From: Stan Hoeppner <stan@hardwarefreak.com>
To: xfs@oss.sgi.com
Subject: Re: NOW: o_direct -- WAS: Re: WARNING in xfs_lwr.c, xfs_write()
Date: Thu, 27 May 2010 19:25:56 -0500 [thread overview]
Message-ID: <4BFF0D94.5030903@hardwarefreak.com> (raw)
In-Reply-To: <20100527114736.GA13112@infradead.org>
Christoph Hellwig put forth on 5/27/2010 6:47 AM:
> O_DIRECT is not a Posix standard and not very portable. It originated
> on IRIX, and Linux inherited it during the 2.4 kernel series days.
> These days FreeBSD/NetBSD and AIX support it as well, but for example
> Solaris, HP-UX and OpenBSD don't, nevermind Windows or Mac OS.
>
> I have no idea why the MTAs don't want to use it - it's generally easier
> to use then memory mapped I/O, and has much more deterministic
> performance.
Thanks for the background Christoph. I can now see why Postfix and Dovecot in
particular don't use O_DIRECT: portability. They both are developed to run on
every Unix/like OS you mention above, half of which don't offer O_DIRECT. I'm
guessing the same may likely be true for the other SMTP MTAs and IMAP servers.
--
Stan
_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs
next prev parent reply other threads:[~2010-05-28 0:22 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-23 5:20 WARNING in xfs_lwr.c, xfs_write() Roman Kononov
2010-05-23 10:18 ` Dave Chinner
2010-05-23 14:23 ` Roman Kononov
2010-05-24 1:19 ` Dave Chinner
2010-06-12 5:00 ` Ilia Mirkin
2010-06-13 22:47 ` Dave Chinner
2010-06-13 23:10 ` Ilia Mirkin
2010-06-14 1:29 ` Dave Chinner
2010-06-14 3:27 ` Ilia Mirkin
2010-06-14 15:11 ` Roman Kononov
2010-05-24 4:12 ` Stan Hoeppner
2010-05-24 5:16 ` Stewart Smith
2010-05-24 19:34 ` Roman Kononov
2010-05-26 7:06 ` Dave Chinner
2010-05-26 15:07 ` NOW: o_direct -- WAS: " Stan Hoeppner
2010-05-27 11:05 ` Michael Monnerie
2010-05-27 11:47 ` Christoph Hellwig
2010-05-27 13:58 ` Stewart Smith
2010-05-27 14:57 ` Christoph Hellwig
2010-05-27 15:45 ` Stewart Smith
2010-05-28 0:25 ` Stan Hoeppner [this message]
2010-05-27 14:05 ` Stewart Smith
2010-05-28 0:42 ` Stan Hoeppner
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=4BFF0D94.5030903@hardwarefreak.com \
--to=stan@hardwarefreak.com \
--cc=xfs@oss.sgi.com \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox