Commit e880a70f authored by Levi Yun's avatar Levi Yun Committed by Namhyung Kim
Browse files

perf stat: Close cork_fd when create_perf_stat_counter() failed 



When create_perf_stat_counter() failed, it doesn't close workload.cork_fd
open in evlist__prepare_workload(). This could make too many open file
error while __run_perf_stat() repeats.

Introduce evlist__cancel_workload to close workload.cork_fd and
wait workload.child_pid until exit to clear child process
when create_perf_stat_counter() is failed.

Signed-off-by: default avatarLevi Yun <yeoreum.yun@arm.com>
Reviewed-by: default avatarJames Clark <james.clark@linaro.org>
Reviewed-by: default avatarAndi Kleen <ak@linux.intel.com>
Cc: nd@arm.com
Cc: howardchu95@gmail.com
Link: https://lore.kernel.org/r/20240925132022.2650180-2-yeoreum.yun@arm.com


Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
parent f115506d

tools/perf/builtin-stat.c

+35 −15
Original line number Diff line number Diff line
@@ -716,15 +716,19 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) 
	}



	if (!cpu_map__is_dummy(evsel_list->core.user_requested_cpus)) {

		if (affinity__setup(&saved_affinity) < 0)

			return -1;

		if (affinity__setup(&saved_affinity) < 0) {

			err = -1;

			goto err_out;

		}

		affinity = &saved_affinity;

	}



	evlist__for_each_entry(evsel_list, counter) {

		counter->reset_group = false;

		if (bpf_counter__load(counter, &target))

			return -1;

		if (bpf_counter__load(counter, &target)) {

			err = -1;

			goto err_out;

		}

		if (!(evsel__is_bperf(counter)))

			all_counters_use_bpf = false;

	}
@@ -767,7 +771,8 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) 


			switch (stat_handle_error(counter)) {

			case COUNTER_FATAL:

				return -1;

				err = -1;

				goto err_out;

			case COUNTER_RETRY:

				goto try_again;

			case COUNTER_SKIP:
@@ -808,7 +813,8 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) 


				switch (stat_handle_error(counter)) {

				case COUNTER_FATAL:

					return -1;

					err = -1;

					goto err_out;

				case COUNTER_RETRY:

					goto try_again_reset;

				case COUNTER_SKIP:
@@ -833,8 +839,10 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) 
			stat_config.unit_width = l;



		if (evsel__should_store_id(counter) &&

		    evsel__store_ids(counter, evsel_list))

			return -1;

		    evsel__store_ids(counter, evsel_list)) {

			err = -1;

			goto err_out;

		}

	}



	if (evlist__apply_filters(evsel_list, &counter, &target)) {
@@ -855,20 +863,23 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) 
		}



		if (err < 0)

			return err;

			goto err_out;



		err = perf_event__synthesize_stat_events(&stat_config, NULL, evsel_list,

							 process_synthesized_event, is_pipe);

		if (err < 0)

			return err;

			goto err_out;



	}



	if (target.initial_delay) {

		pr_info(EVLIST_DISABLED_MSG);

	} else {

		err = enable_counters();

		if (err)

			return -1;

		if (err) {

			err = -1;

			goto err_out;

		}

	}



	/* Exec the command, if any */
@@ -878,8 +889,10 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) 
	if (target.initial_delay > 0) {

		usleep(target.initial_delay * USEC_PER_MSEC);

		err = enable_counters();

		if (err)

			return -1;

		if (err) {

			err = -1;

			goto err_out;

		}



		pr_info(EVLIST_ENABLED_MSG);

	}
@@ -899,7 +912,8 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) 
		if (workload_exec_errno) {

			const char *emsg = str_error_r(workload_exec_errno, msg, sizeof(msg));

			pr_err("Workload failed: %s\n", emsg);

			return -1;

			err = -1;

			goto err_out;

		}



		if (WIFSIGNALED(status))
@@ -946,6 +960,12 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) 
		evlist__close(evsel_list);



	return WEXITSTATUS(status);



err_out:

	if (forks)

		evlist__cancel_workload(evsel_list);



	return err;

}



static int run_perf_stat(int argc, const char **argv, int run_idx)

tools/perf/util/evlist.c

+17 −2
Original line number Diff line number Diff line
@@ -48,6 +48,7 @@ 
#include <sys/mman.h>

#include <sys/prctl.h>

#include <sys/timerfd.h>

#include <sys/wait.h>



#include <linux/bitops.h>

#include <linux/hash.h>
@@ -1484,6 +1485,8 @@ int evlist__prepare_workload(struct evlist *evlist, struct target *target, const 
	int child_ready_pipe[2], go_pipe[2];

	char bf;



	evlist->workload.cork_fd = -1;



	if (pipe(child_ready_pipe) < 0) {

		perror("failed to create 'ready' pipe");

		return -1;
@@ -1536,7 +1539,7 @@ int evlist__prepare_workload(struct evlist *evlist, struct target *target, const 
		 * For cancelling the workload without actually running it,

		 * the parent will just close workload.cork_fd, without writing

		 * anything, i.e. read will return zero and we just exit()

		 * here.

		 * here (See evlist__cancel_workload()).

		 */

		if (ret != 1) {

			if (ret == -1)
@@ -1600,7 +1603,7 @@ int evlist__prepare_workload(struct evlist *evlist, struct target *target, const 


int evlist__start_workload(struct evlist *evlist)

{

	if (evlist->workload.cork_fd > 0) {

	if (evlist->workload.cork_fd >= 0) {

		char bf = 0;

		int ret;

		/*
@@ -1611,12 +1614,24 @@ int evlist__start_workload(struct evlist *evlist) 
			perror("unable to write to pipe");



		close(evlist->workload.cork_fd);

		evlist->workload.cork_fd = -1;

		return ret;

	}



	return 0;

}



void evlist__cancel_workload(struct evlist *evlist)

{

	int status;



	if (evlist->workload.cork_fd >= 0) {

		close(evlist->workload.cork_fd);

		evlist->workload.cork_fd = -1;

		waitpid(evlist->workload.pid, &status, WNOHANG);

	}

}



int evlist__parse_sample(struct evlist *evlist, union perf_event *event, struct perf_sample *sample)

{

	struct evsel *evsel = evlist__event2evsel(evlist, event);

tools/perf/util/evlist.h

+1 −0
Original line number Diff line number Diff line
@@ -186,6 +186,7 @@ int evlist__prepare_workload(struct evlist *evlist, struct target *target, 
			     const char *argv[], bool pipe_output,

			     void (*exec_error)(int signo, siginfo_t *info, void *ucontext));

int evlist__start_workload(struct evlist *evlist);

void evlist__cancel_workload(struct evlist *evlist);



struct option;