public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Theodore Tso <tytso@mit.edu>
To: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>,
	Jens Axboe <jens.axboe@oracle.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Arnaldo Carvalho de Melo <acme@redhat.com>
Subject: Re: blktrace: event traces displayed wrong while ftrace blktrace is active
Date: Tue, 14 Apr 2009 17:32:07 -0400	[thread overview]
Message-ID: <20090414213207.GP955@mit.edu> (raw)
In-Reply-To: <20090414212532.GD5968@nowhere>

On Tue, Apr 14, 2009 at 11:25:33PM +0200, Frederic Weisbecker wrote:
> 
> Indeed. Note that you can overwrite this default by typing:
> 
> echo context-info > trace_option
> 
> after setting bkltrace as the current tracer.

The problem with doing that is that blktrace will then display this:

    fsync-tester-27934 [001]   208.031278:     fsync-tester-27934 [001]   208.031278: 254,4    Q  WS 268392 + 8 [fsync-tester]

I think the real problem is that blk trace is displaying the standard
context-info, so it's suppressing the normal context info.  So I have
the choice on having no context information on my event trace lines,
or two copies of the context information for the block trace lines.  

:-(

I'm guessing things were done this way in order to support the old
legancy blktrace format?

						- Ted

  reply	other threads:[~2009-04-14 21:32 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-04-13 21:59 blktrace: event traces displayed wrong while ftrace blktrace is active Theodore Ts'o
2009-04-13 22:19 ` Ingo Molnar
2009-04-14 10:03 ` Li Zefan
2009-04-14 21:25   ` Frederic Weisbecker
2009-04-14 21:32     ` Theodore Tso [this message]
2009-04-15  0:16       ` Arnaldo Carvalho de Melo
2009-04-15  0:57       ` Li Zefan

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=20090414213207.GP955@mit.edu \
    --to=tytso@mit.edu \
    --cc=acme@redhat.com \
    --cc=fweisbec@gmail.com \
    --cc=jens.axboe@oracle.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=lizf@cn.fujitsu.com \
    --cc=rostedt@goodmis.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