pkt_sched: remove unnecessary xchg() in packet schedulers

[mirror_ubuntu-bionic-kernel.git] / net / sched / sch_prio.c

diff --git a/net/sched/sch_prio.c b/net/sched/sch_prio.c
index ea65a87ec22c6c4f60fdf5115151bff7da53b875..94cecef7014517b5784bdc297c36a8fad644ca28 100644 (file)
--- 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);
                        }