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authornbd <nbd@3c298f89-4303-0410-b956-a3cf2f4a3e73>2012-05-27 14:43:58 +0000
committernbd <nbd@3c298f89-4303-0410-b956-a3cf2f4a3e73>2012-05-27 14:43:58 +0000
commit4cf70ab2e1f2f6b50ccd8d62471507f253c4c003 (patch)
tree437afa2ce20c1a5e28af78144db40d717f81bc48
parent878544bb079df3585b319d65f18633586d57964e (diff)
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
-rw-r--r--target/linux/generic/patches-3.3/653-disable_netlink_trim.patch28
-rw-r--r--target/linux/generic/patches-3.3/654-avoid_skb_cow_realloc.patch20
-rw-r--r--target/linux/generic/patches-3.3/655-increase_skb_pad.patch11
3 files changed, 59 insertions, 0 deletions
diff --git a/target/linux/generic/patches-3.3/653-disable_netlink_trim.patch b/target/linux/generic/patches-3.3/653-disable_netlink_trim.patch
new file mode 100644
index 000000000..c6c7c75a9
--- /dev/null
+++ b/target/linux/generic/patches-3.3/653-disable_netlink_trim.patch
@@ -0,0 +1,28 @@
+--- a/net/netlink/af_netlink.c
++++ b/net/netlink/af_netlink.c
+@@ -854,25 +854,7 @@ void netlink_detachskb(struct sock *sk,
+
+ static struct sk_buff *netlink_trim(struct sk_buff *skb, gfp_t allocation)
+ {
+- int delta;
+-
+ skb_orphan(skb);
+-
+- delta = skb->end - skb->tail;
+- if (delta * 2 < skb->truesize)
+- return skb;
+-
+- if (skb_shared(skb)) {
+- struct sk_buff *nskb = skb_clone(skb, allocation);
+- if (!nskb)
+- return skb;
+- kfree_skb(skb);
+- skb = nskb;
+- }
+-
+- if (!pskb_expand_head(skb, 0, -delta, allocation))
+- skb->truesize -= delta;
+-
+ return skb;
+ }
+
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,
diff --git a/target/linux/generic/patches-3.3/655-increase_skb_pad.patch b/target/linux/generic/patches-3.3/655-increase_skb_pad.patch
new file mode 100644
index 000000000..5d14daadf
--- /dev/null
+++ b/target/linux/generic/patches-3.3/655-increase_skb_pad.patch
@@ -0,0 +1,11 @@
+--- a/include/linux/skbuff.h
++++ b/include/linux/skbuff.h
+@@ -1558,7 +1558,7 @@ static inline int pskb_network_may_pull(
+ * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
+ */
+ #ifndef NET_SKB_PAD
+-#define NET_SKB_PAD max(32, L1_CACHE_BYTES)
++#define NET_SKB_PAD max(48, L1_CACHE_BYTES)
+ #endif
+
+ extern int ___pskb_trim(struct sk_buff *skb, unsigned int len);