[PATCH v2 2/4] perf arm-spe: Correct sample flags for dummy event

[Leo Yan]

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@xxxxxxxxxx>
Reviewed-by: James Clark <james.clark@xxxxxxx>
Tested-by: James Clark <james.clark@xxxxxxx>
---
 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;
 }
-- 
2.25.1