From: Nick Piggin <piggin@cyberone.com.au>
To: Nick Piggin <piggin@cyberone.com.au>
Cc: Chris Mason <mason@suse.com>, Andrea Arcangeli <andrea@suse.de>,
Marc-Christian Petersen <m.c.p@wolk-project.de>,
Jens Axboe <axboe@suse.de>,
Marcelo Tosatti <marcelo@conectiva.com.br>,
Georg Nikodym <georgn@somanetworks.com>,
lkml <linux-kernel@vger.kernel.org>,
Matthias Mueller <matthias.mueller@rz.uni-karlsruhe.de>
Subject: Re: [PATCH] io stalls
Date: Thu, 26 Jun 2003 23:18:08 +1000 [thread overview]
Message-ID: <3EFAF290.9020904@cyberone.com.au> (raw)
In-Reply-To: <3EFAEF71.1080109@cyberone.com.au>
Nick Piggin wrote:
snip
>
> Yeah, something like that. I think that in a queue full situation,
> the processes are wanting to submit more than 1 request though. So
> the better thoughput you can achieve by batching translates to
> better effective throughput. Read my recent debate with Andrea
^^^^^^^^^^
Err, latency
snip
>
> No, the numbers (batch # requests, batch time) are not highly scientific.
> Simply when a process wakes up, we'll let them submit a small burst of
> requests before they go back to sleep.
by this, I mean that its not a big problem that we don't know how many
requests a process wants to submit.
snip
>
> The changes do seem to be a critical fix due to the starvation issue,
> but I'm worried that they take a big step back in performance under
> high disk load. I found my FIFO mechanism to be unacceptably slow for
> 2.5.
BTW. sorry for the lack of better benchmark numbers. I couldn't
find good ones lying around. I found uniprocessor tiobench to
be quite helpful at queue_nr_requests * 0.5, 2 threads to
measure different types of overloadedness.
Also, I didn't see much gain in read performance in my testing -
probably due to AS. I expect 2.4 and 2.5 non AS read performance
to show bigger improvements from batching (ie. regressions).
next prev parent reply other threads:[~2003-06-26 13:04 UTC|newest]
Thread overview: 109+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-05-29 0:55 Linux 2.4.21-rc6 Marcelo Tosatti
2003-05-29 1:22 ` Con Kolivas
2003-05-29 5:24 ` Marc Wilson
2003-05-29 5:34 ` Riley Williams
2003-05-29 5:57 ` Marc Wilson
2003-05-29 7:15 ` Riley Williams
2003-05-29 8:38 ` Willy Tarreau
2003-05-29 8:40 ` Willy Tarreau
2003-06-03 16:02 ` Marcelo Tosatti
2003-06-03 16:13 ` Marc-Christian Petersen
2003-06-04 21:54 ` Pavel Machek
2003-06-05 2:10 ` Michael Frank
2003-06-03 16:30 ` Michael Frank
2003-06-03 16:53 ` Matthias Mueller
2003-06-03 16:59 ` Marc-Christian Petersen
2003-06-03 17:03 ` Marc-Christian Petersen
2003-06-03 18:02 ` Anders Karlsson
2003-06-03 21:12 ` J.A. Magallon
2003-06-03 21:18 ` Marc-Christian Petersen
2003-06-03 17:23 ` Michael Frank
2003-06-04 14:56 ` Jakob Oestergaard
2003-06-04 4:04 ` Marc Wilson
2003-05-29 10:02 ` Con Kolivas
2003-05-29 18:00 ` Georg Nikodym
2003-05-29 19:11 ` -rc7 " Marcelo Tosatti
2003-05-29 19:56 ` Krzysiek Taraszka
2003-05-29 20:18 ` Krzysiek Taraszka
2003-06-04 18:17 ` Marcelo Tosatti
2003-06-04 21:41 ` Krzysiek Taraszka
