net: add a prefetch in socket backlog processing

TCP or UDP stacks have big enough latencies that prefetching next
pointer is worth it.

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

diff --git a/net/core/sock.c b/net/core/sock.c
index 836bca6..1a88351 100644 (file)
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1700,6 +1700,7 @@ static void __release_sock(struct sock *sk)
                do {
                        struct sk_buff *next = skb->next;
 
+                       prefetch(next);
                        WARN_ON_ONCE(skb_dst_is_noref(skb));
                        skb->next = NULL;
                        sk_backlog_rcv(sk, skb);