From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: [PATCH] netem: fix dequeue Date: Thu, 16 Feb 2012 07:28:25 +0100 Message-ID: <1329373705.5646.13.camel@edumazet-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netdev To: David Miller Return-path: Received: from mail-ww0-f44.google.com ([74.125.82.44]:61763 "EHLO mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753942Ab2BPG2a (ORCPT ); Thu, 16 Feb 2012 01:28:30 -0500 Received: by wgbdt10 with SMTP id dt10so1631660wgb.1 for ; Wed, 15 Feb 2012 22:28:29 -0800 (PST) Sender: netdev-owner@vger.kernel.org List-ID: commit 50612537e9 (netem: fix classful handling) added two errors in netem_dequeue() 1) After checking skb at the head of tfifo queue for time constraints, it dequeues tail skb, thus adding unwanted reordering. 2) qdisc stats are updated twice per packet (one when packet dequeued from tfifo, once when delivered) Signed-off-by: Eric Dumazet --- net/sched/sch_netem.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c index e83d61c..5da548f 100644 --- a/net/sched/sch_netem.c +++ b/net/sched/sch_netem.c @@ -501,9 +501,8 @@ tfifo_dequeue: /* if more time remaining? */ if (cb->time_to_send <= psched_get_time()) { - skb = qdisc_dequeue_tail(sch); - if (unlikely(!skb)) - goto qdisc_dequeue; + __skb_unlink(skb, &sch->q); + sch->qstats.backlog -= qdisc_pkt_len(skb); #ifdef CONFIG_NET_CLS_ACT /* @@ -539,7 +538,6 @@ deliver: qdisc_watchdog_schedule(&q->watchdog, cb->time_to_send); } -qdisc_dequeue: if (q->qdisc) { skb = q->qdisc->ops->dequeue(q->qdisc); if (skb)