Re: [PATCHv3 0/3] perf tool: Add new event group management

From: Arnaldo Carvalho de Melo
Date: Thu Jul 05 2012 - 12:45:40 EST


Em Thu, Jul 05, 2012 at 06:15:20PM +0200, Stephane Eranian escreveu:
> On Mon, Jul 2, 2012 at 3:33 PM, Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
> > perf, tool: Enable sampling on specified event group leader
> >
> > Adding the functionality to the group modifier event syntax.
> > Allowing user to select leader event inside the group using
> > event index (command line event position in the group).
> >
> > Following example selects e2 as leader:
> > -e '{e1,e2,e3,e4}:2'
> >
> I don't understand why you actually need the :2 suffix. There can
> only be one leader. So assume it is the first one. Users have to
> know the first one is the leader which seems like a natural thing
> to do for me. It would make you syntax less ugly than it already
> is.

Agreed, looks like creeping featurism.

> I would have thought you could enable this with a simple
> cmdline option which changes the way you interpret the
> multiple -e options:
>
> perf record --group-reads -e e1,e2,e3 -e e4,e5,e6 .....
>
> Would setup the group leaders (e1, e4) for 2 groups.
> NO curly braces, no : needed.

Yeah, curly braces needed just when one wants to add group wide
modifiers.

- Arnaldo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/