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net: ip_queue_rcv_skb() helper

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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
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

1
include/net/ip.h
View file

@ -393,6 +393,7 @@ extern int ip_options_rcv_srr(struct sk_buff *skb);
* Functions provided by ip_sockglue.c * Functions provided by ip_sockglue.c
*/ */
extern int ip_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
extern void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb); extern void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb);
extern int ip_cmsg_send(struct net *net, extern int ip_cmsg_send(struct net *net,
struct msghdr *msg, struct ipcm_cookie *ipc); struct msghdr *msg, struct ipcm_cookie *ipc);

16
net/ipv4/ip_sockglue.c
View file

@ -954,6 +954,22 @@ static int do_ip_setsockopt(struct sock *sk, int level,
return -EINVAL; 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 ip_setsockopt(struct sock *sk, int level,
int optname, char __user *optval, unsigned int optlen) int optname, char __user *optval, unsigned int optlen)
{ {

2
net/ipv4/raw.c
View file

@ -290,7 +290,7 @@ static int raw_rcv_skb(struct sock * sk, struct sk_buff * skb)
{ {
/* Charge it to the socket. */ /* Charge it to the socket. */
if (sock_queue_rcv_skb(sk, skb) < 0) { if (ip_queue_rcv_skb(sk, skb) < 0) {
kfree_skb(skb); kfree_skb(skb);
return NET_RX_DROP; return NET_RX_DROP;
} }

1
net/ipv4/tcp_input.c
View file

@ -4367,6 +4367,7 @@ static void tcp_data_queue(struct sock *sk, struct sk_buff *skb)
if (TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq) if (TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq)
goto drop; goto drop;
skb_dst_drop(skb);
__skb_pull(skb, th->doff * 4); __skb_pull(skb, th->doff * 4);
TCP_ECN_accept_cwr(tp, skb); TCP_ECN_accept_cwr(tp, skb);

2
net/ipv4/udp.c
View file

@ -1264,7 +1264,7 @@ static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
if (inet_sk(sk)->inet_daddr) if (inet_sk(sk)->inet_daddr)
sock_rps_save_rxhash(sk, skb->rxhash); sock_rps_save_rxhash(sk, skb->rxhash);
rc = sock_queue_rcv_skb(sk, skb); rc = ip_queue_rcv_skb(sk, skb);
if (rc < 0) { if (rc < 0) {
int is_udplite = IS_UDPLITE(sk); int is_udplite = IS_UDPLITE(sk);

2
net/ipv6/raw.c
View file

@ -381,7 +381,7 @@ static inline int rawv6_rcv_skb(struct sock * sk, struct sk_buff * skb)
} }
/* Charge it to the socket. */ /* Charge it to the socket. */
if (sock_queue_rcv_skb(sk, skb) < 0) { if (ip_queue_rcv_skb(sk, skb) < 0) {
kfree_skb(skb); kfree_skb(skb);
return NET_RX_DROP; return NET_RX_DROP;
} }

2
net/ipv6/udp.c
View file

@ -514,7 +514,7 @@ int udpv6_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
goto drop; goto drop;
} }
if ((rc = sock_queue_rcv_skb(sk, skb)) < 0) { if ((rc = ip_queue_rcv_skb(sk, skb)) < 0) {
/* Note that an ENOMEM error is charged twice */ /* Note that an ENOMEM error is charged twice */
if (rc == -ENOMEM) if (rc == -ENOMEM)
UDP6_INC_STATS_BH(sock_net(sk), UDP6_INC_STATS_BH(sock_net(sk),