From: Eric Dumazet <edumazet@google.com>
To: "David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Paolo Abeni <pabeni@redhat.com>,
Neal Cardwell <ncardwell@google.com>
Cc: Kuniyuki Iwashima <kuniyu@amazon.com>,
Simon Horman <horms@kernel.org>,
netdev@vger.kernel.org, eric.dumazet@gmail.com,
Eric Dumazet <edumazet@google.com>
Subject: [PATCH v2 net-next 2/2] tcp/dccp: remove icsk->icsk_ack.timeout
Date: Tue, 18 Mar 2025 15:43:59 +0000 [thread overview]
Message-ID: <20250318154359.778438-3-edumazet@google.com> (raw)
In-Reply-To: <20250318154359.778438-1-edumazet@google.com>
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>
---
v2: rebase after "tcp: cache RTAX_QUICKACK metric in a hot cache line"
.../net_cachelines/inet_connection_sock.rst | 1 -
include/net/inet_connection_sock.h | 12 ++++++++----
net/dccp/output.c | 5 ++---
net/dccp/timer.c | 4 ++--
net/ipv4/tcp_output.c | 7 +++----
net/ipv4/tcp_timer.c | 5 +++--
net/mptcp/options.c | 1 -
net/mptcp/protocol.c | 1 -
8 files changed, 18 insertions(+), 18 deletions(-)
diff --git a/Documentation/networking/net_cachelines/inet_connection_sock.rst b/Documentation/networking/net_cachelines/inet_connection_sock.rst
index 5fb0dd70c9af76ca68b3406ce76d4b61957c7da9..8fae85ebb773085b249c606ce37872e0566b70b4 100644
--- 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 018118da0ce15c5ba5e3b7fcc1b36425794ec9a1..597f2b98dcf565a8512e815d9eae2b521bac7807 100644
--- a/include/net/inet_connection_sock.h
+++ b/include/net/inet_connection_sock.h
@@ -117,7 +117,6 @@ 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 */
@@ -195,6 +194,12 @@ 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);
@@ -230,16 +235,15 @@ 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
--- 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
--- 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 e0a4e5432399a3874e471f2d908bf976350f2696..c29e689d966097fabb83876f21d54201989b444d 100644
--- 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
--- 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 fd2de185bc939f8730e87a63ac02a015e610e99c..ad1413e9062d54e60a8441deb12406ed63e4aa72 100644
--- 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
--- 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);
}
--
2.49.0.rc1.451.g8f38331e32-goog
next prev parent reply other threads:[~2025-03-18 15:44 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-18 15:43 [PATCH v2 net-next 0/2] tcp/dccp: remove 16 bytes from icsk Eric Dumazet
2025-03-18 15:43 ` [PATCH v2 net-next 1/2] tcp/dccp: remove icsk->icsk_timeout Eric Dumazet
2025-03-18 15:43 ` Eric Dumazet [this message]
2025-03-20 18:38 ` [PATCH v2 net-next 2/2] tcp/dccp: remove icsk->icsk_ack.timeout Simon Horman
2025-03-20 19:00 ` Eric Dumazet
2025-03-20 20:10 ` Simon Horman
2025-03-24 19:38 ` Jakub Kicinski
2025-03-24 19:44 ` Eric Dumazet
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