From: Jens Axboe <axboe@suse.de>
To: Linux Kernel <linux-kernel@vger.kernel.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Subject: Re: Time sliced CFQ io scheduler
Date: Thu, 2 Dec 2004 14:48:02 +0100 [thread overview]
Message-ID: <20041202134801.GE10458@suse.de> (raw)
In-Reply-To: <20041202130457.GC10458@suse.de>
Hi,
One more test case, while the box is booted... This just demonstrates a
process doing a file write (bs=64k) with a competing process doing a
file read (bs=64k) at the same time, again capped at 30sec.
deadline:
Reader: 2520KiB/sec (max_lat=45msec)
Writer: 1258KiB/sec (max_lat=85msec)
as:
Reader: 27985KiB/sec (max_lat=34msec)
Writer: 64KiB/sec (max_lat=1042msec)
cfq:
Reader: 12703KiB/sec (max_lat=108msec)
Writer: 9743KiB/sec (max_lat=89msec)
If you look at vmstat while running these tests, cfq and deadline give
equal bandwidth for the reader and writer all the time, while as
basically doesn't give anything to the writer (a single block per second
only). Nick, is the write batching broken or something?
--
Jens Axboe
next prev parent reply other threads:[~2004-12-02 13:48 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-12-02 13:04 Time sliced CFQ io scheduler Jens Axboe
2004-12-02 13:48 ` Jens Axboe [this message]
2004-12-02 19:48 ` Andrew Morton
2004-12-02 19:52 ` Jens Axboe
2004-12-02 20:19 ` Andrew Morton
2004-12-02 20:19 ` Jens Axboe
2004-12-02 20:34 ` Andrew Morton
2004-12-02 20:37 ` Jens Axboe
2004-12-07 23:11 ` Nick Piggin
2004-12-02 22:18 ` Prakash K. Cheemplavam
2004-12-03 7:01 ` Jens Axboe
2004-12-03 9:12 ` Prakash K. Cheemplavam
2004-12-03 9:18 ` Jens Axboe
2004-12-03 9:35 ` Prakash K. Cheemplavam
2004-12-03 9:43 ` Jens Axboe
2004-12-03 9:26 ` Andrew Morton
2004-12-03 9:34 ` Prakash K. Cheemplavam
2004-12-03 9:39 ` Jens Axboe
2004-12-03 9:54 ` Prakash K. Cheemplavam
[not found] ` <41B03722.5090001@gmx.de>
2004-12-03 10:31 ` Jens Axboe
2004-12-03 10:38 ` Jens Axboe
2004-12-03 10:45 ` Prakash K. Cheemplavam
2004-12-03 10:48 ` Jens Axboe
2004-12-03 11:27 ` Prakash K. Cheemplavam
2004-12-03 11:29 ` Jens Axboe
2004-12-03 11:52 ` Prakash K. Cheemplavam
2004-12-08 0:37 ` Andrea Arcangeli
2004-12-08 0:54 ` Nick Piggin
2004-12-08 1:37 ` Andrea Arcangeli
2004-12-08 1:47 ` Nick Piggin
2004-12-08 2:09 ` Andrea Arcangeli
2004-12-08 2:11 ` Andrew Morton
2004-12-08 2:22 ` Andrea Arcangeli
2004-12-08 6:52 ` Jens Axboe
2004-12-08 2:00 ` Andrew Morton
2004-12-08 2:08 ` Andrew Morton
2004-12-08 6:55 ` Jens Axboe
2004-12-08 2:20 ` Andrea Arcangeli
2004-12-08 2:25 ` Andrew Morton
2004-12-08 2:33 ` Andrea Arcangeli
2004-12-08 2:33 ` Nick Piggin
2004-12-08 2:51 ` Andrea Arcangeli
2004-12-08 3:02 ` Nick Piggin
2004-12-08 6:58 ` Jens Axboe
2004-12-08 7:14 ` Nick Piggin
2004-12-08 7:20 ` Jens Axboe
2004-12-08 7:29 ` Nick Piggin
2004-12-08 7:32 ` Jens Axboe
2004-12-08 7:30 ` Andrew Morton
2004-12-08 7:36 ` Jens Axboe
2004-12-08 13:48 ` Jens Axboe
2004-12-08 6:55 ` Jens Axboe
2004-12-08 7:08 ` Nick Piggin
2004-12-08 7:11 ` Jens Axboe
2004-12-08 7:19 ` Nick Piggin
2004-12-08 7:26 ` Jens Axboe
2004-12-08 9:35 ` Jens Axboe
2004-12-08 10:08 ` Jens Axboe
2004-12-08 12:47 ` Jens Axboe
2004-12-08 10:52 ` Helge Hafting
2004-12-08 10:49 ` Jens Axboe
2004-12-08 6:49 ` Jens Axboe
2004-12-02 14:28 ` Giuliano Pochini
2004-12-02 14:41 ` Jens Axboe
2004-12-04 13:05 ` Giuliano Pochini
-- strict thread matches above, loose matches on Subject: below --
2004-12-03 20:52 Chuck Ebbert
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