Commit d13648e5 authored by Ravi Bangoria's avatar Ravi Bangoria Committed by PvsNarasimha
Browse files

perf pmu: Parse pmu caps sysfs only once 

mainline inclusion
from mainline-v6.0-rc1
commit 3339ec44
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/IAU6ZD

Reference: https://github.com/torvalds/linux/commit/3339ec44be7f9963c82d5d21e163f16f96e5ca58



--------------------------------

commit 3339ec44 upstream

In addition to returning nr_caps, cache it locally in struct perf_pmu.

Similarly, cache status of whether caps sysfs has already been parsed
or not. These will help to avoid parsing sysfs every time the function
gets called.

Reviewed-by: default avatarKan Liang <kan.liang@linux.intel.com>
Signed-off-by: default avatarRavi Bangoria <ravi.bangoria@amd.com>
Acked-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Ananth Narayan <ananth.narayan@amd.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kim Phillips <kim.phillips@amd.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robert Richter <rrichter@amd.com>
Cc: Sandipan Das <sandipan.das@amd.com>
Cc: Santosh Shukla <santosh.shukla@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: like.xu.linux@gmail.com
Cc: x86@kernel.org
Link: https://lore.kernel.org/r/20220604044519.594-3-ravi.bangoria@amd.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: default avatarchaithanyaLagisetty <lagisettyvenkata.nagachaitanya@amd.com>
Signed-off-by: default avatarPvsNarasimha <PVS.NarasimhaRao@amd.com>
parent 33da5de4

tools/perf/util/pmu.c

+11 −4
Original line number Diff line number Diff line
@@ -1833,7 +1833,11 @@ int perf_pmu__caps_parse(struct perf_pmu *pmu) 
	const char *sysfs = sysfs__mountpoint();

	DIR *caps_dir;

	struct dirent *evt_ent;

	int nr_caps = 0;



	if (pmu->caps_initialized)

		return pmu->nr_caps;



	pmu->nr_caps = 0;



	if (!sysfs)

		return -1;
@@ -1841,8 +1845,10 @@ int perf_pmu__caps_parse(struct perf_pmu *pmu) 
	snprintf(caps_path, PATH_MAX,

		 "%s" EVENT_SOURCE_DEVICE_PATH "%s/caps", sysfs, pmu->name);



	if (stat(caps_path, &st) < 0)

	if (stat(caps_path, &st) < 0) {

		pmu->caps_initialized = true;

		return 0;	/* no error if caps does not exist */

	}



	caps_dir = opendir(caps_path);

	if (!caps_dir)
@@ -1869,13 +1875,14 @@ int perf_pmu__caps_parse(struct perf_pmu *pmu) 
			continue;

		}



		nr_caps++;

		pmu->nr_caps++;

		fclose(file);

	}



	closedir(caps_dir);



	return nr_caps;

	pmu->caps_initialized = true;

	return pmu->nr_caps;

}



int perf_pmu__match(char *pattern, char *name, char *tok)

tools/perf/util/pmu.h

+2 −0
Original line number Diff line number Diff line
@@ -41,6 +41,8 @@ struct perf_pmu { 
	struct perf_cpu_map *cpus;

	struct list_head format;  /* HEAD struct perf_pmu_format -> list */

	struct list_head aliases; /* HEAD struct perf_pmu_alias -> list */

	bool caps_initialized;

	u32 nr_caps;

	struct list_head caps;    /* HEAD struct perf_pmu_caps -> list */

	struct list_head list;    /* ELEM */

};