From: Peter Zijlstra <peterz@infradead.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Jiejing Zhang <kzjeef@gmail.com>,
Frederic Weisbecker <fweisbec@gmail.com>,
Ingo Molnar <mingo@redhat.com>,
linux-kernel@vger.kernel.org, Eric Miao <emiao@nvidia.com>,
Jiejing Zhang <jiejzhang@nvidia.com>
Subject: Re: [PATCH] ftrace: add tgid information in task switch event.
Date: Wed, 21 Aug 2013 17:23:05 +0200 [thread overview]
Message-ID: <20130821152305.GD31370@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <20130821110944.32bdf03a@gandalf.local.home>
On Wed, Aug 21, 2013 at 11:09:44AM -0400, Steven Rostedt wrote:
> > From: Jiejing Zhang <jiejzhang@nvidia.com>
> >
> > ftrace only report pid in task switch event, which is
> > actually thread ID in user space view, the comm of
> > the thread will be like "Thread-1", "Compiler", etc
> > in android system, it's useful if we can add tgid
> > information in ftrace event to find out the process
> > id, and the process id's comm will help us to figure
> > out the application, which was useful on data analysis
> > tools.
Meh.. are you telling me you really can't do that otherwise?
Adding this information makes the tracepoint slower for everybody else.
How about you enable trace_sched_process_fork() and track things that
way?
Also, last time I tried to change one of these stupid tracepoints
userspace broke.. Rostedt says people should be using libtraceevent but
I'm sceptical.
> > Change-Id: Ia99f58a56d691d770b3beb2f76de0351e6194a4a
That needs to die.
next prev parent reply other threads:[~2013-08-21 15:23 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-21 15:05 [PATCH] ftrace: add tgid information in task switch event Jiejing Zhang
2013-08-21 15:09 ` Steven Rostedt
2013-08-21 15:23 ` Peter Zijlstra [this message]
2013-08-23 8:33 ` Jiejing Zhang
2013-08-23 10:12 ` Peter Zijlstra
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