From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Duyck Subject: [v2 PATCH 2/4] tcp: Move code related to head frag in tcp_try_coalesce Date: Thu, 03 May 2012 00:19:04 -0700 Message-ID: <20120503071904.13636.61130.stgit@gitlad.jf.intel.com> References: <20120503071141.13636.37564.stgit@gitlad.jf.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: davem@davemloft.net, jeffrey.t.kirsher@intel.com, edumazet@google.com To: netdev@vger.kernel.org Return-path: Received: from mga03.intel.com ([143.182.124.21]:13473 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752138Ab2ECHS6 (ORCPT ); Thu, 3 May 2012 03:18:58 -0400 In-Reply-To: <20120503071141.13636.37564.stgit@gitlad.jf.intel.com> Sender: netdev-owner@vger.kernel.org List-ID: This change reorders the code related to the use of an skb->head_frag so it is placed before we check the rest of the frags. This allows the code to read more linearly instead of like some sort of loop. Signed-off-by: Alexander Duyck Cc: Eric Dumazet Cc: Jeff Kirsher --- net/ipv4/tcp_input.c | 42 +++++++++++++++++++++++++----------------- 1 files changed, 25 insertions(+), 17 deletions(-) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 3cb273a..41fa5df 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -4562,9 +4562,31 @@ merge: if (skb_has_frag_list(to) || skb_has_frag_list(from)) return false; - if (skb_headlen(from) == 0 && - (skb_shinfo(to)->nr_frags + - skb_shinfo(from)->nr_frags <= MAX_SKB_FRAGS)) { + if (skb_headlen(from) != 0) { + struct page *page; + unsigned int offset; + + if (skb_shinfo(to)->nr_frags + + skb_shinfo(from)->nr_frags >= MAX_SKB_FRAGS) + return false; + + if (!from->head_frag || skb_cloned(from)) + return false; + + delta = from->truesize - SKB_DATA_ALIGN(sizeof(struct sk_buff)); + + page = virt_to_head_page(from->head); + offset = from->data - (unsigned char *)page_address(page); + + skb_fill_page_desc(to, skb_shinfo(to)->nr_frags, + page, offset, skb_headlen(from)); + *fragstolen = true; + goto copyfrags; + } else { + if (skb_shinfo(to)->nr_frags + + skb_shinfo(from)->nr_frags > MAX_SKB_FRAGS) + return false; + delta = from->truesize - SKB_TRUESIZE(skb_end_pointer(from) - from->head); copyfrags: @@ -4587,20 +4609,6 @@ copyfrags: to->data_len += len; goto merge; } - if (from->head_frag && !skb_cloned(from)) { - struct page *page; - unsigned int offset; - - if (skb_shinfo(to)->nr_frags + skb_shinfo(from)->nr_frags >= MAX_SKB_FRAGS) - return false; - page = virt_to_head_page(from->head); - offset = from->data - (unsigned char *)page_address(page); - skb_fill_page_desc(to, skb_shinfo(to)->nr_frags, - page, offset, skb_headlen(from)); - *fragstolen = true; - delta = from->truesize - SKB_DATA_ALIGN(sizeof(struct sk_buff)); - goto copyfrags; - } return false; }