summaryrefslogtreecommitdiffstats
path: root/kernel/trace/trace_selftest.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/trace/trace_selftest.c')
-rw-r--r--kernel/trace/trace_selftest.c27
1 files changed, 13 insertions, 14 deletions
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index 1003a4d5eb25..2c00a691a540 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -1041,6 +1041,8 @@ static int trace_wakeup_test_thread(void *data)
set_current_state(TASK_INTERRUPTIBLE);
schedule();
+ complete(x);
+
/* we are awake, now wait to disappear */
while (!kthread_should_stop()) {
/*
@@ -1084,24 +1086,21 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
/* reset the max latency */
tracing_max_latency = 0;
- /* sleep to let the RT thread sleep too */
- msleep(100);
+ while (p->on_rq) {
+ /*
+ * Sleep to make sure the RT thread is asleep too.
+ * On virtual machines we can't rely on timings,
+ * but we want to make sure this test still works.
+ */
+ msleep(100);
+ }
- /*
- * Yes this is slightly racy. It is possible that for some
- * strange reason that the RT thread we created, did not
- * call schedule for 100ms after doing the completion,
- * and we do a wakeup on a task that already is awake.
- * But that is extremely unlikely, and the worst thing that
- * happens in such a case, is that we disable tracing.
- * Honestly, if this race does happen something is horrible
- * wrong with the system.
- */
+ init_completion(&isrt);
wake_up_process(p);
- /* give a little time to let the thread wake up */
- msleep(100);
+ /* Wait for the task to wake up */
+ wait_for_completion(&isrt);
/* stop the tracing. */
tracing_stop();
OpenPOWER on IntegriCloud