Commit 8b929ab1 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

inet: remove some sk_listener dependencies 



listener can be source of false sharing. request sock has some
useful information like : ireq->ir_iif, ireq->ir_num, ireq->ireq_net

This patch does not solve the major problem of having to read
sk->sk_protocol which is sharing a cache line with sk->sk_wmem_alloc.
(This same field is read later in ip_build_and_send_pkt())

One idea would be to move sk_protocol close to sk_family
(using 8 bits instead of 16 for sk_family seems enough)

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 42cb80a2

net/ipv4/inet_connection_sock.c

+11 −11
Original line number Diff line number Diff line
@@ -403,18 +403,17 @@ struct dst_entry *inet_csk_route_req(struct sock *sk, 
				     struct flowi4 *fl4,

				     const struct request_sock *req)

{

	struct rtable *rt;

	const struct inet_request_sock *ireq = inet_rsk(req);

	struct ip_options_rcu *opt = inet_rsk(req)->opt;

	struct net *net = sock_net(sk);

	int flags = inet_sk_flowi_flags(sk);

	struct net *net = read_pnet(&ireq->ireq_net);

	struct ip_options_rcu *opt = ireq->opt;

	struct rtable *rt;



	flowi4_init_output(fl4, sk->sk_bound_dev_if, ireq->ir_mark,

	flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark,

			   RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,

			   sk->sk_protocol,

			   flags,

			   sk->sk_protocol, inet_sk_flowi_flags(sk),

			   (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,

			   ireq->ir_loc_addr, ireq->ir_rmt_port, inet_sk(sk)->inet_sport);

			   ireq->ir_loc_addr, ireq->ir_rmt_port,

			   htons(ireq->ir_num));

	security_req_classify_flow(req, flowi4_to_flowi(fl4));

	rt = ip_route_output_flow(net, fl4, sk);

	if (IS_ERR(rt))
@@ -436,9 +435,9 @@ struct dst_entry *inet_csk_route_child_sock(struct sock *sk, 
					    const struct request_sock *req)

{

	const struct inet_request_sock *ireq = inet_rsk(req);

	struct net *net = read_pnet(&ireq->ireq_net);

	struct inet_sock *newinet = inet_sk(newsk);

	struct ip_options_rcu *opt;

	struct net *net = sock_net(sk);

	struct flowi4 *fl4;

	struct rtable *rt;
@@ -446,11 +445,12 @@ struct dst_entry *inet_csk_route_child_sock(struct sock *sk, 


	rcu_read_lock();

	opt = rcu_dereference(newinet->inet_opt);

	flowi4_init_output(fl4, sk->sk_bound_dev_if, inet_rsk(req)->ir_mark,

	flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark,

			   RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,

			   sk->sk_protocol, inet_sk_flowi_flags(sk),

			   (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,

			   ireq->ir_loc_addr, ireq->ir_rmt_port, inet_sk(sk)->inet_sport);

			   ireq->ir_loc_addr, ireq->ir_rmt_port,

			   htons(ireq->ir_num));

	security_req_classify_flow(req, flowi4_to_flowi(fl4));

	rt = ip_route_output_flow(net, fl4, sk);

	if (IS_ERR(rt))

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