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authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /net/ipv4/tcp_veno.c
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Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ...
Diffstat (limited to 'net/ipv4/tcp_veno.c')
-rw-r--r--net/ipv4/tcp_veno.c238
1 files changed, 238 insertions, 0 deletions
diff --git a/net/ipv4/tcp_veno.c b/net/ipv4/tcp_veno.c
new file mode 100644
index 000000000..366ff6f21
--- /dev/null
+++ b/net/ipv4/tcp_veno.c
@@ -0,0 +1,238 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * TCP Veno congestion control
+ *
+ * This is based on the congestion detection/avoidance scheme described in
+ * C. P. Fu, S. C. Liew.
+ * "TCP Veno: TCP Enhancement for Transmission over Wireless Access Networks."
+ * IEEE Journal on Selected Areas in Communication,
+ * Feb. 2003.
+ * See https://www.ie.cuhk.edu.hk/fileadmin/staff_upload/soung/Journal/J3.pdf
+ */
+
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/inet_diag.h>
+
+#include <net/tcp.h>
+
+/* Default values of the Veno variables, in fixed-point representation
+ * with V_PARAM_SHIFT bits to the right of the binary point.
+ */
+#define V_PARAM_SHIFT 1
+static const int beta = 3 << V_PARAM_SHIFT;
+
+/* Veno variables */
+struct veno {
+ u8 doing_veno_now; /* if true, do veno for this rtt */
+ u16 cntrtt; /* # of rtts measured within last rtt */
+ u32 minrtt; /* min of rtts measured within last rtt (in usec) */
+ u32 basertt; /* the min of all Veno rtt measurements seen (in usec) */
+ u32 inc; /* decide whether to increase cwnd */
+ u32 diff; /* calculate the diff rate */
+};
+
+/* There are several situations when we must "re-start" Veno:
+ *
+ * o when a connection is established
+ * o after an RTO
+ * o after fast recovery
+ * o when we send a packet and there is no outstanding
+ * unacknowledged data (restarting an idle connection)
+ *
+ */
+static inline void veno_enable(struct sock *sk)
+{
+ struct veno *veno = inet_csk_ca(sk);
+
+ /* turn on Veno */
+ veno->doing_veno_now = 1;
+
+ veno->minrtt = 0x7fffffff;
+}
+
+static inline void veno_disable(struct sock *sk)
+{
+ struct veno *veno = inet_csk_ca(sk);
+
+ /* turn off Veno */
+ veno->doing_veno_now = 0;
+}
+
+static void tcp_veno_init(struct sock *sk)
+{
+ struct veno *veno = inet_csk_ca(sk);
+
+ veno->basertt = 0x7fffffff;
+ veno->inc = 1;
+ veno_enable(sk);
+}
+
+/* Do rtt sampling needed for Veno. */
+static void tcp_veno_pkts_acked(struct sock *sk,
+ const struct ack_sample *sample)
+{
+ struct veno *veno = inet_csk_ca(sk);
+ u32 vrtt;
+
+ if (sample->rtt_us < 0)
+ return;
+
+ /* Never allow zero rtt or baseRTT */
+ vrtt = sample->rtt_us + 1;
+
+ /* Filter to find propagation delay: */
+ if (vrtt < veno->basertt)
+ veno->basertt = vrtt;
+
+ /* Find the min rtt during the last rtt to find
+ * the current prop. delay + queuing delay:
+ */
+ veno->minrtt = min(veno->minrtt, vrtt);
+ veno->cntrtt++;
+}
+
+static void tcp_veno_state(struct sock *sk, u8 ca_state)
+{
+ if (ca_state == TCP_CA_Open)
+ veno_enable(sk);
+ else
+ veno_disable(sk);
+}
+
+/*
+ * If the connection is idle and we are restarting,
+ * then we don't want to do any Veno calculations
+ * until we get fresh rtt samples. So when we
+ * restart, we reset our Veno state to a clean
+ * state. After we get acks for this flight of
+ * packets, _then_ we can make Veno calculations
+ * again.
