From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5418F396588 for ; Thu, 17 Sep 2026 03:13:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789614838; cv=none; b=MMhy/rKxxJBfuZkKBf86ko4Co/WdOnyEGE+Fv6Om0o0vRBhqEOicR+Dyy9gy5IizeQbbxY7D/Vx0PcLDORPF05J+ewTtHrK82u2mavv1ZvI6p8GdZyUPVOFrZYak+NnbIcB7f0n2jrCi27uTUc2uUdGfth3dZWgSswgLLvlh89g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789614838; c=relaxed/simple; bh=TxnV6lLBc+RhXIIu0WmJoe8Ka+K/Maa9CqqGgj7dQe0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=m78GBqo7WGvuhuiaTJCUgJAmV8NGKVnV37+4eylBX6ILN8BJ8QwmPDUWflXBbbBqAiegzwgvxa9qfgn+6EIqQQrWy6pkjJNlVikxUGCdtDhsDOHLPyeEOFjUjSbDfFT7C7d1bwsYXDQQprp8MNckEWC5PK9E+/k9G01O28tvX00= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Tpiwk5g5; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Tpiwk5g5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 70A8D1F00899; Thu, 17 Sep 2026 03:13:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789614837; bh=YRemmFOelfPmh+8UDDJzJMmeBT3xYkqMcRIcOMC2imE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Tpiwk5g5na0kyRfH+50pXhRBGDrQoGwJcfzhXC9IocbmfvK/91UghcpSynLMRkcdN iT4SqKq+Q/UEESLYaY/FFhwQnfWIaWkJ/TidpUI9418y/uQUpzC6amZs0dYyIXu+VS mQpRDkj1eBjq0IrxHEVpQzv+IDvP4sYO4Mc3uRaUD6Ylil4wan3k2/1yWDjeifEgph Sbo4zU419cWcnBwaHTAxGvBOuxKgg+IoWUgIx/XS1wqRiCy8yBeYl2gNFdxE4iWe8z 853X/JJ8SayQpNoS9E9zX7EQV2CT5qIMc4pf4juwO4lOSW2J5i72OgGydK/dqjeK1c 6sYXCNEv9dmNg== From: Sasha Levin To: stable@vger.kernel.org Cc: Kuniyuki Iwashima , Eric Dumazet , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.6.y 4/5] ipv6: Move ipv6_fl_list from ipv6_pinfo to inet_sock. Date: Wed, 16 Sep 2026 23:13:51 -0400 Message-ID: <20260917031352.3971853-4-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260917031352.3971853-1-sashal@kernel.org> References: <2026091655-synthesis-number-1f2b@gregkh> <20260917031352.3971853-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Kuniyuki Iwashima [ Upstream commit 1c17f4373d4db1e1f0ebd3ddcd8e7a642927a826 ] In {tcp6,udp6,raw6}_sock, struct ipv6_pinfo is always placed at the beginning of a new cache line because 1. __alignof__(struct tcp_sock) is 64 due to ____cacheline_aligned of __cacheline_group_begin(tcp_sock_write_tx) 2. __alignof__(struct udp_sock) is 64 due to ____cacheline_aligned of struct numa_drop_counters 3. in raw6_sock, struct numa_drop_counters is placed before struct ipv6_pinfo . struct ipv6_pinfo is 136 bytes, but the last cache line is only used by ipv6_fl_list: $ pahole -C ipv6_pinfo vmlinux struct ipv6_pinfo { ... /* --- cacheline 2 boundary (128 bytes) --- */ struct ipv6_fl_socklist * ipv6_fl_list; /* 128 8 */ /* size: 136, cachelines: 3, members: 23 */ Let's move ipv6_fl_list from struct ipv6_pinfo to struct inet_sock to save a full cache line for {tcp6,udp6,raw6}_sock. Now, struct ipv6_pinfo is 128 bytes, and {tcp6,udp6,raw6}_sock have 64 bytes less, while {tcp,udp,raw}_sock retain the same size. Before: # grep -E "^(RAW|UDP[^L\-]|TCP)" /proc/slabinfo | awk '{print $1, "\t", $4}' RAWv6 1408 UDPv6 1472 TCPv6 2560 RAW 1152 UDP 1280 TCP 2368 After: # grep -E "^(RAW|UDP[^L\-]|TCP)" /proc/slabinfo | awk '{print $1, "\t", $4}' RAWv6 1344 UDPv6 1408 TCPv6 2496 RAW 1152 UDP 1280 TCP 2368 Also, ipv6_fl_list and inet_flags (SNDFLOW bit) are placed in the same cache line. $ pahole -C inet_sock vmlinux ... /* --- cacheline 11 boundary (704 bytes) was 56 bytes ago --- */ struct ipv6_pinfo * pinet6; /* 760 8 */ /* --- cacheline 12 boundary (768 bytes) --- */ struct ipv6_fl_socklist * ipv6_fl_list; /* 768 8 */ unsigned long inet_flags; /* 776 8 */ Doc churn is due to the insufficient Type column (only 1 space short). Suggested-by: Eric Dumazet Signed-off-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20251014224210.2964778-1-kuniyu@google.com Signed-off-by: Jakub Kicinski Backport notes for Linux 6.6: Drop the cacheline documentation update because the file does not exist in this tree. Remove only ipv6_fl_list from the older ipv6_pinfo layout, keeping its transmit options, packet options and cork fields intact. Apply the IPv4-mapped TCP child change in the existing tcp_v6_mapped_child_init() helper. Also update both IPv6 DCCP child paths, which still exist in 6.6, so cloned sockets do not inherit the listener's flow-label list. Retain the ipv6_pinfo pointer in ipv6_flowlabel_get(), where 6.6 still uses it for the repflow flag. No functions are added. This preserves the socket-based flow-label iterator needed by 8d6cd1885085 ("ipv6: flowlabel: cap duplicate leases per socket"). The target applies cleanly with a three-way cherry-pick; retain the stable branch's existing mem_check() policy. [ sashal: Reduced backport -- upstream 1c17f4373d4db touches 7 file(s), this backport carries 7. Not backported here: Documentation/networking/net_cachelines/inet_sock.rst This note is generated from the file lists only; see the resolution record for the reasoning. ] Stable-dep-of: 8d6cd1885085 ("ipv6: flowlabel: cap duplicate leases per socket") Signed-off-by: Sasha Levin --- .../chelsio/inline_crypto/chtls/chtls_cm.c | 4 +- include/linux/ipv6.h | 1 - include/net/inet_sock.h | 1 + net/dccp/ipv6.c | 4 +- net/ipv6/ip6_flowlabel.c | 43 +++++++++---------- net/ipv6/tcp_ipv6.c | 10 ++--- net/sctp/ipv6.c | 8 ++-- 7 files changed, 36 insertions(+), 35 deletions(-) diff --git a/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_cm.c b/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_cm.c index 6f6525983130e..6d69c19ea7c30 100644 --- a/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_cm.c +++ b/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_cm.c @@ -1197,12 +1197,12 @@ static struct sock *chtls_recv_sock(struct sock *lsk, struct ipv6_pinfo *newnp = inet6_sk(newsk); struct ipv6_pinfo *np = inet6_sk(lsk); - inet_sk(newsk)->pinet6 = &newtcp6sk->inet6; + newinet->pinet6 = &newtcp6sk->inet6; + newinet->ipv6_fl_list = NULL; memcpy(newnp, np, sizeof(struct ipv6_pinfo)); newsk->sk_v6_daddr = treq->ir_v6_rmt_addr; newsk->sk_v6_rcv_saddr = treq->ir_v6_loc_addr; inet6_sk(newsk)->saddr = treq->ir_v6_loc_addr; - newnp->ipv6_fl_list = NULL; newnp->pktoptions = NULL; newsk->sk_bound_dev_if = treq->ir_iif; newinet->inet_opt = NULL; diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h index fc52145ab732e..4c577356d7e9d 100644 --- a/include/linux/ipv6.h +++ b/include/linux/ipv6.h @@ -285,7 +285,6 @@ struct ipv6_pinfo { struct ipv6_mc_socklist __rcu *ipv6_mc_list; struct ipv6_ac_socklist *ipv6_ac_list; - struct ipv6_fl_socklist __rcu *ipv6_fl_list; struct ipv6_txoptions __rcu *opt; struct sk_buff *pktoptions; diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h index 2790ba58ffe5c..ee3456bc1a401 100644 --- a/include/net/inet_sock.h +++ b/include/net/inet_sock.h @@ -211,6 +211,7 @@ struct inet_sock { struct sock sk; #if IS_ENABLED(CONFIG_IPV6) struct ipv6_pinfo *pinet6; + struct ipv6_fl_socklist __rcu *ipv6_fl_list; #endif /* Socket demultiplex comparisons on incoming packets. */ #define inet_daddr sk.