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sched: Struct definition and parsing of dualpi2 qdisc
DualPI2 is the reference implementation of IETF RFC9332 DualQ Coupled AQM (https://datatracker.ietf.org/doc/html/rfc9332) providing two queues called low latency (L-queue) and classic (C-queue). By default, it enqueues non-ECN and ECT(0) packets into the C-queue and ECT(1) and CE packets into the low latency queue (L-queue), as per IETF RFC9332 spec. This patch defines the dualpi2 Qdisc structure and parsing, and the following two patches include dumping and enqueue/dequeue for the DualPI2. Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com> Link: https://patch.msgid.link/20250722095915.24485-2-chia-yu.chang@nokia-bell-labs.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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@ -1211,4 +1211,57 @@ enum {
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#define TCA_ETS_MAX (__TCA_ETS_MAX - 1)
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/* DUALPI2 */
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enum tc_dualpi2_drop_overload {
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TC_DUALPI2_DROP_OVERLOAD_OVERFLOW = 0,
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TC_DUALPI2_DROP_OVERLOAD_DROP = 1,
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__TCA_DUALPI2_DROP_OVERLOAD_MAX,
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};
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#define TCA_DUALPI2_DROP_OVERLOAD_MAX (__TCA_DUALPI2_DROP_OVERLOAD_MAX - 1)
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enum tc_dualpi2_drop_early {
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TC_DUALPI2_DROP_EARLY_DROP_DEQUEUE = 0,
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TC_DUALPI2_DROP_EARLY_DROP_ENQUEUE = 1,
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__TCA_DUALPI2_DROP_EARLY_MAX,
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};
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#define TCA_DUALPI2_DROP_EARLY_MAX (__TCA_DUALPI2_DROP_EARLY_MAX - 1)
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enum tc_dualpi2_ecn_mask {
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TC_DUALPI2_ECN_MASK_L4S_ECT = 1,
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TC_DUALPI2_ECN_MASK_CLA_ECT = 2,
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TC_DUALPI2_ECN_MASK_ANY_ECT = 3,
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__TCA_DUALPI2_ECN_MASK_MAX,
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};
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#define TCA_DUALPI2_ECN_MASK_MAX (__TCA_DUALPI2_ECN_MASK_MAX - 1)
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enum tc_dualpi2_split_gso {
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TC_DUALPI2_SPLIT_GSO_NO_SPLIT_GSO = 0,
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TC_DUALPI2_SPLIT_GSO_SPLIT_GSO = 1,
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__TCA_DUALPI2_SPLIT_GSO_MAX,
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};
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#define TCA_DUALPI2_SPLIT_GSO_MAX (__TCA_DUALPI2_SPLIT_GSO_MAX - 1)
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enum {
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TCA_DUALPI2_UNSPEC,
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TCA_DUALPI2_LIMIT, /* Packets */
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TCA_DUALPI2_MEMORY_LIMIT, /* Bytes */
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TCA_DUALPI2_TARGET, /* us */
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TCA_DUALPI2_TUPDATE, /* us */
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TCA_DUALPI2_ALPHA, /* Hz scaled up by 256 */
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TCA_DUALPI2_BETA, /* Hz scaled up by 256 */
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TCA_DUALPI2_STEP_THRESH_PKTS, /* Step threshold in packets */
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TCA_DUALPI2_STEP_THRESH_US, /* Step threshold in microseconds */
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TCA_DUALPI2_MIN_QLEN_STEP, /* Minimum qlen to apply STEP_THRESH */
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TCA_DUALPI2_COUPLING, /* Coupling factor between queues */
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TCA_DUALPI2_DROP_OVERLOAD, /* Whether to drop on overload */
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TCA_DUALPI2_DROP_EARLY, /* Whether to drop on enqueue */
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TCA_DUALPI2_C_PROTECTION, /* Percentage */
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TCA_DUALPI2_ECN_MASK, /* L4S queue classification mask */
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TCA_DUALPI2_SPLIT_GSO, /* Split GSO packets at enqueue */
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TCA_DUALPI2_PAD,
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__TCA_DUALPI2_MAX
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};
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#define TCA_DUALPI2_MAX (__TCA_DUALPI2_MAX - 1)
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#endif
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net/sched/sch_dualpi2.c
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591
net/sched/sch_dualpi2.c
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@ -0,0 +1,591 @@
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// SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
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/* Copyright (C) 2024 Nokia
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*
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* Author: Koen De Schepper <koen.de_schepper@nokia-bell-labs.com>
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* Author: Olga Albisser <olga@albisser.org>
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* Author: Henrik Steen <henrist@henrist.net>
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* Author: Olivier Tilmans <olivier.tilmans@nokia.com>
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* Author: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com>
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*
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* DualPI Improved with a Square (dualpi2):
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* - Supports congestion controls that comply with the Prague requirements
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* in RFC9331 (e.g. TCP-Prague)
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* - Supports coupled dual-queue with PI2 as defined in RFC9332
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* - Supports ECN L4S-identifier (IP.ECN==0b*1)
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*
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* note: Although DCTCP and BBRv3 can use shallow-threshold ECN marks,
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* they do not meet the 'Prague L4S Requirements' listed in RFC 9331
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* Section 4, so they can only be used with DualPI2 in a datacenter
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* context.
