Re: [PATCH] ftrace: add tgid information in task switch event.

From: Peter Zijlstra
Date: Wed Aug 21 2013 - 11:23:18 EST


On Wed, Aug 21, 2013 at 11:09:44AM -0400, Steven Rostedt wrote:
> > From: Jiejing Zhang <jiejzhang@xxxxxxxxxx>
> >
> > 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.
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