perf tools: Reference count struct thread

We need to do that to stop accumulating entries in the dead_threads
linked list, i.e. we were keeping references to threads in struct hists
that continue to exist even after a thread exited and was removed from
the machine threads rbtree.

We still keep the dead_threads list, but just for debugging, allowing us
to iterate at any given point over the threads that still are referenced
by things like struct hist_entry.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-3ejvfyed0r7ue61dkurzjux4@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
index 9ebc8b1f9be5..a5dbba95107f 100644
--- a/tools/perf/util/thread.c
+++ b/tools/perf/util/thread.c
@@ -82,6 +82,20 @@ void thread__delete(struct thread *thread)
 	free(thread);
 }
 
+struct thread *thread__get(struct thread *thread)
+{
+	++thread->refcnt;
+	return thread;
+}
+
+void thread__put(struct thread *thread)
+{
+	if (thread && --thread->refcnt == 0) {
+		list_del_init(&thread->node);
+		thread__delete(thread);
+	}
+}
+
 struct comm *thread__comm(const struct thread *thread)
 {
 	if (list_empty(&thread->comm_list))