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*
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* References:
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* - RFC9332: https://datatracker.ietf.org/doc/html/rfc9332
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* - De Schepper, Koen, et al. "PI 2: A linearized AQM for both classic and
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* scalable TCP." in proc. ACM CoNEXT'16, 2016.
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*/
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#include <linux/errno.h>
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#include <linux/hrtimer.h>
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#include <linux/if_vlan.h>
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#include <linux/kernel.h>
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#include <linux/limits.h>
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/types.h>
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#include <net/gso.h>
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#include <net/inet_ecn.h>
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#include <net/pkt_cls.h>
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#include <net/pkt_sched.h>
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/* 32b enable to support flows with windows up to ~8.6 * 1e9 packets
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* i.e., twice the maximal snd_cwnd.
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* MAX_PROB must be consistent with the RNG in dualpi2_roll().
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*/
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#define MAX_PROB U32_MAX
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/* alpha/beta values exchanged over netlink are in units of 256ns */
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#define ALPHA_BETA_SHIFT 8
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/* Scaled values of alpha/beta must fit in 32b to avoid overflow in later
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* computations. Consequently (see and dualpi2_scale_alpha_beta()), their
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* netlink-provided values can use at most 31b, i.e. be at most (2^23)-1
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* (~4MHz) as those are given in 1/256th. This enable to tune alpha/beta to
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* control flows whose maximal RTTs can be in usec up to few secs.
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*/
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#define ALPHA_BETA_MAX ((1U << 31) - 1)
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/* Internal alpha/beta are in units of 64ns.
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* This enables to use all alpha/beta values in the allowed range without loss
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* of precision due to rounding when scaling them internally, e.g.,
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* scale_alpha_beta(1) will not round down to 0.
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*/
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#define ALPHA_BETA_GRANULARITY 6
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#define ALPHA_BETA_SCALING (ALPHA_BETA_SHIFT - ALPHA_BETA_GRANULARITY)
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/* We express the weights (wc, wl) in %, i.e., wc + wl = 100 */
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#define MAX_WC 100
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struct dualpi2_sched_data {
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struct Qdisc *l_queue; /* The L4S Low latency queue (L-queue) */
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struct Qdisc *sch; /* The Classic queue (C-queue) */
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/* Registered tc filters */
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struct tcf_proto __rcu *tcf_filters;
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struct tcf_block *tcf_block;
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/* PI2 parameters */
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u64 pi2_target; /* Target delay in nanoseconds */
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u32 pi2_tupdate; /* Timer frequency in nanoseconds */
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u32 pi2_prob; /* Base PI probability */
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u32 pi2_alpha; /* Gain factor for the integral rate response */
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u32 pi2_beta; /* Gain factor for the proportional response */
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struct hrtimer pi2_timer; /* prob update timer */
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/* Step AQM (L-queue only) parameters */
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u32 step_thresh; /* Step threshold */
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bool step_in_packets; /* Step thresh in packets (1) or time (0) */
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/* C-queue starvation protection */
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s32 c_protection_credit; /* Credit (sign indicates which queue) */
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s32 c_protection_init; /* Reset value of the credit */
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u8 c_protection_wc; /* C-queue weight (between 0 and MAX_WC) */
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u8 c_protection_wl; /* L-queue weight (MAX_WC - wc) */
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/* General dualQ parameters */
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u32 memory_limit; /* Memory limit of both queues */
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u8 coupling_factor;/* Coupling factor (k) between both queues */
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u8 ecn_mask; /* Mask to match packets into L-queue */
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u32 min_qlen_step; /* Minimum queue length to apply step thresh */
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bool drop_early; /* Drop at enqueue (1) instead of dequeue (0) */
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bool drop_overload; /* Drop (1) on overload, or overflow (0) */
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bool split_gso; /* Split aggregated skb (1) or leave as is (0) */
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/* Statistics */
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u64 c_head_ts; /* Enqueue timestamp of the C-queue head */
