From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
To: Masami Hiramatsu <mhiramat@redhat.com>
Cc: kosaki.motohiro@jp.fujitsu.com, Martin Bligh <mbligh@google.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Mathieu Desnoyers <compudj@krystal.dyndns.org>,
Steven Rostedt <rostedt@goodmis.org>,
od@novell.com, "Frank Ch. Eigler" <fche@redhat.com>,
systemtap-ml <systemtap@sources.redhat.com>
Subject: Re: Unified tracing buffer
Date: Tue, 23 Sep 2008 18:04:00 -0000 [thread overview]
Message-ID: <20080924025457.DC24.KOSAKI.MOTOHIRO@jp.fujitsu.com> (raw)
In-Reply-To: <48D90970.3060409@redhat.com>
> > I can't imazine a merit of the single-channel mode.
> > Could you please explain it?
>
> Actually, single-channel mode is for not-frequently event tracing.
> At least systemtap case, sometimes we just want to collect data
> and watch it periodically(as like as 'top'). Or, just monitoring
> errors as additional printk. in these cases, overhead is not so
> important.
>
> I think the main reason of using single-channel mode is simplicity of
> userspace reader. We can use 'cat' or 'tail' to read the buffer on-line.
> I'm not sure how much overhead ftrace-like buffer merging routine has,
> but if kernel provides an interface which gives us single-merged buffer
> image(like ftrace buffer), we are grad to use it. :-)
Yup, I also think it is better.
Thanks.
next prev parent reply other threads:[~2008-09-23 18:04 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <33307c790809191433w246c0283l55a57c196664ce77@mail.gmail.com>
2008-09-22 19:47 ` Masami Hiramatsu
2008-09-22 20:14 ` Martin Bligh
2008-09-22 22:27 ` Masami Hiramatsu
2008-09-22 23:12 ` Darren Hart
2008-09-23 0:06 ` Masami Hiramatsu
2008-09-22 23:17 ` Martin Bligh
2008-09-23 0:07 ` Masami Hiramatsu
2008-09-23 0:13 ` Martin Bligh
2008-09-23 14:51 ` Masami Hiramatsu
2008-09-23 15:09 ` Mathieu Desnoyers
2008-09-23 15:32 ` Masami Hiramatsu
2008-09-23 16:02 ` Linus Torvalds
2008-09-23 17:07 ` Masami Hiramatsu
2008-09-23 17:33 ` Thomas Gleixner
2008-09-23 19:03 ` Masami Hiramatsu
2008-09-23 19:37 ` Thomas Gleixner
2008-09-23 19:39 ` Martin Bligh
2008-09-23 19:42 ` Thomas Gleixner
2008-09-23 19:51 ` Martin Bligh
2008-09-23 20:05 ` Thomas Gleixner
2008-09-23 21:02 ` Martin Bligh
2008-09-23 20:06 ` Masami Hiramatsu
2008-09-23 20:09 ` Thomas Gleixner
2008-09-23 15:48 ` Linus Torvalds
2008-09-23 0:41 ` Linus Torvalds
2008-09-23 1:28 ` Roland Dreier
2008-09-23 1:40 ` Steven Rostedt
2008-09-23 2:08 ` Mathieu Desnoyers
2008-09-23 2:27 ` Darren Hart
2008-09-23 2:32 ` Mathieu Desnoyers
2008-09-23 3:29 ` Linus Torvalds
2008-09-23 3:42 ` Mathieu Desnoyers
2008-09-23 4:06 ` Linus Torvalds
2008-09-23 3:44 ` Steven Rostedt
2008-09-23 4:12 ` Masami Hiramatsu
2008-09-23 4:18 ` Martin Bligh
2008-09-23 15:25 ` Masami Hiramatsu
2008-09-23 10:54 ` Steven Rostedt
2008-09-23 4:20 ` Linus Torvalds
2008-09-23 14:13 ` Mathieu Desnoyers
2008-09-23 2:31 ` Mathieu Desnoyers
2008-09-23 3:07 ` Masami Hiramatsu
2008-09-23 14:38 ` KOSAKI Motohiro
2008-09-23 15:04 ` Frank Ch. Eigler
2008-09-23 15:23 ` Masami Hiramatsu
2008-09-23 18:04 ` KOSAKI Motohiro [this message]
2008-09-23 18:29 ` Martin Bligh
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