Commit a5df6333 authored by Li RongQing's avatar Li RongQing Committed by David S. Miller
Browse files

skbuff: pass the result of data ksize to __build_skb_around 



Avoid to call ksize again in __build_skb_around by passing
the result of data ksize to __build_skb_around

nginx stress test shows this change can reduce ksize cpu usage,
and give a little performance boost

Signed-off-by: default avatarLi RongQing <lirongqing@baidu.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent db4278c5

net/core/skbuff.c

+5 −3
Original line number Diff line number Diff line
@@ -394,8 +394,9 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask, 
{

	struct kmem_cache *cache;

	struct sk_buff *skb;

	u8 *data;

	unsigned int osize;

	bool pfmemalloc;

	u8 *data;



	cache = (flags & SKB_ALLOC_FCLONE)

		? skbuff_fclone_cache : skbuff_head_cache;
@@ -427,7 +428,8 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask, 
	 * Put skb_shared_info exactly at the end of allocated zone,

	 * to allow max possible filling before reallocation.

	 */

	size = SKB_WITH_OVERHEAD(ksize(data));

	osize = ksize(data);

	size = SKB_WITH_OVERHEAD(osize);

	prefetchw(data + size);



	/*
@@ -436,7 +438,7 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask, 
	 * the tail pointer in struct sk_buff!

	 */

	memset(skb, 0, offsetof(struct sk_buff, tail));

	__build_skb_around(skb, data, 0);

	__build_skb_around(skb, data, osize);

	skb->pfmemalloc = pfmemalloc;



	if (flags & SKB_ALLOC_FCLONE) {