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u64 l_head_ts; /* Enqueue timestamp of the L-queue head */
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u64 last_qdelay; /* Q delay val at the last probability update */
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u32 packets_in_c; /* Enqueue packet counter of the C-queue */
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u32 packets_in_l; /* Enqueue packet counter of the L-queue */
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u32 maxq; /* Maximum queue size of the C-queue */
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u32 ecn_mark; /* ECN mark pkt counter due to PI probability */
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u32 step_marks; /* ECN mark pkt counter due to step AQM */
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u32 memory_used; /* Memory used of both queues */
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u32 max_memory_used;/* Maximum used memory */
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};
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static u32 dualpi2_scale_alpha_beta(u32 param)
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{
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u64 tmp = ((u64)param * MAX_PROB >> ALPHA_BETA_SCALING);
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do_div(tmp, NSEC_PER_SEC);
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return tmp;
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}
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static ktime_t next_pi2_timeout(struct dualpi2_sched_data *q)
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{
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return ktime_add_ns(ktime_get_ns(), q->pi2_tupdate);
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}
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static void dualpi2_reset_c_protection(struct dualpi2_sched_data *q)
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{
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q->c_protection_credit = q->c_protection_init;
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}
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/* This computes the initial credit value and WRR weight for the L queue (wl)
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* from the weight of the C queue (wc).
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* If wl > wc, the scheduler will start with the L queue when reset.
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*/
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static void dualpi2_calculate_c_protection(struct Qdisc *sch,
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struct dualpi2_sched_data *q, u32 wc)
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{
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q->c_protection_wc = wc;
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q->c_protection_wl = MAX_WC - wc;
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q->c_protection_init = (s32)psched_mtu(qdisc_dev(sch)) *
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((int)q->c_protection_wc - (int)q->c_protection_wl);
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dualpi2_reset_c_protection(q);
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}
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static s64 __scale_delta(u64 diff)
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{
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do_div(diff, 1 << ALPHA_BETA_GRANULARITY);
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return diff;
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}
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static void get_queue_delays(struct dualpi2_sched_data *q, u64 *qdelay_c,
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u64 *qdelay_l)
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{
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u64 now, qc, ql;
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now = ktime_get_ns();
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qc = q->c_head_ts;
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ql = q->l_head_ts;
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*qdelay_c = qc ? now - qc : 0;
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*qdelay_l = ql ? now - ql : 0;
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}
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static u32 calculate_probability(struct Qdisc *sch)
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{
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struct dualpi2_sched_data *q = qdisc_priv(sch);
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u32 new_prob;
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u64 qdelay_c;
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u64 qdelay_l;
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u64 qdelay;
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s64 delta;
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get_queue_delays(q, &qdelay_c, &qdelay_l);
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qdelay = max(qdelay_l, qdelay_c);
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/* Alpha and beta take at most 32b, i.e, the delay difference would
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* overflow for queuing delay differences > ~4.2sec.
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*/
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delta = ((s64)qdelay - (s64)q->pi2_target) * q->pi2_alpha;
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delta += ((s64)qdelay - (s64)q->last_qdelay) * q->pi2_beta;
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q->last_qdelay = qdelay;
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/* Bound new_prob between 0 and MAX_PROB */
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if (delta > 0) {
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new_prob = __scale_delta(delta) + q->pi2_prob;
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if (new_prob < q->pi2_prob)
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new_prob = MAX_PROB;
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} else {
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new_prob = q->pi2_prob - __scale_delta(~delta + 1);
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if (new_prob > q->pi2_prob)
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new_prob = 0;
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}
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/* If we do not drop on overload, ensure we cap the L4S probability to
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* 100% to keep window fairness when overflowing.
