Messages in this thread | | | Date | Tue, 23 Jun 2009 09:24:57 -0700 | From | Corey Ashford <> | Subject | Re: I.2 - Grouping |
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stephane eranian wrote: > On Tue, Jun 23, 2009 at 10:26 AM, Paul Mackerras<paulus@samba.org> wrote: >> stephane eranian writes: >> >>> What happens if I do: >>> fd0 = perf_counter_open(&hwc1, getpid(), -1, -1, 0); >>> fd1 = perf_counter_open(&hwc2, getpid(), -1, fd0, 0); >>> >>> And then: >>> fd2 = perf_counter_open(&hwc2, getpid(), -1, fd1, 0); >> That perf_counter_open call will fail with an EINVAL error because fd1 >> is not a group leader. >> > Okay. Thanks. > > But that leads me to another question related to grouping > which was hinted for by Peter's comment about IBS. > > Can you have multiple sampling events in a group?
There's a PAPI ctest which exercises this - profile_two_events - and it does work with the PCL substrate.
- Corey
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