pkt_sched: remove unnecessary xchg() in packet schedulers

The use of xchg() hasn't been necessary since 2.2.something when proper
locking was added to packet schedulers.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 7 deletions

diff --git a/net/sched/sch_multiq.c b/net/sched/sch_multiq.c
index f645ac55a1a..7e151861794 100644
--- a/net/sched/sch_multiq.c
+++ b/net/sched/sch_multiq.c
@@ -214,7 +214,8 @@ static int multiq_tune(struct Qdisc *sch, struct nlattr *opt)
 	q->bands = qopt->bands;
 	for (i = q->bands; i < q->max_bands; i++) {
 		if (q->queues[i] != &noop_qdisc) {
-			struct Qdisc *child = xchg(&q->queues[i], &noop_qdisc);
+			struct Qdisc *child = q->queues[i];
+			q->queues[i] = &noop_qdisc;
 			qdisc_tree_decrease_qlen(child, child->q.qlen);
 			qdisc_destroy(child);
 		}
@@ -224,7 +225,7 @@ static int multiq_tune(struct Qdisc *sch, struct nlattr *opt)
 
 	for (i = 0; i < q->bands; i++) {
 		if (q->queues[i] == &noop_qdisc) {
-			struct Qdisc *child;
+			struct Qdisc *child, *old;
 			child = qdisc_create_dflt(qdisc_dev(sch),
 						  sch->dev_queue,
 						  &pfifo_qdisc_ops,
@@ -232,12 +233,13 @@ static int multiq_tune(struct Qdisc *sch, struct nlattr *opt)
 							    i + 1));
 			if (child) {
 				sch_tree_lock(sch);
-				child = xchg(&q->queues[i], child);
+				old = q->queues[i];
+				q->queues[i] = child;
 
-				if (child != &noop_qdisc) {
-					qdisc_tree_decrease_qlen(child,
-								 child->q.qlen);
-					qdisc_destroy(child);
+				if (old != &noop_qdisc) {
+					qdisc_tree_decrease_qlen(old,
+								 old->q.qlen);
+					qdisc_destroy(old);
 				}
 				sch_tree_unlock(sch);
 			}