From mboxrd@z Thu Jan 1 00:00:00 1970 From: Krishna Kumar Subject: [RFC PATCH] sched: Fix resource limiting in pfifo_fast Date: Sun, 30 Aug 2009 11:53:44 +0530 Message-ID: <20090830062344.6380.16713.sendpatchset@localhost.localdomain> Cc: netdev@vger.kernel.org, Krishna Kumar To: davem@davemloft.net Return-path: Received: from e28smtp08.in.ibm.com ([59.145.155.8]:48529 "EHLO e28smtp08.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750990AbZH3GXm (ORCPT ); Sun, 30 Aug 2009 02:23:42 -0400 Received: from d28relay03.in.ibm.com (d28relay03.in.ibm.com [9.184.220.60]) by e28smtp08.in.ibm.com (8.14.3/8.13.1) with ESMTP id n7U6MYt4031146 for ; Sun, 30 Aug 2009 11:52:35 +0530 Received: from d28av05.in.ibm.com (d28av05.in.ibm.com [9.184.220.67]) by d28relay03.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id n7U6NgfE2224178 for ; Sun, 30 Aug 2009 11:53:42 +0530 Received: from d28av05.in.ibm.com (loopback [127.0.0.1]) by d28av05.in.ibm.com (8.14.3/8.13.1/NCO v10.0 AVout) with ESMTP id n7U6NgaM023098 for ; Sun, 30 Aug 2009 16:23:42 +1000 Sender: netdev-owner@vger.kernel.org List-ID: From: Krishna Kumar 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. 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 --- 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);