kernel/linux.git/Documentation/networking, branch v6.6.142

bonding: add support for per-port LACP actor priority

2026-05-23T11:03:30+00:00

[ Upstream commit 6b6dc81ee7e8ca87c71a533e1d69cf96a4f1e986 ] Introduce a new netlink attribute 'actor_port_prio' to allow setting the LACP actor port priority on a per-slave basis. This extends the existing bonding infrastructure to support more granular control over LACP negotiations. The priority value is embedded in LACPDU packets and will be used by subsequent patches to influence aggregator selection policies. Signed-off-by: Hangbin Liu Link: https://patch.msgid.link/20250902064501.360822-2-liuhangbin@gmail.com Signed-off-by: Paolo Abeni Stable-dep-of: c4f050ce06c5 ("bonding: 3ad: implement proper RCU rules for port->aggregator") Signed-off-by: Sasha Levin

net: bonding: add broadcast_neighbor option for 802.3ad

2026-05-23T11:03:30+00:00

[ Upstream commit ce7a381697cb3958ffe0b45e5028ac69444e9288 ] Stacking technology is a type of technology used to expand ports on Ethernet switches. It is widely used as a common access method in large-scale Internet data center architectures. Years of practice have proved that stacking technology has advantages and disadvantages in high-reliability network architecture scenarios. For instance, in stacking networking arch, conventional switch system upgrades require multiple stacked devices to restart at the same time. Therefore, it is inevitable that the business will be interrupted for a while. It is for this reason that "no-stacking" in data centers has become a trend. Additionally, when the stacking link connecting the switches fails or is abnormal, the stack will split. Although it is not common, it still happens in actual operation. The problem is that after the split, it is equivalent to two switches with the same configuration appearing in the network, causing network configuration conflicts and ultimately interrupting the services carried by the stacking system. To improve network stability, "non-stacking" solutions have been increasingly adopted, particularly by public cloud providers and tech companies like Alibaba, Tencent, and Didi. "non-stacking" is a method of mimicing switch stacking that convinces a LACP peer, bonding in this case, connected to a set of "non-stacked" switches that all of its ports are connected to a single switch (i.e., LACP aggregator), as if those switches were stacked. This enables the LACP peer's ports to aggregate together, and requires (a) special switch configuration, described in the linked article, and (b) modifications to the bonding 802.3ad (LACP) mode to send all ARP/ND packets across all ports of the active aggregator. Note that, with multiple aggregators, the current broadcast mode logic will send only packets to the selected aggregator(s). +-----------+ +-----------+ | switch1 | | switch2 | +-----------+ +-----------+ ^ ^ | | +-----------------+ | bond4 lacp | +-----------------+ | | | NIC1 | NIC2 +-----------------+ | server | +-----------------+ - https://www.ruijie.com/fr-fr/support/tech-gallery/de-stack-data-center-network-architecture/ Cc: Jay Vosburgh Cc: "David S. Miller" Cc: Eric Dumazet Cc: Jakub Kicinski Cc: Paolo Abeni Cc: Simon Horman Cc: Jonathan Corbet Cc: Andrew Lunn Cc: Steven Rostedt Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Cc: Nikolay Aleksandrov Signed-off-by: Tonghao Zhang Signed-off-by: Zengbing Tu Link: https://patch.msgid.link/84d0a044514157bb856a10b6d03a1028c4883561.1751031306.git.tonghao@bamaicloud.com Signed-off-by: Paolo Abeni Stable-dep-of: c4f050ce06c5 ("bonding: 3ad: implement proper RCU rules for port->aggregator") Signed-off-by: Sasha Levin

