[PATCH 2/5] tracing: Have tracer selftests call cond_resched() before running

[Steven Rostedt]

From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx>

As there are more and more internal selftests being added to the Linux
kernel (KSAN, lockdep, etc) the selftests are taking longer to run when
these are enabled. Add a cond_resched() to the calling of
do_run_tracer_selftest() to force a schedule if NEED_RESCHED is set,
otherwise the soft lockup watchdog may trigger on boot up.

Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
---
 kernel/trace/trace.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 87e5920b141f..70f2b511b9cd 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2045,6 +2045,13 @@ static int do_run_tracer_selftest(struct tracer *type)
 {
 	int ret;
 
+	/*
+	 * Tests can take a long time, especially if they are run one after the
+	 * other, as does happen during bootup when all the tracers are
+	 * registered. This could cause the soft lockup watchdog to trigger.
+	 */
+	cond_resched();
+
 	tracing_selftest_running = true;
 	ret = run_tracer_selftest(type);
 	tracing_selftest_running = false;
-- 
2.39.2