[tip:perf/core] perf tests: Fix map_groups refcount test

tip-bot for Arnaldo Carvalho de Melo
2015-05-15T06:46:13Z

Commit-ID: 8b00f46951bed1edd9c5cb9d9adb62d28bbe7623
Gitweb: http://git.kernel.org/tip/8b00f46951bed1edd9c5cb9d9adb62d28bbe7623
Author: Arnaldo Carvalho de Melo <acme@redhat.com>
AuthorDate: Mon, 11 May 2015 18:13:14 -0300
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Tue, 12 May 2015 09:59:52 -0300

perf tests: Fix map_groups refcount test

When introducing reference counting for struct thread instances I forgot
to remove the synthetic threads from the machine's rbtree so that it
then the threads would have just one reference and thus the
thread__put() replacing the thread__delete() really turns into a
thread__delete() (thread->refcnt == 1 at thread__put() time) and thus
drop the thread->mg refcount, as expected by the this test.

Fix it by calling machine__remove_thread() (the counterpart of
machine__findnew_thread()) on all the synthetic threads after the
checks that involves the rbtree were done.

Before:

# perf test -v mg
30: Test thread mg sharing :
--- start ---
test child forked, pid 26995
FAILED tests/thread-mg-share.c:68 wrong refcnt (4 != 3)
test child finished with -1
---- end ----
Test thread mg sharing: FAILED!
#

After:

# perf test mg
30: Test thread mg sharing: Ok
#

Fixes: b91fc39f4ad7 ("perf machine: Protect the machine->threads with a rwlock")
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-uoqq0fjei90ohhhcboz6ay33@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/tests/thread-mg-share.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/tools/perf/tests/thread-mg-share.c b/tools/perf/tests/thread-mg-share.c
index 04eccee..c0ed56f 100644
--- a/tools/perf/tests/thread-mg-share.c
+++ b/tools/perf/tests/thread-mg-share.c
@@ -58,6 +58,18 @@ int test__thread_mg_share(void)
other_leader = machine__find_thread(machine, 4, 4);
TEST_ASSERT_VAL("failed to find other leader", other_leader);

+ /*
+ * Ok, now that all the rbtree related operations were done,
+ * lets remove all of them from there so that we can do the
+ * refcounting tests.
+ */
+ machine__remove_thread(machine, leader);
+ machine__remove_thread(machine, t1);
+ machine__remove_thread(machine, t2);
+ machine__remove_thread(machine, t3);
+ machine__remove_thread(machine, other);
+ machine__remove_thread(machine, other_leader);
+
other_mg = other->mg;
TEST_ASSERT_EQUAL("wrong refcnt", other_mg->refcnt, 2);

@@ -81,11 +93,6 @@ int test__thread_mg_share(void)

thread__put(other);

- /*
- * Cannot call machine__delete_threads(machine) now,
- * because we've already released all the threads.
- */
-
machines__exit(&machines);
return 0;
}