udp: Use hlist_nulls in UDP RCU code

This is a straightforward patch, using hlist_nulls infrastructure.

RCUification already done on UDP two weeks ago.

Using hlist_nulls permits us to avoid some memory barriers, both
at lookup time and delete time.

Patch is large because it adds new macros to include/net/sock.h.
These macros will be used by TCP & DCCP in next patch.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/net/udp.h b/include/net/udp.h
index df2bfe545374..90e6ce56be65 100644
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -51,7 +51,7 @@ struct udp_skb_cb {
 #define UDP_SKB_CB(__skb)       ((struct udp_skb_cb *)((__skb)->cb))
 
 struct udp_hslot {
-        struct hlist_head       head;
+        struct hlist_nulls_head head;
         spinlock_t              lock;
 } __attribute__((aligned(2 * sizeof(long))));
 struct udp_table {