1 files changed, 39 insertions, 43 deletions

diff --git a/net/sched/sch_multiq.c b/net/sched/sch_multiq.c
index 915f3149dde2..7e151861794b 100644
--- a/net/sched/sch_multiq.c
+++ b/net/sched/sch_multiq.c
@@ -92,40 +92,6 @@ multiq_enqueue(struct sk_buff *skb, struct Qdisc *sch)
         return ret;
 }
 
-
-static int
-multiq_requeue(struct sk_buff *skb, struct Qdisc *sch)
-{
-        struct Qdisc *qdisc;
-        struct multiq_sched_data *q = qdisc_priv(sch);
-        int ret;
-
-        qdisc = multiq_classify(skb, sch, &ret);
-#ifdef CONFIG_NET_CLS_ACT
-        if (qdisc == NULL) {
-                if (ret & __NET_XMIT_BYPASS)
-                        sch->qstats.drops++;
-                kfree_skb(skb);
-                return ret;
-        }
-#endif
-
-        ret = qdisc->ops->requeue(skb, qdisc);
-        if (ret == NET_XMIT_SUCCESS) {
-                sch->q.qlen++;
-                sch->qstats.requeues++;
-                if (q->curband)
-                        q->curband--;
-                else
-                        q->curband = q->bands - 1;
-                return NET_XMIT_SUCCESS;
-        }
-        if (net_xmit_drop_count(ret))
-                sch->qstats.drops++;
-        return ret;
-}
-
-
 static struct sk_buff *multiq_dequeue(struct Qdisc *sch)
 {
         struct multiq_sched_data *q = qdisc_priv(sch);
@@ -140,7 +106,7 @@ static struct sk_buff *multiq_dequeue(struct Qdisc *sch)
                         q->curband = 0;
 
                 /* Check that target subqueue is available before
-                 * pulling an skb to avoid excessive requeues
+                 * pulling an skb to avoid head-of-line blocking.
                  */
                 if (!__netif_subqueue_stopped(qdisc_dev(sch), q->curband)) {
                         qdisc = q->queues[q->curband];
@@ -155,6 +121,34 @@ static struct sk_buff *multiq_dequeue(struct Qdisc *sch)
 
 }
 
+static struct sk_buff *multiq_peek(struct Qdisc *sch)
+{
+        struct multiq_sched_data *q = qdisc_priv(sch);
+        unsigned int curband = q->curband;
+        struct Qdisc *qdisc;
+        struct sk_buff *skb;
+        int band;
+
+        for (band = 0; band < q->bands; band++) {
+                /* cycle through bands to ensure fairness */
+                curband++;
+                if (curband >= q->bands)
+                        curband = 0;
+
+                /* Check that target subqueue is available before
+                 * pulling an skb to avoid head-of-line blocking.
+                 */
+                if (!__netif_subqueue_stopped(qdisc_dev(sch), curband)) {
+                        qdisc = q->queues[curband];
+                        skb = qdisc->ops->peek(qdisc);
+                        if (skb)
+                                return skb;
+                }
+        }
+        return NULL;
+
+}
+
 static unsigned int multiq_drop(struct Qdisc *sch)
 {
         struct multiq_sched_data *q = qdisc_priv(sch);
@@ -220,7 +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);
                 }
@@ -230,7 +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,
@@ -238,12 +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);
                         }
@@ -451,7 +447,7 @@ static struct Qdisc_ops multiq_qdisc_ops __read_mostly = {
         .priv_size      =       sizeof(struct multiq_sched_data),
         .enqueue        =       multiq_enqueue,
         .dequeue        =       multiq_dequeue,
-        .requeue        =       multiq_requeue,
+        .peek           =       multiq_peek,
         .drop           =       multiq_drop,
         .init           =       multiq_init,
         .reset          =       multiq_reset,