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*/
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if (!q->drop_overload)
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return min_t(u32, new_prob, MAX_PROB / q->coupling_factor);
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return new_prob;
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}
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static u32 get_memory_limit(struct Qdisc *sch, u32 limit)
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{
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/* Apply rule of thumb, i.e., doubling the packet length,
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* to further include per packet overhead in memory_limit.
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*/
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u64 memlim = mul_u32_u32(limit, 2 * psched_mtu(qdisc_dev(sch)));
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if (upper_32_bits(memlim))
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return U32_MAX;
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else
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return lower_32_bits(memlim);
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}
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static u32 convert_us_to_nsec(u32 us)
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{
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u64 ns = mul_u32_u32(us, NSEC_PER_USEC);
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if (upper_32_bits(ns))
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return U32_MAX;
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return lower_32_bits(ns);
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}
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static enum hrtimer_restart dualpi2_timer(struct hrtimer *timer)
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{
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struct dualpi2_sched_data *q = timer_container_of(q, timer, pi2_timer);
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struct Qdisc *sch = q->sch;
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spinlock_t *root_lock; /* to lock qdisc for probability calculations */
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rcu_read_lock();
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root_lock = qdisc_lock(qdisc_root_sleeping(sch));
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spin_lock(root_lock);
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q->pi2_prob = calculate_probability(sch);
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hrtimer_set_expires(&q->pi2_timer, next_pi2_timeout(q));
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spin_unlock(root_lock);
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rcu_read_unlock();
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return HRTIMER_RESTART;
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}
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static struct netlink_range_validation dualpi2_alpha_beta_range = {
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.min = 1,
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.max = ALPHA_BETA_MAX,
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};
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static const struct nla_policy dualpi2_policy[TCA_DUALPI2_MAX + 1] = {
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[TCA_DUALPI2_LIMIT] = NLA_POLICY_MIN(NLA_U32, 1),
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[TCA_DUALPI2_MEMORY_LIMIT] = NLA_POLICY_MIN(NLA_U32, 1),
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[TCA_DUALPI2_TARGET] = { .type = NLA_U32 },
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[TCA_DUALPI2_TUPDATE] = NLA_POLICY_MIN(NLA_U32, 1),
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[TCA_DUALPI2_ALPHA] =
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NLA_POLICY_FULL_RANGE(NLA_U32, &dualpi2_alpha_beta_range),
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[TCA_DUALPI2_BETA] =
