tcp/dccp: remove icsk->icsk_ack.timeout

icsk->icsk_ack.timeout can be replaced by icsk->csk_delack_timer.expires

This saves 8 bytes in TCP/DCCP sockets and helps for better cache locality.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250324203607.703850-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/Documentation/networking/net_cachelines/inet_connection_sock.rst b/Documentation/networking/net_cachelines/inet_connection_sock.rst
index 5fb0dd70c9af76ca68b3406ce76d4b61957c7da9..8fae85ebb773085b249c606ce37872e0566b70b4 100644 (file)
--- a/Documentation/networking/net_cachelines/inet_connection_sock.rst
+++ b/Documentation/networking/net_cachelines/inet_connection_sock.rst
@@ -38,7 +38,6 @@ struct icsk_ack_u8                  quick                  read_write          w
 struct icsk_ack_u8                  pingpong
 struct icsk_ack_u8                  retry                  write_mostly        read_write          inet_csk_clear_xmit_timer,tcp_rearm_rto,tcp_event_new_data_sent,tcp_write_xmit,__tcp_send_ack,tcp_send_ack,
 struct icsk_ack_u8                  ato                    read_mostly         write_mostly        tcp_dec_quickack_mode,tcp_event_ack_sent,__tcp_transmit_skb,__tcp_send_ack,tcp_send_ack
-struct icsk_ack_unsigned_long       timeout                read_write          read_write          inet_csk_reset_xmit_timer,tcp_connect
 struct icsk_ack_u32                 lrcvtime               read_write                              tcp_finish_connect,tcp_connect,tcp_event_data_sent,__tcp_transmit_skb
 struct icsk_ack_u16                 rcv_mss                write_mostly        read_mostly         __tcp_select_window,__tcp_cleanup_rbuf,tcp_initialize_rcv_mss,tcp_connect_init
 struct icsk_mtup_int                search_high            read_write                              tcp_mtup_init,tcp_sync_mss,tcp_connect_init,tcp_mtu_check_reprobe,tcp_write_xmit

diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h
index 6dca0ac6fbc6f50be447e2a554593c77bd9cf1b6..1735db332aab56173e45e8754c8d17b21e7e77c5 100644 (file)
--- a/include/net/inet_connection_sock.h
+++ b/include/net/inet_connection_sock.h
@@ -113,7 +113,6 @@ struct inet_connection_sock {
                                  lrcv_flowlabel:20, /* last received ipv6 flowlabel       */
                                  dst_quick_ack:1, /* cache dst RTAX_QUICKACK              */
                                  unused:3;
-               unsigned long     timeout;       /* Currently scheduled timeout            */
                __u32             lrcvtime;      /* timestamp of last received data packet */
                __u16             last_seg_size; /* Size of last incoming segment          */
                __u16             rcv_mss;       /* MSS used for delayed ACK decisions     */
@@ -191,6 +190,12 @@ icsk_timeout(const struct inet_connection_sock *icsk)
        return READ_ONCE(icsk->icsk_retransmit_timer.expires);
 }
 
+static inline unsigned long
+icsk_delack_timeout(const struct inet_connection_sock *icsk)
+{
+       return READ_ONCE(icsk->icsk_delack_timer.expires);
+}
+
 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
 {
        struct inet_connection_sock *icsk = inet_csk(sk);
@@ -226,16 +231,15 @@ static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
                when = max_when;
        }
 
+       when += jiffies;
        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);
-               when += jiffies;
                sk_reset_timer(sk, &icsk->icsk_retransmit_timer, when);
        } else if (what == ICSK_TIME_DACK) {
                smp_store_release(&icsk->icsk_ack.pending,
                                  icsk->icsk_ack.pending | ICSK_ACK_TIMER);
-               icsk->icsk_ack.timeout = jiffies + when;
-               sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
+               sk_reset_timer(sk, &icsk->icsk_delack_timer, when);
        } else {
                pr_debug("inet_csk BUG: unknown timer value\n");
        }

diff --git a/net/dccp/output.c b/net/dccp/output.c
index 5c2e24f3c39b7ff4ee1d5d96d5e406c96609a022..39cf3430177ac597b0a9fd40bf0d8dfbff5fd92d 100644 (file)
--- a/net/dccp/output.c
+++ b/net/dccp/output.c
@@ -627,11 +627,10 @@ void dccp_send_delayed_ack(struct sock *sk)
                        return;
                }
 
