From 70355602879229c6f8bd694ec9c0814222bc4936 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 26 Nov 2008 01:08:18 -0800 Subject: [PATCH] net: release skb->dst in sock_queue_rcv_skb() When queuing a skb to sk->sk_receive_queue, we can release its dst, not anymore needed. Since current cpu did the dst_hold(), refcount is probably still hot int this cpu caches. This avoids readers to access the original dst to decrement its refcount, possibly a long time after packet reception. This should speedup UDP and RAW receive path. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/core/sock.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/net/core/sock.c b/net/core/sock.c index 7a081b647bf9..b28764558a7d 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -289,7 +289,11 @@ int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) skb->dev = NULL; skb_set_owner_r(skb, sk); - + /* + * release dst right now while its hot + */ + dst_release(skb->dst); + skb->dst = NULL; /* Cache the SKB length before we tack it onto the receive * queue. Once it is added it no longer belongs to us and * may be freed by other threads of control pulling packets -- 2.30.2