Messages in this thread | | | Date | Fri, 6 Jul 2012 03:06:41 +0200 | Subject | Re: [PATCHv3 0/3] perf tool: Add new event group management | From | Stephane Eranian <> |
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On Thu, Jul 5, 2012 at 6:44 PM, Arnaldo Carvalho de Melo <acme@redhat.com> wrote: > 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@redhat.com> 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. And even, in that case that seems overkill too. You can simply repeat the modifier on each event. A group cannot big that big. It is limited in size by the number of physical counters plus the events constraints.
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