[PATCH v3 2/4] perf arm-spe: Update --switch-events docs in perf-record

From: German Gomez
Date: Thu Nov 11 2021 - 08:50:37 EST


Update perf-record docs and Arm SPE recording options so that they are
consistent. This includes supporting the --no-switch-events flag in Arm
SPE as well.

Signed-off-by: German Gomez <german.gomez@xxxxxxx>
Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Reviewed-by: Leo Yan <leo.yan@xxxxxxxxxx>
---
tools/perf/Documentation/perf-record.txt | 2 +-
tools/perf/arch/arm64/util/arm-spe.c | 4 +++-
2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index 2d7df8703..3cf7bac67 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -469,7 +469,7 @@ This option sets the time out limit. The default value is 500 ms.

--switch-events::
Record context switch events i.e. events of type PERF_RECORD_SWITCH or
-PERF_RECORD_SWITCH_CPU_WIDE. In some cases (e.g. Intel PT or CoreSight)
+PERF_RECORD_SWITCH_CPU_WIDE. In some cases (e.g. Intel PT, CoreSight or Arm SPE)
switch events will be enabled automatically, which can be suppressed by
by the option --no-switch-events.

diff --git a/tools/perf/arch/arm64/util/arm-spe.c b/tools/perf/arch/arm64/util/arm-spe.c
index 58ba8d15c..725a06cd2 100644
--- a/tools/perf/arch/arm64/util/arm-spe.c
+++ b/tools/perf/arch/arm64/util/arm-spe.c
@@ -169,8 +169,10 @@ static int arm_spe_recording_options(struct auxtrace_record *itr,
if (!perf_cpu_map__empty(cpus)) {
evsel__set_sample_bit(tracking_evsel, TIME);
evsel__set_sample_bit(tracking_evsel, CPU);
+
/* also track task context switch */
- tracking_evsel->core.attr.context_switch = 1;
+ if (!record_opts__no_switch_events(opts))
+ tracking_evsel->core.attr.context_switch = 1;
}

return 0;
--
2.25.1