[PATCH] sched: configure a lockdep class for rq->lock

[Max Kellermann <mk@cm4all.com>]

This fixes the warning that disables lockdep at runtime:

 INFO: trying to register non-static key.
 the code is fine but needs lockdep annotation.
 turning off the locking correctness validator.

Signed-off-by: Max Kellermann <mk@cm4all.com>
---
 kernel/sched.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/kernel/sched.c b/kernel/sched.c
index b50b0f0..57f9b37 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -574,6 +574,8 @@ struct rq {
 #endif
 };
 
+static struct lock_class_key rq_lock_class;
+
 static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
 
 
@@ -8077,6 +8079,7 @@ void __init sched_init(void)
 
 		rq = cpu_rq(i);
 		raw_spin_lock_init(&rq->lock);
+		lockdep_set_class(&rq->lock, &rq_lock_class);
 		rq->nr_running = 0;
 		rq->calc_load_active = 0;
 		rq->calc_load_update = jiffies + LOAD_FREQ;