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: Riccardo 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: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 943ddea..f370b88 100644 (file)
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -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 @@ try_fallback:
         * 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;
-                               goto retry_open;
-                       }
-               }
-               errno = old_errno;
-       }
+       if (err == -EMFILE && evsel__increase_rlimit(&set_rlimit))
+               goto retry_open;
 
        if (err != -EINVAL || cpu > 0 || thread > 0)
                goto out_close;

diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index e683f4a..47916db 100644 (file)
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -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);