__sk_common.skc_daddr diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c index ae617bd8afab8..a4158fc6a6846 100644 --- a/net/dccp/ipv6.c +++ b/net/dccp/ipv6.c @@ -454,7 +454,7 @@ static struct sock *dccp_v6_request_recv_sock(const struct sock *sk, newnp->opt = NULL; newnp->ipv6_mc_list = NULL; newnp->ipv6_ac_list = NULL; - newnp->ipv6_fl_list = NULL; + newinet->ipv6_fl_list = NULL; newnp->mcast_oif = inet_iif(skb); newnp->mcast_hops = ip_hdr(skb)->ttl; @@ -521,7 +521,7 @@ static struct sock *dccp_v6_request_recv_sock(const struct sock *sk, newnp->ipv6_mc_list = NULL; newnp->ipv6_ac_list = NULL; - newnp->ipv6_fl_list = NULL; + newinet->ipv6_fl_list = NULL; newnp->pktoptions = NULL; newnp->opt = NULL; newnp->mcast_oif = inet6_iif(skb); diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c index bf909fa69a977..04ec8f0bda7d1 100644 --- a/net/ipv6/ip6_flowlabel.c +++ b/net/ipv6/ip6_flowlabel.c @@ -66,8 +66,8 @@ EXPORT_SYMBOL(ipv6_flowlabel_exclusive); fl != NULL; \ fl = rcu_dereference(fl->next)) -#define for_each_sk_fl_rcu(np, sfl) \ - for (sfl = rcu_dereference(np->ipv6_fl_list); \ +#define for_each_sk_fl_rcu(sk, sfl) \ + for (sfl = rcu_dereference(inet_sk(sk)->ipv6_fl_list); \ sfl != NULL; \ sfl = rcu_dereference(sfl->next)) @@ -257,12 +257,11 @@ static struct ip6_flowlabel *fl_intern(struct net *net, struct ip6_flowlabel *__fl6_sock_lookup(struct sock *sk, __be32 label) { struct ipv6_fl_socklist *sfl; - struct ipv6_pinfo *np = inet6_sk(sk); label &= IPV6_FLOWLABEL_MASK; rcu_read_lock(); - for_each_sk_fl_rcu(np, sfl) { + for_each_sk_fl_rcu(sk, sfl) { struct ip6_flowlabel *fl = sfl->fl; if (fl->label == label && atomic_inc_not_zero(&fl->users)) { @@ -278,16 +277,16 @@ EXPORT_SYMBOL_GPL(__fl6_sock_lookup); void fl6_free_socklist(struct sock *sk) { - struct ipv6_pinfo *np = inet6_sk(sk); + struct inet_sock *inet = inet_sk(sk); struct ipv6_fl_socklist *sfl; - if (!rcu_access_pointer(np->ipv6_fl_list)) + if (!rcu_access_pointer(inet->ipv6_fl_list)) return; spin_lock_bh(&ip6_sk_fl_lock); - while ((sfl = rcu_dereference_protected(np->ipv6_fl_list, + while ((sfl = rcu_dereference_protected(inet->ipv6_fl_list, lockdep_is_held(&ip6_sk_fl_lock))) != NULL) { - np->ipv6_fl_list = sfl->next; + inet->ipv6_fl_list = sfl->next; spin_unlock_bh(&ip6_sk_fl_lock); fl_release(sfl->fl); @@ -465,16 +464,15 @@ fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq, static int mem_check(struct sock *sk) { - struct ipv6_pinfo *np = inet6_sk(sk); - struct ipv6_fl_socklist *sfl; int room = FL_MAX_SIZE - atomic_read(&fl_size); + struct ipv6_fl_socklist *sfl; int count = 0; if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK) return 0; rcu_read_lock(); - for_each_sk_fl_rcu(np, sfl) + for_each_sk_fl_rcu(sk, sfl) count++; rcu_read_unlock(); @@ -487,13 +485,15 @@ static int mem_check(struct sock *sk) return 0; } -static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl, - struct ip6_flowlabel *fl) +static inline void fl_link(struct sock *sk, struct ipv6_fl_socklist *sfl, + struct ip6_flowlabel *fl) { + struct inet_sock *inet = inet_sk(sk); + spin_lock_bh(&ip6_sk_fl_lock); sfl->fl = fl; - sfl->next = np->ipv6_fl_list; - rcu_assign_pointer(np->ipv6_fl_list, sfl); + sfl->next = inet->ipv6_fl_list; + rcu_assign_pointer(inet->ipv6_fl_list, sfl); spin_unlock_bh(&ip6_sk_fl_lock); } @@ -515,7 +515,7 @@ int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq, rcu_read_lock(); - for_each_sk_fl_rcu(np, sfl) { + for_each_sk_fl_rcu(sk, sfl) { if (sfl->fl->label == (np->flow_label & IPV6_FLOWLABEL_MASK)) { spin_lock_bh(&ip6_fl_lock); freq->flr_label = sfl->fl->label; @@ -554,7 +554,7 @@ static int ipv6_flowlabel_put(struct sock *sk, struct in6_flowlabel_req *freq) } spin_lock_bh(&ip6_sk_fl_lock); - for (sflp = &np->ipv6_fl_list; + for (sflp = &inet_sk(sk)->ipv6_fl_list; (sfl = socklist_dereference(*sflp)) != NULL; sflp = &sfl->next) { if (sfl->fl->label == freq->flr_label) @@ -574,13 +574,12 @@ static int ipv6_flowlabel_put(struct sock *sk, struct