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NLA_POLICY_FULL_RANGE(NLA_U32, &dualpi2_alpha_beta_range),
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[TCA_DUALPI2_STEP_THRESH_PKTS] = { .type = NLA_U32 },
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[TCA_DUALPI2_STEP_THRESH_US] = { .type = NLA_U32 },
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[TCA_DUALPI2_MIN_QLEN_STEP] = { .type = NLA_U32 },
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[TCA_DUALPI2_COUPLING] = NLA_POLICY_MIN(NLA_U8, 1),
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[TCA_DUALPI2_DROP_OVERLOAD] =
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NLA_POLICY_MAX(NLA_U8, TCA_DUALPI2_DROP_OVERLOAD_MAX),
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[TCA_DUALPI2_DROP_EARLY] =
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NLA_POLICY_MAX(NLA_U8, TCA_DUALPI2_DROP_EARLY_MAX),
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[TCA_DUALPI2_C_PROTECTION] =
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NLA_POLICY_RANGE(NLA_U8, 0, MAX_WC),
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[TCA_DUALPI2_ECN_MASK] =
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NLA_POLICY_RANGE(NLA_U8, TC_DUALPI2_ECN_MASK_L4S_ECT,
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TCA_DUALPI2_ECN_MASK_MAX),
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[TCA_DUALPI2_SPLIT_GSO] =
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NLA_POLICY_MAX(NLA_U8, TCA_DUALPI2_SPLIT_GSO_MAX),
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};
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static int dualpi2_change(struct Qdisc *sch, struct nlattr *opt,
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struct netlink_ext_ack *extack)
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{
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struct nlattr *tb[TCA_DUALPI2_MAX + 1];
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struct dualpi2_sched_data *q;
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int old_backlog;
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int old_qlen;
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int err;
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if (!opt || !nla_len(opt)) {
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NL_SET_ERR_MSG_MOD(extack, "Dualpi2 options are required");
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return -EINVAL;
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}
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err = nla_parse_nested(tb, TCA_DUALPI2_MAX, opt, dualpi2_policy,
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extack);
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if (err < 0)
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return err;
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if (tb[TCA_DUALPI2_STEP_THRESH_PKTS] && tb[TCA_DUALPI2_STEP_THRESH_US]) {
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NL_SET_ERR_MSG_MOD(extack, "multiple step thresh attributes");
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return -EINVAL;
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}
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q = qdisc_priv(sch);
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sch_tree_lock(sch);
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if (tb[TCA_DUALPI2_LIMIT]) {
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u32 limit = nla_get_u32(tb[TCA_DUALPI2_LIMIT]);
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sch->limit = limit;
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q->memory_limit = get_memory_limit(sch, limit);
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}
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if (tb[TCA_DUALPI2_MEMORY_LIMIT])
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q->memory_limit = nla_get_u32(tb[TCA_DUALPI2_MEMORY_LIMIT]);
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if (tb[TCA_DUALPI2_TARGET]) {
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u64 target = nla_get_u32(tb[TCA_DUALPI2_TARGET]);
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|
