1 files changed, 22 insertions, 0 deletions
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 36e23e49817d..50d4b61aef3a 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1546,6 +1546,28 @@ static inline void rq_clock_cancel_skipupdate(struct rq *rq)
 	rq->clock_update_flags &= ~RQCF_REQ_SKIP;
 }
 
+/*
+ * During cpu offlining and rq wide unthrottling, we can trigger
+ * an update_rq_clock() for several cfs and rt runqueues (Typically
+ * when using list_for_each_entry_*)
+ * rq_clock_start_loop_update() can be called after updating the clock
+ * once and before iterating over the list to prevent multiple update.
+ * After the iterative traversal, we need to call rq_clock_stop_loop_update()
+ * to clear RQCF_ACT_SKIP of rq->clock_update_flags.
+ */
+static inline void rq_clock_start_loop_update(struct rq *rq)
+{
+	lockdep_assert_rq_held(rq);
+	SCHED_WARN_ON(rq->clock_update_flags & RQCF_ACT_SKIP);
+	rq->clock_update_flags |= RQCF_ACT_SKIP;
+}
+
+static inline void rq_clock_stop_loop_update(struct rq *rq)
+{
+	lockdep_assert_rq_held(rq);
+	rq->clock_update_flags &= ~RQCF_ACT_SKIP;
+}
+
 struct rq_flags {
 	unsigned long flags;
 	struct pin_cookie cookie;