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authorDavid S. Miller <davem@davemloft.net>2005-08-17 14:57:30 -0700
committerDavid S. Miller <davem@sunset.davemloft.net>2005-08-29 16:01:54 -0700
commitd179cd12928443f3ec29cfbc3567439644bd0afc (patch)
tree0bfc57e73f0bf9f7bb9d5c8ce7d3d5afe550f94e /include
parente92ae93a8aa66aea12935420cb22d4df1c18d023 (diff)
[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.h26
-rw-r--r--include/net/sock.h2
2 files changed, 24 insertions, 4 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index db10335e419..42edce6abe2 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 14183883e8e..d57aece9492 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 ||