pkt_sched: Add qdisc->ops->peek() implementation.
Add qdisc->ops->peek() implementation for work-conserving qdiscs.
With feedback from Patrick McHardy.
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_multiq.c b/net/sched/sch_multiq.c
index 915f314..155648d 100644
--- a/net/sched/sch_multiq.c
+++ b/net/sched/sch_multiq.c
@@ -155,6 +155,34 @@
}
+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 excessive requeues
+ */
+ 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);
@@ -451,6 +479,7 @@
.priv_size = sizeof(struct multiq_sched_data),
.enqueue = multiq_enqueue,
.dequeue = multiq_dequeue,
+ .peek = multiq_peek,
.requeue = multiq_requeue,
.drop = multiq_drop,
.init = multiq_init,