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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_yeah.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
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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 '')
-rw-r--r--net/ipv4/tcp_yeah.c239
1 files changed, 239 insertions, 0 deletions
diff --git a/net/ipv4/tcp_yeah.c b/net/ipv4/tcp_yeah.c
new file mode 100644
index 000000000..18b07ff5d
--- /dev/null
+++ b/net/ipv4/tcp_yeah.c
@@ -0,0 +1,239 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *
+ * YeAH TCP
+ *
+ * For further details look at:
+ * https://web.archive.org/web/20080316215752/http://wil.cs.caltech.edu/pfldnet2007/paper/YeAH_TCP.pdf
+ *
+ */
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/inet_diag.h>
+
+#include <net/tcp.h>
+
+#include "tcp_vegas.h"
+
+#define TCP_YEAH_ALPHA 80 /* number of packets queued at the bottleneck */
+#define TCP_YEAH_GAMMA 1 /* fraction of queue to be removed per rtt */
+#define TCP_YEAH_DELTA 3 /* log minimum fraction of cwnd to be removed on loss */
+#define TCP_YEAH_EPSILON 1 /* log maximum fraction to be removed on early decongestion */
+#define TCP_YEAH_PHY 8 /* maximum delta from base */
+#define TCP_YEAH_RHO 16 /* minimum number of consecutive rtt to consider competition on loss */
+#define TCP_YEAH_ZETA 50 /* minimum number of state switches to reset reno_count */
+
+#define TCP_SCALABLE_AI_CNT 100U
+
+/* YeAH variables */
+struct yeah {
+ struct vegas vegas; /* must be first */
+
+ /* YeAH */
+ u32 lastQ;
+ u32 doing_reno_now;
+
+ u32 reno_count;
+ u32 fast_count;
+};
+
+static void tcp_yeah_init(struct sock *sk)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct yeah *yeah = inet_csk_ca(sk);
+
+ tcp_vegas_init(sk);
+
+ yeah->doing_reno_now = 0;
+ yeah->lastQ = 0;
+
+ yeah->reno_count = 2;
+
+ /* Ensure the MD arithmetic works. This is somewhat pedantic,
+ * since I don't think we will see a cwnd this large. :) */
+ tp->snd_cwnd_clamp = min_t(u32, tp->snd_cwnd_clamp, 0xffffffff/128);
+}
+
+static void tcp_yeah_cong_avoid(struct sock *sk, u32 ack, u32 acked)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct yeah *yeah = inet_csk_ca(sk);
+
+ if (!tcp_is_cwnd_limited(sk))
+ return;
+
+ if (tcp_in_slow_start(tp)) {
+ acked = tcp_slow_start(tp, acked);
+ if (!acked)
+ goto do_vegas;
+ }
+
+ if (!yeah->doing_reno_now) {
+ /* Scalable */
+ tcp_cong_avoid_ai(tp, min(tcp_snd_cwnd(tp), TCP_SCALABLE_AI_CNT),
+ acked);
+ } else {
+ /* Reno */
+ tcp_cong_avoid_ai(tp, tcp_snd_cwnd(tp), acked);
+ }
+
+ /* The key players are v_vegas.beg_snd_una and v_beg_snd_nxt.
+ *
+ * These are so named because they represent the approximate values
+ * of snd_una and snd_nxt at the beginning of the current RTT. More
+ * precisely, they represent the amount of data sent during the RTT.
+ * At the end of the RTT, when we receive an ACK for v_beg_snd_nxt,
+ * we will calculate that (v_beg_snd_nxt - v_vegas.beg_snd_una) outstanding
+ * bytes of data have been ACKed during the course of the RTT, giving
+ * an "actual" rate of:
+ *
+ * (v_beg_snd_nxt - v_vegas.beg_snd_una) / (rtt duration)
+ *
+ * Unfortunately, v_vegas.beg_snd_una is not exactly equal to snd_una,
+ * because delayed ACKs can cover more than one segment, so they
+ * don't line up yeahly with the boundaries of RTTs.
+ *
+ * Another unfortunate fact of life is that delayed ACKs delay the
+ * advance of the left edge of our send window, so that the number
+ * of bytes we send in an RTT is often less than our cwnd will allow.
+ * So we keep track of our cwnd separately, in v_beg_snd_cwnd.
+ */
+do_vegas:
+ if (after(ack, yeah->vegas.beg_snd_nxt)) {
+ /* We do the Vegas calculations only if we got enough RTT
+ * samples that we can be reasonably sure that we got
+ * at least one RTT sample that wasn't from a delayed ACK.
+ * If we only had 2 samples total,
+ * then that means we're getting only 1 ACK per RTT, which
+ * means they're almost certainly delayed ACKs.
+ * If we have 3 samples, we should be OK.
