From: Leo Yan leo.yan@linaro.org
mainline inclusion from mainline-v5.14-rc1 commit e582badf1706 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I4NGPV CVE: NA
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The dummy event is mainly used for mmap, the TIME sample is only needed for per-cpu case so that the perf tool can rely on the correct timing for parsing symbols. And the CPU sample is useless for mmap.
The BRANCH_STACK sample bit will be always reset for the dummy event in the function evsel__config(), so don't need to repeatedly reset it for Arm SPE specific.
So this patch only enables TIME sample for per-cpu mmap.
Signed-off-by: Leo Yan leo.yan@linaro.org Reviewed-by: James Clark james.clark@arm.com Tested-by: James Clark james.clark@arm.com Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Al Grant Al.Grant@arm.com Cc: Ingo Molnar mingo@redhat.com Cc: Jiri Olsa jolsa@redhat.com Cc: John Garry john.garry@huawei.com Cc: Mark Rutland mark.rutland@arm.com Cc: Mathieu Poirier mathieu.poirier@linaro.org Cc: Namhyung Kim namhyung@kernel.org Cc: Peter Zijlstra peterz@infradead.org Cc: Will Deacon will@kernel.org Cc: linux-arm-kernel@lists.infradead.org Link: https://lore.kernel.org/r/20210519041546.1574961-3-leo.yan@linaro.org Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Wei Li liwei391@huawei.com Reviewed-by: Yang Jihong yangjihong1@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- tools/perf/arch/arm64/util/arm-spe.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/tools/perf/arch/arm64/util/arm-spe.c b/tools/perf/arch/arm64/util/arm-spe.c index 35e7c7e774c2..119d8d7656b9 100644 --- a/tools/perf/arch/arm64/util/arm-spe.c +++ b/tools/perf/arch/arm64/util/arm-spe.c @@ -135,9 +135,10 @@ static int arm_spe_recording_options(struct auxtrace_record *itr,
tracking_evsel->core.attr.freq = 0; tracking_evsel->core.attr.sample_period = 1; - evsel__set_sample_bit(tracking_evsel, TIME); - evsel__set_sample_bit(tracking_evsel, CPU); - evsel__reset_sample_bit(tracking_evsel, BRANCH_STACK); + + /* In per-cpu case, always need the time of mmap events etc */ + if (!perf_cpu_map__empty(cpus)) + evsel__set_sample_bit(tracking_evsel, TIME);
return 0; }