1 files changed, 153 insertions, 47 deletions

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 9be020e0098a..483a28ef4ec4 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -188,6 +188,8 @@ static struct perf_stat_config stat_config = {
 	.metric_only_len	= METRIC_ONLY_LEN,
 	.walltime_nsecs_stats	= &walltime_nsecs_stats,
 	.big_num		= true,
+	.ctl_fd			= -1,
+	.ctl_fd_ack		= -1
 };
 
 static bool cpus_map_matched(struct evsel *a, struct evsel *b)
@@ -475,18 +477,38 @@ static void process_interval(void)
 	print_counters(&rs, 0, NULL);
 }
 
+static bool handle_interval(unsigned int interval, int *times)
+{
+	if (interval) {
+		process_interval();
+		if (interval_count && !(--(*times)))
+			return true;
+	}
+	return false;
+}
+
 static void enable_counters(void)
 {
-	if (stat_config.initial_delay)
+	if (stat_config.initial_delay < 0) {
+		pr_info(EVLIST_DISABLED_MSG);
+		return;
+	}
+
+	if (stat_config.initial_delay > 0) {
+		pr_info(EVLIST_DISABLED_MSG);
 		usleep(stat_config.initial_delay * USEC_PER_MSEC);
+	}
 
 	/*
 	 * We need to enable counters only if:
 	 * - we don't have tracee (attaching to task or cpu)
 	 * - we have initial delay configured
 	 */
-	if (!target__none(&target) || stat_config.initial_delay)
+	if (!target__none(&target) || stat_config.initial_delay) {
 		evlist__enable(evsel_list);
+		if (stat_config.initial_delay > 0)
+			pr_info(EVLIST_ENABLED_MSG);
+	}
 }
 
 static void disable_counters(void)
@@ -540,6 +562,86 @@ static bool is_target_alive(struct target *_target,
 	return false;
 }
 
+static void process_evlist(struct evlist *evlist, unsigned int interval)
+{
+	enum evlist_ctl_cmd cmd = EVLIST_CTL_CMD_UNSUPPORTED;
+
+	if (evlist__ctlfd_process(evlist, &cmd) > 0) {
+		switch (cmd) {
+		case EVLIST_CTL_CMD_ENABLE:
+			pr_info(EVLIST_ENABLED_MSG);
+			if (interval)
+				process_interval();
+			break;
+		case EVLIST_CTL_CMD_DISABLE:
+			if (interval)
+				process_interval();
+			pr_info(EVLIST_DISABLED_MSG);
+			break;
+		case EVLIST_CTL_CMD_ACK:
+		case EVLIST_CTL_CMD_UNSUPPORTED:
+		default:
+			break;
+		}
+	}
+}
+
+static void compute_tts(struct timespec *time_start, struct timespec *time_stop,
+			int *time_to_sleep)
+{
+	int tts = *time_to_sleep;
+	struct timespec time_diff;
+
+	diff_timespec(&time_diff, time_stop, time_start);
+
+	tts -= time_diff.tv_sec * MSEC_PER_SEC +
+	       time_diff.tv_nsec / NSEC_PER_MSEC;
+
+	if (tts < 0)
+		tts = 0;
+
+	*time_to_sleep = tts;
+}
+
+static int dispatch_events(bool forks, int timeout, int interval, int *times)
+{
+	int child_exited = 0, status = 0;
+	int time_to_sleep, sleep_time;
+	struct timespec time_start, time_stop;
+
+	if (interval)
+		sleep_time = interval;
+	else if (timeout)
+		sleep_time = timeout;
+	else
+		sleep_time = 1000;
+
+	time_to_sleep = sleep_time;
+
+	while (!done) {
+		if (forks)
+			child_exited = waitpid(child_pid, &status, WNOHANG);
+		else
+			child_exited = !is_target_alive(&target, evsel_list->core.threads) ? 1 : 0;
+
+		if (child_exited)
+			break;
+
+		clock_gettime(CLOCK_MONOTONIC, &time_start);
+		if (!(evlist__poll(evsel_list, time_to_sleep) > 0)) { /* poll timeout or EINTR */
+			if (timeout || handle_interval(interval, times))
+				break;
+			time_to_sleep = sleep_time;
+		} else { /* fd revent */
+			process_evlist(evsel_list, interval);
+			clock_gettime(CLOCK_MONOTONIC, &time_stop);
+			compute_tts(&time_start, &time_stop, &time_to_sleep);
+		}
+	}
+
+	return status;
+}
+
 enum counter_recovery {
 	COUNTER_SKIP,
 	COUNTER_RETRY,
@@ -603,7 +705,6 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
 	char msg[BUFSIZ];
 	unsigned long long t0, t1;
 	struct evsel *counter;
-	struct timespec ts;
 	size_t l;
 	int status = 0;
 	const bool forks = (argc > 0);
@@ -612,17 +713,6 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
 	int i, cpu;
 	bool second_pass = false;
 
