From patchwork Thu Apr 22 07:41:36 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: David Miller X-Patchwork-Id: 50695 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 [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 1F06FB7D18 for ; Thu, 22 Apr 2010 17:41:50 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752292Ab0DVHld (ORCPT ); Thu, 22 Apr 2010 03:41:33 -0400 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:47252 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750714Ab0DVHlc convert rfc822-to-8bit (ORCPT ); Thu, 22 Apr 2010 03:41:32 -0400 Received: from localhost (localhost [127.0.0.1]) by sunset.davemloft.net (Postfix) with ESMTP id 9E68C24C11B; Thu, 22 Apr 2010 00:41:36 -0700 (PDT) Date: Thu, 22 Apr 2010 00:41:36 -0700 (PDT) Message-Id: <20100422.004136.151480121.davem@davemloft.net> To: eric.dumazet@gmail.com Cc: netdev@vger.kernel.org Subject: Re: [PATCH net-next-2.6] net: Introduce skb_orphan_try() From: David Miller In-Reply-To: <1271921637.7895.4791.camel@edumazet-laptop> References: <1271921045.7895.4763.camel@edumazet-laptop> <20100422.002623.00784210.davem@davemloft.net> <1271921637.7895.4791.camel@edumazet-laptop> X-Mailer: Mew version 6.3 on Emacs 23.1 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Eric Dumazet Date: Thu, 22 Apr 2010 09:33:57 +0200 > Le jeudi 22 avril 2010 à 00:26 -0700, David Miller a écrit : >> @@ -1865,6 +1865,7 @@ static int dev_gso_segment(struct sk_buff *skb) >> int features = dev->features & ~(illegal_highdma(dev, skb) ? >> NETIF_F_SG : 0); >> >> + skb_orphan_try(skb); >> segs = skb_gso_segment(skb, features); >> >> /* Verifying header integrity only. */ > > Yes, it seems better. > > What about the > > if (dev->priv_flags & IFF_XMIT_DST_RELEASE) > skb_dst_drop(skb); > > This thing might also be moved before the split, since split probably > clone all dst ? Good catch, agreed. --- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/net/core/dev.c b/net/core/dev.c index 3ba774b..4f897e2 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1851,6 +1851,17 @@ static void dev_gso_skb_destructor(struct sk_buff *skb) cb->destructor(skb); } +/* + * Try to orphan skb early, right before transmission by the device. + * We cannot orphan skb if tx timestamp is requested, since + * drivers need to call skb_tstamp_tx() to send the timestamp. + */ +static inline void skb_orphan_try(struct sk_buff *skb) +{ + if (!skb_tx(skb)->flags) + skb_orphan(skb); +} + /** * dev_gso_segment - Perform emulated hardware segmentation on skb. * @skb: buffer to segment @@ -1865,6 +1876,7 @@ static int dev_gso_segment(struct sk_buff *skb) int features = dev->features & ~(illegal_highdma(dev, skb) ? NETIF_F_SG : 0); + skb_orphan_try(skb); segs = skb_gso_segment(skb, features); /* Verifying header integrity only. */ @@ -1881,17 +1893,6 @@ static int dev_gso_segment(struct sk_buff *skb) return 0; } -/* - * Try to orphan skb early, right before transmission by the device. - * We cannot orphan skb if tx timestamp is requested, since - * drivers need to call skb_tstamp_tx() to send the timestamp. - */ -static inline void skb_orphan_try(struct sk_buff *skb) -{ - if (!skb_tx(skb)->flags) - skb_orphan(skb); -} - int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev, struct netdev_queue *txq) { @@ -1902,13 +1903,6 @@ int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev, if (!list_empty(&ptype_all)) dev_queue_xmit_nit(skb, dev); - if (netif_needs_gso(dev, skb)) { - if (unlikely(dev_gso_segment(skb))) - goto out_kfree_skb; - if (skb->next) - goto gso; - } - /* * If device doesnt need skb->dst, release it right now while * its hot in this cpu cache @@ -1916,6 +1910,13 @@ int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev, if (dev->priv_flags & IFF_XMIT_DST_RELEASE) skb_dst_drop(skb); + if (netif_needs_gso(dev, skb)) { + if (unlikely(dev_gso_segment(skb))) + goto out_kfree_skb; + if (skb->next) + goto gso; + } + skb_orphan_try(skb); rc = ops->ndo_start_xmit(skb, dev); if (rc == NETDEV_TX_OK)