From: Eugene Teo <eteo@redhat.com>
To: Helge Hafting <helge.hafting@aitel.hist.no>
Cc: "Böszörményi Zoltán" <zboszor@dunaweb.hu>, linux-kernel@vger.kernel.org
Subject: Re: How to determine whether a file was opened O_DIRECT?
Date: Mon, 09 Oct 2006 11:44:53 +0800 [thread overview]
Message-ID: <4529C5B5.4040804@redhat.com> (raw)
In-Reply-To: <44F400EA.5020506@aitel.hist.no>
Helge Hafting wrote:
> Böszörményi Zoltán wrote:
>> Hi,
>>
>> I would like to run some diagnostics on a database
>> process and I would like to know what flags it used
>> for opening its files. Is there any way to get this info?
>>
>> Thanks in advance,
>> Zoltán Böszörményi
>>
> 1. Look at the source code for the database - if you have it.
> 2. Run your database under strace, then search the voluminous
> output for "open" calls and look at the flags.
> 3. Patch your kernel to "printk" information whenever
> someone opens with O_DIRECT.
$ stap -x PID -e 'probe syscall.open { if (target() == pid()) log(argstr) }' \
| grep O_DIRECT
"/net", O_RDONLY|O_DIRECTORY|O_LARGEFILE|O_NONBLOCK
"/net", O_RDONLY|O_DIRECTORY|O_LARGEFILE|O_NONBLOCK
...
http://www.sourceware.org/systemtap
Eugene
--
eteo redhat.com ph: +65 6490 4142 http://www.kernel.org/~eugeneteo
gpg fingerprint: 47B9 90F6 AE4A 9C51 37E0 D6E1 EA84 C6A2 58DF 8823
prev parent reply other threads:[~2006-10-09 8:25 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-08-29 8:03 How to determine whether a file was opened O_DIRECT? Böszörményi Zoltán
2006-08-29 8:55 ` Helge Hafting
2006-08-29 9:15 ` Böszörményi Zoltán
2006-10-09 3:44 ` Eugene Teo [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=4529C5B5.4040804@redhat.com \
--to=eteo@redhat.com \
--cc=helge.hafting@aitel.hist.no \
--cc=linux-kernel@vger.kernel.org \
--cc=zboszor@dunaweb.hu \
/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.