Re: [PATCH 0/2] tracing: Tracing integration - dynamic ftrace for SystemTap

[Atsushi Tsuji <a-tsuji at bk dot jp dot nec dot com>]

Peter Zijlstra wrote:
> 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 ;-)

Thank you for your comments.

I understood that I need to make the mechanism to dynamically add tracepoints using
a mcount hook. I'll try to make it.

Thanks,
Atsushi