perf events: Add PERF_COUNT_HW_REF_CPU_CYCLES generic PMU event

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>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1323559734-3488-3-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Stephane Eranian 2011-12-11 00:28:52 +01:00 committed by Ingo Molnar
parent cd09c0c40a
commit c37e17497e

View file

@ -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 */
};