From 4cf70ab2e1f2f6b50ccd8d62471507f253c4c003 Mon Sep 17 00:00:00 2001 From: nbd Date: Sun, 27 May 2012 14:43:58 +0000 Subject: kernel: add a few patches for avoiding unnecessary skb reallocations - significantly improves ethernet<->wireless performance with mac80211 based drivers git-svn-id: svn://svn.openwrt.org/openwrt/trunk@31886 3c298f89-4303-0410-b956-a3cf2f4a3e73 --- .../patches-3.3/654-avoid_skb_cow_realloc.patch | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) create mode 100644 target/linux/generic/patches-3.3/654-avoid_skb_cow_realloc.patch (limited to 'target/linux/generic/patches-3.3/654-avoid_skb_cow_realloc.patch') diff --git a/target/linux/generic/patches-3.3/654-avoid_skb_cow_realloc.patch b/target/linux/generic/patches-3.3/654-avoid_skb_cow_realloc.patch new file mode 100644 index 000000000..dfa98198e --- /dev/null +++ b/target/linux/generic/patches-3.3/654-avoid_skb_cow_realloc.patch @@ -0,0 +1,20 @@ +--- a/include/linux/skbuff.h ++++ b/include/linux/skbuff.h +@@ -1850,12 +1850,15 @@ static inline int skb_clone_writable(con + static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom, + int cloned) + { ++ unsigned int alloc_headroom = headroom; + int delta = 0; + + if (headroom < NET_SKB_PAD) +- headroom = NET_SKB_PAD; +- if (headroom > skb_headroom(skb)) ++ alloc_headroom = NET_SKB_PAD; ++ if (headroom > skb_headroom(skb) || ++ (cloned && alloc_headroom > skb_headroom(skb))) { + delta = headroom - skb_headroom(skb); ++ } + + if (delta || cloned) + return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0, -- cgit v1.2.3