tcp: Set pingpong threshold via sysctl

2026-03-04T12:20:22+00:00

[ Upstream commit 562b1fdf061bff9394ccd884456ed1173c224fdc ] TCP pingpong threshold is 1 by default. But some applications, like SQL DB may prefer a higher pingpong threshold to activate delayed acks in quick ack mode for better performance. The pingpong threshold and related code were changed to 3 in the year 2019 in: commit 4a41f453bedf ("tcp: change pingpong threshold to 3") And reverted to 1 in the year 2022 in: commit 4d8f24eeedc5 ("Revert "tcp: change pingpong threshold to 3"") There is no single value that fits all applications. Add net.ipv4.tcp_pingpong_thresh sysctl tunable, so it can be tuned for optimal performance based on the application needs. Signed-off-by: Haiyang Zhang Reviewed-by: Simon Horman Reviewed-by: Eric Dumazet Acked-by: Neal Cardwell Reviewed-by: Kuniyuki Iwashima Link: https://lore.kernel.org/r/1697056244-21888-1-git-send-email-haiyangz@microsoft.com Signed-off-by: Jakub Kicinski Stable-dep-of: 87b08913a9ae ("inet: move icmp_global_{credit,stamp} to a separate cache line") Signed-off-by: Sasha Levin

tcp: defer regular ACK while processing socket backlog

2026-03-04T12:20:22+00:00

[ Upstream commit 133c4c0d37175f510a10fa9bed51e223936073fc ] This idea came after a particular workload requested the quickack attribute set on routes, and a performance drop was noticed for large bulk transfers. For high throughput flows, it is best to use one cpu running the user thread issuing socket system calls, and a separate cpu to process incoming packets from BH context. (With TSO/GRO, bottleneck is usually the 'user' cpu) Problem is the user thread can spend a lot of time while holding the socket lock, forcing BH handler to queue most of incoming packets in the socket backlog. Whenever the user thread releases the socket lock, it must first process all accumulated packets in the backlog, potentially adding latency spikes. Due to flood mitigation, having too many packets in the backlog increases chance of unexpected drops. Backlog processing unfortunately shifts a fair amount of cpu cycles from the BH cpu to the 'user' cpu, thus reducing max throughput. This patch takes advantage of the backlog processing, and the fact that ACK are mostly cumulative. The idea is to detect we are in the backlog processing and defer all eligible ACK into a single one, sent from tcp_release_cb(). This saves cpu cycles on both sides, and network resources. Performance of a single TCP flow on a 200Gbit NIC: - Throughput is increased by 20% (100Gbit -> 120Gbit). - Number of generated ACK per second shrinks from 240,000 to 40,000. - Number of backlog drops per second shrinks from 230 to 0. Benchmark context: - Regular netperf TCP_STREAM (no zerocopy) - Intel(R) Xeon(R) Platinum 8481C (Saphire Rapids) - MAX_SKB_FRAGS = 17 (~60KB per GRO packet) This feature is guarded by a new sysctl, and enabled by default: /proc/sys/net/ipv4/tcp_backlog_ack_defer Signed-off-by: Eric Dumazet Acked-by: Yuchung Cheng Acked-by: Neal Cardwell Acked-by: Soheil Hassas Yeganeh Acked-by: Dave Taht Signed-off-by: Paolo Abeni Stable-dep-of: 87b08913a9ae ("inet: move icmp_global_{credit,stamp} to a separate cache line") Signed-off-by: Sasha Levin

octeon_ep: support Octeon CN10K devices

2026-03-04T12:19:55+00:00

[ Upstream commit 0807dc76f3bf500f9a22465eedd2290da7357efb ] Add PCI Endpoint NIC support for Octeon CN10K devices. CN10K devices are part of Octeon 10 family products with similar PCI NIC characteristics. These include: - CN10KA - CNF10KA - CNF10KB - CN10KB Update supported device list in Documentation Signed-off-by: Shinas Rasheed Link: https://lore.kernel.org/r/20231117103817.2468176-1-srasheed@marvell.com Signed-off-by: Paolo Abeni Stable-dep-of: 73e6ffa37ceb ("octeon_ep: disable per ring interrupts") Signed-off-by: Sasha Levin

doc: fix seg6_flowlabel path

2025-10-23T14:16:30+00:00

[ Upstream commit 0b4b77eff5f8cd9be062783a1c1e198d46d0a753 ] This sysctl is not per interface; it's global per netns. Fixes: 292ecd9f5a94 ("doc: move seg6_flowlabel to seg6-sysctl.rst") Reported-by: Philippe Guibert Signed-off-by: Nicolas Dichtel Reviewed-by: Simon Horman Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

docs: networking: can: change bcm_msg_head frames member to support flexible array

