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| author | David S. Miller <davem@davemloft.net> | 2005-08-17 14:57:30 -0700 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2005-08-29 16:01:54 -0700 |
| commit | d179cd12928443f3ec29cfbc3567439644bd0afc (patch) | |
| tree | 0bfc57e73f0bf9f7bb9d5c8ce7d3d5afe550f94e /include | |
| parent | e92ae93a8aa66aea12935420cb22d4df1c18d023 (diff) | |
| download | linux-d179cd12928443f3ec29cfbc3567439644bd0afc.tar.gz linux-d179cd12928443f3ec29cfbc3567439644bd0afc.tar.bz2 linux-d179cd12928443f3ec29cfbc3567439644bd0afc.zip | |
[NET]: Implement SKB fast cloning.
Protocols that make extensive use of SKB cloning,
for example TCP, eat at least 2 allocations per
packet sent as a result.
To cut the kmalloc() count in half, we implement
a pre-allocation scheme wherein we allocate
2 sk_buff objects in advance, then use a simple
reference count to free up the memory at the
correct time.
Based upon an initial patch by Thomas Graf and
suggestions from Herbert Xu.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/skbuff.h | 26 | ||||
| -rw-r--r-- | include/net/sock.h | 2 |
2 files changed, 24 insertions, 4 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index db10335e4192..42edce6abe23 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -162,6 +162,13 @@ struct skb_timeval { u32 off_usec; }; + +enum { + SKB_FCLONE_UNAVAILABLE, + SKB_FCLONE_ORIG, + SKB_FCLONE_CLONE, +}; + /** * struct sk_buff - socket buffer * @next: Next buffer in list @@ -255,7 +262,8 @@ struct sk_buff { ip_summed:2, nohdr:1, nfctinfo:3; - __u8 pkt_type; + __u8 pkt_type:3, + fclone:2; __be16 protocol; void (*destructor)(struct sk_buff *skb); @@ -295,8 +303,20 @@ struct sk_buff { #include <asm/system.h> extern void __kfree_skb(struct sk_buff *skb); -extern struct sk_buff *alloc_skb(unsigned int size, - unsigned int __nocast priority); +extern struct sk_buff *__alloc_skb(unsigned int size, + unsigned int __nocast priority, int fclone); +static inline struct sk_buff *alloc_skb(unsigned int size, + unsigned int __nocast priority) +{ + return __alloc_skb(size, priority, 0); +} + +static inline struct sk_buff *alloc_skb_fclone(unsigned int size, + unsigned int __nocast priority) +{ + return __alloc_skb(size, priority, 1); +} + extern struct sk_buff *alloc_skb_from_cache(kmem_cache_t *cp, unsigned int size, unsigned int __nocast priority); diff --git a/include/net/sock.h b/include/net/sock.h index 14183883e8e6..d57aece9492c 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1200,7 +1200,7 @@ static inline struct sk_buff *sk_stream_alloc_pskb(struct sock *sk, int hdr_len; hdr_len = SKB_DATA_ALIGN(sk->sk_prot->max_header); - skb = alloc_skb(size + hdr_len, gfp); + skb = alloc_skb_fclone(size + hdr_len, gfp); if (skb) { skb->truesize += mem; if (sk->sk_forward_alloc >= (int)skb->truesize || |