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_prio.c b/net/sched/sch_prio.c
index ea65a87ec22c..94cecef70145 100644
--- a/net/sched/sch_prio.c
+++ b/net/sched/sch_prio.c
@@ -187,7 +187,8 @@ static int prio_tune(struct Qdisc *sch, struct nlattr *opt)
         memcpy(q->prio2band, qopt->priomap, TC_PRIO_MAX+1);
 
         for (i=q->bands; i<TCQ_PRIO_BANDS; i++) {
-                struct Qdisc *child = xchg(&q->queues[i], &noop_qdisc);
+                struct Qdisc *child = q->queues[i];
+                q->queues[i] = &noop_qdisc;
                 if (child != &noop_qdisc) {
                         qdisc_tree_decrease_qlen(child, child->q.qlen);
                         qdisc_destroy(child);
@@ -197,18 +198,19 @@ static int prio_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,
                                                   TC_H_MAKE(sch->handle, 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);
                         }