From e582badf1706a005359ef3e184fa97384e93f83a Mon Sep 17 00:00:00 2001 From: Leo Yan Date: Wed, 19 May 2021 12:15:44 +0800 Subject: [PATCH] perf arm-spe: Correct sample flags for dummy event 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 Reviewed-by: James Clark Tested-by: James Clark Cc: Alexander Shishkin Cc: Al Grant Cc: Ingo Molnar Cc: Jiri Olsa Cc: John Garry Cc: Mark Rutland Cc: Mathieu Poirier Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Will Deacon 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 --- 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 902e73a64184..4c916626c203 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; } -- 2.20.1