Merge branches 'pm-core', 'pm-qos', 'pm-domains' and 'pm-opp'

[linux.git] / tools / perf / util / evsel.c

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 04e536ae4d88423e3c05a98fd1bd97ff64379b14..ac59710b79e0b4cbee35cacc1e40a2102e091d8e 100644 (file)
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1448,8 +1448,8 @@ static bool ignore_missing_thread(struct perf_evsel *evsel,
        return true;
 }
 
-static int __perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
-                             struct thread_map *threads)
+int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
+                    struct thread_map *threads)
 {
        int cpu, thread, nthreads;
        unsigned long flags = PERF_FLAG_FD_CLOEXEC;
@@ -1459,6 +1459,30 @@ static int __perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
        if (perf_missing_features.write_backward && evsel->attr.write_backward)
                return -EINVAL;
 
+       if (cpus == NULL) {
+               static struct cpu_map *empty_cpu_map;
+
+               if (empty_cpu_map == NULL) {
+                       empty_cpu_map = cpu_map__dummy_new();
+                       if (empty_cpu_map == NULL)
+                               return -ENOMEM;
+               }
+
+               cpus = empty_cpu_map;
+       }
+
+       if (threads == NULL) {
+               static struct thread_map *empty_thread_map;
+
+               if (empty_thread_map == NULL) {
+                       empty_thread_map = thread_map__new_by_tid(-1);
+                       if (empty_thread_map == NULL)
+                               return -ENOMEM;
+               }
+
+               threads = empty_thread_map;
+       }
+
        if (evsel->system_wide)
                nthreads = 1;
        else
@@ -1655,46 +1679,16 @@ void perf_evsel__close(struct perf_evsel *evsel, int ncpus, int nthreads)
        perf_evsel__free_fd(evsel);
 }
 
-static struct {
-       struct cpu_map map;
-       int cpus[1];
-} empty_cpu_map = {
-       .map.nr = 1,
-       .cpus   = { -1, },
-};
-
-static struct {
-       struct thread_map map;
-       int threads[1];
-} empty_thread_map = {
-       .map.nr  = 1,
-       .threads = { -1, },
-};
-
-int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
-                    struct thread_map *threads)
-{
-       if (cpus == NULL) {
-               /* Work around old compiler warnings about strict aliasing */
-               cpus = &empty_cpu_map.map;
-       }
-
-       if (threads == NULL)
-               threads = &empty_thread_map.map;
-
-       return __perf_evsel__open(evsel, cpus, threads);
-}
-
 int perf_evsel__open_per_cpu(struct perf_evsel *evsel,
                             struct cpu_map *cpus)
 {
-       return __perf_evsel__open(evsel, cpus, &empty_thread_map.map);
+       return perf_evsel__open(evsel, cpus, NULL);
 }
 
 int perf_evsel__open_per_thread(struct perf_evsel *evsel,
                                struct thread_map *threads)
 {
-       return __perf_evsel__open(evsel, &empty_cpu_map.map, threads);
+       return perf_evsel__open(evsel, NULL, threads);
 }
 
 static int perf_evsel__parse_id_sample(const struct perf_evsel *evsel,
@@ -2469,7 +2463,9 @@ int perf_evsel__open_strerror(struct perf_evsel *evsel, struct target *target,
                 "  -1: Allow use of (almost) all events by all users\n"
                 ">= 0: Disallow raw tracepoint access by users without CAP_IOC_LOCK\n"
                 ">= 1: Disallow CPU event access by users without CAP_SYS_ADMIN\n"
-                ">= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN",
+                ">= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN\n\n"
+                "To make this setting permanent, edit /etc/sysctl.conf too, e.g.:\n\n"
+                "      kernel.perf_event_paranoid = -1\n" ,
                                 target->system_wide ? "system-wide " : "",
                                 perf_event_paranoid());
        case ENOENT: