From 1a37e412a0225fcba5587f24c0dfc7636efc8b69 Mon Sep 17 00:00:00 2001 From: Simon Horman Date: Thu, 23 May 2013 21:02:51 +0000 Subject: [PATCH] net: Use 16bits for *_headers fields of struct skbuff In order to mitigate ongoing incresase in the size of struct skbuff use 16 bit integer offsets rather than pointers for inner_*_headers. This appears to reduce the size of struct skbuff from 0xd0 to 0xc0 bytes on x86_64 with the following all unset. CONFIG_XFRM CONFIG_NF_CONNTRACK CONFIG_NF_CONNTRACK_MODULE NET_SKBUFF_NF_DEFRAG_NEEDED CONFIG_BRIDGE_NETFILTER CONFIG_NET_SCHED CONFIG_IPV6_NDISC_NODETYPE CONFIG_NET_DMA CONFIG_NETWORK_SECMARK Signed-off-by: Simon Horman Signed-off-by: David S. Miller --- include/linux/skbuff.h | 119 +++-------------------------------------- 1 file changed, 6 insertions(+), 113 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 2e0ced1af3b1..5663e3592784 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -509,12 +509,12 @@ struct sk_buff { __u32 reserved_tailroom; }; - sk_buff_data_t inner_transport_header; - sk_buff_data_t inner_network_header; - sk_buff_data_t inner_mac_header; - sk_buff_data_t transport_header; - sk_buff_data_t network_header; - sk_buff_data_t mac_header; + __u16 inner_transport_header; + __u16 inner_network_header; + __u16 inner_mac_header; + __u16 transport_header; + __u16 network_header; + __u16 mac_header; /* These elements must be at the end, see alloc_skb() for details. */ sk_buff_data_t tail; sk_buff_data_t end; @@ -1527,7 +1527,6 @@ static inline void skb_reset_mac_len(struct sk_buff *skb) skb->mac_len = skb->network_header - skb->mac_header; } -#ifdef NET_SKBUFF_DATA_USES_OFFSET static inline unsigned char *skb_inner_transport_header(const struct sk_buff *skb) { @@ -1638,112 +1637,6 @@ static inline void skb_set_mac_header(struct sk_buff *skb, const int offset) skb->mac_header += offset; } -#else /* NET_SKBUFF_DATA_USES_OFFSET */ -static inline unsigned char *skb_inner_transport_header(const struct sk_buff - *skb) -{ - return skb->inner_transport_header; -} - -static inline void skb_reset_inner_transport_header(struct sk_buff *skb) -{ - skb->inner_transport_header = skb->data; -} - -static inline void skb_set_inner_transport_header(struct sk_buff *skb, - const int offset) -{ - skb->inner_transport_header = skb->data + offset; -} - -static inline unsigned char *skb_inner_network_header(const struct sk_buff *skb) -{ - return skb->inner_network_header; -} - -static inline void skb_reset_inner_network_header(struct sk_buff *skb) -{ - skb->inner_network_header = skb->data; -} - -static inline void skb_set_inner_network_header(struct sk_buff *skb, - const int offset) -{ - skb->inner_network_header = skb->data + offset; -} - -static inline unsigned char *skb_inner_mac_header(const struct sk_buff *skb) -{ - return skb->inner_mac_header; -} - -static inline void skb_reset_inner_mac_header(struct sk_buff *skb) -{ - skb->inner_mac_header = skb->data; -} - -static inline void skb_set_inner_mac_header(struct sk_buff *skb, - const int offset) -{ - skb->inner_mac_header = skb->data + offset; -} -static inline bool skb_transport_header_was_set(const struct sk_buff *skb) -{ - return skb->transport_header != NULL; -} - -static inline unsigned char *skb_transport_header(const struct sk_buff *skb) -{ - return skb->transport_header; -} - -static inline void skb_reset_transport_header(struct sk_buff *skb) -{ - skb->transport_header = skb->data; -} - -static inline void skb_set_transport_header(struct sk_buff *skb, - const int offset) -{ - skb->transport_header = skb->data + offset; -} - -static inline unsigned char *skb_network_header(const struct sk_buff *skb) -{ - return skb->network_header; -} - -static inline void skb_reset_network_header(struct sk_buff *skb) -{ - skb->network_header = skb->data; -} - -static inline void skb_set_network_header(struct sk_buff *skb, const int offset) -{ - skb->network_header = skb->data + offset; -} - -static inline unsigned char *skb_mac_header(const struct sk_buff *skb) -{ - return skb->mac_header; -} - -static inline int skb_mac_header_was_set(const struct sk_buff *skb) -{ - return skb->mac_header != NULL; -} - -static inline void skb_reset_mac_header(struct sk_buff *skb) -{ - skb->mac_header = skb->data; -} - -static inline void skb_set_mac_header(struct sk_buff *skb, const int offset) -{ - skb->mac_header = skb->data + offset; -} -#endif /* NET_SKBUFF_DATA_USES_OFFSET */ - static inline void skb_probe_transport_header(struct sk_buff *skb, const int offset_hint) { -- 2.30.2