in6_flowlabel_req *freq) static int ipv6_flowlabel_renew(struct sock *sk, struct in6_flowlabel_req *freq) { - struct ipv6_pinfo *np = inet6_sk(sk); struct net *net = sock_net(sk); struct ipv6_fl_socklist *sfl; int err; rcu_read_lock(); - for_each_sk_fl_rcu(np, sfl) { + for_each_sk_fl_rcu(sk, sfl) { if (sfl->fl->label == freq->flr_label) { err = fl6_renew(sfl->fl, freq->flr_linger, freq->flr_expires); @@ -640,7 +639,7 @@ static int ipv6_flowlabel_get(struct sock *sk, struct in6_flowlabel_req *freq, if (freq->flr_label) { err = -EEXIST; rcu_read_lock(); - for_each_sk_fl_rcu(np, sfl) { + for_each_sk_fl_rcu(sk, sfl) { if (sfl->fl->label == freq->flr_label) { if (freq->flr_flags & IPV6_FL_F_EXCL) { rcu_read_unlock(); @@ -677,7 +676,7 @@ static int ipv6_flowlabel_get(struct sock *sk, struct in6_flowlabel_req *freq, fl1->linger = fl->linger; if ((long)(fl->expires - fl1->expires) > 0) fl1->expires = fl->expires; - fl_link(np, sfl1, fl1); + fl_link(sk, sfl1, fl1); fl_free(fl); return 0; @@ -711,7 +710,7 @@ static int ipv6_flowlabel_get(struct sock *sk, struct in6_flowlabel_req *freq, } } - fl_link(np, sfl1, fl); + fl_link(sk, sfl1, fl); return 0; done: fl_free(fl); diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index aef3c7bc3d80d..458c1d6e9021c 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -1187,6 +1187,7 @@ static void tcp_v6_mapped_child_init(struct sock *newsk, const struct sock *sk) struct ipv6_pinfo *newnp; newinet->pinet6 = newnp = tcp_inet6_sk(newsk); + newinet->ipv6_fl_list = NULL; memcpy(newnp, tcp_inet6_sk(sk), sizeof(struct ipv6_pinfo)); @@ -1202,7 +1203,6 @@ static void tcp_v6_mapped_child_init(struct sock *newsk, const struct sock *sk) newnp->ipv6_mc_list = NULL; newnp->ipv6_ac_list = NULL; - newnp->ipv6_fl_list = NULL; newnp->pktoptions = NULL; newnp->opt = NULL; @@ -1265,10 +1265,12 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff * newsk->sk_gso_type = SKB_GSO_TCPV6; inet6_sk_rx_dst_set(newsk, skb); - inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk); + newinet = inet_sk(newsk); + newinet->pinet6 = tcp_inet6_sk(newsk); + newinet->ipv6_fl_list = NULL; + newinet->inet_opt = NULL; newtp = tcp_sk(newsk); - newinet = inet_sk(newsk); newnp = tcp_inet6_sk(newsk); memcpy(newnp, np, sizeof(struct ipv6_pinfo)); @@ -1284,10 +1286,8 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff * First: no IPv4 options. */ - newinet->inet_opt = NULL; newnp->ipv6_mc_list = NULL; newnp->ipv6_ac_list = NULL; - newnp->ipv6_fl_list = NULL; /* Clone RX bits */ newnp->rxopt.all = np->rxopt.all; diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c index 0673857cb3d8b..5db4220aacf72 100644 --- a/net/sctp/ipv6.c +++ b/net/sctp/ipv6.c @@ -782,9 +782,10 @@ static struct sock *sctp_v6_create_accept_sk(struct sock *sk, struct sctp_association *asoc, bool kern) { - struct sock *newsk; struct ipv6_pinfo *newnp, *np = inet6_sk(sk); struct sctp6_sock *newsctp6sk; + struct inet_sock *newinet; + struct sock *newsk; newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern); if (!newsk) @@ -796,7 +797,9 @@ static struct sock *sctp_v6_create_accept_sk(struct sock *sk, sock_reset_flag(sk, SOCK_ZAPPED); newsctp6sk = (struct sctp6_sock *)newsk; - inet_sk(newsk)->pinet6 = &newsctp6sk->inet6; + newinet = inet_sk(newsk); + newinet->pinet6 = &newsctp6sk->inet6; + newinet->ipv6_fl_list = NULL; sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped; @@ -805,7 +808,6 @@ static struct sock *sctp_v6_create_accept_sk(struct sock *sk, memcpy(newnp, np, sizeof(struct ipv6_pinfo)); newnp->ipv6_mc_list = NULL; newnp->ipv6_ac_list = NULL; - newnp->ipv6_fl_list = NULL; sctp_v6_copy_ip_options(sk, newsk); -- 2.53.0