Merge branch 'tcp-provide-better-locality-for-retransmit-timer'

Eric Dumazet says:

====================
tcp: provide better locality for retransmit timer

TCP stack uses three timers per flow, currently spread this way:

- sk->sk_timer : keepalive timer
- icsk->icsk_retransmit_timer : retransmit timer
- icsk->icsk_delack_timer : delayed ack timer

This series moves the retransmit timer to sk->sk_timer location,
to increase data locality in TX paths.

keepalive timers are not often used, this change should be neutral for them.

After the series we have following fields:

- sk->tcp_retransmit_timer : retransmit timer, in sock_write_tx group
- icsk->icsk_delack_timer : delayed ack timer
- icsk->icsk_keepalive_timer : keepalive timer

Moving icsk_delack_timer in a beter location would also be welcomed.
====================

Link: https://patch.msgid.link/20251124175013.1473655-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 4 insertions, 4 deletions

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index e0bb8d9e2d9c..f8a9596e8f4d 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2869,13 +2869,13 @@ static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i)
 	    icsk_pending == ICSK_TIME_REO_TIMEOUT ||
 	    icsk_pending == ICSK_TIME_LOSS_PROBE) {
 		timer_active	= 1;
-		timer_expires	= icsk_timeout(icsk);
+		timer_expires	= tcp_timeout_expires(sk);
 	} else if (icsk_pending == ICSK_TIME_PROBE0) {
 		timer_active	= 4;
-		timer_expires	= icsk_timeout(icsk);
-	} else if (timer_pending(&sk->sk_timer)) {
+		timer_expires	= tcp_timeout_expires(sk);
+	} else if (timer_pending(&icsk->icsk_keepalive_timer)) {
 		timer_active	= 2;
-		timer_expires	= sk->sk_timer.expires;
+		timer_expires	= icsk->icsk_keepalive_timer.expires;
 	} else {
 		timer_active	= 0;
 		timer_expires = jiffies;