From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793213008; b=Z17Lz6nxy+avsiJOfOuP6qHL0qldMpxTmCSE6iItfkfm/ZUDzXbNIw7vQN6KDB3nroWZ 2P+gD50wpP4yhHtZVPmV6v74hprevrIb8krsJdZ4sw+aUQdCsDXfQAygUhpLwNvOYJXsJ u/EFkjI84/pivG2TSg/Ch/c4TvMGekbx5yIAalF7zMO9M6YsUlxe8ZPlTeLYVJpclLj0e rdl1XejCNWGueU0xZuKwwtd4ct1PyR+bbTVXqgRNEJ89wLktVgCEToKnAZkPGn5JrIY0Y l1JhSyEv/YLyt1T7J1vJCbN1DCXms62Bs8jK3pIbywmCmv4rSsUc9uooT8iQyNUpUfw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793213008; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=oF80QaTAyC6T8Z38MPlTEfa07j54EHqVtin0L3XBaB8=; b=ReAS1QB1E82akw5ZxJwz//5XQimqMbVz9/q3DK9Zj48QhIOziRY4QbA+2u6mtf0ysWwu aqBhRIUMnbQ6KzyjpbNW2EKRWclswzp7R12GRhhQZgYF7xgDN/nyT+hKxjxb8bs4A3/P8 OYuYuPqh/NH3K1JGBQRyMuiIQTFY1GaZo7SOYlcHo2CWXwYfcUkMGKiBB74zgnBXkdKE9 Zt6/cKddVzzRKj0EzkXuR982PN/c9K9vthckSt5SuqdVMDWcm2tNwc2CwbZupIlezH/gR 2Kh7PC9ajorFtpe1ZEZxP1ri6iil4rBnUfCAOrzvx1DewiySEvKr2GSWz56ddqhnGsA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=isuIX96E; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CF994606A31A; Wed, 28 Oct 2026 18:43:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=isuIX96E Received: by smtp.kernel.org (Postfix) with ESMTPSA id EAA041F01825; Wed, 28 Oct 2026 18:43:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793213007; bh=oF80QaTAyC6T8Z38MPlTEfa07j54EHqVtin0L3XBaB8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=isuIX96E4AFYHVU+8TBXhtsutPNTEAD8ZDRC345nbefmHsiVr1gevNpnDkdosW625 9CAhqNDZifJHwHd89YIKeRlbaKExIg9dWeR7pLs92bvxfsIbRBpxmjDiuydGAx783j MTQ31PWO4SDdr3txnciKJBHoZzW2YAOBs0R+srrU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , Kuniyuki Iwashima , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.1 0355/1887] tcp: introduce icsk->icsk_keepalive_timer Date: Wed, 28 Oct 2026 17:40:51 +0100 Message-ID: <20261028170507.310090743@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028170459.200466217@linuxfoundation.org> References: <20261028170459.200466217@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 08dfe370239e53494453cee1e2ded2cdaa1efd12 ] sk->sk_timer has been used for TCP keepalives. Keepalive timers are not in fast path, we want to use sk->sk_timer storage for retransmit timers, for better cache locality. Create icsk->icsk_keepalive_timer and change keepalive code to no longer use sk->sk_timer. Added space is reclaimed in the following patch. This includes changes to MPTCP, which was also using sk_timer. Alias icsk->mptcp_tout_timer and icsk->icsk_keepalive_timer for inet_sk_diag_fill() sake. Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20251124175013.1473655-4-edumazet@google.com Signed-off-by: Jakub Kicinski Backport to 6.1 as a dependency of 85c580b0d859 ("mptcp: prevent race between disconnect() and rtx"): Keep icsk_timeout and the existing TCP retransmit timer. Update the existing inet_csk keepalive helpers in inet_connection_sock.c instead of introducing the newer TCP helpers, and use from_timer() in the callbacks. Adjust the DCCP callback, since DCCP still shares the inet_csk timer setup in this branch. Omit the absent net_cachelines document. Also alias sk_timer as mptcp_retransmit_timer and move all MPTCP retransmit timer users there. The target directly stops this timer and the new mptcp_tout_timer, so both names must identify the timers actually in use. Initialize the MPTCP icsk_rto_min to this branch's TCP_RTO_MIN so the target restores a valid retransmit interval during disconnect. No functions are added. [ sashal: Reduced backport -- upstream 08dfe370239e5 touches 11 file(s), this backport carries 12. Not backported here: Documentation/networking/net_cachelines/inet_connection_sock.rst This note is generated from the file lists only; see the resolution record for the reasoning. ] Stable-dep-of: 85c580b0d859 ("mptcp: prevent race between disconnect() and rtx") Signed-off-by: Sasha Levin --- include/net/inet_connection_sock.h | 11 ++++++-- include/net/sock.h | 6 +++- net/dccp/timer.c | 4 ++- net/ipv4/inet_connection_sock.c | 10 +++---- net/ipv4/inet_diag.c | 4 +-- net/ipv4/tcp_ipv4.c | 4 +-- net/ipv4/tcp_timer.c | 5 ++-- net/ipv6/tcp_ipv6.c | 4 +-- net/mptcp/protocol.c | 28 +++++++++---------- net/mptcp/protocol.h | 2 +- .../selftests/bpf/progs/bpf_iter_tcp4.c | 4 +-- .../selftests/bpf/progs/bpf_iter_tcp6.c | 4 +-- 12 files changed, 49 insertions(+), 37 deletions(-) diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h index 9760ba0516b6c..51be99667a23c 100644 --- a/include/net/inet_connection_sock.h +++ b/include/net/inet_connection_sock.h @@ -63,6 +63,9 @@ struct inet_connection_sock_af_ops { * @icsk_bind2_hash: Bind node in the bhash2 table * @icsk_timeout: Timeout * @icsk_retransmit_timer: Resend (no ack) + * @icsk_delack_timer: Delayed ACK timer + * @icsk_keepalive_timer: Keepalive timer + * @mptcp_tout_timer: MPTCP timeout timer * @icsk_rto: Retransmit timeout * @icsk_pmtu_cookie Last pmtu seen by socket * @icsk_ca_ops Pluggable congestion control hook @@ -89,8 +92,12 @@ struct inet_connection_sock { struct inet_bind_bucket *icsk_bind_hash; struct inet_bind2_bucket *icsk_bind2_hash; unsigned long icsk_timeout; - struct timer_list icsk_retransmit_timer; - struct timer_list icsk_delack_timer; + struct timer_list icsk_retransmit_timer; + struct timer_list icsk_delack_timer; + union { + struct timer_list icsk_keepalive_timer; + struct timer_list mptcp_tout_timer; + }; __u32 icsk_rto; __u32 icsk_rto_min; __u32 icsk_delack_max; diff --git a/include/net/sock.h b/include/net/sock.h index d195cddb8559b..4006584514f24 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -315,6 +315,7 @@ struct sk_filter; * @sk_txrehash: enable TX hash rethink * @sk_filter: socket filtering instructions * @sk_timer: sock cleanup 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 @@ -459,7 +460,10 @@ struct sock { __u32 sk_dst_pending_confirm; u32 sk_pacing_status; /* see enum sk_pacing */ long sk_sndtimeo; - struct timer_list sk_timer; + union { + struct timer_list sk_timer; + struct timer_list mptcp_retransmit_timer; + }; __u32 sk_priority; __u32 sk_mark; unsigned long sk_pacing_rate; /* bytes per second */ diff --git a/net/dccp/timer.c b/net/dccp/timer.c index 27a3b37acd2ef..ff9c0184e3f68 100644 --- a/net/dccp/timer.c +++ b/net/dccp/timer.c @@ -160,7 +160,9 @@ static void dccp_write_timer(struct timer_list *t) static void dccp_keepalive_timer(struct timer_list *t) { - struct sock *sk = from_timer(sk, t, sk_timer); + struct inet_connection_sock *icsk = + from_timer(icsk, t, icsk_keepalive_timer); + struct sock *sk = &icsk->icsk_inet.sk; pr_err("dccp should not use a keepalive timer !\n"); sock_put(sk); diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index 6184534aa1bf5..5e31302b42505 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -749,7 +749,7 @@ void inet_csk_init_xmit_timers(struct sock *sk, timer_setup(&icsk->icsk_retransmit_timer, retransmit_handler, 0); timer_setup(&icsk->icsk_delack_timer, delack_handler, 0); - timer_setup(&sk->sk_timer, keepalive_handler, 0); + timer_setup(&icsk->icsk_keepalive_timer, keepalive_handler, 0); icsk->icsk_pending = icsk->icsk_ack.pending = 0; } EXPORT_SYMBOL(inet_csk_init_xmit_timers); @@ -762,7 +762,7 @@ void inet_csk_clear_xmit_timers(struct sock *sk) sk_stop_timer(sk, &icsk->icsk_retransmit_timer); sk_stop_timer(sk, &icsk->icsk_delack_timer); - sk_stop_timer(sk, &sk->sk_timer); + sk_stop_timer(sk, &icsk->icsk_keepalive_timer); } EXPORT_SYMBOL(inet_csk_clear_xmit_timers); @@ -777,18 +777,18 @@ void inet_csk_clear_xmit_timers_sync(struct sock *sk) sk_stop_timer_sync(sk, &icsk->icsk_retransmit_timer); sk_stop_timer_sync(sk, &icsk->icsk_delack_timer); - sk_stop_timer_sync(sk, &sk->sk_timer); + sk_stop_timer_sync(sk, &icsk->icsk_keepalive_timer); } void inet_csk_delete_keepalive_timer(struct sock *sk) { - sk_stop_timer(sk, &sk->sk_timer); + sk_stop_timer(sk, &inet_csk(sk)->icsk_keepalive_timer); } EXPORT_SYMBOL(inet_csk_delete_keepalive_timer); void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len) { - sk_reset_timer(sk, &sk->sk_timer, jiffies + len); + sk_reset_timer(sk, &inet_csk(sk)->icsk_keepalive_timer, jiffies + len); } EXPORT_SYMBOL(inet_csk_reset_keepalive_timer); diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c index 2bd5d0ed7a6fc..02d8a63f39ebf 100644 --- a/net/ipv4/inet_diag.c +++ b/net/ipv4/inet_diag.c @@ -310,11 +310,11 @@ int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk, r->idiag_retrans = icsk->icsk_probes_out; r->idiag_expires = jiffies_delta_to_msecs(icsk->icsk_timeout - jiffies); - } else if (timer_pending(&sk->sk_timer)) { + } else if (timer_pending(&icsk->icsk_keepalive_timer)) { r->idiag_timer = 2; r->idiag_retrans = icsk->icsk_probes_out; r->idiag_expires = - jiffies_delta_to_msecs(sk->sk_timer.expires - jiffies); + jiffies_delta_to_msecs(icsk->icsk_keepalive_timer.expires - jiffies); } if ((ext & (1 << (INET_DIAG_INFO - 1))) && handler->idiag_info_size) { diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 9c5d227b749c4..dc92f20942957 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -2647,9 +2647,9 @@ static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i) } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) { timer_active = 4; timer_expires = icsk->icsk_timeout; - } else if (timer_pending(&sk->sk_timer)) { + } 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; diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index 3662b49ce71ae..d086026018d62 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -706,8 +706,9 @@ EXPORT_SYMBOL_GPL(tcp_set_keepalive); static void tcp_keepalive_timer (struct timer_list *t) { - struct sock *sk = from_timer(sk, t, sk_timer); - struct inet_connection_sock *icsk = inet_csk(sk); + struct inet_connection_sock *icsk = + from_timer(icsk, t, icsk_keepalive_timer); + struct sock *sk = &icsk->icsk_inet.sk; struct tcp_sock *tp = tcp_sk(sk); u32 elapsed; diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index ec668c19cb976..9e199a2a43ef1 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -2001,9 +2001,9 @@ static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i) } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) { timer_active = 4; timer_expires = icsk->icsk_timeout; - } else if (timer_pending(&sp->sk_timer)) { + } else if (timer_pending(&icsk->icsk_keepalive_timer)) { timer_active = 2; - timer_expires = sp->sk_timer.expires; + timer_expires = icsk->icsk_keepalive_timer.expires; } else { timer_active = 0; timer_expires = jiffies; diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 10be901f8c026..593d196dfa8bb 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -426,9 +426,7 @@ static bool __mptcp_move_skb(struct mptcp_sock *msk, struct sock *ssk, static void mptcp_stop_rtx_timer(struct sock *sk) { - struct inet_connection_sock *icsk = inet_csk(sk); - - sk_stop_timer(sk, &icsk->icsk_retransmit_timer); + sk_stop_timer(sk, &sk->mptcp_retransmit_timer); mptcp_sk(sk)->timer_ival = 0; } @@ -976,12 +974,11 @@ static void __mptcp_flush_join_list(struct sock *sk, struct list_head *join_list static bool mptcp_rtx_timer_pending(struct sock *sk) { - return timer_pending(&inet_csk(sk)->icsk_retransmit_timer); + return timer_pending(&sk->mptcp_retransmit_timer); } static void mptcp_reset_rtx_timer(struct sock *sk) { - struct inet_connection_sock *icsk = inet_csk(sk); unsigned long tout; /* prevent rescheduling on close */ @@ -989,7 +986,7 @@ static void mptcp_reset_rtx_timer(struct sock *sk) return; tout = mptcp_sk(sk)->timer_ival; - sk_reset_timer(sk, &icsk->icsk_retransmit_timer, jiffies + tout); + sk_reset_timer(sk, &sk->mptcp_retransmit_timer, jiffies + tout); } bool mptcp_schedule_work(struct sock *sk) @@ -2349,9 +2346,7 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, static void