Commit b009b51e authored by Ian Rogers's avatar Ian Rogers Committed by Arnaldo Carvalho de Melo
Browse files

perf intel-tpebs: Separate evsel__tpebs_prepare() out of evsel__tpebs_open() 



Separate the creation of the tpebs_retire_lat result out of the opening
step.

This is in preparation for adding a prepare operation for evlists.

Reviewed-by: default avatarKan Liang <kan.liang@linux.intel.com>
Signed-off-by: default avatarIan Rogers <irogers@google.com>
Tested-by: default avatarWeilin Wang <weilin.wang@intel.com>
Acked-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>
Cc: Andreas Färber <afaerber@suse.de>
Cc: Caleb Biggers <caleb.biggers@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Perry Taylor <perry.taylor@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Falcon <thomas.falcon@intel.com>
Link: https://lore.kernel.org/r/20250414174134.3095492-5-irogers@google.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 2332f682

tools/perf/util/intel-tpebs.c

+86 −47
Original line number Diff line number Diff line
@@ -37,7 +37,7 @@ static struct child_process tpebs_cmd; 
struct tpebs_retire_lat {

	struct list_head nd;

	/* Event name */

	const char *name;

	char *name;

	/* Event name with the TPEBS modifier R */

	const char *tpebs_name;

	/* Count of retire_latency values found in sample data */
@@ -190,68 +190,105 @@ static int tpebs_stop(void) 
	return ret;

}



static char *evsel__tpebs_name(struct evsel *evsel)

{

	char *name, *modifier;



	name = strdup(evsel->name);

	if (!name)

		return NULL;



	modifier = strrchr(name, 'R');

	if (!modifier) {

		pr_err("Tpebs event missing modifier '%s'\n", name);

		free(name);

		return NULL;

	}



	*modifier = 'p';

	return name;

}



static struct tpebs_retire_lat *tpebs_retire_lat__new(struct evsel *evsel)

{

	struct tpebs_retire_lat *result = zalloc(sizeof(*result));



	if (!result)

		return NULL;



	result->tpebs_name = evsel->name;

	result->name = evsel__tpebs_name(evsel);

	if (!result->name) {

		free(result);

		return NULL;

	}

	list_add_tail(&result->nd, &tpebs_results);

	tpebs_event_size++;

	return result;

}



/**

 * evsel__tpebs_open - starts tpebs execution.

 * @evsel: retire_latency evsel, all evsels on its list will be selected. Each

 *         evsel is sampled to get the average retire_latency value.

 * evsel__tpebs_prepare - create tpebs data structures ready for opening.

 * @evsel: retire_latency evsel, all evsels on its list will be prepared.

 */

int evsel__tpebs_open(struct evsel *evsel)

static int evsel__tpebs_prepare(struct evsel *evsel)

{

	int ret = 0;

	struct evsel *pos;

	struct evlist *evsel_list = evsel->evlist;

	char cpumap_buf[50];

	struct tpebs_retire_lat *tpebs_event;



	list_for_each_entry(tpebs_event, &tpebs_results, nd) {

		if (!strcmp(tpebs_event->tpebs_name, evsel->name)) {

			/*

	 * We should only run tpebs_start when tpebs_recording is enabled.

	 * And we should only run it once with all the required events.

			 * evsel, or an identically named one, was already

			 * prepared.

			 */

	if (tpebs_cmd.pid != 0 || !tpebs_recording)

			return 0;

		}

	}

	tpebs_event = tpebs_retire_lat__new(evsel);

	if (!tpebs_event)

		return -ENOMEM;



	cpu_map__snprint(evsel_list->core.user_requested_cpus, cpumap_buf, sizeof(cpumap_buf));

	/*

	 * Prepare perf record for sampling event retire_latency before fork and

	 * prepare workload

	 * Eagerly prepare all other evsels on the list to try to ensure that by

	 * open they are all known.

	 */

	evlist__for_each_entry(evsel_list, pos) {

		int i;

		char *name;

		struct tpebs_retire_lat *new;

	evlist__for_each_entry(evsel->evlist, pos) {

		int ret;



		if (!pos->retire_lat)

		if (pos == evsel || !pos->retire_lat)

			continue;



		pr_debug("tpebs: Retire_latency of event %s is required\n", pos->name);

		for (i = strlen(pos->name) - 1; i > 0; i--) {

			if (pos->name[i] == 'R')

				break;

		ret = evsel__tpebs_prepare(pos);

		if (ret)

			return ret;

	}

		if (i <= 0 || pos->name[i] != 'R') {

			ret = -1;

			goto err;

	return 0;

}



		name = strdup(pos->name);

		if (!name) {

			ret = -ENOMEM;

			goto err;

		}

		name[i] = 'p';

/**

 * evsel__tpebs_open - starts tpebs execution.

 * @evsel: retire_latency evsel, all evsels on its list will be selected. Each

 *         evsel is sampled to get the average retire_latency value.

 */

int evsel__tpebs_open(struct evsel *evsel)

{

	int ret;



		new = zalloc(sizeof(*new));

		if (!new) {

			ret = -1;

			zfree(&name);

			goto err;

		}

		new->name = name;

		new->tpebs_name = pos->name;

		list_add_tail(&new->nd, &tpebs_results);

		tpebs_event_size += 1;

	}

	/*

	 * We should only run tpebs_start when tpebs_recording is enabled.

	 * And we should only run it once with all the required events.

	 */

	if (tpebs_cmd.pid != 0 || !tpebs_recording)

		return 0;



	ret = evsel__tpebs_prepare(evsel);

	if (ret)

		return ret;



	if (tpebs_event_size > 0) {

		struct evlist *evsel_list = evsel->evlist;

		char cpumap_buf[50];

		struct pollfd pollfd = { .events = POLLIN, };

		int control_fd[2], ack_fd[2], len;

		char ack_buf[8];
@@ -268,6 +305,9 @@ int evsel__tpebs_open(struct evsel *evsel) 
			goto out;

		}



		cpu_map__snprint(evsel_list->core.user_requested_cpus, cpumap_buf,

				 sizeof(cpumap_buf));



		ret = start_perf_record(control_fd, ack_fd, cpumap_buf);

		if (ret)

			goto out;
@@ -321,7 +361,6 @@ int evsel__tpebs_open(struct evsel *evsel) 
		close(ack_fd[0]);

		close(ack_fd[1]);

	}

err:

	if (ret)

		tpebs_delete();

	return ret;