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Commit 5c816728 authored by James Clark's avatar James Clark Committed by Peter Zijlstra
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arm_pmu: Add PERF_PMU_CAP_EXTENDED_HW_TYPE capability



This capability gives us the ability to open PERF_TYPE_HARDWARE and
PERF_TYPE_HW_CACHE events on a specific PMU for free. All the
implementation is contained in the Perf core and tool code so no change
to the Arm PMU driver is needed.

The following basic use case now results in Perf opening the event on
all PMUs rather than picking only one in an unpredictable way:

  $ perf stat -e cycles -- taskset --cpu-list 0,1 stress -c 2

   Performance counter stats for 'taskset --cpu-list 0,1 stress -c 2':

         963279620      armv8_cortex_a57/cycles/                (99.19%)
         752745657      armv8_cortex_a53/cycles/                (94.80%)

Fixes: 55bcf6ef ("perf: Extend PERF_TYPE_HARDWARE and PERF_TYPE_HW_CACHE")
Suggested-by: default avatarIan Rogers <irogers@google.com>
Signed-off-by: default avatarJames Clark <james.clark@arm.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarAnshuman Khandual <anshuman.khandual@arm.com>
Acked-by: default avatarIan Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20230724134500.970496-2-james.clark@arm.com
parent 8bfc20ba
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