From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Bill Davidsen <davidsen@tmr.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: mmap vs. O_DIRECT
Date: Wed, 10 Nov 2004 22:19:58 +0000 [thread overview]
Message-ID: <1100125196.20792.15.camel@localhost.localdomain> (raw)
In-Reply-To: <cmtsoo$j55$1@gatekeeper.tmr.com>
On Mer, 2004-11-10 at 00:05, Bill Davidsen wrote:
> I have an application which does a lot of mmap to process its data. The
> huge waitio time makes me think that mmap isn't doing direct i/o even
> when things are alligned.
Make sure you are using MAP_SHARED in such cases so that the object you
have is the page cache object, also remember to use madvise
prev parent reply other threads:[~2004-11-10 23:23 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-11-10 0:05 mmap vs. O_DIRECT Bill Davidsen
2004-11-10 21:13 ` Robert Love
2004-11-11 14:50 ` Bill Davidsen
2004-11-11 15:41 ` Robert Love
2004-11-11 17:13 ` Robert Love
2004-11-11 17:19 ` Avi Kivity
2004-11-11 17:22 ` Robert Love
2004-11-10 22:19 ` Alan Cox [this message]
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=1100125196.20792.15.camel@localhost.localdomain \
--to=alan@lxorguk.ukuu.org.uk \
--cc=davidsen@tmr.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox