Commit 9a5e5334 authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

tcp: remove icsk->icsk_retransmit_timer 



Now sk->sk_timer is no longer used by TCP keepalive, we can use
its storage for TCP and MPTCP retransmit timers for better
cache locality.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarKuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20251124175013.1473655-5-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 08dfe370

Documentation/networking/net_cachelines/inet_connection_sock.rst

+0 −1
Original line number Diff line number Diff line
@@ -12,7 +12,6 @@ struct inet_sock icsk_inet read_mostly r 
struct request_sock_queue           icsk_accept_queue

struct inet_bind_bucket             icsk_bind_hash         read_mostly                             tcp_set_state

struct inet_bind2_bucket            icsk_bind2_hash        read_mostly                             tcp_set_state,inet_put_port

struct timer_list                   icsk_retransmit_timer  read_write                              inet_csk_reset_xmit_timer,tcp_connect

struct timer_list                   icsk_delack_timer      read_mostly                             inet_csk_reset_xmit_timer,tcp_connect

struct timer_list                   icsk_keepalive_timer

u32                                 icsk_rto               read_write                              tcp_cwnd_validate,tcp_schedule_loss_probe,tcp_connect_init,tcp_connect,tcp_write_xmit,tcp_push_one

include/net/inet_connection_sock.h

+3 −5
Original line number Diff line number Diff line
@@ -56,7 +56,6 @@ struct inet_connection_sock_af_ops { 
 * @icsk_accept_queue:	   FIFO of established children

 * @icsk_bind_hash:	   Bind node

 * @icsk_bind2_hash:	   Bind node in the bhash2 table

 * @icsk_retransmit_timer: Resend (no ack)

 * @icsk_delack_timer:     Delayed ACK timer

 * @icsk_keepalive_timer:  Keepalive timer

 * @mptcp_tout_timer: mptcp timer
@@ -84,7 +83,6 @@ struct inet_connection_sock { 
	struct request_sock_queue icsk_accept_queue;

	struct inet_bind_bucket	  *icsk_bind_hash;

	struct inet_bind2_bucket  *icsk_bind2_hash;

	struct timer_list	  icsk_retransmit_timer;

	struct timer_list	  icsk_delack_timer;

	union {

		struct timer_list icsk_keepalive_timer;
@@ -193,7 +191,7 @@ static inline void inet_csk_delack_init(struct sock *sk) 


static inline unsigned long tcp_timeout_expires(const struct sock *sk)

{

	return READ_ONCE(inet_csk(sk)->icsk_retransmit_timer.expires);

	return READ_ONCE(sk->tcp_retransmit_timer.expires);

}



static inline unsigned long
@@ -209,7 +207,7 @@ static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what) 
	if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {

		smp_store_release(&icsk->icsk_pending, 0);

#ifdef INET_CSK_CLEAR_TIMERS

		sk_stop_timer(sk, &icsk->icsk_retransmit_timer);

		sk_stop_timer(sk, &sk->tcp_retransmit_timer);

#endif

	} else if (what == ICSK_TIME_DACK) {

		smp_store_release(&icsk->icsk_ack.pending, 0);
@@ -241,7 +239,7 @@ static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what, 
	if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 ||

	    what == ICSK_TIME_LOSS_PROBE || what == ICSK_TIME_REO_TIMEOUT) {

		smp_store_release(&icsk->icsk_pending, what);

		sk_reset_timer(sk, &icsk->icsk_retransmit_timer, when);

		sk_reset_timer(sk, &sk->tcp_retransmit_timer, when);

	} else if (what == ICSK_TIME_DACK) {

		smp_store_release(&icsk->icsk_ack.pending,

				  icsk->icsk_ack.pending | ICSK_ACK_TIMER);

include/net/sock.h

+7 −2
Original line number Diff line number Diff line
@@ -305,6 +305,8 @@ struct sk_filter; 
  *	@sk_txrehash: enable TX hash rethink

  *	@sk_filter: socket filtering instructions

  *	@sk_timer: sock cleanup timer

  *	@tcp_retransmit_timer: tcp retransmit timer

  *	@mptcp_retransmit_timer: mptcp retransmit timer

  *	@sk_stamp: time stamp of last packet received

  *	@sk_stamp_seq: lock for accessing sk_stamp on 32 bit architectures only

  *	@sk_tsflags: SO_TIMESTAMPING flags
@@ -482,8 +484,11 @@ struct sock { 
	};

	struct sk_buff_head	sk_write_queue;

	struct page_frag	sk_frag;

	union {

		struct timer_list	sk_timer;



		struct timer_list	tcp_retransmit_timer;

		struct timer_list	mptcp_retransmit_timer;

	};

	unsigned long		sk_pacing_rate; /* bytes per second */

	atomic_t		sk_zckey;

	atomic_t		sk_tskey;

net/ipv4/inet_connection_sock.c

+3 −3
Original line number Diff line number Diff line
@@ -737,7 +737,7 @@ void inet_csk_init_xmit_timers(struct sock *sk, 
{

	struct inet_connection_sock *icsk = inet_csk(sk);



	timer_setup(&icsk->icsk_retransmit_timer, retransmit_handler, 0);

	timer_setup(&sk->tcp_retransmit_timer, retransmit_handler, 0);

	timer_setup(&icsk->icsk_delack_timer, delack_handler, 0);

	timer_setup(&icsk->icsk_keepalive_timer, keepalive_handler, 0);

	icsk->icsk_pending = icsk->icsk_ack.pending = 0;
@@ -750,7 +750,7 @@ void inet_csk_clear_xmit_timers(struct sock *sk) 
	smp_store_release(&icsk->icsk_pending, 0);

	smp_store_release(&icsk->icsk_ack.pending, 0);



	sk_stop_timer(sk, &icsk->icsk_retransmit_timer);

	sk_stop_timer(sk, &sk->tcp_retransmit_timer);

	sk_stop_timer(sk, &icsk->icsk_delack_timer);

	sk_stop_timer(sk, &icsk->icsk_keepalive_timer);

}
@@ -765,7 +765,7 @@ void inet_csk_clear_xmit_timers_sync(struct sock *sk) 
	smp_store_release(&icsk->icsk_pending, 0);

	smp_store_release(&icsk->icsk_ack.pending, 0);



	sk_stop_timer_sync(sk, &icsk->icsk_retransmit_timer);

	sk_stop_timer_sync(sk, &sk->tcp_retransmit_timer);

	sk_stop_timer_sync(sk, &icsk->icsk_delack_timer);

	sk_stop_timer_sync(sk, &icsk->icsk_keepalive_timer);

}

net/ipv4/tcp_timer.c

+3 −5
Original line number Diff line number Diff line
@@ -698,7 +698,7 @@ void tcp_write_timer_handler(struct sock *sk) 
		return;



	if (time_after(tcp_timeout_expires(sk), jiffies)) {

		sk_reset_timer(sk, &icsk->icsk_retransmit_timer,

		sk_reset_timer(sk, &sk->tcp_retransmit_timer,

			       tcp_timeout_expires(sk));

		return;

	}
@@ -725,12 +725,10 @@ void tcp_write_timer_handler(struct sock *sk) 


static void tcp_write_timer(struct timer_list *t)

{

	struct inet_connection_sock *icsk =

			timer_container_of(icsk, t, icsk_retransmit_timer);

	struct sock *sk = &icsk->icsk_inet.sk;

	struct sock *sk = timer_container_of(sk, t, tcp_retransmit_timer);



	/* Avoid locking the socket when there is no pending event. */

	if (!smp_load_acquire(&icsk->icsk_pending))

	if (!smp_load_acquire(&inet_csk(sk)->icsk_pending))

		goto out;



	bh_lock_sock(sk);