[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>
diff --git a/kernel/audit.c b/kernel/audit.c
index 76c9a11..ea85214 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1073,7 +1073,7 @@
goto out;
}
va_copy(args2, args);
- len = vsnprintf(skb->tail, avail, fmt, args);
+ len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args);
if (len >= avail) {
/* The printk buffer is 1024 bytes long, so if we get
* here and AUDIT_BUFSIZ is at least 1024, then we can
@@ -1082,7 +1082,7 @@
max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
if (!avail)
goto out;
- len = vsnprintf(skb->tail, avail, fmt, args2);
+ len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
}
if (len > 0)
skb_put(skb, len);
@@ -1143,7 +1143,7 @@
return;
}
- ptr = skb->tail;
+ ptr = skb_tail_pointer(skb);
for (i=0; i<len; i++) {
*ptr++ = hex[(buf[i] & 0xF0)>>4]; /* Upper nibble */
*ptr++ = hex[buf[i] & 0x0F]; /* Lower nibble */
@@ -1175,7 +1175,7 @@
if (!avail)
return;
}
- ptr = skb->tail;
+ ptr = skb_tail_pointer(skb);
*ptr++ = '"';
memcpy(ptr, string, slen);
ptr += slen;