Re: User defined metrics for perf stat?

[Andreas Hollmann <hollmann@in.tum.de>]

Thanks again, Jiri!

I'm wondering why stat_interva(time) and the
time parameter has a second meaning for non
interval code?

What intention was behind your decision?

Isn't it redundant and maybe ambiguous
since we have trace_end()?

The issue I see is that you have to distinguish
between time for interval and non interval mode
in your python script and then you could use
trace_end() anyway?

Maybe I'm missing something.

  def stat__interval(time):

    - is called for every interval with its time,
      in non interval mode it's called after last
      stat event with total measured time in ns

2016-02-03 15:09 GMT+01:00 Jiri Olsa <jolsa@redhat.com>:
> On Wed, Feb 03, 2016 at 12:43:48PM +0100, Andreas Hollmann wrote:
>> Thanks! Now it works.
>>
>> Are there any other callbacks specific to the new functionality?
>>
>> I saw this:
>>
>> def stat__interval(time):
>>    ...
>>
>> The name suggests that it is called once for each interval event entry?
>>
>> Anything else?
>
> there was explanation in one of the patch changelogs, attached
> I'll make it appear in some doc soon
>
>>
>> Would it make sense to extend "perf script -g" to generate the callbacks?
>
> yep, I thought about that.. will make it happen ;-)
>
> thanks,
> jirka
>
>
> ---
> Add support to get stat events data in perf python scripts.
>
> The python script shall implement following
> new interface to process stat data:
>
>   def stat__<event_name>_[<modifier>](cpu, thread, time, val, ena, run):
>
>     - is called for every stat event for given counter,
>       if user monitors 'cycles,instructions:u" following
>       callbacks should be defined:
>
>       def stat__cycles(cpu, thread, time, val, ena, run):
>       def stat__instructions_u(cpu, thread, time, val, ena, run):
>
>   def stat__interval(time):
>
>     - is called for every interval with its time,
>       in non interval mode it's called after last
>       stat event with total measured time in ns
>
> The rest of the current interface stays untouched..
>
> Please check example CPI metrics script in following patch
> with command line examples in changelogs.