Commit d685819b authored by Ian Rogers's avatar Ian Rogers Committed by Namhyung Kim
Browse files

perf pmus: Add notion of default PMU for JSON events 



JSON events created in pmu-events.c by jevents.py may not specify a
PMU they are associated with, in which case it is implied that it is
the first core PMU. Care is needed to select this for regular 'cpu',
s390 'cpum_cf' and ARMs many names as at the point the name is first
needed the core PMUs list hasn't been initialized. Add a helper in
perf_pmus to create this value, in the worst case by scanning sysfs.

v2. Add missing close if fdopendir fails.

Signed-off-by: default avatarIan Rogers <irogers@google.com>
Tested-by: default avatarThomas Richter <tmricht@linux.ibm.com>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: James Clark <james.clark@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Link: https://lore.kernel.org/r/20230623043843.4080180-1-irogers@google.com


Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
parent 33941dbd

tools/perf/util/pmu.c

+16 −19
Original line number Diff line number Diff line
@@ -741,9 +741,11 @@ static bool pmu_uncore_alias_match(const char *pmu_name, const char *name) 
}



struct pmu_add_cpu_aliases_map_data {

	/* List being added to. */

	struct list_head *head;

	const char *name;

	const char *cpu_name;

	/* If a pmu_event lacks a given PMU the default used. */

	char *default_pmu_name;

	/* The PMU that we're searching for events for. */

	struct perf_pmu *pmu;

};
@@ -752,37 +754,32 @@ static int pmu_add_cpu_aliases_map_callback(const struct pmu_event *pe, 
					void *vdata)

{

	struct pmu_add_cpu_aliases_map_data *data = vdata;

	const char *pname = pe->pmu ? pe->pmu : data->cpu_name;

	const char *pname = pe->pmu ?: data->default_pmu_name;



	if (data->pmu->is_uncore && pmu_uncore_alias_match(pname, data->name))

		goto new_alias;



	if (strcmp(pname, data->name))

		return 0;



new_alias:

	if (!strcmp(pname, data->pmu->name) ||

	    (data->pmu->is_uncore && pmu_uncore_alias_match(pname, data->pmu->name))) {

		/* need type casts to override 'const' */

		__perf_pmu__new_alias(data->head, -1, (char *)pe->name, (char *)pe->desc,

				      (char *)pe->event, pe);

	}

	return 0;

}



/*

 * From the pmu_events_map, find the table of PMU events that corresponds

 * to the current running CPU. Then, add all PMU events from that table

 * as aliases.

 * From the pmu_events_table, find the events that correspond to the given

 * PMU and add them to the list 'head'.

 */

void pmu_add_cpu_aliases_table(struct list_head *head, struct perf_pmu *pmu,

			const struct pmu_events_table *table)

{

	struct pmu_add_cpu_aliases_map_data data = {

		.head = head,

		.name = pmu->name,

		.cpu_name = is_sysfs_pmu_core(pmu->name) ? pmu->name : "cpu",

		.default_pmu_name = perf_pmus__default_pmu_name(),

		.pmu = pmu,

	};



	pmu_events_table_for_each_event(table, pmu_add_cpu_aliases_map_callback, &data);

	free(data.default_pmu_name);

}



static void pmu_add_cpu_aliases(struct list_head *head, struct perf_pmu *pmu)

tools/perf/util/pmus.c

+36 −1
Original line number Diff line number Diff line
@@ -137,8 +137,10 @@ static void pmu_read_sysfs(bool core_only) 
		return;



	dir = fdopendir(fd);

	if (!dir)

	if (!dir) {

		close(fd);

		return;

	}



	while ((dent = readdir(dir))) {

		if (!strcmp(dent->d_name, ".") || !strcmp(dent->d_name, ".."))
@@ -524,6 +526,39 @@ bool perf_pmus__supports_extended_type(void) 
	return perf_pmus__do_support_extended_type;

}



char *perf_pmus__default_pmu_name(void)

{

	int fd;

	DIR *dir;

	struct dirent *dent;

	char *result = NULL;



	if (!list_empty(&core_pmus))

		return strdup(list_first_entry(&core_pmus, struct perf_pmu, list)->name);



	fd = perf_pmu__event_source_devices_fd();

	if (fd < 0)

		return strdup("cpu");



	dir = fdopendir(fd);

	if (!dir) {

		close(fd);

		return strdup("cpu");

	}



	while ((dent = readdir(dir))) {

		if (!strcmp(dent->d_name, ".") || !strcmp(dent->d_name, ".."))

			continue;

		if (is_pmu_core(dent->d_name)) {

			result = strdup(dent->d_name);

			break;

		}

	}



	closedir(dir);

	return result ?: strdup("cpu");

}



struct perf_pmu *evsel__find_pmu(const struct evsel *evsel)

{

	struct perf_pmu *pmu = evsel->pmu;

tools/perf/util/pmus.h

+1 −0
Original line number Diff line number Diff line
@@ -20,5 +20,6 @@ void perf_pmus__print_pmu_events(const struct print_callbacks *print_cb, void *p 
bool perf_pmus__have_event(const char *pname, const char *name);

int perf_pmus__num_core_pmus(void);

bool perf_pmus__supports_extended_type(void);

char *perf_pmus__default_pmu_name(void);



#endif /* __PMUS_H */