net: switch secpath to use skb extension infrastructure
Remove skb->sp and allocate secpath storage via extension
infrastructure. This also reduces sk_buff by 8 bytes on x86_64.
Total size of allyesconfig kernel is reduced slightly, as there is
less inlined code (one conditional atomic op instead of two on
skb_clone).
No differences in throughput in following ipsec performance tests:
- transport mode with aes on 10GB link
- tunnel mode between two network namespaces with aes and null cipher
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/Documentation/networking/xfrm_device.txt b/Documentation/networking/xfrm_device.txt
index 267f55b..a1c904d 100644
--- a/Documentation/networking/xfrm_device.txt
+++ b/Documentation/networking/xfrm_device.txt
@@ -111,9 +111,10 @@
xfrm_state_hold(xs);
store the state information into the skb
- skb->sp = secpath_dup(skb->sp);
- skb->sp->xvec[skb->sp->len++] = xs;
- skb->sp->olen++;
+ sp = secpath_set(skb);
+ if (!sp) return;
+ sp->xvec[sp->len++] = xs;
+ sp->olen++;
indicate the success and/or error status of the offload
xo = xfrm_offload(skb);