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 <ho...@verge.net.au>
---
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 2e0ced1..5663e35 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)
{
--
1.8.2.1
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