2025-09-19T14:32:06+00:00

[ Upstream commit 641427d5bf90af0625081bf27555418b101274cd ] The documentation of the 'bcm_msg_head' struct does not match how it is defined in 'bcm.h'. Changed the frames member to a flexible array, matching the definition in the header file. See commit 94dfc73e7cf4 ("treewide: uapi: Replace zero-length arrays with flexible-array members") Signed-off-by: Alex Tran Acked-by: Oliver Hartkopp Link: https://patch.msgid.link/20250904031709.1426895-1-alex.t.tran@gmail.com Fixes: 94dfc73e7cf4 ("treewide: uapi: Replace zero-length arrays with flexible-array members") Link: https://bugzilla.kernel.org/show_bug.cgi?id=217783 Signed-off-by: Marc Kleine-Budde Signed-off-by: Sasha Levin

bonding: Add independent control state machine

2025-08-28T14:28:49+00:00

[ Upstream commit 240fd405528bbf7fafa0559202ca7aa524c9cd96 ] Add support for the independent control state machine per IEEE 802.1AX-2008 5.4.15 in addition to the existing implementation of the coupled control state machine. Introduces two new states, AD_MUX_COLLECTING and AD_MUX_DISTRIBUTING in the LACP MUX state machine for separated handling of an initial Collecting state before the Collecting and Distributing state. This enables a port to be in a state where it can receive incoming packets while not still distributing. This is useful for reducing packet loss when a port begins distributing before its partner is able to collect. Added new functions such as bond_set_slave_tx_disabled_flags and bond_set_slave_rx_enabled_flags to precisely manage the port's collecting and distributing states. Previously, there was no dedicated method to disable TX while keeping RX enabled, which this patch addresses. Note that the regular flow process in the kernel's bonding driver remains unaffected by this patch. The extension requires explicit opt-in by the user (in order to ensure no disruptions for existing setups) via netlink support using the new bonding parameter coupled_control. The default value for coupled_control is set to 1 so as to preserve existing behaviour. Signed-off-by: Aahil Awatramani Reviewed-by: Hangbin Liu Link: https://lore.kernel.org/r/20240202175858.1573852-1-aahila@google.com Signed-off-by: Paolo Abeni Stable-dep-of: 0599640a21e9 ("bonding: send LACPDUs periodically in passive mode after receiving partner's LACPDU") Signed-off-by: Sasha Levin

mptcp: disable add_addr retransmission when timeout is 0

2025-08-28T14:28:44+00:00

commit f5ce0714623cffd00bf2a83e890d09c609b7f50a upstream. When add_addr_timeout was set to 0, this caused the ADD_ADDR to be retransmitted immediately, which looks like a buggy behaviour. Instead, interpret 0 as "no retransmissions needed". The documentation is updated to explicitly state that setting the timeout to 0 disables retransmission. Fixes: 93f323b9cccc ("mptcp: add a new sysctl add_addr_timeout") Cc: stable@vger.kernel.org Suggested-by: Matthieu Baerts Signed-off-by: Geliang Tang Reviewed-by: Matthieu Baerts (NGI0) Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20250815-net-mptcp-misc-fixes-6-17-rc2-v1-5-521fe9957892@kernel.org Signed-off-by: Jakub Kicinski [ Before commit e4c28e3d5c09 ("mptcp: pm: move generic PM helpers to pm.c"), mptcp_pm_alloc_anno_list() was in pm_netlink.c. The same patch can be applied there without conflicts. ] Signed-off-by: Matthieu Baerts (NGI0) Signed-off-by: Greg Kroah-Hartman

strparser: Add read_sock callback

2025-02-27T12:10:50+00:00

[ Upstream commit 0532a79efd68a4d9686b0385e4993af4b130ff82 ] Added a new read_sock handler, allowing users to customize read operations instead of relying on the native socket's read_sock. Signed-off-by: Jiayuan Chen Signed-off-by: Martin KaFai Lau Reviewed-by: Jakub Sitnicki Acked-by: John Fastabend Link: https://patch.msgid.link/20250122100917.49845-2-mrpre@163.com Stable-dep-of: 36b62df5683c ("bpf: Fix wrong copied_seq calculation") Signed-off-by: Sasha Levin