From 1b44d700023e77dd92821e7811db825e75a1a394 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 19 Sep 2025 20:48:52 +0000 Subject: tcp: move tcp->rcv_tstamp to tcp_sock_write_txrx group tcp_ack() writes this field, it belongs to tcp_sock_write_txrx. Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250919204856.2977245-5-edumazet@google.com Signed-off-by: Jakub Kicinski --- include/linux/tcp.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/tcp.h b/include/linux/tcp.h index 3ca5ed02de6d..1e6c2ded22c9 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -238,7 +238,6 @@ struct tcp_sock { /* RX read-mostly hotpath cache lines */ __cacheline_group_begin(tcp_sock_read_rx); u32 copied_seq; /* Head of yet unread data */ - u32 rcv_tstamp; /* timestamp of last received ACK (for keepalives) */ u32 snd_wl1; /* Sequence for window update */ u32 tlp_high_seq; /* snd_nxt at the time of TLP */ u32 rttvar_us; /* smoothed mdev_max */ @@ -246,13 +245,13 @@ struct tcp_sock { u16 advmss; /* Advertised MSS */ u16 urg_data; /* Saved octet of OOB data and control flags */ u32 lost; /* Total data packets lost incl. rexmits */ + u32 snd_ssthresh; /* Slow start size threshold */ struct minmax rtt_min; /* OOO segments go in this rbtree. Socket lock must be held. */ struct rb_root out_of_order_queue; #if defined(CONFIG_TLS_DEVICE) void (*tcp_clean_acked)(struct sock *sk, u32 acked_seq); #endif - u32 snd_ssthresh; /* Slow start size threshold */ u8 recvmsg_inq : 1;/* Indicate # of bytes in queue upon recvmsg */ __cacheline_group_end(tcp_sock_read_rx); @@ -319,6 +318,7 @@ struct tcp_sock { */ u32 app_limited; /* limited until "delivered" reaches this val */ u32 rcv_wnd; /* Current receiver window */ + u32 rcv_tstamp; /* timestamp of last received ACK (for keepalives) */ /* * Options received (usually on last packet, some only on SYN packets). */ -- cgit v1.2.3 From 969904dcd77dbb0a773d66cddaa59eccc6415d03 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 19 Sep 2025 20:48:53 +0000 Subject: tcp: move recvmsg_inq to tcp_sock_read_txrx Fill a hole in tcp_sock_read_txrx, instead of possibly wasting a cache line. Note that tcp_recvmsg_locked() is also reading tp->repair, so this removes one cache line miss in tcp recvmsg(). Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250919204856.2977245-6-edumazet@google.com Signed-off-by: Jakub Kicinski --- Documentation/networking/net_cachelines/tcp_sock.rst | 2 +- include/linux/tcp.h | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/Documentation/networking/net_cachelines/tcp_sock.rst b/Documentation/networking/net_cachelines/tcp_sock.rst index 429df29fba8b..c2138619b995 100644 --- a/Documentation/networking/net_cachelines/tcp_sock.rst +++ b/Documentation/networking/net_cachelines/tcp_sock.rst @@ -57,7 +57,7 @@ u8:1 is_sack_reneg read_m u8:2 fastopen_client_fail u8:4 nonagle read_write tcp_skb_entail,tcp_push_pending_frames u8:1 thin_lto -u8:1 recvmsg_inq +u8:1 recvmsg_inq read_mostly tcp_recvmsg u8:1 repair read_mostly tcp_write_xmit u8:1 frto u8 repair_queue diff --git a/include/linux/tcp.h b/include/linux/tcp.h index 1e6c2ded22c9..c1d7fce251d7 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -232,7 +232,8 @@ struct tcp_sock { repair : 1, tcp_usec_ts : 1, /* TSval values in usec */ is_sack_reneg:1, /* in recovery from loss with SACK reneg? */ - is_cwnd_limited:1;/* forward progress limited by snd_cwnd? */ + is_cwnd_limited:1,/* forward progress limited by snd_cwnd? */ + recvmsg_inq : 1;/* Indicate # of bytes in queue upon recvmsg */ __cacheline_group_end(tcp_sock_read_txrx); /* RX read-mostly hotpath cache lines */ @@ -252,7 +253,6 @@ struct tcp_sock { #if defined(CONFIG_TLS_DEVICE) void (*tcp_clean_acked)(struct sock *sk, u32 acked_seq); #endif - u8 recvmsg_inq : 1;/* Indicate # of bytes in queue upon recvmsg */ __cacheline_group_end(tcp_sock_read_rx); /* TX read-write hotpath cache lines */ -- cgit v1.2.3 From a105ea47a4e855d24ebf65f1c5fb907162e7b8cf Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 19 Sep 2025 20:48:54 +0000 Subject: tcp: move tcp_clean_acked to tcp_sock_read_tx group tp->tcp_clean_acked is fetched in tx path when snd_una is updated. This field thus belongs to tcp_sock_read_tx group. Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250919204856.2977245-7-edumazet@google.com Signed-off-by: Jakub Kicinski --- Documentation/networking/net_cachelines/tcp_sock.rst | 2 +- include/linux/tcp.h | 6 +++--- net/ipv4/tcp.c | 6 +++--- 3 files changed, 7 insertions(+), 7 deletions(-) (limited to 'include/linux') diff --git a/Documentation/networking/net_cachelines/tcp_sock.rst b/Documentation/networking/net_cachelines/tcp_sock.rst index c2138619b995..26f32dbcf6ec 100644 --- a/Documentation/networking/net_cachelines/tcp_sock.rst +++ b/Documentation/networking/net_cachelines/tcp_sock.rst @@ -27,7 +27,7 @@ u32 dsack_dups u32 snd_una read_mostly read_write tcp_wnd_end,tcp_urg_mode,tcp_minshall_check,tcp_cwnd_validate(tx);tcp_ack,tcp_may_update_window,tcp_clean_rtx_queue(write),tcp_ack_tstamp(rx) u32 snd_sml read_write tcp_minshall_check,tcp_minshall_update u32 rcv_tstamp read_write read_write tcp_ack -void * tcp_clean_acked read_mostly tcp_ack +void * tcp_clean_acked read_mostly tcp_ack u32 lsndtime read_write tcp_slow_start_after_idle_check,tcp_event_data_sent u32 last_oow_ack_time u32 compressed_ack_rcv_nxt diff --git a/include/linux/tcp.h b/include/linux/tcp.h index c1d7fce251d7..3f282130c863 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -215,6 +215,9 @@ struct tcp_sock { u16 gso_segs; /* Max number of segs per GSO packet */ /* from STCP, retrans queue hinting */ struct sk_buff *retransmit_skb_hint; +#if defined(CONFIG_TLS_DEVICE) + void (*tcp_clean_acked)(struct sock *sk, u32 acked_seq); +#endif __cacheline_group_end(tcp_sock_read_tx); /* TXRX read-mostly hotpath cache lines */ @@ -250,9 +253,6 @@ struct tcp_sock { struct minmax rtt_min; /* OOO segments go in this rbtree. Socket lock must be held. */ struct rb_root out_of_order_queue; -#if defined(CONFIG_TLS_DEVICE) - void (*tcp_clean_acked)(struct sock *sk, u32 acked_seq); -#endif __cacheline_group_end(tcp_sock_read_rx); /* TX read-write hotpath cache lines */ diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 721287ca3328..7949d16506a4 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -5101,6 +5101,9 @@ static void __init tcp_struct_check(void) CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_tx, notsent_lowat); CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_tx, gso_segs); CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_tx, retransmit_skb_hint); +#if IS_ENABLED(CONFIG_TLS_DEVICE) + CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_tx, tcp_clean_acked); +#endif /* TXRX read-mostly hotpath cache lines */ CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_txrx, tsoffset); @@ -5124,9 +5127,6 @@ static void __init tcp_struct_check(void) CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_rx, rtt_min); CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_rx, out_of_order_queue); CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_rx, snd_ssthresh); -#if IS_ENABLED(CONFIG_TLS_DEVICE) - CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_rx, tcp_clean_acked); -#endif /* TX read-write hotpath cache lines */ CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, segs_out); -- cgit v1.2.3 From 31c4511bbb0c75c525b6e4f4fe4167f2e9d3b05c Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 19 Sep 2025 20:48:55 +0000 Subject: tcp: move mtu_info to remove two 32bit holes This removes 8bytes waste on 64bit builds. Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250919204856.2977245-8-edumazet@google.com Signed-off-by: Jakub Kicinski --- include/linux/tcp.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/tcp.h b/include/linux/tcp.h index 3f282130c863..20b8c6e21fef 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -448,6 +448,9 @@ struct tcp_sock { * the first SYN. */ u32 undo_marker; /* snd_una upon a new recovery episode. */ int undo_retrans; /* number of undoable retransmissions. */ + u32 mtu_info; /* We received an ICMP_FRAG_NEEDED / ICMPV6_PKT_TOOBIG + * while socket was owned by user. + */ u64 bytes_retrans; /* RFC4898 tcpEStatsPerfOctetsRetrans * Total data bytes retransmitted */ @@ -494,9 +497,6 @@ struct tcp_sock { u32 probe_seq_end; } mtu_probe; u32 plb_rehash; /* PLB-triggered rehash attempts */ - u32 mtu_info; /* We received an ICMP_FRAG_NEEDED / ICMPV6_PKT_TOOBIG - * while socket was owned by user. - */ #if IS_ENABLED(CONFIG_MPTCP) bool is_mptcp; #endif -- cgit v1.2.3