[PATCH 3/4 v2] SCHED - Only adjust overload state when changing

[Steven Rostedt]

From: Gregory Haskins <ghaskins@xxxxxxxxxx>

The overload set/clears were originally idempotent when this logic was first
implemented.  But that is no longer true due to the addition of the atomic
counter and this logic was never updated to work properly with that change.
So only adjust the overload state if it is actually changing to avoid
getting out of sync.

Signed-off-by: Gregory Haskins <ghaskins@xxxxxxxxxx>
---

 kernel/sched_rt.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

Index: linux-sched/kernel/sched_rt.c
===================================================================
--- linux-sched.orig/kernel/sched_rt.c	2007-12-10 20:39:17.000000000 -0500
+++ linux-sched/kernel/sched_rt.c	2007-12-10 20:39:19.000000000 -0500
@@ -34,9 +34,11 @@ static inline void rt_clear_overload(str
 static void update_rt_migration(struct rq *rq)
 {
 	if (rq->rt.rt_nr_migratory && (rq->rt.rt_nr_running > 1)) {
-		rt_set_overload(rq);
-		rq->rt.overloaded = 1;
-	} else {
+		if (!rq->rt.overloaded) {
+			rt_set_overload(rq);
+			rq->rt.overloaded = 1;
+		}
+	} else if (rq->rt.overloaded) {
 		rt_clear_overload(rq);
 		rq->rt.overloaded = 0;
 	}

-- 
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