1 files changed, 45 insertions, 7 deletions

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index d144d464ce39..1b16dd1edc8e 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -404,13 +404,40 @@ const char *perf_evsel__name(struct perf_evsel *evsel)
         return evsel->name ?: "unknown";
 }
 
-void perf_evsel__config(struct perf_evsel *evsel, struct perf_record_opts *opts,
-                        struct perf_evsel *first)
+/*
+ * The enable_on_exec/disabled value strategy:
+ *
+ *  1) For any type of traced program:
+ *    - all independent events and group leaders are disabled
+ *    - all group members are enabled
+ *
+ *     Group members are ruled by group leaders. They need to
+ *     be enabled, because the group scheduling relies on that.
+ *
+ *  2) For traced programs executed by perf:
+ *     - all independent events and group leaders have
+ *       enable_on_exec set
+ *     - we don't specifically enable or disable any event during
+ *       the record command
+ *
+ *     Independent events and group leaders are initially disabled
+ *     and get enabled by exec. Group members are ruled by group
+ *     leaders as stated in 1).
+ *
+ *  3) For traced programs attached by perf (pid/tid):
+ *     - we specifically enable or disable all events during
+ *       the record command
+ *
+ *     When attaching events to already running traced we
+ *     enable/disable events specifically, as there's no
+ *     initial traced exec call.
+ */
+void perf_evsel__config(struct perf_evsel *evsel,
+                        struct perf_record_opts *opts)
 {
         struct perf_event_attr *attr = &evsel->attr;
         int track = !evsel->idx; /* only the first counter needs these */
 
-        attr->disabled = 1;
         attr->sample_id_all = opts->sample_id_all_missing ? 0 : 1;
         attr->inherit       = !opts->no_inherit;
         attr->read_format   = PERF_FORMAT_TOTAL_TIME_ENABLED |
@@ -486,10 +513,21 @@ void perf_evsel__config(struct perf_evsel *evsel, struct perf_record_opts *opts,
         attr->mmap = track;
         attr->comm = track;
 
-        if (perf_target__none(&opts->target) &&
-            (!opts->group || evsel == first)) {
+        /*
+         * XXX see the function comment above
+         *
+         * Disabling only independent events or group leaders,
+         * keeping group members enabled.
+         */
+        if (!perf_evsel__is_group_member(evsel))
+                attr->disabled = 1;
+
+        /*
+         * Setting enable_on_exec for independent events and
+         * group leaders for traced executed by perf.
+         */
+        if (perf_target__none(&opts->target) && !perf_evsel__is_group_member(evsel))
                 attr->enable_on_exec = 1;
-        }
 }
 
 int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
@@ -669,7 +707,7 @@ static int get_group_fd(struct perf_evsel *evsel, int cpu, int thread)
         struct perf_evsel *leader = evsel->leader;
         int fd;
 
-        if (!leader)
+        if (!perf_evsel__is_group_member(evsel))
                 return -1;
 
         /*