Messages in this thread | | | Date | Tue, 20 Mar 2012 23:36:36 +0100 | From | Jiri Olsa <> | Subject | Re: [PATCH 3/3] perf, tool: Add new event group management |
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On Tue, Mar 20, 2012 at 07:44:41PM +0100, Peter Zijlstra wrote: > On Tue, 2012-03-20 at 19:15 +0100, Jiri Olsa wrote: > > Examples (first event in brackets is group leader): > > > > # 1 group (cpu-clock,task-clock) > > perf record --group -e cpu-clock,task-clock ls > > perf record --group parsed -e cpu-clock,task-clock ls > > > > # 2 groups (cpu-clock,task-clock) (minor-faults,major-faults) > > perf record --group parsed -e cpu-clock,task-clock \ > > -e minor-faults,major-faults ls > > > > # 1 group (cpu-clock,task-clock,minor-faults,major-faults) > > perf record --group -e cpu-clock,task-clock \ > > -e minor-faults,major-faults ls > > > > # 2 groups (cpu-clock,task-clock) (minor-faults,major-faults) > > perf record --group parsed -e cpu-clock,task-clock \ > > -e minor-faults,major-faults -e instructions ls > > > > # 1 group (cpu-clock,task-clock,minor-faults,major-faults,instructions) > > perf record --group -e cpu-clock,task-clock \ > > -e minor-faults,major-faults -e instructions ls > > I can't help but dislike the --group/--group parsed thing... > > How about something like: > > event_group = "{", events, "}" , [ ":", event_group_mod ] > > Such that you can write things like: > > perf record -e "{cpu-clock,cache-misses,cache-references}" > > perf stat -e "{cpu-clock,cycles},{cpu-clock,cache-misses,cache-references}" > perf stat -e "{cpu-clock,cycles}" -e "{cpu-clock,cache-misses,cache-references}"
there should be no problem with that
> > I'm not sure what the current behaviour of --group is, if you create a > group like this, do they all sample?
I think so.. the --group switch just set the group_fd for the event syscall, nothing else
> > 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.
never happy, are you.. ;) seems like nice feature, will check
> > 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.
looks like Arnaldo could use [] but I get different results:
[jolsa@dhcp-26-214 perf]$ ./perf stat -e [cycles,instructions] ls invalid or unsupported event: 't'
need to check.. maybe escaping is small price for good readability, but I'll think about some other way as well.
thanks for comments, jirka
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