net: ip_queue_rcv_skb() helper

When queueing a skb to socket, we can immediately release its dst if
target socket do not use IP_CMSG_PKTINFO.

tcp_data_queue() can drop dst too.

This to benefit from a hot cache line and avoid the receiver, possibly
on another cpu, to dirty this cache line himself.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet
2010-04-28 15:31:51 -07:00
committed by David S. Miller
parent 4b0b72f7dd
commit f84af32cbc
7 changed files with 22 additions and 4 deletions

View File

@@ -954,6 +954,22 @@ e_inval:
return -EINVAL;
}
/**
* ip_queue_rcv_skb - Queue an skb into sock receive queue
* @sk: socket
* @skb: buffer
*
* Queues an skb into socket receive queue. If IP_CMSG_PKTINFO option
* is not set, we drop skb dst entry now, while dst cache line is hot.
*/
int ip_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
if (!(inet_sk(sk)->cmsg_flags & IP_CMSG_PKTINFO))
skb_dst_drop(skb);
return sock_queue_rcv_skb(sk, skb);
}
EXPORT_SYMBOL(ip_queue_rcv_skb);
int ip_setsockopt(struct sock *sk, int level,
int optname, char __user *optval, unsigned int optlen)
{