[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>
This commit is contained in:
Arnaldo Carvalho de Melo
2007-04-19 20:29:13 -07:00
committed by David S. Miller
parent be8bd86321
commit 27a884dc3c
110 changed files with 396 additions and 329 deletions

View File

@ -89,7 +89,7 @@ struct sk_buff *tipc_cfg_reply_alloc(int payload_size)
int tipc_cfg_append_tlv(struct sk_buff *buf, int tlv_type,
void *tlv_data, int tlv_data_size)
{
struct tlv_desc *tlv = (struct tlv_desc *)buf->tail;
struct tlv_desc *tlv = (struct tlv_desc *)skb_tail_pointer(buf);
int new_tlv_space = TLV_SPACE(tlv_data_size);
if (skb_tailroom(buf) < new_tlv_space) {

View File

@ -1020,7 +1020,7 @@ restart:
if (!err) {
buf_crs = (unsigned char *)(TIPC_SKB_CB(buf)->handle);
sz = buf->tail - buf_crs;
sz = skb_tail_pointer(buf) - buf_crs;
needed = (buf_len - sz_copied);
sz_to_copy = (sz <= needed) ? sz : needed;