From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Fastabend Subject: [RFC PATCH 09/17] net: sched: check for frozen queue before skb_bad_txq check Date: Tue, 02 May 2017 08:27:39 -0700 Message-ID: <20170502152739.8871.29058.stgit@john-Precision-Tower-5810> References: <20170502151445.8871.43089.stgit@john-Precision-Tower-5810> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, john.fastabend@gmail.com To: eric.dumazet@gmail.com Return-path: Received: from mail-pf0-f194.google.com ([209.85.192.194]:33021 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750733AbdEBP1w (ORCPT ); Tue, 2 May 2017 11:27:52 -0400 Received: by mail-pf0-f194.google.com with SMTP id b23so17867364pfc.0 for ; Tue, 02 May 2017 08:27:52 -0700 (PDT) In-Reply-To: <20170502151445.8871.43089.stgit@john-Precision-Tower-5810> Sender: netdev-owner@vger.kernel.org List-ID: I can not think of any good reason to pull the bad txq skb off the qdisc if the txq we plan to send this on is still frozen. So check for frozen queue first and abort before dequeuing either skb_bad_txq skb or normal qdisc dequeue() skb. Signed-off-by: John Fastabend --- net/sched/sch_generic.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index d4194c2..db5f7a0 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -203,7 +203,7 @@ static struct sk_buff *dequeue_skb(struct Qdisc *q, bool *validate, int *packets) { const struct netdev_queue *txq = q->dev_queue; - struct sk_buff *skb; + struct sk_buff *skb = NULL; *packets = 1; if (unlikely(!skb_queue_empty(&q->gso_skb))) { @@ -247,12 +247,15 @@ static struct sk_buff *dequeue_skb(struct Qdisc *q, bool *validate, } validate: *validate = true; + + if ((q->flags & TCQ_F_ONETXQUEUE) && + netif_xmit_frozen_or_stopped(txq)) + return skb; + skb = qdisc_dequeue_skb_bad_txq(q); if (unlikely(skb)) goto bulk; - if (!(q->flags & TCQ_F_ONETXQUEUE) || - !netif_xmit_frozen_or_stopped(txq)) - skb = q->dequeue(q); + skb = q->dequeue(q); if (skb) { bulk: if (qdisc_may_bulk(q))