1 files changed, 55 insertions, 6 deletions

diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
index 45fcb715a..8b10a5541 100644
--- a/tools/perf/util/thread.c
+++ b/tools/perf/util/thread.c
@@ -43,9 +43,6 @@ struct thread *thread__new(pid_t pid, pid_t tid)
 		thread->cpu = -1;
 		INIT_LIST_HEAD(&thread->comm_list);
 
-		if (unwind__prepare_access(thread) < 0)
-			goto err_thread;
-
 		comm_str = malloc(32);
 		if (!comm_str)
 			goto err_thread;
@@ -201,10 +198,51 @@ size_t thread__fprintf(struct thread *thread, FILE *fp)
 	       map_groups__fprintf(thread->mg, fp);
 }
 
-void thread__insert_map(struct thread *thread, struct map *map)
+int thread__insert_map(struct thread *thread, struct map *map)
 {
+	int ret;
+
+	ret = unwind__prepare_access(thread, map, NULL);
+	if (ret)
+		return ret;
+
 	map_groups__fixup_overlappings(thread->mg, map, stderr);
 	map_groups__insert(thread->mg, map);
+
+	return 0;
+}
+
+static int __thread__prepare_access(struct thread *thread)
+{
+	bool initialized = false;
+	int i, err = 0;
+
+	for (i = 0; i < MAP__NR_TYPES; ++i) {
+		struct maps *maps = &thread->mg->maps[i];
+		struct map *map;
+
+		pthread_rwlock_rdlock(&maps->lock);
+
+		for (map = maps__first(maps); map; map = map__next(map)) {
+			err = unwind__prepare_access(thread, map, &initialized);
+			if (err || initialized)
+				break;
+		}
+
+		pthread_rwlock_unlock(&maps->lock);
+	}
+
+	return err;
+}
+
+static int thread__prepare_access(struct thread *thread)
+{
+	int err = 0;
+
+	if (symbol_conf.use_callchain)
+		err = __thread__prepare_access(thread);
+
+	return err;
 }
 
 static int thread__clone_map_groups(struct thread *thread,
@@ -214,7 +252,7 @@ static int thread__clone_map_groups(struct thread *thread,
 
 	/* This is new thread, we share map groups for process. */
 	if (thread->pid_ == parent->pid_)
-		return 0;
+		return thread__prepare_access(thread);
 
 	if (thread->mg == parent->mg) {
 		pr_debug("broken map groups on thread %d/%d parent %d/%d\n",
@@ -224,7 +262,7 @@ static int thread__clone_map_groups(struct thread *thread,
 
 	/* But this one is new process, copy maps. */
 	for (i = 0; i < MAP__NR_TYPES; ++i)
-		if (map_groups__clone(thread->mg, parent->mg, i) < 0)
+		if (map_groups__clone(thread, parent->mg, i) < 0)
 			return -ENOMEM;
 
 	return 0;
@@ -265,3 +303,14 @@ void thread__find_cpumode_addr_location(struct thread *thread,
 			break;
 	}
 }
+
+struct thread *thread__main_thread(struct machine *machine, struct thread *thread)
+{
+	if (thread->pid_ == thread->tid)
+		return thread__get(thread);
+
+	if (thread->pid_ == -1)
+		return NULL;
+
+	return machine__find_thread(machine, thread->pid_, thread->pid_);
+}