From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161914Ab2GLXnx (ORCPT ); Thu, 12 Jul 2012 19:43:53 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:58752 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759548Ab2GLWhs (ORCPT ); Thu, 12 Jul 2012 18:37:48 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg KH , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Eric Dumazet , Oliver Hartkopp , "David S. Miller" Subject: [ 039/187] net: remove skb_orphan_try() Date: Thu, 12 Jul 2012 15:33:15 -0700 Message-Id: <20120712191525.953445138@linuxfoundation.org> X-Mailer: git-send-email 1.7.10.1.362.g242cab3 In-Reply-To: <20120712191522.742634173@linuxfoundation.org> References: <20120712192421.GA28926@kroah.com> <20120712191522.742634173@linuxfoundation.org> User-Agent: quilt/0.60-20.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Greg KH 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 62b1a8ab9b3660bb820d8dfe23148ed6cda38574 ] Orphaning skb in dev_hard_start_xmit() makes bonding behavior unfriendly for applications sending big UDP bursts : Once packets pass the bonding device and come to real device, they might hit a full qdisc and be dropped. Without orphaning, the sender is automatically throttled because sk->sk_wmemalloc reaches sk->sk_sndbuf (assuming sk_sndbuf is not too big) We could try to defer the orphaning adding another test in dev_hard_start_xmit(), but all this seems of little gain, now that BQL tends to make packets more likely to be parked in Qdisc queues instead of NIC TX ring, in cases where performance matters. Reverts commits : fc6055a5ba31 net: Introduce skb_orphan_try() 87fd308cfc6b net: skb_tx_hash() fix relative to skb_orphan_try() and removes SKBTX_DRV_NEEDS_SK_REF flag Reported-and-bisected-by: Jean-Michel Hautbois Signed-off-by: Eric Dumazet Tested-by: Oliver Hartkopp Acked-by: Oliver Hartkopp Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- include/linux/skbuff.h | 7 ++----- net/can/raw.c | 3 --- net/core/dev.c | 23 +---------------------- net/iucv/af_iucv.c | 1 - 4 files changed, 3 insertions(+), 31 deletions(-) --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -225,14 +225,11 @@ enum { /* device driver is going to provide hardware time stamp */ SKBTX_IN_PROGRESS = 1 << 2, - /* ensure the originating sk reference is available on driver level */ - SKBTX_DRV_NEEDS_SK_REF = 1 << 3, - /* device driver supports TX zero-copy buffers */ - SKBTX_DEV_ZEROCOPY = 1 << 4, + SKBTX_DEV_ZEROCOPY = 1 << 3, /* generate wifi status information (where possible) */ - SKBTX_WIFI_STATUS = 1 << 5, + SKBTX_WIFI_STATUS = 1 << 4, }; /* --- a/net/can/raw.c +++ b/net/can/raw.c @@ -681,9 +681,6 @@ static int raw_sendmsg(struct kiocb *ioc if (err < 0) goto free_skb; - /* to be able to check the received tx sock reference in raw_rcv() */ - skb_shinfo(skb)->tx_flags |= SKBTX_DRV_NEEDS_SK_REF; - skb->dev = dev; skb->sk = sk; --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2091,25 +2091,6 @@ static int dev_gso_segment(struct sk_buf return 0; } -/* - * Try to orphan skb early, right before transmission by the device. - * We cannot orphan skb if tx timestamp is requested or the sk-reference - * is needed on driver level for other reasons, e.g. see net/can/raw.c - */ -static inline void skb_orphan_try(struct sk_buff *skb) -{ - struct sock *sk = skb->sk; - - if (sk && !skb_shinfo(skb)->tx_flags) { - /* skb_tx_hash() wont be able to get sk. - * We copy sk_hash into skb->rxhash - */ - if (!skb->rxhash) - skb->rxhash = sk->sk_hash; - skb_orphan(skb); - } -} - static bool can_checksum_protocol(netdev_features_t features, __be16 protocol) { return ((features & NETIF_F_GEN_CSUM) || @@ -2195,8 +2176,6 @@ int dev_hard_start_xmit(struct sk_buff * if (!list_empty(&ptype_all)) dev_queue_xmit_nit(skb, dev); - skb_orphan_try(skb); - features = netif_skb_features(skb); if (vlan_tx_tag_present(skb) && @@ -2306,7 +2285,7 @@ u16 __skb_tx_hash(const struct net_devic if (skb->sk && skb->sk->sk_hash) hash = skb->sk->sk_hash; else - hash = (__force u16) skb->protocol ^ skb->rxhash; + hash = (__force u16) skb->protocol; hash = jhash_1word(hash, hashrnd); return (u16) (((u64) hash * qcount) >> 32) + qoffset; --- a/net/iucv/af_iucv.c +++ b/net/iucv/af_iucv.c @@ -372,7 +372,6 @@ static int afiucv_hs_send(struct iucv_me skb_trim(skb, skb->dev->mtu); } skb->protocol = ETH_P_AF_IUCV; - skb_shinfo(skb)->tx_flags |= SKBTX_DRV_NEEDS_SK_REF; nskb = skb_clone(skb, GFP_ATOMIC); if (!nskb) return -ENOMEM;