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* [PATCH] perf arm-spe: Use advertised caps/min_interval as default sample_period
@ 2022-02-21 17:10 ` German Gomez
  0 siblings, 0 replies; 6+ messages in thread
From: German Gomez @ 2022-02-21 17:10 UTC (permalink / raw)
  To: linux-kernel, linux-perf-users, acme
  Cc: German Gomez, John Garry, Will Deacon, Mathieu Poirier, Leo Yan,
	Mark Rutland, Alexander Shishkin, Jiri Olsa, Namhyung Kim,
	linux-arm-kernel

When recording SPE traces, the default sample_period is currently being
set to 1 in the perf_event_attr fields, instead of the value advertised
in '/sys/devices/arm_spe_0/caps/min_interval':

Before:

$ perf record -e arm_spe// -vv -- sleep 1
[...]
  { sample_period, sample_freq }   1
[...]

Use the value from the above sysfs location as a more sensible default
(it was already being read, but the value not being used)

After:

$ perf record -e arm_spe// -vv -- sleep 1
[...]
  { sample_period, sample_freq }   1024
[...]

Signed-off-by: German Gomez <german.gomez@arm.com>
---
 tools/perf/arch/arm64/util/arm-spe.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/arch/arm64/util/arm-spe.c b/tools/perf/arch/arm64/util/arm-spe.c
index 2100d46cc..5860bbaea 100644
--- a/tools/perf/arch/arm64/util/arm-spe.c
+++ b/tools/perf/arch/arm64/util/arm-spe.c
@@ -158,7 +158,7 @@ static int arm_spe_recording_options(struct auxtrace_record *itr,
 				return -EINVAL;
 			}
 			evsel->core.attr.freq = 0;
-			evsel->core.attr.sample_period = 1;
+			evsel->core.attr.sample_period = arm_spe_pmu->default_config->sample_period;
 			arm_spe_evsel = evsel;
 			opts->full_auxtrace = true;
 		}
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2022-02-23 10:04 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2022-02-21 17:10 [PATCH] perf arm-spe: Use advertised caps/min_interval as default sample_period German Gomez
2022-02-21 17:10 ` German Gomez
2022-02-23  1:14 ` Leo Yan
2022-02-23  1:14   ` Leo Yan
2022-02-23 10:02   ` Arnaldo Carvalho de Melo
2022-02-23 10:02     ` Arnaldo Carvalho de Melo

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