From: Jens Axboe <jens.axboe@oracle.com>
To: Li Zefan <lizf@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>,
Arnaldo Carvalho de Melo <acme@redhat.com>,
Frederic Weisbecker <fweisbec@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [RFC][PATCH] blktrace: fix original blktrace
Date: Wed, 25 Mar 2009 08:07:26 +0100 [thread overview]
Message-ID: <20090325070726.GD27476@kernel.dk> (raw)
In-Reply-To: <49C99BD2.9090503@cn.fujitsu.com>
On Wed, Mar 25 2009, Li Zefan wrote:
> I'm wondering what we are going to do with the original blktrace which
> is using relay and is used via ioctl.
>
> The problem is currently it's totally broken. You can use ftrace to see
> the output of blktrace, but user-space blktrace is unusable.
>
> With this patch, both ioctl and ftrace can be used, but of course you
> can't use both of them at the same time.
Even if ftrace was as fast as storing huge amounts of data as blktrace,
it's still of utmost importance that nothing is broken there. There are
people actually USING this tracing to do real work, it's not a
playground.
I appreciate the efforts to unify and improve our tracing, but we must
not be breaking blktrace along the way. Otherwise the whole thing goes
back to block/blktrace.c, period.
--
Jens Axboe
next prev parent reply other threads:[~2009-03-25 7:07 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-25 2:49 [RFC][PATCH] blktrace: fix original blktrace Li Zefan
2009-03-25 7:07 ` Jens Axboe [this message]
2009-03-25 7:25 ` Li Zefan
2009-03-25 7:27 ` Jens Axboe
2009-03-25 12:52 ` Ingo Molnar
2009-03-25 13:01 ` 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=20090325070726.GD27476@kernel.dk \
--to=jens.axboe@oracle.com \
--cc=acme@redhat.com \
--cc=fweisbec@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=lizf@cn.fujitsu.com \
--cc=mingo@elte.hu \
--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