-	if (interval) {
-		ts.tv_sec  = interval / USEC_PER_MSEC;
-		ts.tv_nsec = (interval % USEC_PER_MSEC) * NSEC_PER_MSEC;
-	} else if (timeout) {
-		ts.tv_sec  = timeout / USEC_PER_MSEC;
-		ts.tv_nsec = (timeout % USEC_PER_MSEC) * NSEC_PER_MSEC;
-	} else {
-		ts.tv_sec  = 1;
-		ts.tv_nsec = 0;
-	}
-
 	if (forks) {
 		if (perf_evlist__prepare_workload(evsel_list, &target, argv, is_pipe,
 						  workload_exec_failed_signal) < 0) {
@@ -779,16 +869,8 @@ try_again_reset:
 		perf_evlist__start_workload(evsel_list);
 		enable_counters();
 
-		if (interval || timeout) {
-			while (!waitpid(child_pid, &status, WNOHANG)) {
-				nanosleep(&ts, NULL);
-				if (timeout)
-					break;
-				process_interval();
-				if (interval_count && !(--times))
-					break;
-			}
-		}
+		if (interval || timeout || evlist__ctlfd_initialized(evsel_list))
+			status = dispatch_events(forks, timeout, interval, &times);
 		if (child_pid != -1) {
 			if (timeout)
 				kill(child_pid, SIGTERM);
@@ -805,18 +887,7 @@ try_again_reset:
 			psignal(WTERMSIG(status), argv[0]);
 	} else {
 		enable_counters();
-		while (!done) {
-			nanosleep(&ts, NULL);
-			if (!is_target_alive(&target, evsel_list->core.threads))
-				break;
-			if (timeout)
-				break;
-			if (interval) {
-				process_interval();
-				if (interval_count && !(--times))
-					break;
-			}
-		}
+		status = dispatch_events(forks, timeout, interval, &times);
 	}
 
 	disable_counters();
@@ -970,6 +1041,33 @@ static int parse_metric_groups(const struct option *opt,
 					 &stat_config.metric_events);
 }
 
+static int parse_control_option(const struct option *opt,
+				const char *str,
+				int unset __maybe_unused)
+{
+	char *comma = NULL, *endptr = NULL;
+	struct perf_stat_config *config = (struct perf_stat_config *)opt->value;
+
+	if (strncmp(str, "fd:", 3))
+		return -EINVAL;
+
+	config->ctl_fd = strtoul(&str[3], &endptr, 0);
+	if (endptr == &str[3])
+		return -EINVAL;
+
+	comma = strchr(str, ',');
+	if (comma) {
+		if (endptr != comma)
+			return -EINVAL;
+
+		config->ctl_fd_ack = strtoul(comma + 1, &endptr, 0);
+		if (endptr == comma + 1 || *endptr != '\0')
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
 static struct option stat_options[] = {
 	OPT_BOOLEAN('T', "transaction", &transaction_run,
 		    "hardware transaction statistics"),
@@ -1041,8 +1139,8 @@ static struct option stat_options[] = {
 		     "aggregate counts per thread", AGGR_THREAD),
 	OPT_SET_UINT(0, "per-node", &stat_config.aggr_mode,
 		     "aggregate counts per numa node", AGGR_NODE),
-	OPT_UINTEGER('D', "delay", &stat_config.initial_delay,
-		     "ms to wait before starting measurement after program start"),
+	OPT_INTEGER('D', "delay", &stat_config.initial_delay,
+		    "ms to wait before starting measurement after program start (-1: start with events disabled)"),
 	OPT_CALLBACK_NOOPT(0, "metric-only", &stat_config.metric_only, NULL,
 			"Only print computed metrics. No raw values", enable_metric_only),
 	OPT_BOOLEAN(0, "metric-no-group", &stat_config.metric_no_group,
@@ -1071,6 +1169,10 @@ static struct option stat_options[] = {
 		"libpfm4 event selector. use 'perf list' to list available events",
 		parse_libpfm_events_option),
 #endif
+	OPT_CALLBACK(0, "control", &stat_config, "fd:ctl-fd[,ack-fd]",
+		     "Listen on ctl-fd descriptor for command to control measurement ('enable': enable events, 'disable': disable events).\n"
+		     "\t\t\t  Optionally send control command completion ('ack\\n') to ack-fd descriptor.",
+		      parse_control_option),
 	OPT_END()
 };
 
