From patchwork Thu Oct 30 13:06:33 2008 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarek Poplawski X-Patchwork-Id: 6496 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by ozlabs.org (Postfix) with ESMTP id 79928DDDEF for ; Fri, 31 Oct 2008 00:06:45 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754126AbYJ3NGk (ORCPT ); Thu, 30 Oct 2008 09:06:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754115AbYJ3NGk (ORCPT ); Thu, 30 Oct 2008 09:06:40 -0400 Received: from nf-out-0910.google.com ([64.233.182.186]:42755 "EHLO nf-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754086AbYJ3NGj (ORCPT ); Thu, 30 Oct 2008 09:06:39 -0400 Received: by nf-out-0910.google.com with SMTP id d3so256454nfc.21 for ; Thu, 30 Oct 2008 06:06:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:date:from:to:cc:subject :message-id:mime-version:content-type:content-disposition:x-mutt-fcc :user-agent; bh=nR2jwWaagSy9fK+UKPrd+Jtj2xwD+fe1Gl3Y1ihDpc8=; b=w2n68l+sRX93FzVKp9zdS1c/pAnOTX3seQNPE3Iq/tt1qWoWY6BmONl/FMmy12Lz5A e6iohacRV+XDVgP8NO+fYpTuFrPu5dklm7BAnvzpa/NpWI+P7W7iWA1qsSrUZEpoUfJk Oankz/ltDOR48NSxmaHTEnEk8Os3sEaMOHbSQ= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:mime-version:content-type :content-disposition:x-mutt-fcc:user-agent; b=Yve7QL2dx5R+95INb7kk2Lex39d4T60jGtTzfJIX6SyPluHeeApcqaeIoKwg7KVjLD A0QMocF1qUITpFGCNag/Z+O7+0LijrP0xkbDH9tLymTzPpcYWf7xJa3BGSxnSGMcYyK1 yGQLWiinT9d20ZnV+2YGoqmfy9fku6qJnWZrQ= Received: by 10.210.119.16 with SMTP id r16mr11635426ebc.190.1225371998541; Thu, 30 Oct 2008 06:06:38 -0700 (PDT) Received: from ff.dom.local (bv170.internetdsl.tpnet.pl [80.53.205.170]) by mx.google.com with ESMTPS id 10sm1772008eyd.6.2008.10.30.06.06.36 (version=SSLv3 cipher=RC4-MD5); Thu, 30 Oct 2008 06:06:38 -0700 (PDT) Date: Thu, 30 Oct 2008 13:06:33 +0000 From: Jarek Poplawski To: Patrick McHardy Cc: David Miller , netdev@vger.kernel.org, Herbert Xu Subject: [PATCH 6/6 RESEND] pkt_sched: Add peek emulation for non-work-conserving qdiscs. Message-ID: <20081030130632.GG22853@ff.dom.local> MIME-Version: 1.0 Content-Disposition: inline X-Mutt-Fcc: =outbox User-Agent: Mutt/1.5.18 (2008-05-17) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This patch adds qdisc_peek_dequeued() wrapper to emulate peek method with qdisc->dequeue() and storing "peeked" skb in qdisc->gso_skb until dequeuing. This is mainly for compatibility reasons not to break some strange configs because peeking is expected for non-work-conserving parent qdiscs to query work-conserving child qdiscs. This implementation requires using qdisc_dequeue_peeked() wrapper instead of directly calling qdisc->dequeue() for all qdiscs ever querried with qdisc->ops->peek() or qdisc_peek_dequeued(). Signed-off-by: Jarek Poplawski --- include/net/sch_generic.h | 23 +++++++++++++++++++++++ net/sched/sch_atm.c | 4 ++-- net/sched/sch_cbq.c | 1 + net/sched/sch_hfsc.c | 3 ++- net/sched/sch_htb.c | 1 + net/sched/sch_netem.c | 5 +++-- net/sched/sch_tbf.c | 3 ++- 7 files changed, 34 insertions(+), 6 deletions(-) diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index da6839a..9dcb5bf 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -438,6 +438,29 @@ static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch) return skb_peek(&sch->q); } +/* generic pseudo peek method for non-work-conserving qdisc */ +static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch) +{ + /* we can reuse ->gso_skb because peek isn't called for root qdiscs */ + if (!sch->gso_skb) + sch->gso_skb = sch->dequeue(sch); + + return sch->gso_skb; +} + +/* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */ +static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch) +{ + struct sk_buff *skb = sch->gso_skb; + + if (skb) + sch->gso_skb = NULL; + else + skb = sch->dequeue(sch); + + return skb; +} + static inline int __qdisc_requeue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff_head *list) { diff --git a/net/sched/sch_atm.c b/net/sched/sch_atm.c index 2ee0c1a..6eb9a65 100644 --- a/net/sched/sch_atm.c +++ b/net/sched/sch_atm.c @@ -484,7 +484,7 @@ static void sch_atm_dequeue(unsigned long data) if (!atm_may_send(flow->vcc, skb->truesize)) break; - skb = flow->q->dequeue(flow->q); + skb = qdisc_dequeue_peeked(flow->q); if (unlikely(!skb)) break; @@ -519,7 +519,7 @@ static struct sk_buff *atm_tc_dequeue(struct Qdisc *sch) pr_debug("atm_tc_dequeue(sch %p,[qdisc %p])\n", sch, p); tasklet_schedule(&p->task); - skb = p->link.q->dequeue(p->link.q); + skb = qdisc_dequeue_peeked(p->link.q); if (skb) sch->q.qlen--; return skb; diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c index 03e389e..63efa70 100644 --- a/net/sched/sch_cbq.c +++ b/net/sched/sch_cbq.c @@ -2066,6 +2066,7 @@ static struct Qdisc_ops cbq_qdisc_ops __read_mostly = { .priv_size = sizeof(struct cbq_sched_data), .enqueue = cbq_enqueue, .dequeue = cbq_dequeue, + .peek = qdisc_peek_dequeued, .requeue = cbq_requeue, .drop = cbq_drop, .init = cbq_init, diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c index ddfc408..d90b165 100644 --- a/net/sched/sch_hfsc.c +++ b/net/sched/sch_hfsc.c @@ -1634,7 +1634,7 @@ hfsc_dequeue(struct Qdisc *sch) } } - skb = cl->qdisc->dequeue(cl->qdisc); + skb = qdisc_dequeue_peeked(cl->qdisc); if (skb == NULL) { if (net_ratelimit()) printk("HFSC: Non-work-conserving qdisc ?\n"); @@ -1727,6 +1727,7 @@ static struct Qdisc_ops hfsc_qdisc_ops __read_mostly = { .dump = hfsc_dump_qdisc, .enqueue = hfsc_enqueue, .dequeue = hfsc_dequeue, + .peek = qdisc_peek_dequeued, .requeue = hfsc_requeue, .drop = hfsc_drop, .cl_ops = &hfsc_class_ops, diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c index d14f020..3fda819 100644 --- a/net/sched/sch_htb.c +++ b/net/sched/sch_htb.c @@ -1565,6 +1565,7 @@ static struct Qdisc_ops htb_qdisc_ops __read_mostly = { .priv_size = sizeof(struct htb_sched), .enqueue = htb_enqueue, .dequeue = htb_dequeue, + .peek = qdisc_peek_dequeued, .requeue = htb_requeue, .drop = htb_drop, .init = htb_init, diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c index 74fbdb5..3080bd6 100644 --- a/net/sched/sch_netem.c +++ b/net/sched/sch_netem.c @@ -290,8 +290,8 @@ static struct sk_buff *netem_dequeue(struct Qdisc *sch) /* if more time remaining? */ if (cb->time_to_send <= now) { - skb = q->qdisc->dequeue(q->qdisc); - if (!skb) + skb = qdisc_dequeue_peeked(q->qdisc); + if (unlikely(!skb)) return NULL; pr_debug("netem_dequeue: return skb=%p\n", skb); @@ -714,6 +714,7 @@ static struct Qdisc_ops netem_qdisc_ops __read_mostly = { .priv_size = sizeof(struct netem_sched_data), .enqueue = netem_enqueue, .dequeue = netem_dequeue, + .peek = qdisc_peek_dequeued, .requeue = netem_requeue, .drop = netem_drop, .init = netem_init, diff --git a/net/sched/sch_tbf.c b/net/sched/sch_tbf.c index 61fdc77..435076c 100644 --- a/net/sched/sch_tbf.c +++ b/net/sched/sch_tbf.c @@ -192,7 +192,7 @@ static struct sk_buff *tbf_dequeue(struct Qdisc* sch) toks -= L2T(q, len); if ((toks|ptoks) >= 0) { - skb = q->qdisc->dequeue(q->qdisc); + skb = qdisc_dequeue_peeked(q->qdisc); if (unlikely(!skb)) return NULL; @@ -467,6 +467,7 @@ static struct Qdisc_ops tbf_qdisc_ops __read_mostly = { .priv_size = sizeof(struct tbf_sched_data), .enqueue = tbf_enqueue, .dequeue = tbf_dequeue, + .peek = qdisc_peek_dequeued, .requeue = tbf_requeue, .drop = tbf_drop, .init = tbf_init,