From d7e8883cfcf4851afe74fb380cc62b7fa9cf66ba Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 30 Apr 2012 08:10:34 +0000 Subject: net: make GRO aware of skb->head_frag MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit GRO can check if skb to be merged has its skb->head mapped to a page fragment, instead of a kmalloc() area. We 'upgrade' skb->head as a fragment in itself This avoids the frag_list fallback, and permits to build true GRO skb (one sk_buff and up to 16 fragments), using less memory. This reduces number of cache misses when user makes its copy, since a single sk_buff is fetched. This is a followup of patch "net: allow skb->head to be a page fragment" Signed-off-by: Eric Dumazet Cc: Ilpo Järvinen Cc: Herbert Xu Cc: Maciej Żenczykowski Cc: Neal Cardwell Cc: Tom Herbert Cc: Jeff Kirsher Cc: Ben Hutchings Cc: Matt Carlson Cc: Michael Chan Signed-off-by: David S. Miller --- include/linux/netdevice.h | 2 ++ include/linux/skbuff.h | 1 + 2 files changed, 3 insertions(+) (limited to 'include/linux') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index e0b70e961e61..7f377fb8b527 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1509,6 +1509,8 @@ struct napi_gro_cb { /* Free the skb? */ int free; +#define NAPI_GRO_FREE 1 +#define NAPI_GRO_FREE_STOLEN_HEAD 2 }; #define NAPI_GRO_CB(skb) ((struct napi_gro_cb *)(skb)->cb) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 9d28a22a8554..2c75e98953b2 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -561,6 +561,7 @@ static inline struct rtable *skb_rtable(const struct sk_buff *skb) extern void kfree_skb(struct sk_buff *skb); extern void consume_skb(struct sk_buff *skb); extern void __kfree_skb(struct sk_buff *skb); +extern struct kmem_cache *skbuff_head_cache; extern struct sk_buff *__alloc_skb(unsigned int size, gfp_t priority, int fclone, int node); extern struct sk_buff *build_skb(void *data, unsigned int frag_size); -- cgit v1.2.3