2003-06-04 22:37 ` Alan Cox
2003-06-04 10:22 ` Andrea Arcangeli
2003-06-04 10:35 ` Marc-Christian Petersen
2003-06-04 10:42 ` Jens Axboe
2003-06-04 10:46 ` Marc-Christian Petersen
2003-06-04 10:48 ` Andrea Arcangeli
2003-06-04 11:57 ` Nick Piggin
2003-06-04 12:00 ` Jens Axboe
2003-06-04 12:09 ` Andrea Arcangeli
2003-06-04 12:20 ` Jens Axboe
2003-06-04 20:50 ` Rob Landley
2003-06-04 12:11 ` Nick Piggin
2003-06-04 12:35 ` Miquel van Smoorenburg
2003-06-09 21:39 ` [PATCH] io stalls (was: -rc7 Re: Linux 2.4.21-rc6) Chris Mason
2003-06-09 22:19 ` Andrea Arcangeli
2003-06-10 0:27 ` Chris Mason
2003-06-10 23:13 ` Chris Mason
2003-06-11 0:16 ` Andrea Arcangeli
2003-06-11 0:44 ` Chris Mason
2003-06-09 23:51 ` [PATCH] io stalls Nick Piggin
2003-06-10 0:32 ` Chris Mason
2003-06-10 0:47 ` Nick Piggin
2003-06-10 1:48 ` Robert White
2003-06-10 2:13 ` Chris Mason
2003-06-10 23:04 ` Robert White
2003-06-11 0:58 ` Chris Mason
2003-06-10 3:22 ` Nick Piggin
2003-06-10 21:17 ` Robert White
2003-06-11 0:40 ` Nick Piggin
2003-06-11 0:33 ` [PATCH] io stalls (was: -rc7 Re: Linux 2.4.21-rc6) Andrea Arcangeli
2003-06-11 0:48 ` [PATCH] io stalls Nick Piggin
2003-06-11 1:07 ` Andrea Arcangeli
2003-06-11 0:54 ` [PATCH] io stalls (was: -rc7 Re: Linux 2.4.21-rc6) Chris Mason
2003-06-11 1:06 ` Andrea Arcangeli
2003-06-11 1:57 ` Chris Mason
2003-06-11 2:10 ` Andrea Arcangeli
2003-06-11 12:24 ` Chris Mason
2003-06-11 17:42 ` Chris Mason
2003-06-11 18:12 ` Andrea Arcangeli
2003-06-11 18:27 ` Chris Mason
2003-06-11 18:35 ` Andrea Arcangeli
2003-06-12 1:04 ` [PATCH] io stalls Nick Piggin
2003-06-12 1:12 ` Chris Mason
2003-06-12 1:29 ` Andrea Arcangeli
2003-06-12 1:37 ` Andrea Arcangeli
2003-06-12 2:22 ` Chris Mason
2003-06-12 2:41 ` Nick Piggin
2003-06-12 2:46 ` Andrea Arcangeli
2003-06-12 2:49 ` Nick Piggin
2003-06-12 2:51 ` Nick Piggin
2003-06-12 2:52 ` Nick Piggin
2003-06-12 3:04 ` Andrea Arcangeli
2003-06-12 2:58 ` Andrea Arcangeli
2003-06-12 3:04 ` Nick Piggin
2003-06-12 3:12 ` Andrea Arcangeli
2003-06-12 3:20 ` Nick Piggin
2003-06-12 3:33 ` Andrea Arcangeli
2003-06-12 3:48 ` Nick Piggin
2003-06-12 4:17 ` Andrea Arcangeli
2003-06-12 4:41 ` Nick Piggin
2003-06-12 16:06 ` Chris Mason
2003-06-12 16:16 ` Nick Piggin
2003-06-25 19:03 ` Chris Mason
2003-06-25 19:25 ` Andrea Arcangeli
2003-06-25 20:18 ` Chris Mason
2003-06-27 8:41 ` write-caches, I/O stalls: MUST-FIX (was: [PATCH] io stalls) Matthias Andree
2003-06-26 5:48 ` [PATCH] io stalls Nick Piggin
2003-06-26 11:48 ` Chris Mason
2003-06-26 13:04 ` Nick Piggin
2003-06-26 13:18 ` Nick Piggin [this message]
2003-06-26 15:55 ` Chris Mason
2003-06-27 1:21 ` Nick Piggin
2003-06-27 1:39 ` Chris Mason
2003-06-27 9:45 ` Nick Piggin
2003-06-27 12:41 ` Chris Mason
2003-06-12 11:57 ` Chris Mason
2003-06-04 10:43 ` -rc7 Re: Linux 2.4.21-rc6 Andrea Arcangeli
2003-06-04 11:01 ` Marc-Christian Petersen
2003-06-03 19:45 ` Config issue (CONFIG_X86_TSC) " Paul
2003-06-03 20:18 ` Jan-Benedict Glaw
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