Re: [RFC PATCH] sched: Fix resource limiting in pfifo_fast
From: Eric Dumazet <hidden>
Date: 2009-08-30 06:54:59
Krishna Kumar a écrit :
From: Krishna Kumar <redacted>
pfifo_fast_enqueue has this check:
if (skb_queue_len(list) < qdisc_dev(qdisc)->tx_queue_len) {
which allows each band to enqueue upto tx_queue_len skbs for a
total of 3*tx_queue_len skbs. I am not sure if this was the
intention of limiting in qdisc.Yes I noticed that and said to myself : This was to let high priority packets have their own limit, independent on fact that low priority packets filled their queue.
quoted hunk ↗ jump to hunk
Patch compiled and 32 simultaneous netperf testing ran fine. Also: # tc -s qdisc show dev eth2 qdisc pfifo_fast 0: root bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1 Sent 16835026752 bytes 373116 pkt (dropped 0, overlimits 0 requeues 25) rate 0bit 0pps backlog 0b 0p requeues 25 (I am taking next week off, so sorry for any delay in responding) Signed-off-by: Krishna Kumar <redacted> --- net/sched/sch_generic.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff -ruNp org/net/sched/sch_generic.c new/net/sched/sch_generic.c--- org/net/sched/sch_generic.c 2009-08-30 11:18:23.000000000 +0530 +++ new/net/sched/sch_generic.c 2009-08-30 11:21:50.000000000 +0530@@ -432,11 +432,11 @@ static inline struct sk_buff_head *band2 static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc* qdisc) { - int band = prio2band[skb->priority & TC_PRIO_MAX]; - struct pfifo_fast_priv *priv = qdisc_priv(qdisc); - struct sk_buff_head *list = band2list(priv, band); + if (skb_queue_len(&qdisc->q) < qdisc_dev(qdisc)->tx_queue_len) { + int band = prio2band[skb->priority & TC_PRIO_MAX]; + struct pfifo_fast_priv *priv = qdisc_priv(qdisc); + struct sk_buff_head *list = band2list(priv, band); - if (skb_queue_len(list) < qdisc_dev(qdisc)->tx_queue_len) { priv->bitmap |= (1 << band); qdisc->q.qlen++; return __qdisc_enqueue_tail(skb, qdisc, list);