Messages in this thread | | | From | Stephane Eranian <> | Date | Thu, 7 Jun 2018 09:09:10 -0700 | Subject | Re: [PATCH 01/10] perf tools: Uniquify the event name if there's no other matched event |
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On Wed, Jun 6, 2018 at 11:22 PM Jiri Olsa <jolsa@redhat.com> wrote: > > On Wed, Jun 06, 2018 at 04:19:02PM -0700, Andi Kleen wrote: > > On Thu, Jun 07, 2018 at 12:15:04AM +0200, Jiri Olsa wrote: > > > Currently by default we try to match the user specified PMU > > > name to all PMU units available and use them to aggregate > > > all matched PMUs event counts into one 'pattern' event. > > > > > > While this is useful for uncore events, it screws up names > > > for other events, where this is not desirable, like: > > > > > > Before: > > > # perf stat -e cp/cpu-cycles/ kill > > > > I assume you mean cpU/cpu-cycles/ > > > > > > Performance counter stats for 'kill': > > > > > > 1,573,757 cp/cpu-cycles/ > > > > > > Keeping the pattern matching logic, but making the name unique > > > in case there's no other match found. That fixes the example > > > above and hopefully does not screw up anything else. > > > And the problem I have with this approach, is that you do not really know what you are measuring. You have not way of knowing that the count comes from multiple PMU instances:
perf stat -a -e uncore_cb/clockticks/ kill 0 uncore_cb/clockticks/
I think you need to report that this is aggregated from uncore_cbox_0 and uncore_cbox_1. Otherwise it is not clear what I am monitoring. And you hope that what you match in the regex is related. In my example should say: 0 uncore_cbox[0-1]/clockticks/
then it is clear what happened.
> > > After: > > > # perf stat -e cp/cpu-cycles/ kill > > > > > > Performance counter stats for 'kill': > > > > > > 1,573,757 cpu/cpu-cycles/ > > > > > > The output is 100% identical? > > nope, the U is actualy missing.. that's the thing, the patern > matching allows you to put 'cp' instead of 'cpu' and the final > output is screwed.. also the metrics won't match the proper event > > jirka
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