@@ -1679,19 +1781,17 @@ static int add_default_attributes(void)
 		if (target__has_cpu(&target))
 			default_attrs0[0].config = PERF_COUNT_SW_CPU_CLOCK;
 
-		if (perf_evlist__add_default_attrs(evsel_list, default_attrs0) < 0)
+		if (evlist__add_default_attrs(evsel_list, default_attrs0) < 0)
 			return -1;
 		if (pmu_have_event("cpu", "stalled-cycles-frontend")) {
-			if (perf_evlist__add_default_attrs(evsel_list,
-						frontend_attrs) < 0)
+			if (evlist__add_default_attrs(evsel_list, frontend_attrs) < 0)
 				return -1;
 		}
 		if (pmu_have_event("cpu", "stalled-cycles-backend")) {
-			if (perf_evlist__add_default_attrs(evsel_list,
-						backend_attrs) < 0)
+			if (evlist__add_default_attrs(evsel_list, backend_attrs) < 0)
 				return -1;
 		}
-		if (perf_evlist__add_default_attrs(evsel_list, default_attrs1) < 0)
+		if (evlist__add_default_attrs(evsel_list, default_attrs1) < 0)
 			return -1;
 	}
 
@@ -1701,21 +1801,21 @@ static int add_default_attributes(void)
 		return 0;
 
 	/* Append detailed run extra attributes: */
-	if (perf_evlist__add_default_attrs(evsel_list, detailed_attrs) < 0)
+	if (evlist__add_default_attrs(evsel_list, detailed_attrs) < 0)
 		return -1;
 
 	if (detailed_run < 2)
 		return 0;
 
 	/* Append very detailed run extra attributes: */
-	if (perf_evlist__add_default_attrs(evsel_list, very_detailed_attrs) < 0)
+	if (evlist__add_default_attrs(evsel_list, very_detailed_attrs) < 0)
 		return -1;
 
 	if (detailed_run < 3)
 		return 0;
 
 	/* Append very, very detailed run extra attributes: */
-	return perf_evlist__add_default_attrs(evsel_list, very_very_detailed_attrs);
+	return evlist__add_default_attrs(evsel_list, very_very_detailed_attrs);
 }
 
 static const char * const stat_record_usage[] = {
@@ -2242,6 +2342,9 @@ int cmd_stat(int argc, const char **argv)
 	signal(SIGALRM, skip_signal);
 	signal(SIGABRT, skip_signal);
 
+	if (evlist__initialize_ctlfd(evsel_list, stat_config.ctl_fd, stat_config.ctl_fd_ack))
+		goto out;
+
 	status = 0;
 	for (run_idx = 0; forever || run_idx < stat_config.run_count; run_idx++) {
 		if (stat_config.run_count != 1 && verbose > 0)
@@ -2261,6 +2364,8 @@ int cmd_stat(int argc, const char **argv)
 	if (!forever && status != -1 && (!interval || stat_config.summary))
 		print_counters(NULL, argc, argv);
 
+	evlist__finalize_ctlfd(evsel_list);
+
 	if (STAT_RECORD) {
 		/*
 		 * We synthesize the kernel mmap record just so that older tools
@@ -2307,6 +2412,7 @@ out:
 
 	evlist__delete(evsel_list);
 
+	metricgroup__rblist_exit(&stat_config.metric_events);
 	runtime_stat_delete(&stat_config);
 
 	return status;