Messages in this thread Patch in this message | | | From | John Garry <> | Subject | [RFC PATCH v2 07/13] perf pmu: Add pmu_id() | Date | Fri, 17 Apr 2020 18:41:18 +0800 |
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Add a function to read the PMU id sysfs entry. We only do it for uncore PMUs where this would be relevant.
Signed-off-by: John Garry <john.garry@huawei.com> --- tools/perf/util/pmu.c | 36 ++++++++++++++++++++++++++++++++++++ tools/perf/util/pmu.h | 1 + 2 files changed, 37 insertions(+)
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c index ef6a63f3d386..6a67c6a28d08 100644 --- a/tools/perf/util/pmu.c +++ b/tools/perf/util/pmu.c @@ -594,6 +594,7 @@ static struct perf_cpu_map *__pmu_cpumask(const char *path) * Uncore PMUs have a "cpumask" file under sysfs. CPU PMUs (e.g. on arm/arm64) * may have a "cpus" file. */ +#define CPUS_TEMPLATE_ID "%s/bus/event_source/devices/%s/identifier" #define CPUS_TEMPLATE_UNCORE "%s/bus/event_source/devices/%s/cpumask" #define CPUS_TEMPLATE_CPU "%s/bus/event_source/devices/%s/cpus" @@ -632,6 +633,39 @@ static bool pmu_is_uncore(const char *name) return file_available(path); } +static char *pmu_id(const char *name) +{ + char path[PATH_MAX], *id; + const char *sysfs; + FILE *file; + int n; + + sysfs = sysfs__mountpoint(); + snprintf(path, PATH_MAX, CPUS_TEMPLATE_ID, sysfs, name); + + id = malloc(PATH_MAX); + if (!id) + return NULL; + + file = fopen(path, "r"); + if (!file) { + free(id); + return NULL; + } + + n = fscanf(file, "%s", id); + + fclose(file); + + if (!n) { + free(id); + return NULL; + } + + return id; +} + + /* * PMU CORE devices have different name other than cpu in sysfs on some * platforms. @@ -844,6 +878,8 @@ static struct perf_pmu *pmu_lookup(const char *name) pmu->name = strdup(name); pmu->type = type; pmu->is_uncore = pmu_is_uncore(name); + if (pmu->is_uncore) + pmu->id = pmu_id(name); pmu->max_precise = pmu_max_precise(name); pmu_add_cpu_aliases(&aliases, pmu); diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h index 5fb3f16828df..62ebca9481fe 100644 --- a/tools/perf/util/pmu.h +++ b/tools/perf/util/pmu.h @@ -24,6 +24,7 @@ struct perf_event_attr; struct perf_pmu { char *name; + char *id; __u32 type; bool selectable; bool is_uncore; -- 2.16.4
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