-               if (!time_before(timeout, icsk->icsk_ack.timeout))
-                       timeout = icsk->icsk_ack.timeout;
+               if (!time_before(timeout, icsk_delack_timeout(icsk)))
+                       timeout = icsk_delack_timeout(icsk);
        }
        icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER;
-       icsk->icsk_ack.timeout = timeout;
        sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout);
 }
 #endif

diff --git a/net/dccp/timer.c b/net/dccp/timer.c
index 9fd14a3361893d5f2d9f0ad18a65cff963cc7e22..232ac4ae0a73ff31beca730c14d8b02107aeb926 100644 (file)
--- a/net/dccp/timer.c
+++ b/net/dccp/timer.c
@@ -185,9 +185,9 @@ static void dccp_delack_timer(struct timer_list *t)
        if (sk->sk_state == DCCP_CLOSED ||
            !(icsk->icsk_ack.pending & ICSK_ACK_TIMER))
                goto out;
-       if (time_after(icsk->icsk_ack.timeout, jiffies)) {
+       if (time_after(icsk_delack_timeout(icsk), jiffies)) {
                sk_reset_timer(sk, &icsk->icsk_delack_timer,
-                              icsk->icsk_ack.timeout);
+                              icsk_delack_timeout(icsk));
                goto out;
        }
 

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 9a606101711450db2cf554ef1c2a64fc4eacb6e2..13295a59d22e65305d8c4094313e4aa37306cbff 100644 (file)
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -4225,17 +4225,16 @@ void tcp_send_delayed_ack(struct sock *sk)
        /* Use new timeout only if there wasn't a older one earlier. */
        if (icsk->icsk_ack.pending & ICSK_ACK_TIMER) {
                /* If delack timer is about to expire, send ACK now. */
-               if (time_before_eq(icsk->icsk_ack.timeout, jiffies + (ato >> 2))) {
+               if (time_before_eq(icsk_delack_timeout(icsk), jiffies + (ato >> 2))) {
                        tcp_send_ack(sk);
                        return;
                }
 
-               if (!time_before(timeout, icsk->icsk_ack.timeout))
-                       timeout = icsk->icsk_ack.timeout;
+               if (!time_before(timeout, icsk_delack_timeout(icsk)))
+                       timeout = icsk_delack_timeout(icsk);
        }
        smp_store_release(&icsk->icsk_ack.pending,
                          icsk->icsk_ack.pending | ICSK_ACK_SCHED | ICSK_ACK_TIMER);
-       icsk->icsk_ack.timeout = timeout;
        sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout);
 }
 

diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index d828b74c3e73d75cdae777645e8e8856c0751201..d64383b06a295affb735f60edd4dfd64ad5fb1c8 100644 (file)
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -322,8 +322,9 @@ void tcp_delack_timer_handler(struct sock *sk)
        if (!(icsk->icsk_ack.pending & ICSK_ACK_TIMER))
                return;
 
-       if (time_after(icsk->icsk_ack.timeout, jiffies)) {
-               sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
+       if (time_after(icsk_delack_timeout(icsk), jiffies)) {
+               sk_reset_timer(sk, &icsk->icsk_delack_timer,
+                              icsk_delack_timeout(icsk));
                return;
        }
        icsk->icsk_ack.pending &= ~ICSK_ACK_TIMER;

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 23949ae2a3a8db19d05c5c8373f45c885c3523ad..421ced0312890b98dde560932b5f9437a15c4030 100644 (file)
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -432,7 +432,6 @@ static void clear_3rdack_retransmission(struct sock *sk)
        struct inet_connection_sock *icsk = inet_csk(sk);
 
        sk_stop_timer(sk, &icsk->icsk_delack_timer);
-       icsk->icsk_ack.timeout = 0;
        icsk->icsk_ack.ato = 0;
        icsk->icsk_ack.pending &= ~(ICSK_ACK_SCHED | ICSK_ACK_TIMER);
 }

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 1ac378ba1d67cd17449ab6c4b4793b65d520ec44..44f7ab463d7550ad728651bad2b1aeb4cd4dea05 100644 (file)
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -3420,7 +3420,6 @@ static void schedule_3rdack_retransmission(struct sock *ssk)
        WARN_ON_ONCE(icsk->icsk_ack.pending & ICSK_ACK_TIMER);
        smp_store_release(&icsk->icsk_ack.pending,
                          icsk->icsk_ack.pending | ICSK_ACK_SCHED | ICSK_ACK_TIMER);
-       icsk->icsk_ack.timeout = timeout;
        sk_reset_timer(ssk, &icsk->icsk_delack_timer, timeout);
 }