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authorJarek Poplawski <jarkao2@gmail.com>2008-10-31 00:47:01 -0700
committerDavid S. Miller <davem@davemloft.net>2008-10-31 00:47:01 -0700
commit77be155cba4e163e8bba9fd27222a8b6189ec4f7 (patch)
tree0819d4c0bb760080aaba8a00060a774205914034
parent03c05f0d4bb0c267edf12d614025a40e33c5a6f9 (diff)
downloadblackbird-op-linux-77be155cba4e163e8bba9fd27222a8b6189ec4f7.tar.gz
blackbird-op-linux-77be155cba4e163e8bba9fd27222a8b6189ec4f7.zip
pkt_sched: Add peek emulation for non-work-conserving qdiscs.
This patch adds qdisc_peek_dequeued() wrapper to emulate peek method with qdisc->dequeue() and storing "peeked" skb in qdisc->gso_skb until dequeuing. This is mainly for compatibility reasons not to break some strange configs because peeking is expected for non-work-conserving parent qdiscs to query work-conserving child qdiscs. This implementation requires using qdisc_dequeue_peeked() wrapper instead of directly calling qdisc->dequeue() for all qdiscs ever querried with qdisc->ops->peek() or qdisc_peek_dequeued(). Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/net/sch_generic.h23
-rw-r--r--net/sched/sch_atm.c4
-rw-r--r--net/sched/sch_cbq.c1
-rw-r--r--net/sched/sch_hfsc.c3
-rw-r--r--net/sched/sch_htb.c1
-rw-r--r--net/sched/sch_netem.c5
-rw-r--r--net/sched/sch_tbf.c3
7 files changed, 34 insertions, 6 deletions
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index da6839a7ff50..9dcb5bfe094a 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -438,6 +438,29 @@ static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch)
return skb_peek(&sch->q);
}
+/* generic pseudo peek method for non-work-conserving qdisc */
+static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch)
+{
+ /* we can reuse ->gso_skb because peek isn't called for root qdiscs */
+ if (!sch->gso_skb)
+ sch->gso_skb = sch->dequeue(sch);
+
+ return sch->gso_skb;
+}
+
+/* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */
+static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch)
+{
+ struct sk_buff *skb = sch->gso_skb;
+
+ if (skb)
+ sch->gso_skb = NULL;
+ else
+ skb = sch->dequeue(sch);
+
+ return skb;
+}
+
static inline int __qdisc_requeue(struct sk_buff *skb, struct Qdisc *sch,
struct sk_buff_head *list)
{
diff --git a/net/sched/sch_atm.c b/net/sched/sch_atm.c
index 2ee0c1a8efa9..6eb9a650b63d 100644
--- a/net/sched/sch_atm.c
+++ b/net/sched/sch_atm.c
@@ -484,7 +484,7 @@ static void sch_atm_dequeue(unsigned long data)
if (!atm_may_send(flow->vcc, skb->truesize))
break;
- skb = flow->q->dequeue(flow->q);
+ skb = qdisc_dequeue_peeked(flow->q);
if (unlikely(!skb))
break;
@@ -519,7 +519,7 @@ static struct sk_buff *atm_tc_dequeue(struct Qdisc *sch)
pr_debug("atm_tc_dequeue(sch %p,[qdisc %p])\n", sch, p);
tasklet_schedule(&p->task);
- skb = p->link.q->dequeue(p->link.q);
+ skb = qdisc_dequeue_peeked(p->link.q);
if (skb)
sch->q.qlen--;
return skb;
diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c
index 03e389e8d945..63efa70abbea 100644
--- a/net/sched/sch_cbq.c
+++ b/net/sched/sch_cbq.c
@@ -2066,6 +2066,7 @@ static struct Qdisc_ops cbq_qdisc_ops __read_mostly = {
.priv_size = sizeof(struct cbq_sched_data),
.enqueue = cbq_enqueue,
.dequeue = cbq_dequeue,
+ .peek = qdisc_peek_dequeued,
.requeue = cbq_requeue,
.drop = cbq_drop,
.init = cbq_init,
diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c
index ddfc40887848..d90b1652f2af 100644
--- a/net/sched/sch_hfsc.c
+++ b/net/sched/sch_hfsc.c
@@ -1634,7 +1634,7 @@ hfsc_dequeue(struct Qdisc *sch)
}
}
- skb = cl->qdisc->dequeue(cl->qdisc);
+ skb = qdisc_dequeue_peeked(cl->qdisc);
if (skb == NULL) {
if (net_ratelimit())
printk("HFSC: Non-work-conserving qdisc ?\n");
@@ -1727,6 +1727,7 @@ static struct Qdisc_ops hfsc_qdisc_ops __read_mostly = {
.dump = hfsc_dump_qdisc,
.enqueue = hfsc_enqueue,
.dequeue = hfsc_dequeue,
+ .peek = qdisc_peek_dequeued,
.requeue = hfsc_requeue,
.drop = hfsc_drop,
.cl_ops = &hfsc_class_ops,
diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index d14f02056ae6..3fda8199713d 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -1565,6 +1565,7 @@ static struct Qdisc_ops htb_qdisc_ops __read_mostly = {
.priv_size = sizeof(struct htb_sched),
.enqueue = htb_enqueue,
.dequeue = htb_dequeue,
+ .peek = qdisc_peek_dequeued,
.requeue = htb_requeue,
.drop = htb_drop,
.init = htb_init,
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index 74fbdb52baed..3080bd6ee332 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -290,8 +290,8 @@ static struct sk_buff *netem_dequeue(struct Qdisc *sch)
/* if more time remaining? */
if (cb->time_to_send <= now) {
- skb = q->qdisc->dequeue(q->qdisc);
- if (!skb)
+ skb = qdisc_dequeue_peeked(q->qdisc);
+ if (unlikely(!skb))
return NULL;
pr_debug("netem_dequeue: return skb=%p\n", skb);
@@ -714,6 +714,7 @@ static struct Qdisc_ops netem_qdisc_ops __read_mostly = {
.priv_size = sizeof(struct netem_sched_data),
.enqueue = netem_enqueue,
.dequeue = netem_dequeue,
+ .peek = qdisc_peek_dequeued,
.requeue = netem_requeue,
.drop = netem_drop,
.init = netem_init,
diff --git a/net/sched/sch_tbf.c b/net/sched/sch_tbf.c
index 61fdc77a48d2..435076cf620e 100644
--- a/net/sched/sch_tbf.c
+++ b/net/sched/sch_tbf.c
@@ -192,7 +192,7 @@ static struct sk_buff *tbf_dequeue(struct Qdisc* sch)
toks -= L2T(q, len);
if ((toks|ptoks) >= 0) {
- skb = q->qdisc->dequeue(q->qdisc);
+ skb = qdisc_dequeue_peeked(q->qdisc);
if (unlikely(!skb))
return NULL;
@@ -467,6 +467,7 @@ static struct Qdisc_ops tbf_qdisc_ops __read_mostly = {
.priv_size = sizeof(struct tbf_sched_data),
.enqueue = tbf_enqueue,
.dequeue = tbf_dequeue,
+ .peek = qdisc_peek_dequeued,
.requeue = tbf_requeue,
.drop = tbf_drop,
.init = tbf_init,
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