Messages in this thread | | | Subject | Re: [PATCH 2/4] perf_event: add PERF_COUNT_HW_REF_CPU_CYCLES generic PMU event | From | Peter Zijlstra <> | Date | Mon, 12 Dec 2011 13:57:37 +0100 |
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On Sun, 2011-12-11 at 00:28 +0100, Stephane Eranian wrote: > This event counts the number of reference core cpu cycles. > Reference means that the event increments at a constant rate which > is not subject to core CPU frequency adjustments. The event may > not count when the processor is in halted (low power) state. > As such, it may not be equivalent to wall clock time. However, > when the processor is not halted state, the event keeps > a constant correlation with wall clock time. > > Signed-off-by: Stephane Eranian <eranian@google.com> > --- > include/linux/perf_event.h | 1 + > 1 files changed, 1 insertions(+), 0 deletions(-) > > diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h > index 564769c..0885561 100644 > --- a/include/linux/perf_event.h > +++ b/include/linux/perf_event.h > @@ -54,6 +54,7 @@ enum perf_hw_id { > PERF_COUNT_HW_BUS_CYCLES = 6, > PERF_COUNT_HW_STALLED_CYCLES_FRONTEND = 7, > PERF_COUNT_HW_STALLED_CYCLES_BACKEND = 8, > + PERF_COUNT_HW_REF_CPU_CYCLES = 9, > > PERF_COUNT_HW_MAX, /* non-ABI */ > };
Does it make sense to add this to the 'generic' events? Are other archs going to use this?
That is, I already queued patch 1, I'm just wondering if the generic bit makes sense, Even BUS_CYCLES seems to be a questionable 'generic' event, but that's history and we can't fix it.
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