Messages in this thread Patch in this message | | | From | Stephane Eranian <> | Subject | [PATCH 2/4] perf_event: add PERF_COUNT_HW_REF_CPU_CYCLES generic PMU event | Date | Sun, 11 Dec 2011 00:28:52 +0100 |
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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 */ }; -- 1.7.1
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