[NET]: Convert hh_lock to seqlock.
The hard header cache is in the main output path, so using
seqlock instead of reader/writer lock should reduce overhead.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index a35209d..f071f84 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -164,7 +164,6 @@
static inline int ip_finish_output2(struct sk_buff *skb)
{
struct dst_entry *dst = skb->dst;
- struct hh_cache *hh = dst->hh;
struct net_device *dev = dst->dev;
int hh_len = LL_RESERVED_SPACE(dev);
@@ -183,16 +182,9 @@
skb = skb2;
}
- if (hh) {
- int hh_alen;
-
- read_lock_bh(&hh->hh_lock);
- hh_alen = HH_DATA_ALIGN(hh->hh_len);
- memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
- read_unlock_bh(&hh->hh_lock);
- skb_push(skb, hh->hh_len);
- return hh->hh_output(skb);
- } else if (dst->neighbour)
+ if (dst->hh)
+ return neigh_hh_output(dst->hh, skb);
+ else if (dst->neighbour)
return dst->neighbour->output(skb);
if (net_ratelimit())