+ */
+static void tcp_veno_cwnd_event(struct sock *sk, enum tcp_ca_event event)
+{
+ if (event == CA_EVENT_CWND_RESTART || event == CA_EVENT_TX_START)
+ tcp_veno_init(sk);
+}
+
+static void tcp_veno_cong_avoid(struct sock *sk, u32 ack, u32 acked)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct veno *veno = inet_csk_ca(sk);
+
+ if (!veno->doing_veno_now) {
+ tcp_reno_cong_avoid(sk, ack, acked);
+ return;
+ }
+
+ /* limited by applications */
+ if (!tcp_is_cwnd_limited(sk))
+ return;
+
+ /* We do the Veno calculations only if we got enough rtt samples */
+ if (veno->cntrtt <= 2) {
+ /* We don't have enough rtt samples to do the Veno
+ * calculation, so we'll behave like Reno.
+ */
+ tcp_reno_cong_avoid(sk, ack, acked);
+ } else {
+ u64 target_cwnd;
+ u32 rtt;
+
+ /* We have enough rtt samples, so, using the Veno
+ * algorithm, we determine the state of the network.
+ */
+
+ rtt = veno->minrtt;
+
+ target_cwnd = (u64)tcp_snd_cwnd(tp) * veno->basertt;
+ target_cwnd <<= V_PARAM_SHIFT;
+ do_div(target_cwnd, rtt);
+
+ veno->diff = (tcp_snd_cwnd(tp) << V_PARAM_SHIFT) - target_cwnd;
+
+ if (tcp_in_slow_start(tp)) {
+ /* Slow start. */
+ acked = tcp_slow_start(tp, acked);
+ if (!acked)
+ goto done;
+ }
+
+ /* Congestion avoidance. */
+ if (veno->diff < beta) {
+ /* In the "non-congestive state", increase cwnd
+ * every rtt.
+ */
+ tcp_cong_avoid_ai(tp, tcp_snd_cwnd(tp), acked);
+ } else {
+ /* In the "congestive state", increase cwnd
+ * every other rtt.
+ */
+ if (tp->snd_cwnd_cnt >= tcp_snd_cwnd(tp)) {
+ if (veno->inc &&
+ tcp_snd_cwnd(tp) < tp->snd_cwnd_clamp) {
+ tcp_snd_cwnd_set(tp, tcp_snd_cwnd(tp) + 1);
+ veno->inc = 0;
+ } else
+ veno->inc = 1;
+ tp->snd_cwnd_cnt = 0;
+ } else
+ tp->snd_cwnd_cnt += acked;
+ }
+done:
+ if (tcp_snd_cwnd(tp) < 2)
+ tcp_snd_cwnd_set(tp, 2);
+ else if (tcp_snd_cwnd(tp) > tp->snd_cwnd_clamp)
+ tcp_snd_cwnd_set(tp, tp->snd_cwnd_clamp);
+ }
+ /* Wipe the slate clean for the next rtt. */
+ /* veno->cntrtt = 0; */
+ veno->minrtt = 0x7fffffff;
+}
+
+/* Veno MD phase */
+static u32 tcp_veno_ssthresh(struct sock *sk)
+{
+ const struct tcp_sock *tp = tcp_sk(sk);
+ struct veno *veno = inet_csk_ca(sk);
+
+ if (veno->diff < beta)
+ /* in "non-congestive state", cut cwnd by 1/5 */
+ return max(tcp_snd_cwnd(tp) * 4 / 5, 2U);
+ else
+ /* in "congestive state", cut cwnd by 1/2 */
+ return max(tcp_snd_cwnd(tp) >> 1U, 2U);
+}
+
+static struct tcp_congestion_ops tcp_veno __read_mostly = {
+ .init = tcp_veno_init,
+ .ssthresh = tcp_veno_ssthresh,
+ .undo_cwnd = tcp_reno_undo_cwnd,
+ .cong_avoid = tcp_veno_cong_avoid,
+ .pkts_acked = tcp_veno_pkts_acked,
+ .set_state = tcp_veno_state,
+ .cwnd_event = tcp_veno_cwnd_event,
+
+ .owner = THIS_MODULE,
+ .name = "veno",
+};
+
+static int __init tcp_veno_register(void)
+{
+ BUILD_BUG_ON(sizeof(struct veno) > ICSK_CA_PRIV_SIZE);
+ tcp_register_congestion_control(&tcp_veno);
+ return 0;
+}
+
+static void __exit tcp_veno_unregister(void)
+{
+ tcp_unregister_congestion_control(&tcp_veno);
+}
+
+module_init(tcp_veno_register);
+module_exit(tcp_veno_unregister);
+
+MODULE_AUTHOR("Bin Zhou, Cheng Peng Fu");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("TCP Veno");