[PATCH 02/25] perf: cs-etm: Optimize option setup for CPU-wide sessions

From: Arnaldo Carvalho de Melo
Date: Fri Jun 21 2019 - 13:39:23 EST


From: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>

Call function cs_etm_set_option() once with all relevant options set
rather than multiple times to avoid going through the list of CPU more
than once.

Suggested-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20190611204528.20093-1-mathieu.poirier@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/arch/arm/util/cs-etm.c | 20 ++++++++------------
1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/tools/perf/arch/arm/util/cs-etm.c b/tools/perf/arch/arm/util/cs-etm.c
index 279c69caef91..c6f1ab5499b5 100644
--- a/tools/perf/arch/arm/util/cs-etm.c
+++ b/tools/perf/arch/arm/util/cs-etm.c
@@ -162,20 +162,19 @@ static int cs_etm_set_option(struct auxtrace_record *itr,
!cpu_map__has(online_cpus, i))
continue;

- switch (option) {
- case ETM_OPT_CTXTID:
+ if (option & ETM_OPT_CTXTID) {
err = cs_etm_set_context_id(itr, evsel, i);
if (err)
goto out;
- break;
- case ETM_OPT_TS:
+ }
+ if (option & ETM_OPT_TS) {
err = cs_etm_set_timestamp(itr, evsel, i);
if (err)
goto out;
- break;
- default:
- goto out;
}
+ if (option & ~(ETM_OPT_CTXTID | ETM_OPT_TS))
+ /* Nothing else is currently supported */
+ goto out;
}

err = 0;
@@ -398,11 +397,8 @@ static int cs_etm_recording_options(struct auxtrace_record *itr,
if (!cpu_map__empty(cpus)) {
perf_evsel__set_sample_bit(cs_etm_evsel, CPU);

- err = cs_etm_set_option(itr, cs_etm_evsel, ETM_OPT_CTXTID);
- if (err)
- goto out;
-
- err = cs_etm_set_option(itr, cs_etm_evsel, ETM_OPT_TS);
+ err = cs_etm_set_option(itr, cs_etm_evsel,
+ ETM_OPT_CTXTID | ETM_OPT_TS);
if (err)
goto out;
}
--
2.20.1