From fd11a83dd3630ec6a60f8a702446532c5c7e1991 Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Tue, 9 Dec 2014 19:40:49 -0800 Subject: net: Pull out core bits of __netdev_alloc_skb and add __napi_alloc_skb This change pulls the core functionality out of __netdev_alloc_skb and places them in a new function named __alloc_rx_skb. The reason for doing this is to make these bits accessible to a new function __napi_alloc_skb. In addition __alloc_rx_skb now has a new flags value that is used to determine which page frag pool to allocate from. If the SKB_ALLOC_NAPI flag is set then the NAPI pool is used. The advantage of this is that we do not have to use local_irq_save/restore when accessing the NAPI pool from NAPI context. In my test setup I saw at least 11ns of savings using the napi_alloc_skb function versus the netdev_alloc_skb function, most of this being due to the fact that we didn't have to call local_irq_save/restore. The main use case for napi_alloc_skb would be for things such as copybreak or page fragment based receive paths where an skb is allocated after the data has been received instead of before. Signed-off-by: Alexander Duyck Signed-off-by: David S. Miller --- include/linux/skbuff.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'include/linux/skbuff.h') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 736cc99f3f6c..85ab7d72b54c 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -151,6 +151,7 @@ struct net_device; struct scatterlist; struct pipe_inode_info; struct iov_iter; +struct napi_struct; #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) struct nf_conntrack { @@ -673,6 +674,7 @@ struct sk_buff { #define SKB_ALLOC_FCLONE 0x01 #define SKB_ALLOC_RX 0x02 +#define SKB_ALLOC_NAPI 0x04 /* Returns true if the skb was allocated from PFMEMALLOC reserves */ static inline bool skb_pfmemalloc(const struct sk_buff *skb) @@ -2165,6 +2167,13 @@ static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev, } void *napi_alloc_frag(unsigned int fragsz); +struct sk_buff *__napi_alloc_skb(struct napi_struct *napi, + unsigned int length, gfp_t gfp_mask); +static inline struct sk_buff *napi_alloc_skb(struct napi_struct *napi, + unsigned int length) +{ + return __napi_alloc_skb(napi, length, GFP_ATOMIC); +} /** * __dev_alloc_pages - allocate page for network Rx -- cgit v1.2.3-55-g7522