[tip:perf/core] perf machine: Mark removed threads as such

[tip-bot for Arnaldo Carvalho de Melo <tipbot@zytor.com>]

Commit-ID:  0170b14f5f5462524d05ee96275b7a0a0d34ae77
Gitweb:     http://git.kernel.org/tip/0170b14f5f5462524d05ee96275b7a0a0d34ae77
Author:     Arnaldo Carvalho de Melo <acme@redhat.com>
AuthorDate: Mon, 25 May 2015 15:23:05 -0300
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Wed, 27 May 2015 12:21:45 -0300

perf machine: Mark removed threads as such

We use:

  BUG_ON(!RB_EMPTY_NODE(&thread->rb_node));

in the thread destructor as a debugging check to find out about
possibly still referenced thread instances being deleted, to do that
we need to make sure we use RB_CLEAR_NODE() right after rb_erase(),
i.e. that we use the newly introduced rb_erase_init(), that works
just like list_del_init().

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-4fcqo5ypy1cjjf15ilb0hn78@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/machine.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 7ec3188..6bf8457 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -400,7 +400,7 @@ static struct thread *____machine__findnew_thread(struct machine *machine,
 		 * leader and that would screwed the rb tree.
 		 */
 		if (thread__init_map_groups(th, machine)) {
-			rb_erase(&th->rb_node, &machine->threads);
+			rb_erase_init(&th->rb_node, &machine->threads);
 			RB_CLEAR_NODE(&th->rb_node);
 			thread__delete(th);
 			return NULL;
@@ -1314,7 +1314,7 @@ static void __machine__remove_thread(struct machine *machine, struct thread *th,
 	BUG_ON(atomic_read(&th->refcnt) == 0);
 	if (lock)
 		pthread_rwlock_wrlock(&machine->threads_lock);
-	rb_erase(&th->rb_node, &machine->threads);
+	rb_erase_init(&th->rb_node, &machine->threads);
 	RB_CLEAR_NODE(&th->rb_node);
 	/*
 	 * Move it first to the dead_threads list, then drop the reference,