Re: [PATCH 0/6] Add qdisc->ops->peek() support.
From: Jarek Poplawski <hidden>
Date: 2008-10-16 22:08:15
Subsystem:
netem network emulator, networking [general], tc subsystem, the rest · Maintainers:
Stephen Hemminger, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Jamal Hadi Salim, Jiri Pirko, Linus Torvalds
Patrick McHardy wrote, On 10/16/2008 02:38 PM:
Jarek Poplawski wrote:
...
quoted
PS: after this patchset only netem_enqueue() needs qdisc->requeue(), but I hope this won't take too long.Assuming work-conserving qdiscs are used with netem, the currently code will always send out a reorder packet immediately. This behaviour is trivial to implement without ->requeue. The problematic case is non-work-conserving inner qdiscs, but that doesn't seem important at all since you'd usually add it as parent of netem, which still works.
How about something like this (example only)? Jarek P. --- include/net/sch_generic.h | 1 + net/sched/sch_netem.c | 7 ++++++- 2 files changed, 7 insertions(+), 1 deletions(-)
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 9dcb5bf..9157766 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h@@ -45,6 +45,7 @@ struct Qdisc #define TCQ_F_BUILTIN 1 #define TCQ_F_THROTTLED 2 #define TCQ_F_INGRESS 4 +#define TCQ_F_REQUEUE 8 int padded; struct Qdisc_ops *ops; struct qdisc_size_table *stab;
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index 3080bd6..6ac8efc 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c@@ -233,7 +233,9 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch) */ cb->time_to_send = psched_get_time(); q->counter = 0; - ret = q->qdisc->ops->requeue(skb, q->qdisc); + q->qdisc->flags |= TCQ_F_REQUEUE; + ret = qdisc_equeue(skb, q->qdisc); + q->qdisc->flags &= ~TCQ_F_REQUEUE; } if (likely(ret == NET_XMIT_SUCCESS)) {
@@ -478,6 +480,9 @@ static int tfifo_enqueue(struct sk_buff *nskb, struct Qdisc *sch) psched_time_t tnext = netem_skb_cb(nskb)->time_to_send; struct sk_buff *skb; + if (unlikely(sch->flags & TCQ_F_REQUEUE)) + return qdisc_requeue(nskb, sch); + if (likely(skb_queue_len(list) < q->limit)) { /* Optimize for add at tail */ if (likely(skb_queue_empty(list) || tnext >= q->oldest)) {