[PATCH] arm64: perf: Add general hardware LLC events for PMUv3

Leo Yan leo.yan at linaro.org
Tue Aug 11 01:35:05 EDT 2020


This patch is to add the general hardware last level cache (LLC) events
for PMUv3: one event is for LLC access and another is for LLC miss.

With this change, perf tool can support last level cache profiling,
below is an example to demonstrate the usage on Arm64:

  $ perf stat -e LLC-load-misses -e LLC-loads -- \
	  perf bench mem memcpy -s 1024MB -l 100 -f default

  [...]

    Performance counter stats for 'perf bench mem memcpy -s 1024MB -l 100 -f default':

        35,534,262      LLC-load-misses           #    2.16% of all LL-cache hits
     1,643,946,443      LLC-loads

  [...]

Signed-off-by: Leo Yan <leo.yan at linaro.org>
---
 arch/arm64/kernel/perf_event.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c
index 462f9a9cc44b..86e2328b0c2e 100644
--- a/arch/arm64/kernel/perf_event.c
+++ b/arch/arm64/kernel/perf_event.c
@@ -69,6 +69,9 @@ static const unsigned armv8_pmuv3_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
 	[C(ITLB)][C(OP_READ)][C(RESULT_MISS)]	= ARMV8_PMUV3_PERFCTR_L1I_TLB_REFILL,
 	[C(ITLB)][C(OP_READ)][C(RESULT_ACCESS)]	= ARMV8_PMUV3_PERFCTR_L1I_TLB,
 
+	[C(LL)][C(OP_READ)][C(RESULT_MISS)]	= ARMV8_PMUV3_PERFCTR_LL_CACHE_MISS_RD,
+	[C(LL)][C(OP_READ)][C(RESULT_ACCESS)]	= ARMV8_PMUV3_PERFCTR_LL_CACHE_RD,
+
 	[C(BPU)][C(OP_READ)][C(RESULT_ACCESS)]	= ARMV8_PMUV3_PERFCTR_BR_PRED,
 	[C(BPU)][C(OP_READ)][C(RESULT_MISS)]	= ARMV8_PMUV3_PERFCTR_BR_MIS_PRED,
 };
-- 
2.17.1




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