| Submitter | Jiri Pirko |
|---|---|
| Date | Feb. 15, 2013, 3:24 p.m. |
| Message ID | <1360941882-6727-1-git-send-email-jiri@resnulli.us> |
| Download | mbox | patch |
| Permalink | /patch/220760/ |
| State | RFC |
| Headers | show |
Comments
On Fri, 2013-02-15 at 16:24 +0100, Jiri Pirko wrote: > So far, gso skbs has been handled by tbf in the same way as any other > ones. Given their pkt_len they got dropped which leads to very > inaccurate rates. This patch makes tbf gso-aware. > > According to Eric's suggestion, when gso skb can't be sent in one mtu > time, resegment it. > > + do { > + next_skb = skb->next; > + qdisc_skb_cb(skb)->pkt_len = skb->len; > + qdisc_calculate_pkt_len(skb, qdisc); > + __skb_queue_after(&qdisc->q, prev_skb, skb); > + prev_skb = skb; > + skb = next_skb; > + num_skbs++; > + } while (skb); This only works if qdisc is a fifo (holding packets in qdisc->q) Please try : tc qdisc del dev eth0 root 2>/dev/null tc qdisc add dev eth0 root handle 10 tbf rate 0.5mbit burst 5kb latency 70ms peakrate 1mbit minburst 1540 tc qd add dev eth0 parent 10: handle 20 fq_codel I guess we need a per qdisc ops to reinject the packets at the right place. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, 2013-02-15 at 08:13 -0800, Eric Dumazet wrote: > tc qdisc del dev eth0 root 2>/dev/null > tc qdisc add dev eth0 root handle 10 tbf rate 0.5mbit burst 5kb latency 70ms peakrate 1mbit minburst 1540 > tc qd add dev eth0 parent 10: handle 20 fq_codel > > I guess we need a per qdisc ops to reinject the packets at the right place. > Or you could hold these packets in a private list (private to this TBF) and dequeue packets from this private list before packets from child qdisc. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Patch
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index 2761c90..9f57762 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -366,6 +366,7 @@ extern struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue, extern void qdisc_reset(struct Qdisc *qdisc); extern void qdisc_destroy(struct Qdisc *qdisc); extern void qdisc_tree_decrease_qlen(struct Qdisc *qdisc, unsigned int n); +extern bool qdisc_gso_segment(struct Qdisc *qdisc, struct sk_buff *skb); extern struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue, struct Qdisc_ops *ops); extern struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue, diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c index fe1ba54..cd8df6b 100644 --- a/net/sched/sch_api.c +++ b/net/sched/sch_api.c @@ -666,6 +666,34 @@ void qdisc_tree_decrease_qlen(struct Qdisc *sch, unsigned int n) } EXPORT_SYMBOL(qdisc_tree_decrease_qlen); +bool qdisc_gso_segment(struct Qdisc *qdisc, struct sk_buff *skb) +{ + struct sk_buff *segs; + struct sk_buff *next_skb; + struct sk_buff *prev_skb; + int num_skbs = 0; + + segs = skb_gso_segment(skb, 0); + if (IS_ERR(segs) || !segs) + return false; + __skb_unlink(skb, &qdisc->q); + kfree_skb(skb); + skb = segs; + prev_skb = (struct sk_buff *) &qdisc->q; + do { + next_skb = skb->next; + qdisc_skb_cb(skb)->pkt_len = skb->len; + qdisc_calculate_pkt_len(skb, qdisc); + __skb_queue_after(&qdisc->q, prev_skb, skb); + prev_skb = skb; + skb = next_skb; + num_skbs++; + } while (skb); + qdisc_tree_decrease_qlen(qdisc, 1 - num_skbs); + return true; +} +EXPORT_SYMBOL(qdisc_gso_segment); + static void notify_and_destroy(struct net *net, struct sk_buff *skb, struct nlmsghdr *n, u32 clid, struct Qdisc *old, struct Qdisc *new) diff --git a/net/sched/sch_tbf.c b/net/sched/sch_tbf.c index c8388f3..5680562 100644 --- a/net/sched/sch_tbf.c +++ b/net/sched/sch_tbf.c @@ -121,7 +121,7 @@ static int tbf_enqueue(struct sk_buff *skb, struct Qdisc *sch) struct tbf_sched_data *q = qdisc_priv(sch); int ret; - if (qdisc_pkt_len(skb) > q->max_size) + if (qdisc_pkt_len(skb) > q->max_size && !skb_is_gso(skb)) return qdisc_reshape_fail(skb, sch); ret = qdisc_enqueue(skb, q->qdisc); @@ -164,10 +164,21 @@ static struct sk_buff *tbf_dequeue(struct Qdisc *sch) toks = min_t(s64, now - q->t_c, q->buffer); if (q->peak_present) { + s64 skb_ptoks = (s64) psched_l2t_ns(&q->peak, len); + ptoks = toks + q->ptokens; if (ptoks > q->mtu) ptoks = q->mtu; - ptoks -= (s64) psched_l2t_ns(&q->peak, len); + if (skb_is_gso(skb) && skb_ptoks > q->mtu && + qdisc_gso_segment(q->qdisc, skb)) { + q->qdisc->gso_skb = NULL; + skb = q->qdisc->ops->peek(q->qdisc); + if (unlikely(!skb)) + return NULL; + len = qdisc_pkt_len(skb); + skb_ptoks = (s64) psched_l2t_ns(&q->peak, len); + } + ptoks -= skb_ptoks; } toks += q->tokens; if (toks > q->buffer)
So far, gso skbs has been handled by tbf in the same way as any other ones. Given their pkt_len they got dropped which leads to very inaccurate rates. This patch makes tbf gso-aware. According to Eric's suggestion, when gso skb can't be sent in one mtu time, resegment it. Signed-off-by: Jiri Pirko <jiri@resnulli.us> --- include/net/sch_generic.h | 1 + net/sched/sch_api.c | 28 ++++++++++++++++++++++++++++ net/sched/sch_tbf.c | 15 +++++++++++++-- 3 files changed, 42 insertions(+), 2 deletions(-)