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 <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Don Zickus <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: http://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

1 files changed, 3 insertions, 3 deletions

diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
index 788506eef567..ad312d91caed 100644
--- a/tools/perf/ui/browsers/hists.c
+++ b/tools/perf/ui/browsers/hists.c
@@ -1467,7 +1467,7 @@ static int perf_evsel__hists_browse(struct perf_evsel *evsel, int nr_events,
 		perf_hpp__set_user_width(symbol_conf.col_width_list_str);
 
 	while (1) {
-		const struct thread *thread = NULL;
+		struct thread *thread = NULL;
 		const struct dso *dso = NULL;
 		int choice = 0,
 		    annotate = -2, zoom_dso = -2, zoom_thread = -2,
@@ -1754,13 +1754,13 @@ zoom_thread:
 				pstack__remove(fstack, &browser->hists->thread_filter);
 zoom_out_thread:
 				ui_helpline__pop();
-				browser->hists->thread_filter = NULL;
+				thread__zput(browser->hists->thread_filter);
 				perf_hpp__set_elide(HISTC_THREAD, false);
 			} else {
 				ui_helpline__fpush("To zoom out press <- or -> + \"Zoom out of %s(%d) thread\"",
 						   thread->comm_set ? thread__comm_str(thread) : "",
 						   thread->tid);
-				browser->hists->thread_filter = thread;
+				browser->hists->thread_filter = thread__get(thread);
 				perf_hpp__set_elide(HISTC_THREAD, false);
 				pstack__push(fstack, &browser->hists->thread_filter);
 			}