From: Steven Rostedt <rostedt@goodmis.org>
To: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Theodore Tso <tedtso@gmail.com>, Theodore Tso <tytso@mit.edu>,
linux-kernel@vger.kernel.org, Ingo Molnar <mingo@elte.hu>,
Frederic Weisbecker <fweisbec@gmail.com>
Subject: Re: [PATCH] tracing: reduce latency and remove percpu trace_seq
Date: Tue, 20 Jul 2010 22:03:01 -0400 [thread overview]
Message-ID: <1279677781.4818.23.camel@gandalf.stny.rr.com> (raw)
In-Reply-To: <4C0CA4BE.9000703@cn.fujitsu.com>
On Mon, 2010-06-07 at 15:50 +0800, Lai Jiangshan wrote:
> Steven Rostedt wrote:
> > On Fri, 2010-06-04 at 10:23 +0800, Lai Jiangshan wrote:
> >> Steven Rostedt wrote:
> >>
> >>> The "print" in the trace_seq_printf() is the TP_printk() field of the
> >>> TRACE_EVENT. I believe that there were some events (ext4?) that did
> >>> things that required preemption disabled.
> >>>
> >> It seems that ext4 has no such events.
> >> I find jbd2_dev_to_name() in the TP_printk() field of ext4's tracepoints.
> >> And it seems that jbd2_dev_to_name() requires preemption enabled and sleepable.
> >>
> >> Maybe there were some events did things that required preemption disabled.
> >> But No document ensure TP_printk() preemption disabled, such events should
> >> be fixed, I think.
> >
> > Well, I had a private email conversation with Ted last year where IIRC,
> > adding the preempt disable would fix things.
> >
> > I'd like to make sure Ted is OK with removing that before we do so.
> >
> > Ted?
> >
>
> Hi, Ted
>
> Could you give some comments?
> I'm waiting and will appreciate your help.
Since I've not heard anything, I'm pulling this in for 2.6.36.
-- Steve
next prev parent reply other threads:[~2010-07-21 2:03 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-03 10:26 Lai Jiangshan
2010-06-03 13:36 ` Steven Rostedt
2010-06-04 2:23 ` Lai Jiangshan
2010-06-04 3:03 ` Steven Rostedt
2010-06-07 7:50 ` Lai Jiangshan
2010-07-21 2:03 ` Steven Rostedt [this message]
2010-07-23 12:10 ` [tip:perf/core] tracing: Reduce " tip-bot for Lai Jiangshan
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