[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: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2006-11-09 19:58:25 -08:00
parent ef56e622c6
commit 931731123a
8 changed files with 10 additions and 12 deletions

View File

@ -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 */

View File

@ -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);

View File

@ -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,

View File

@ -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;
}

View File

@ -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;

View File

@ -426,7 +426,6 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
th = (struct tcphdr *) skb_push(skb, tcp_header_size);
skb->h.th = th;
skb_set_owner_w(skb, sk);
/* Build TCP header and checksum it. */
th->source = inet->sport;
@ -479,7 +478,7 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
if (after(tcb->end_seq, tp->snd_nxt) || tcb->seq == tcb->end_seq)
TCP_INC_STATS(TCP_MIB_OUTSEGS);
err = icsk->icsk_af_ops->queue_xmit(skb, 0);
err = icsk->icsk_af_ops->queue_xmit(skb, sk, 0);
if (likely(err <= 0))
return err;

View File

@ -139,9 +139,8 @@ void inet6_csk_addr2sockaddr(struct sock *sk, struct sockaddr * uaddr)
EXPORT_SYMBOL_GPL(inet6_csk_addr2sockaddr);
int inet6_csk_xmit(struct sk_buff *skb, int ipfragok)
int inet6_csk_xmit(struct sk_buff *skb, struct sock *sk, int ipfragok)
{
struct sock *sk = skb->sk;
struct inet_sock *inet = inet_sk(sk);
struct ipv6_pinfo *np = inet6_sk(sk);
struct flowi fl;

View File

@ -808,7 +808,7 @@ static inline int sctp_v4_xmit(struct sk_buff *skb,
NIPQUAD(((struct rtable *)skb->dst)->rt_dst));
SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
return ip_queue_xmit(skb, ipfragok);
return ip_queue_xmit(skb, skb->sk, ipfragok);
}
static struct sctp_af sctp_ipv4_specific;