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 f645ac55a1a1..7e151861794b 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);
                         }