mptcp_retransmit_timer(struct timer_list *t) { - struct inet_connection_sock *icsk = from_timer(icsk, t, - icsk_retransmit_timer); - struct sock *sk = &icsk->icsk_inet.sk; + struct sock *sk = from_timer(sk, t, mptcp_retransmit_timer); struct mptcp_sock *msk = mptcp_sk(sk); bh_lock_sock(sk); @@ -2369,7 +2364,9 @@ static void mptcp_retransmit_timer(struct timer_list *t) static void mptcp_tout_timer(struct timer_list *t) { - struct sock *sk = from_timer(sk, t, sk_timer); + struct inet_connection_sock *icsk = + from_timer(icsk, t, mptcp_tout_timer); + struct sock *sk = &icsk->icsk_inet.sk; mptcp_schedule_work(sk); sock_put(sk); @@ -2801,7 +2798,7 @@ void mptcp_reset_tout_timer(struct mptcp_sock *msk, unsigned long fail_tout) */ timeout = inet_csk(sk)->icsk_mtup.probe_timestamp ? close_timeout : fail_tout; - sk_reset_timer(sk, &sk->sk_timer, timeout); + sk_reset_timer(sk, &inet_csk(sk)->mptcp_tout_timer, timeout); } static void mptcp_mp_fail_no_response(struct mptcp_sock *msk) @@ -2919,6 +2916,8 @@ static int __mptcp_init_sock(struct sock *sk) msk->first_pending = NULL; msk->rmem_fwd_alloc = 0; WRITE_ONCE(msk->rmem_released, 0); + /* MPTCP sockets do not go through tcp_init_sock(). */ + inet_csk(sk)->icsk_rto_min = TCP_RTO_MIN; msk->timer_ival = TCP_RTO_MIN; WRITE_ONCE(msk->first, NULL); @@ -2931,9 +2930,8 @@ static int __mptcp_init_sock(struct sock *sk) mptcp_pm_data_init(msk); spin_lock_init(&msk->fallback_lock); - /* re-use the csk retrans timer for MPTCP-level retrans */ - timer_setup(&msk->sk.icsk_retransmit_timer, mptcp_retransmit_timer, 0); - timer_setup(&sk->sk_timer, mptcp_tout_timer, 0); + timer_setup(&sk->mptcp_retransmit_timer, mptcp_retransmit_timer, 0); + timer_setup(&msk->sk.mptcp_tout_timer, mptcp_tout_timer, 0); return 0; } @@ -3110,7 +3108,7 @@ static void __mptcp_destroy_sock(struct sock *sk) might_sleep(); mptcp_stop_rtx_timer(sk); - sk_stop_timer(sk, &sk->sk_timer); + sk_stop_timer(sk, &inet_csk(sk)->mptcp_tout_timer); msk->pm.status = 0; sk->sk_prot->destroy(sk); diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 1de257b868399..716a6947fba74 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -698,7 +698,7 @@ static inline void mptcp_stop_tout_timer(struct sock *sk) if (!inet_csk(sk)->icsk_mtup.probe_timestamp) return; - sk_stop_timer(sk, &sk->sk_timer); + sk_stop_timer(sk, &inet_csk(sk)->mptcp_tout_timer); inet_csk(sk)->icsk_mtup.probe_timestamp = 0; } diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_tcp4.c b/tools/testing/selftests/bpf/progs/bpf_iter_tcp4.c index 92267abb462fc..be540970fcc1f 100644 --- a/tools/testing/selftests/bpf/progs/bpf_iter_tcp4.c +++ b/tools/testing/selftests/bpf/progs/bpf_iter_tcp4.c @@ -103,9 +103,9 @@ static int dump_tcp_sock(struct seq_file *seq, struct tcp_sock *tp, } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) { timer_active = 4; timer_expires = icsk->icsk_timeout; - } else if (timer_pending(&sp->sk_timer)) { + } else if (timer_pending(&icsk->icsk_keepalive_timer)) { timer_active = 2; - timer_expires = sp->sk_timer.expires; + timer_expires = icsk->icsk_keepalive_timer.expires; } else { timer_active = 0; timer_expires = bpf_jiffies64(); diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_tcp6.c b/tools/testing/selftests/bpf/progs/bpf_iter_tcp6.c index 943f7bba180e7..9f72398fc3cc3 100644 --- a/tools/testing/selftests/bpf/progs/bpf_iter_tcp6.c +++ b/tools/testing/selftests/bpf/progs/bpf_iter_tcp6.c @@ -103,9 +103,9 @@ static int dump_tcp6_sock(struct seq_file *seq, struct tcp6_sock *tp, } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) { timer_active = 4; timer_expires = icsk->icsk_timeout; - } else if (timer_pending(&sp->sk_timer)) { + } else if (timer_pending(&icsk->icsk_keepalive_timer)) { timer_active = 2; - timer_expires = sp->sk_timer.expires; + timer_expires = icsk->icsk_keepalive_timer.expires; } else { timer_active = 0; timer_expires = bpf_jiffies64(); -- 2.53.0