Commit 71efc48a authored by Riccardo Mancini's avatar Riccardo Mancini Committed by Arnaldo Carvalho de Melo
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perf evsel: Separate rlimit increase from evsel__open_cpu() 



This is a preparatory patch for the workqueue patches with the goal to
separate from evlist__open_cpu() the actual opening (which could be
performed in parallel), from the existing fallback mechanisms, which
should be handled sequentially.

This patch separates the rlimit increase from evsel__open_cpu().

Signed-off-by: default avatarRiccardo Mancini <rickyman7@gmail.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/2f256de8ec37b9809a5cef73c2fa7bce416af5d3.1629490974.git.rickyman7@gmail.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent d21fc5f0

tools/perf/util/evsel.c

+30 −20
Original line number Diff line number Diff line
@@ -1931,13 +1931,40 @@ bool evsel__detect_missing_features(struct evsel *evsel) 
	}

}



bool evsel__increase_rlimit(enum rlimit_action *set_rlimit)

{

	int old_errno;

	struct rlimit l;



	if (*set_rlimit < INCREASED_MAX) {

		old_errno = errno;



		if (getrlimit(RLIMIT_NOFILE, &l) == 0) {

			if (*set_rlimit == NO_CHANGE) {

				l.rlim_cur = l.rlim_max;

			} else {

				l.rlim_cur = l.rlim_max + 1000;

				l.rlim_max = l.rlim_cur;

			}

			if (setrlimit(RLIMIT_NOFILE, &l) == 0) {

				(*set_rlimit) += 1;

				errno = old_errno;

				return true;

			}

		}

		errno = old_errno;

	}



	return false;

}



static int evsel__open_cpu(struct evsel *evsel, struct perf_cpu_map *cpus,

		struct perf_thread_map *threads,

		int start_cpu, int end_cpu)

{

	int cpu, thread, nthreads;

	int pid = -1, err, old_errno;

	enum { NO_CHANGE, SET_TO_MAX, INCREASED_MAX } set_rlimit = NO_CHANGE;

	enum rlimit_action set_rlimit = NO_CHANGE;



	err = __evsel__prepare_open(evsel, cpus, threads);

	if (err)
@@ -2046,25 +2073,8 @@ static int evsel__open_cpu(struct evsel *evsel, struct perf_cpu_map *cpus, 
	 * perf stat needs between 5 and 22 fds per CPU. When we run out

	 * of them try to increase the limits.

	 */

	if (err == -EMFILE && set_rlimit < INCREASED_MAX) {

		struct rlimit l;



		old_errno = errno;

		if (getrlimit(RLIMIT_NOFILE, &l) == 0) {

			if (set_rlimit == NO_CHANGE)

				l.rlim_cur = l.rlim_max;

			else {

				l.rlim_cur = l.rlim_max + 1000;

				l.rlim_max = l.rlim_cur;

			}

			if (setrlimit(RLIMIT_NOFILE, &l) == 0) {

				set_rlimit++;

				errno = old_errno;

	if (err == -EMFILE && evsel__increase_rlimit(&set_rlimit))

		goto retry_open;

			}

		}

		errno = old_errno;

	}



	if (err != -EINVAL || cpu > 0 || thread > 0)

		goto out_close;

tools/perf/util/evsel.h

+3 −0
Original line number Diff line number Diff line
@@ -291,6 +291,9 @@ int evsel__prepare_open(struct evsel *evsel, struct perf_cpu_map *cpus, 
		struct perf_thread_map *threads);

bool evsel__detect_missing_features(struct evsel *evsel);



enum rlimit_action { NO_CHANGE, SET_TO_MAX, INCREASED_MAX };

bool evsel__increase_rlimit(enum rlimit_action *set_rlimit);



struct perf_sample;



void *evsel__rawptr(struct evsel *evsel, struct perf_sample *sample, const char *name);