Commit 48a3adcf authored by Wyes Karny's avatar Wyes Karny Committed by Namhyung Kim
Browse files

perf pmu: Fix perf stat output with correct scale and unit 



The perf_pmu__parse_* functions for the sysfs files of pmu event’s
scale, unit, per-pkg and snapshot were updated in commit 7b723dbb
("perf pmu: Be lazy about loading event info files from sysfs").
However, the paths for these sysfs files were incorrect. This resulted
in perf stat reporting values with wrong scaling and missing units. This
is fixed by correcting the paths for these sysfs files.

Before this fix:

 $sudo perf stat -e power/energy-pkg/ -- sleep 2

 Performance counter stats for 'system wide':

   351,217,188,864      power/energy-pkg/

          2.004127961 seconds time elapsed

After this fix:

 $sudo perf stat -e power/energy-pkg/ -- sleep 2

 Performance counter stats for 'system wide':

             80.58 Joules power/energy-pkg/

 	     2.004009749 seconds time elapsed

Fixes: 7b723dbb ("perf pmu: Be lazy about loading event info files from sysfs")
Signed-off-by: default avatarWyes Karny <wyes.karny@amd.com>
Reviewed-by: default avatarIan Rogers <irogers@google.com>
Cc: ravi.bangoria@amd.com
Cc: sandipan.das@amd.com
Cc: james.clark@arm.com
Cc: kan.liang@linux.intel.com
Link: https://lore.kernel.org/r/20230920122349.418673-1-wyes.karny@amd.com


Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
parent e47749f1

tools/perf/util/pmu.c

+4 −4
Original line number Diff line number Diff line
@@ -295,7 +295,7 @@ static int perf_pmu__parse_scale(struct perf_pmu *pmu, struct perf_pmu_alias *al 
	len = perf_pmu__event_source_devices_scnprintf(path, sizeof(path));

	if (!len)

		return 0;

	scnprintf(path + len, sizeof(path) - len, "%s/%s.scale", pmu->name, alias->name);

	scnprintf(path + len, sizeof(path) - len, "%s/events/%s.scale", pmu->name, alias->name);



	fd = open(path, O_RDONLY);

	if (fd == -1)
@@ -330,7 +330,7 @@ static int perf_pmu__parse_unit(struct perf_pmu *pmu, struct perf_pmu_alias *ali 
	len = perf_pmu__event_source_devices_scnprintf(path, sizeof(path));

	if (!len)

		return 0;

	scnprintf(path + len, sizeof(path) - len, "%s/%s.unit", pmu->name, alias->name);

	scnprintf(path + len, sizeof(path) - len, "%s/events/%s.unit", pmu->name, alias->name);



	fd = open(path, O_RDONLY);

	if (fd == -1)
@@ -364,7 +364,7 @@ perf_pmu__parse_per_pkg(struct perf_pmu *pmu, struct perf_pmu_alias *alias) 
	len = perf_pmu__event_source_devices_scnprintf(path, sizeof(path));

	if (!len)

		return 0;

	scnprintf(path + len, sizeof(path) - len, "%s/%s.per-pkg", pmu->name, alias->name);

	scnprintf(path + len, sizeof(path) - len, "%s/events/%s.per-pkg", pmu->name, alias->name);



	fd = open(path, O_RDONLY);

	if (fd == -1)
@@ -385,7 +385,7 @@ static int perf_pmu__parse_snapshot(struct perf_pmu *pmu, struct perf_pmu_alias 
	len = perf_pmu__event_source_devices_scnprintf(path, sizeof(path));

	if (!len)

		return 0;

	scnprintf(path + len, sizeof(path) - len, "%s/%s.snapshot", pmu->name, alias->name);

	scnprintf(path + len, sizeof(path) - len, "%s/events/%s.snapshot", pmu->name, alias->name);



	fd = open(path, O_RDONLY);

	if (fd == -1)