002-05-07 19:21 ` Richard Gooch
2002-05-07 19:58 ` Patrick Mochel
2002-05-07 18:49 ` Thunder from the hill
2002-05-07 19:47 ` Patrick Mochel
2002-05-07 22:03 ` Richard Gooch
2002-05-08 8:14 ` Russell King
2002-05-08 16:07 ` Richard Gooch
2002-05-08 17:07 ` Russell King
2002-05-08 8:18 ` Martin Dalecki
2002-05-08 8:07 ` Martin Dalecki
2002-05-08 7:58 ` Martin Dalecki
2002-05-08 12:18 ` Alan Cox
2002-05-08 11:09 ` Martin Dalecki
2002-05-08 12:42 ` Alan Cox
2002-05-08 11:23 ` Martin Dalecki
2002-05-09 2:37 ` Lincoln Dale
2002-05-09 3:10 ` Andrew Morton
2002-05-09 10:05 ` Lincoln Dale
2002-05-09 18:50 ` Andrew Morton
2002-05-10 0:33 ` Andi Kleen
2002-05-10 0:48 ` Andrew Morton
2002-05-10 1:06 ` Andi Kleen
2002-05-13 17:51 ` Pavel Machek
2002-05-14 21:44 ` Andi Kleen
2002-05-10 6:50 ` O_DIRECT performance impact on 2.4.18 (was: Re: [PATCH] 2.5.14 IDE 56) Lincoln Dale
2002-05-10 7:15 ` Andrew Morton [this message]
2002-05-10 7:21 ` O_DIRECT performance impact on 2.4.18 (was: Re: [PATCH] 2.5.14IDE 56) Jens Axboe
2002-05-10 8:12 ` Andrea Arcangeli
2002-05-10 10:14 ` Lincoln Dale
2002-05-10 12:36 ` Andrea Arcangeli
2002-05-11 3:23 ` Lincoln Dale
2002-05-13 11:19 ` Andrea Arcangeli
2002-05-13 23:58 ` Lincoln Dale
2002-05-14 0:22 ` Andrea Arcangeli
2002-05-14 2:43 ` O_DIRECT on 2.4.19pre8aa2 md device Lincoln Dale
2002-05-21 15:51 ` Andrea Arcangeli
2002-05-22 1:18 ` Lincoln Dale
2002-05-22 2:51 ` Andrea Arcangeli
2002-06-03 4:53 ` high-end i/o performance of 2.4.19pre8aa2 (was: Re: O_DIRECT on 2.4.19pre8aa2 device) Lincoln Dale
2002-05-12 11:23 ` O_DIRECT performance impact on 2.4.18 (was: Re: [PATCH] 2.5.14IDE 56) Lincoln Dale
2002-05-13 11:37 ` Andrea Arcangeli
2002-05-10 15:55 ` O_DIRECT performance impact on 2.4.18 (was: Re: [PATCH] 2.5.14 IDE 56) Linus Torvalds
2002-05-11 1:01 ` Gerrit Huizenga
2002-05-11 18:04 ` Linus Torvalds
2002-05-11 18:19 ` Larry McVoy
2002-05-11 18:35 ` Linus Torvalds
2002-05-11 18:37 ` Larry McVoy
2002-05-11 18:56 ` Linus Torvalds
2002-05-11 21:42 ` Gerrit Huizenga
2002-05-11 18:43 ` Mr. James W. Laferriere
2002-05-11 23:38 ` Lincoln Dale
2002-05-12 0:36 ` yodaiken
2002-05-12 2:40 ` Andrew Morton
2002-05-11 18:26 ` O_DIRECT performance impact on 2.4.18 (was: Re: [PATCH] 2.5.14 Alan Cox
2002-05-11 18:09 ` Linus Torvalds
2002-05-11 18:45 ` O_DIRECT performance impact on 2.4.18 (was: Re: [PATCH] 2.5.14 IDE 56) yodaiken
2002-05-11 19:55 ` O_DIRECT performance impact on 2.4.18 Bernd Eckenfels
2002-05-11 14:18 ` O_DIRECT performance impact on 2.4.18 (was: Re: [PATCH] 2.5.14 IDE 56) Roy Sigurd Karlsbakk
2002-05-11 14:24 ` Jens Axboe
2002-05-11 18:25 ` Gerrit Huizenga
2002-05-11 20:17 ` Jens Axboe
2002-05-11 22:27 ` Gerrit Huizenga
2002-05-11 23:17 ` Lincoln Dale
2002-05-09 4:16 ` [PATCH] 2.5.14 IDE 56 Andre Hedrick
2002-05-09 13:32 ` Alan Cox
2002-05-09 14:58 ` Alan Cox
2002-05-08 18:21 ` Erik Andersen
2002-05-08 18:59 ` Dave Jones
2002-05-08 19:31 ` Alan Cox
2002-05-08 21:16 ` Erik Andersen
