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authorJarek Poplawski <jarkao2@gmail.com>2008-10-31 00:45:55 -0700
committerDavid S. Miller <davem@davemloft.net>2008-10-31 00:45:55 -0700
commit8e3af97899db433111287e07d5105189f56fe191 (patch)
tree40e7779ea4b587c9c3b882018ccaac1b53419f1c /net/sched/sch_multiq.c
parentpkt_sched: sch_generic: Add generic qdisc->ops->peek() implementation. (diff)
downloadlinux-dev-8e3af97899db433111287e07d5105189f56fe191.tar.xz
linux-dev-8e3af97899db433111287e07d5105189f56fe191.zip
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>
Diffstat (limited to 'net/sched/sch_multiq.c')
-rw-r--r--net/sched/sch_multiq.c29
1 files changed, 29 insertions, 0 deletions
diff --git a/net/sched/sch_multiq.c b/net/sched/sch_multiq.c
index 915f3149dde2..155648d23b7c 100644
--- a/net/sched/sch_multiq.c
+++ b/net/sched/sch_multiq.c
@@ -155,6 +155,34 @@ 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 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 @@ static struct Qdisc_ops multiq_qdisc_ops __read_mostly = {
.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,