From: Steven Pratt <slpratt@austin.ibm.com>
To: linux-kernel <linux-kernel@vger.kernel.org>
Subject: 2.5.70-mm2 causes performance drop of random read O_DIRECT
Date: Mon, 09 Jun 2003 18:32:29 -0500 [thread overview]
Message-ID: <3EE5190D.3070401@austin.ibm.com> (raw)
Starting in 2.5.70-mm2 and continuing in the mm tree, there is a
significant degrade in random read for block devices using O_DIRECT.
The drop occurs for all block sizes and ranges from 30%-40. CPU usage
is also lower although it may already be so low as to be irrelavent.
tolerance = 0.00 + 3.00% of 2.5.70-mm1
2.5.70-mm1 2.5.70-mm2
Blocksize KBs/sec KBs/sec %diff diff tolerance
---------- ------------ ------------ -------- ------------ ------------
4096 1567 924 -41.03 -643.00 47.01 *
8192 3057 1815 -40.63 -1242.00 91.71 *
16384 5745 3509 -38.92 -2236.00 172.35 *
65536 17357 11283 -34.99 -6074.00 520.71 *
262144 37537 27302 -27.27 -10235.00 1126.11 *
Full results can be found at:
http://www-124.ibm.com/developerworks/oss/linuxperf/regression/2.5.70-mm2/2.5.70-mm1-vs-2.5.70-mm2/
Steve
next reply other threads:[~2003-06-09 22:56 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-06-09 23:32 Steven Pratt [this message]
2003-06-10 0:13 ` 2.5.70-mm2 causes performance drop of random read O_DIRECT Nick Piggin
2003-06-10 14:05 ` Steven Pratt
2003-06-11 1:00 ` Nick Piggin
2003-06-11 15:16 ` Steven Pratt
2003-06-12 1:14 ` Nick Piggin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=3EE5190D.3070401@austin.ibm.com \
--to=slpratt@austin.ibm.com \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.