Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit a9d6532b authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

ipv4: tcp: set SOCK_USE_WRITE_QUEUE for ip_send_unicast_reply() 



TCP uses per cpu 'sockets' to send some packets :
- RST packets ( tcp_v4_send_reset()) )
- ACK packets for SYN_RECV and TIMEWAIT sockets

By setting SOCK_USE_WRITE_QUEUE flag, we tell sock_wfree()
to not call sk_write_space() since these internal sockets
do not care.

This gives a small performance improvement, merely by allowing
cpu to properly predict the sock_wfree() conditional branch,
and avoiding one atomic operation.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 9caad864

net/ipv4/tcp_ipv4.c

+1 −0
Original line number Diff line number Diff line
@@ -2384,6 +2384,7 @@ static int __net_init tcp_sk_init(struct net *net) 
					   IPPROTO_TCP, net);

		if (res)

			goto fail;

		sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);

		*per_cpu_ptr(net->ipv4.tcp_sk, cpu) = sk;

	}