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| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2007-04-19 20:29:13 -0700 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2007-04-25 22:26:28 -0700 |
| commit | 27a884dc3cb63b93c2b3b643f5b31eed5f8a4d26 (patch) | |
| tree | 5a267e40f9b94014be38dad5de0a52b6628834e0 /include/linux/rtnetlink.h | |
| parent | be8bd86321fa7f06359d866ef61fb4d2f3e9dce9 (diff) | |
| download | lwn-27a884dc3cb63b93c2b3b643f5b31eed5f8a4d26.tar.gz lwn-27a884dc3cb63b93c2b3b643f5b31eed5f8a4d26.zip | |
[SK_BUFF]: Convert skb->tail to sk_buff_data_t
So that it is also an offset from skb->head, reduces its size from 8 to 4 bytes
on 64bit architectures, allowing us to combine the 4 bytes hole left by the
layer headers conversion, reducing struct sk_buff size to 256 bytes, i.e. 4
64byte cachelines, and since the sk_buff slab cache is SLAB_HWCACHE_ALIGN...
:-)
Many calculations that previously required that skb->{transport,network,
mac}_header be first converted to a pointer now can be done directly, being
meaningful as offsets or pointers.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/rtnetlink.h')
| -rw-r--r-- | include/linux/rtnetlink.h | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h index 4a629ea70cc4..3a4cb242ecd2 100644 --- a/include/linux/rtnetlink.h +++ b/include/linux/rtnetlink.h @@ -605,7 +605,7 @@ extern void __rta_fill(struct sk_buff *skb, int attrtype, int attrlen, const voi #define RTA_PUT_NOHDR(skb, attrlen, data) \ ({ RTA_APPEND(skb, RTA_ALIGN(attrlen), data); \ - memset(skb->tail - (RTA_ALIGN(attrlen) - attrlen), 0, \ + memset(skb_tail_pointer(skb) - (RTA_ALIGN(attrlen) - attrlen), 0, \ RTA_ALIGN(attrlen) - attrlen); }) #define RTA_PUT_U8(skb, attrtype, value) \ @@ -637,12 +637,12 @@ extern void __rta_fill(struct sk_buff *skb, int attrtype, int attrlen, const voi RTA_PUT(skb, attrtype, 0, NULL); #define RTA_NEST(skb, type) \ -({ struct rtattr *__start = (struct rtattr *) (skb)->tail; \ +({ struct rtattr *__start = (struct rtattr *)skb_tail_pointer(skb); \ RTA_PUT(skb, type, 0, NULL); \ __start; }) #define RTA_NEST_END(skb, start) \ -({ (start)->rta_len = ((skb)->tail - (unsigned char *) (start)); \ +({ (start)->rta_len = skb_tail_pointer(skb) - (unsigned char *)(start); \ (skb)->len; }) #define RTA_NEST_CANCEL(skb, start) \ |