Commit 05e22e83 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

tcp: remove indirect calls for icsk->icsk_af_ops->queue_xmit 



Mitigate RETPOLINE costs in __tcp_transmit_skb()
by using INDIRECT_CALL_INET() wrapper.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 902053f1

include/net/ip.h

+1 −5
Original line number Diff line number Diff line
@@ -231,11 +231,7 @@ struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4, 
			    struct ipcm_cookie *ipc, struct rtable **rtp,

			    struct inet_cork *cork, unsigned int flags);



static inline int ip_queue_xmit(struct sock *sk, struct sk_buff *skb,

				struct flowi *fl)

{

	return __ip_queue_xmit(sk, skb, fl, inet_sk(sk)->tos);

}

int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl);



static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)

{

include/net/tcp.h

+1 −0
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ 
#include <linux/skbuff.h>

#include <linux/kref.h>

#include <linux/ktime.h>

#include <linux/indirect_call_wrapper.h>



#include <net/inet_connection_sock.h>

#include <net/inet_timewait_sock.h>

net/ipv4/ip_output.c

+6 −0
Original line number Diff line number Diff line
@@ -539,6 +539,12 @@ int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl, 
}

EXPORT_SYMBOL(__ip_queue_xmit);



int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl)

{

	return __ip_queue_xmit(sk, skb, fl, inet_sk(sk)->tos);

}

EXPORT_SYMBOL(ip_queue_xmit);



static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from)

{

	to->pkt_type = from->pkt_type;

net/ipv4/tcp_output.c

+6 −1
Original line number Diff line number Diff line
@@ -1064,6 +1064,9 @@ static void tcp_update_skb_after_send(struct sock *sk, struct sk_buff *skb, 
	list_move_tail(&skb->tcp_tsorted_anchor, &tp->tsorted_sent_queue);

}



INDIRECT_CALLABLE_DECLARE(int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl));

INDIRECT_CALLABLE_DECLARE(int inet6_csk_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl));



/* This routine actually transmits TCP packets queued in by

 * tcp_do_sendmsg().  This is used by both the initial

 * transmission and possible later retransmissions.
@@ -1235,7 +1238,9 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, 


	tcp_add_tx_delay(skb, tp);



	err = icsk->icsk_af_ops->queue_xmit(sk, skb, &inet->cork.fl);

	err = INDIRECT_CALL_INET(icsk->icsk_af_ops->queue_xmit,

				 inet6_csk_xmit, ip_queue_xmit,

				 sk, skb, &inet->cork.fl);



	if (unlikely(err > 0)) {

		tcp_enter_cwr(sk);