Re: [PATCH 3/3] perf, tool: Add new event group management

[Arnaldo Carvalho de Melo <acme@redhat.com>]

Em Wed, Mar 21, 2012 at 11:42:14AM +0100, Jiri Olsa escreveu:
> On Tue, Mar 20, 2012 at 07:44:41PM +0100, Peter Zijlstra wrote:
> > If so, we need some option like:
> > 
> >   perf record -e "{cpu-clock,cache-misses,cache-references}:1"
> > 
> > to mean, only sample on cpu-clock but use PERF_SAMPLE_READ and
> > PERF_FORMAT_GROUP to read all siblings on every cpu-clock sample.
> > 
> > Now the disadvantage is that {} needs quotes on bash, the advantage is
> > that its completely natural on how to construct groups, without weird
> > --group/--group parsed. Also it provides a place for group modifiers.
> 
> how about '=group' keyword followed by ':' modifier
>   perf record -e "cpu-clock,cache-misses,cache-references=group:1"
> 
> or '=$groupname' and use the group name in output like
>   perf stat -e "task-clock,context-switches=krava:1" ls
> 
>      Performance counter stats for 'ls':
> 
>           1.003695 task-clock/krava          #    0.083 CPUs utilized          
>                  0 context-switches/krava    #    0.000 K/sec                  
> 

Humm, interesting, perhaps putting the group name before the =event_list
will be more intuitive?

I.e.:

  perf stat -e "krava=task-clock,context-switches:1" ls

- Arnaldo