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From: Dave Jones <davej@suse.de>
To: Linux Kernel <linux-kernel@vger.kernel.org>
Cc: andrea@suse.de, davej@codemonkey.org.uk
Subject: Possible O_DIRECT problems ?
Date: Fri, 21 Dec 2001 00:08:06 +0000	[thread overview]
Message-ID: <20011221000806.A26849@suse.de> (raw)

Andrea, lk,
 I just experimented with O_DIRECT in conjunction with fsx,
and the results aren't pretty.

Over NFS it survives around 921 operations, all local filesystems
(ext2,ext3,reiser tested) just 6 operations.
I've put the source to a modified fsx at
http://www.codemonkey.org.uk/cruft/fsx-odirect.c

It's possible I've done something wrong here, so look it over.
Just adding O_DIRECT flag to open() should be all thats necessary
correct ?

Also note, that by changing the flags on line 988 to have O_DIRECT
also, we get different failure type.

So, did I get the usage of O_DIRECT correct and find some bugs,
or have I had a little too much xmas spirits already ? 8-)


Dave.

-- 
| Dave Jones.                    http://www.codemonkey.org.uk
| SuSE Labs .

             reply	other threads:[~2001-12-21  0:06 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2001-12-21  0:08 Dave Jones [this message]
2001-12-21  0:23 ` Possible O_DIRECT problems ? Trond Myklebust
2001-12-21  0:39   ` Dave Jones
     [not found]     ` <w53ellp2out.wl@megaela.fe.dis.titech.ac.jp>
2001-12-21 12:46       ` Trond Myklebust
2001-12-21 16:14         ` Chuck Lever
2001-12-21 16:04       ` Chuck Lever
2001-12-29 15:25     ` Andrea Arcangeli
2001-12-29 18:46       ` CJ
2001-12-30  5:39         ` Andre Hedrick
2001-12-30 11:16           ` Gérard Roudier

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