Messages in this thread | | | Subject | Re: [PATCH 3/3] perf, tool: Add new event group management | From | Peter Zijlstra <> | Date | Tue, 20 Mar 2012 19:44:41 +0100 |
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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}"
I'm not sure what the current behaviour of --group is, if you create a group like this, do they all sample?
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.
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