File perf-pmu-Parse-pmu-caps-sysfs-only-once.patch of Package perf.29801
From: Ravi Bangoria <ravi.bangoria@amd.com>
Date: Sat, 4 Jun 2022 10:15:13 +0530
Subject: perf pmu: Parse pmu caps sysfs only once
Git-commit: 3339ec44be7f9963c82d5d21e163f16f96e5ca58
References: jsc#SLE-24578
Signed-off-by: Tony Jones <tonyj@suse.de>
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: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
Acked-by: Namhyung 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: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Tony Jones <tonyj@suse.de>
---
tools/perf/util/pmu.c | 15 +++++++++++----
tools/perf/util/pmu.h | 2 ++
2 files changed, 13 insertions(+), 4 deletions(-)
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 9a1c7e63e663..0112e1c36418 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -1890,7 +1890,11 @@ 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;
@@ -1898,8 +1902,10 @@ 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)
@@ -1926,13 +1932,14 @@ 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;
}
void perf_pmu__warn_invalid_config(struct perf_pmu *pmu, __u64 config,
diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
index 541889fa9f9c..4b45fd8da5a3 100644
--- a/tools/perf/util/pmu.h
+++ b/tools/perf/util/pmu.h
@@ -46,6 +46,8 @@ 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 */
struct list_head hybrid_list;
