Commit 93173112 authored by David S. Miller's avatar David S. Miller
Browse files

[TCP]: Don't set SKB owner in tcp_transmit_skb(). 



The data itself is already charged to the SKB, doing
the skb_set_owner_w() just generates a lot of noise and
extra atomics we don't really need.

Lmbench improvements on lat_tcp are minimal:

before:
TCP latency using localhost: 23.2701 microseconds
TCP latency using localhost: 23.1994 microseconds
TCP latency using localhost: 23.2257 microseconds

after:
TCP latency using localhost: 22.8380 microseconds
TCP latency using localhost: 22.9465 microseconds
TCP latency using localhost: 22.8462 microseconds

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ef56e622

include/net/inet6_connection_sock.h

+1 −1
Original line number Diff line number Diff line
@@ -38,5 +38,5 @@ extern void inet6_csk_reqsk_queue_hash_add(struct sock *sk, 


extern void inet6_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);



extern int inet6_csk_xmit(struct sk_buff *skb, int ipfragok);

extern int inet6_csk_xmit(struct sk_buff *skb, struct sock *sk, int ipfragok);

#endif /* _INET6_CONNECTION_SOCK_H */

include/net/inet_connection_sock.h

+2 −1
Original line number Diff line number Diff line
@@ -36,7 +36,8 @@ struct tcp_congestion_ops; 
 * (i.e. things that depend on the address family)

 */

struct inet_connection_sock_af_ops {

	int	    (*queue_xmit)(struct sk_buff *skb, int ipfragok);

	int	    (*queue_xmit)(struct sk_buff *skb, struct sock *sk,

				  int ipfragok);

	void	    (*send_check)(struct sock *sk, int len,

				  struct sk_buff *skb);

	int	    (*rebuild_header)(struct sock *sk);

include/net/ip.h

+1 −1
Original line number Diff line number Diff line
@@ -97,7 +97,7 @@ extern int ip_mc_output(struct sk_buff *skb); 
extern int		ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *));

extern int		ip_do_nat(struct sk_buff *skb);

extern void		ip_send_check(struct iphdr *ip);

extern int		ip_queue_xmit(struct sk_buff *skb, int ipfragok);

extern int		ip_queue_xmit(struct sk_buff *skb, struct sock *sk, int ipfragok);

extern void		ip_init(void);

extern int		ip_append_data(struct sock *sk,

				       int getfrag(void *from, char *to, int offset, int len,

net/dccp/output.c

+2 −2
Original line number Diff line number Diff line
@@ -125,7 +125,7 @@ static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb) 
		DCCP_INC_STATS(DCCP_MIB_OUTSEGS);



		memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));

		err = icsk->icsk_af_ops->queue_xmit(skb, 0);

		err = icsk->icsk_af_ops->queue_xmit(skb, sk, 0);

		if (err <= 0)

			return err;
@@ -426,7 +426,7 @@ int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code) 
						      code);

		if (skb != NULL) {

			memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));

			err = inet_csk(sk)->icsk_af_ops->queue_xmit(skb, 0);

			err = inet_csk(sk)->icsk_af_ops->queue_xmit(skb, sk, 0);

			if (err == NET_XMIT_CN)

				err = 0;

		}

net/ipv4/ip_output.c

+1 −2
Original line number Diff line number Diff line
@@ -288,9 +288,8 @@ int ip_output(struct sk_buff *skb) 
			    !(IPCB(skb)->flags & IPSKB_REROUTED));

}



int ip_queue_xmit(struct sk_buff *skb, int ipfragok)

int ip_queue_xmit(struct sk_buff *skb, struct sock *sk, int ipfragok)

{

	struct sock *sk = skb->sk;

	struct inet_sock *inet = inet_sk(sk);

	struct ip_options *opt = inet->opt;

	struct rtable *rt;

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