2002-05-08 22:14 ` Alan Cox
2002-05-09 13:13 ` Pavel Machek
2002-05-09 19:22 ` Daniel Jacobowitz
2002-05-10 12:01 ` Padraig Brady
2002-05-09 13:18 ` Pavel Machek
2002-05-07 17:10 ` Richard B. Johnson
2002-05-08 7:36 ` Martin Dalecki
2002-05-08 17:22 ` Greg KH
2002-05-08 18:46 ` Denis Vlasenko
2002-05-07 11:27 ` [PATCH] 2.5.14 IDE 57 Martin Dalecki
2002-05-07 13:16 ` Anton Altaparmakov
2002-05-07 12:34 ` Martin Dalecki
2002-05-07 13:56 ` Mikael Pettersson
2002-05-07 14:04 ` Dave Jones
2002-05-07 13:57 ` Anton Altaparmakov
2002-05-07 14:08 ` Dave Jones
2002-05-07 13:11 ` Martin Dalecki
2002-05-07 14:29 ` Anton Altaparmakov
2002-05-07 13:36 ` Martin Dalecki
2002-05-07 15:08 ` Anton Altaparmakov
2002-05-07 16:51 ` Dave Jones
2002-05-08 3:38 ` Anton Altaparmakov
2002-05-08 11:47 ` Dave Jones
2002-05-07 15:07 ` Padraig Brady
2002-05-07 17:21 ` Andre Hedrick
2002-05-11 14:09 ` Aaron Lehmann
2002-05-07 15:03 ` [PATCH] IDE 58 Martin Dalecki
2002-05-08 6:42 ` Paul Mackerras
2002-05-08 8:53 ` Martin Dalecki
2002-05-08 10:37 ` Bjorn Wesen
2002-05-08 10:16 ` Martin Dalecki
2002-05-08 19:06 ` Linus Torvalds
2002-05-08 19:10 ` Benjamin Herrenschmidt
2002-05-08 20:31 ` Alan Cox
2002-05-08 19:49 ` Benjamin Herrenschmidt
2002-05-08 20:44 ` Alan Cox
2002-05-08 20:04 ` Benjamin Herrenschmidt
2002-05-09 20:20 ` Ian Molton
2002-05-08 20:36 ` Andre Hedrick
2002-05-08 20:29 ` Andre Hedrick
2002-05-08 20:06 ` Benjamin Herrenschmidt
2002-05-09 12:14 ` Martin Dalecki
2002-05-09 15:19 ` Eric W. Biederman
2002-05-09 20:20 ` Ian Molton
2002-05-08 11:00 ` Benjamin Herrenschmidt
2002-05-09 19:58 ` [PATCH] 2.5.14 IDE 59 Martin Dalecki
2002-05-11 4:16 ` William Lee Irwin III
2002-05-11 16:59 ` [PATCH] 2.5.15 IDE 60 Martin Dalecki
2002-05-11 18:47 ` Pierre Rousselet
2002-05-11 19:12 ` Andre Hedrick
2002-05-11 19:52 ` Pierre Rousselet
2002-05-11 23:48 ` Andre Hedrick
2002-05-12 19:19 ` pdc202xx.c fails to compile in 2.5.15 Zlatko Calusic
2002-05-12 19:40 ` Jurriaan on Alpha
2002-05-12 22:00 ` Petr Vandrovec
2002-05-13 12:03 ` Alan Cox
2002-05-13 9:48 ` [PATCH] 2.5.15 IDE 61 Martin Dalecki
2002-05-13 12:17 ` [PATCH] 2.5.15 IDE 62 Martin Dalecki
2002-05-13 13:48 ` Jens Axboe
2002-05-13 13:02 ` Martin Dalecki
2002-05-13 15:38 ` Jens Axboe
2002-05-13 15:45 ` Martin Dalecki
2002-05-13 16:54 ` Linus Torvalds
2002-05-13 16:55 ` Jens Axboe
2002-05-13 16:00 ` Martin Dalecki
2002-05-13 18:02 ` benh
2002-05-13 15:50 ` Martin Dalecki
2002-05-13 17:52 ` benh
2002-05-13 15:55 ` Martin Dalecki
2002-05-13 19:13 ` benh
2002-05-14 8:48 ` Martin Dalecki
2002-05-17 11:40 ` Martin Dalecki
2002-05-17 2:27 ` Benjamin Herrenschmidt
2002-05-13 15:36 ` Tom Rini
2002-05-14 10:26 ` [PATCH] 2.5.15 IDE 62a Martin Dalecki
2002-05-14 10:28 ` [PATCH] 2.5.15 IDE 63 Martin Dalecki
2002-05-15 12:04 ` [PATCH] 2.5.15 IDE 64 Martin Dalecki
2002-05-15 13:12 ` Russell King
2002-05-15 12:14 ` Martin Dalecki
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