[v2 PATCH 2/4] tcp: Move code related to head frag in tcp_try_coalesce
From: Alexander Duyck <hidden>
Date: 2012-05-03 07:18:58
Subsystem:
networking [general], networking [tcp], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Neal Cardwell, Linus Torvalds
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 <redacted> Cc: Eric Dumazet <edumazet@google.com> Cc: Jeff Kirsher <redacted> --- 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; }