Subject: Re: [PATCH 0/2] tracing: Tracing integration - dynamic ftrace for
 SystemTap
From: Peter Zijlstra <peterz@infradead.org>
To: rostedt@goodmis.org
Cc: Atsushi Tsuji <a-tsuji@bk.jp.nec.com>, linux-kernel@vger.kernel.org,
       Ingo Molnar <mingo@elte.hu>, fweisbec@gmail.com,
       "Frank Ch. Eigler" <fche@redhat.com>, paulus@samba.org,
       systemtap@sources.redhat.com
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Date: Tue, 15 Sep 2009 15:36:56 +0200
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On Tue, 2009-09-15 at 09:28 -0400, Steven Rostedt wrote:
> On Tue, 2009-09-15 at 12:19 +0200, Peter Zijlstra wrote:
> > On Tue, 2009-09-15 at 12:15 +0200, Peter Zijlstra wrote:
> > > On Tue, 2009-09-15 at 19:06 +0900, Atsushi Tsuji wrote:
> > > > The patches doesn't contain the performance counters integration,
> > > > since it is still in development. I think following implementations are
> > > > needed:
> > > > - add new type to perf_id (like PERF_TYPE_FTRACE)
> > > > - add event ids to struct dyn_ftrace
> > > > - add interfaces to reference event ids by user (via debugfs?)
> > > > - add probe function to count ftrace events (call do_perf_swcounter_event)
> > > 
> > > That's long since been done,.. 
> > 
> > Or are you talking about the mcount thing? Simply expose the mcount hook
> > as a regular tracepoint and perf can already use it.
> > 

> I'm not sure what you mean by exposing the mcount hook as a tracepoint.
> Or you mean make it a special file in debug/tracing/events/ that lets
> you enable it as a profile trace?

Either make it a single tracepoint on which you can apply filters or
make it generate a tracepoint per mcount site, I don't really mind ;-)

If kprobes can live in the same space, then surely the function tracer
can too ;-)

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