+ */
+
+ if (yeah->vegas.cntRTT > 2) {
+ u32 rtt, queue;
+ u64 bw;
+
+ /* We have enough RTT samples, so, using the Vegas
+ * algorithm, we determine if we should increase or
+ * decrease cwnd, and by how much.
+ */
+
+ /* Pluck out the RTT we are using for the Vegas
+ * calculations. This is the min RTT seen during the
+ * last RTT. Taking the min filters out the effects
+ * of delayed ACKs, at the cost of noticing congestion
+ * a bit later.
+ */
+ rtt = yeah->vegas.minRTT;
+
+ /* Compute excess number of packets above bandwidth
+ * Avoid doing full 64 bit divide.
+ */
+ bw = tcp_snd_cwnd(tp);
+ bw *= rtt - yeah->vegas.baseRTT;
+ do_div(bw, rtt);
+ queue = bw;
+
+ if (queue > TCP_YEAH_ALPHA ||
+ rtt - yeah->vegas.baseRTT > (yeah->vegas.baseRTT / TCP_YEAH_PHY)) {
+ if (queue > TCP_YEAH_ALPHA &&
+ tcp_snd_cwnd(tp) > yeah->reno_count) {
+ u32 reduction = min(queue / TCP_YEAH_GAMMA ,
+ tcp_snd_cwnd(tp) >> TCP_YEAH_EPSILON);
+
+ tcp_snd_cwnd_set(tp, tcp_snd_cwnd(tp) - reduction);
+
+ tcp_snd_cwnd_set(tp, max(tcp_snd_cwnd(tp),
+ yeah->reno_count));
+
+ tp->snd_ssthresh = tcp_snd_cwnd(tp);
+ }
+
+ if (yeah->reno_count <= 2)
+ yeah->reno_count = max(tcp_snd_cwnd(tp)>>1, 2U);
+ else
+ yeah->reno_count++;
+
+ yeah->doing_reno_now = min(yeah->doing_reno_now + 1,
+ 0xffffffU);
+ } else {
+ yeah->fast_count++;
+
+ if (yeah->fast_count > TCP_YEAH_ZETA) {
+ yeah->reno_count = 2;
+ yeah->fast_count = 0;
+ }
+
+ yeah->doing_reno_now = 0;
+ }
+
+ yeah->lastQ = queue;
+ }
+
+ /* Save the extent of the current window so we can use this
+ * at the end of the next RTT.
+ */
+ yeah->vegas.beg_snd_una = yeah->vegas.beg_snd_nxt;
+ yeah->vegas.beg_snd_nxt = tp->snd_nxt;
+ yeah->vegas.beg_snd_cwnd = tcp_snd_cwnd(tp);
+
+ /* Wipe the slate clean for the next RTT. */
+ yeah->vegas.cntRTT = 0;
+ yeah->vegas.minRTT = 0x7fffffff;
+ }
+}
+
+static u32 tcp_yeah_ssthresh(struct sock *sk)
+{
+ const struct tcp_sock *tp = tcp_sk(sk);
+ struct yeah *yeah = inet_csk_ca(sk);
+ u32 reduction;
+
+ if (yeah->doing_reno_now < TCP_YEAH_RHO) {
+ reduction = yeah->lastQ;
+
+ reduction = min(reduction, max(tcp_snd_cwnd(tp)>>1, 2U));
+
+ reduction = max(reduction, tcp_snd_cwnd(tp) >> TCP_YEAH_DELTA);
+ } else
+ reduction = max(tcp_snd_cwnd(tp)>>1, 2U);
+
+ yeah->fast_count = 0;
+ yeah->reno_count = max(yeah->reno_count>>1, 2U);
+
+ return max_t(int, tcp_snd_cwnd(tp) - reduction, 2);
+}
+
+static struct tcp_congestion_ops tcp_yeah __read_mostly = {
+ .init = tcp_yeah_init,
+ .ssthresh = tcp_yeah_ssthresh,
+ .undo_cwnd = tcp_reno_undo_cwnd,
+ .cong_avoid = tcp_yeah_cong_avoid,
+ .set_state = tcp_vegas_state,
+ .cwnd_event = tcp_vegas_cwnd_event,
+ .get_info = tcp_vegas_get_info,
+ .pkts_acked = tcp_vegas_pkts_acked,
+
+ .owner = THIS_MODULE,
+ .name = "yeah",
+};
+
+static int __init tcp_yeah_register(void)
+{
+ BUILD_BUG_ON(sizeof(struct yeah) > ICSK_CA_PRIV_SIZE);
+ tcp_register_congestion_control(&tcp_yeah);
+ return 0;
+}
+
+static void __exit tcp_yeah_unregister(void)
+{
+ tcp_unregister_congestion_control(&tcp_yeah);
+}
+
+module_init(tcp_yeah_register);
+module_exit(tcp_yeah_unregister);
+
+MODULE_AUTHOR("Angelo P. Castellani");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("YeAH TCP");