perf evlist: Add perf_evlist__enable_event_idx()

Add a function to enable a specific event within a specific perf event
buffer.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1406786474-9306-14-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

2 files changed, 49 insertions, 0 deletions

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 9d863db3f4b2..5dcd28c79c6e 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -355,6 +355,53 @@ int perf_evlist__enable_event(struct perf_evlist *evlist,
         return 0;
 }
 
+static int perf_evlist__enable_event_cpu(struct perf_evlist *evlist,
+                                         struct perf_evsel *evsel, int cpu)
+{
+        int thread, err;
+        int nr_threads = perf_evlist__nr_threads(evlist, evsel);
+
+        if (!evsel->fd)
+                return -EINVAL;
+
+        for (thread = 0; thread < nr_threads; thread++) {
+                err = ioctl(FD(evsel, cpu, thread),
+                            PERF_EVENT_IOC_ENABLE, 0);
+                if (err)
+                        return err;
+        }
+        return 0;
+}
+
+static int perf_evlist__enable_event_thread(struct perf_evlist *evlist,
+                                            struct perf_evsel *evsel,
+                                            int thread)
+{
+        int cpu, err;
+        int nr_cpus = cpu_map__nr(evlist->cpus);
+
+        if (!evsel->fd)
+                return -EINVAL;
+
+        for (cpu = 0; cpu < nr_cpus; cpu++) {
+                err = ioctl(FD(evsel, cpu, thread), PERF_EVENT_IOC_ENABLE, 0);
+                if (err)
+                        return err;
+        }
+        return 0;
+}
+
+int perf_evlist__enable_event_idx(struct perf_evlist *evlist,
+                                  struct perf_evsel *evsel, int idx)
+{
+        bool per_cpu_mmaps = !cpu_map__empty(evlist->cpus);
+
+        if (per_cpu_mmaps)
+                return perf_evlist__enable_event_cpu(evlist, evsel, idx);
+        else
+                return perf_evlist__enable_event_thread(evlist, evsel, idx);
+}
+
 static int perf_evlist__alloc_pollfd(struct perf_evlist *evlist)
 {
         int nr_cpus = cpu_map__nr(evlist->cpus);
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index e0084f90c271..106de53a6a74 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -122,6 +122,8 @@ int perf_evlist__disable_event(struct perf_evlist *evlist,
                                struct perf_evsel *evsel);
 int perf_evlist__enable_event(struct perf_evlist *evlist,
                               struct perf_evsel *evsel);
+int perf_evlist__enable_event_idx(struct perf_evlist *evlist,
+                                  struct perf_evsel *evsel, int idx);
 
 void perf_evlist__set_selected(struct perf_evlist *evlist,
                                struct perf_evsel *evsel);