From: Nathan Scott <nathans@sgi.com>
To: Jens Axboe <axboe@suse.de>
Cc: Linux Kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] blk queue io tracing support
Date: Wed, 24 Aug 2005 11:03:46 +1000 [thread overview]
Message-ID: <20050824010346.GA1021@frodo> (raw)
In-Reply-To: <20050823123235.GG16461@suse.de>
On Tue, Aug 23, 2005 at 02:32:36PM +0200, Jens Axboe wrote:
> Hi,
>
> This is a little something I have played with. It allows you to see
> exactly what is going on in the block layer for a given queue. Currently
> it can logs request queueing and building, dispatches, requeues, and
> completions.
Ah, fabulous. Thanks Jens!
> + t.magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
> + t.sequence = atomic_add_return(1, &bt->sequence);
> + t.time = sched_clock() / 1000;
Wouldn't it be better to pass out the highest precision available here
& then do the conversion in userspace instead? I guess one might want
that little bit more for a RAM disk or something ... actually, talking
to one of the SGI people here with alot of experience on IRIX with a
similar facility, the msec resolution there is apparently sometimes an
issue already with fast storage.
cheers.
--
Nathan
next prev parent reply other threads:[~2005-08-24 1:12 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-08-23 12:32 [PATCH] blk queue io tracing support Jens Axboe
2005-08-24 1:03 ` Nathan Scott [this message]
2005-08-24 7:08 ` Jens Axboe
2005-08-24 7:19 ` Nathan Scott
2005-08-24 7:25 ` Jens Axboe
2005-08-24 9:28 ` Jens Axboe
2005-08-29 4:53 ` Nathan Scott
2005-08-29 5:57 ` Jens Axboe
2005-08-30 23:43 ` Nathan Scott
2005-08-31 7:31 ` Jens Axboe
2005-08-30 23:48 ` Nathan Scott
2005-08-30 23:58 ` Nathan Scott
2005-08-31 4:19 ` Tom Zanussi
2005-08-31 4:33 ` Nathan Scott
2005-08-31 4:53 ` Nathan Scott
2005-08-31 4:55 ` Tom Zanussi
2005-08-31 7:33 ` Jens Axboe
2005-09-02 11:20 ` Jens Axboe
2005-08-24 6:24 ` Nathan Scott
2005-08-24 7:08 ` Jens Axboe
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=20050824010346.GA1021@frodo \
--to=nathans@sgi.com \
--cc=axboe@suse.de \
--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