||||
q->pi2_target = target * NSEC_PER_USEC;
|
||||
}
|
||||
|
||||
if (tb[TCA_DUALPI2_TUPDATE]) {
|
||||
u64 tupdate = nla_get_u32(tb[TCA_DUALPI2_TUPDATE]);
|
||||
|
||||
q->pi2_tupdate = convert_us_to_nsec(tupdate);
|
||||
}
|
||||
|
||||
if (tb[TCA_DUALPI2_ALPHA]) {
|
||||
u32 alpha = nla_get_u32(tb[TCA_DUALPI2_ALPHA]);
|
||||
|
||||
q->pi2_alpha = dualpi2_scale_alpha_beta(alpha);
|
||||
}
|
||||
|
||||
if (tb[TCA_DUALPI2_BETA]) {
|
||||
u32 beta = nla_get_u32(tb[TCA_DUALPI2_BETA]);
|
||||
|
||||
q->pi2_beta = dualpi2_scale_alpha_beta(beta);
|
||||
}
|
||||
|
||||
if (tb[TCA_DUALPI2_STEP_THRESH_PKTS]) {
|
||||
u32 step_th = nla_get_u32(tb[TCA_DUALPI2_STEP_THRESH_PKTS]);
|
||||
|
||||
q->step_in_packets = true;
|
||||
q->step_thresh = step_th;
|
||||
} else if (tb[TCA_DUALPI2_STEP_THRESH_US]) {
|
||||
u32 step_th = nla_get_u32(tb[TCA_DUALPI2_STEP_THRESH_US]);
|
||||
|
||||
q->step_in_packets = false;
|
||||
q->step_thresh = convert_us_to_nsec(step_th);
|
||||
}
|
||||
|
||||
if (tb[TCA_DUALPI2_MIN_QLEN_STEP])
|
||||
q->min_qlen_step = nla_get_u32(tb[TCA_DUALPI2_MIN_QLEN_STEP]);
|
||||
|
||||
if (tb[TCA_DUALPI2_COUPLING]) {
|
||||
u8 coupling = nla_get_u8(tb[TCA_DUALPI2_COUPLING]);
|
||||
|
||||
q->coupling_factor = coupling;
|
||||
}
|
||||
|
||||
if (tb[TCA_DUALPI2_DROP_OVERLOAD]) {
|
||||
u8 drop_overload = nla_get_u8(tb[TCA_DUALPI2_DROP_OVERLOAD]);
|
||||
|
||||
q->drop_overload = (bool)drop_overload;
|
||||
}
|
||||
|
||||
if (tb[TCA_DUALPI2_DROP_EARLY]) {
|
||||
u8 drop_early = nla_get_u8(tb[TCA_DUALPI2_DROP_EARLY]);
|
||||
|
||||
q->drop_early = (bool)drop_early;
|
||||
}
|
||||
|
||||
if (tb[TCA_DUALPI2_C_PROTECTION]) {
|
||||
u8 wc = nla_get_u8(tb[TCA_DUALPI2_C_PROTECTION]);
|
||||
|
||||
dualpi2_calculate_c_protection(sch, q, wc);
|
||||
}
|
||||
|
||||
if (tb[TCA_DUALPI2_ECN_MASK]) {
|
||||
u8 ecn_mask = nla_get_u8(tb[TCA_DUALPI2_ECN_MASK]);
|
||||
|
||||
q->ecn_mask = ecn_mask;
|
||||
}
|
||||
|
||||
if (tb[TCA_DUALPI2_SPLIT_GSO]) {
|
||||
u8 split_gso = nla_get_u8(tb[TCA_DUALPI2_SPLIT_GSO]);
|
||||
|
||||
q->split_gso = (bool)split_gso;
|
||||
}
|
||||
|
||||
old_qlen = qdisc_qlen(sch);
|
||||
old_backlog = sch->qstats.backlog;
|
||||
while (qdisc_qlen(sch) > sch->limit ||
|
||||
q->memory_used > q->memory_limit) {
|
||||
struct sk_buff *skb = qdisc_dequeue_internal(sch, true);
|
||||
|
||||
q->memory_used -= skb->truesize;
|
||||
qdisc_qstats_backlog_dec(sch, skb);
|
||||
rtnl_qdisc_drop(skb, sch);
|
||||
}
|
||||
qdisc_tree_reduce_backlog(sch, old_qlen - qdisc_qlen(sch),
|
||||
old_backlog - sch->qstats.backlog);
|
||||
|
||||
sch_tree_unlock(sch);
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* Default alpha/beta values give a 10dB stability margin with max_rtt=100ms. */
|
||||
static void dualpi2_reset_default(struct Qdisc *sch)
|
||||
{
|
||||
struct dualpi2_sched_data *q = qdisc_priv(sch);
|
||||
|
||||
q->sch->limit = 10000; /* Max 125ms at 1Gbps */
|
||||
q->memory_limit = get_memory_limit(sch, q->sch->limit);
|
||||
|
||||
q->pi2_target = 15 * NSEC_PER_MSEC;
|
||||
q->pi2_tupdate = 16 * NSEC_PER_MSEC;
|
||||
q->pi2_alpha = dualpi2_scale_alpha_beta(41); /* ~0.16 Hz * 256 */
|
||||
q->pi2_beta = dualpi2_scale_alpha_beta(819); /* ~3.20 Hz * 256 */
|
||||
|
||||
q->step_thresh = 1 * NSEC_PER_MSEC;
|
||||
q->step_in_packets = false;
|
||||
|
||||
dualpi2_calculate_c_protection(q->sch, q, 10); /* wc=10%, wl=90% */
|
||||
|
||||
q->ecn_mask = TC_DUALPI2_ECN_MASK_L4S_ECT; /* INET_ECN_ECT_1 */
|
||||
q->min_qlen_step = 0; /* Always apply step mark in L-queue */
|
||||
q->coupling_factor = 2; /* window fairness for equal RTTs */
|
||||
q->drop_overload = TC_DUALPI2_DROP_OVERLOAD_DROP; /* Drop overload */
|
||||
q->drop_early = TC_DUALPI2_DROP_EARLY_DROP_DEQUEUE; /* Drop dequeue */
|
||||
q->split_gso = TC_DUALPI2_SPLIT_GSO_SPLIT_GSO; /* Split GSO */
|
||||
}
|
||||
|
||||
static int dualpi2_init(struct Qdisc *sch, struct nlattr *opt,
|
||||
struct netlink_ext_ack *extack)
|
||||
{
|
||||
struct dualpi2_sched_data *q = qdisc_priv(sch);
|
||||
int err;
|
||||
|
||||
q->l_queue = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
|
||||
TC_H_MAKE(sch->handle, 1), extack);
|
||||
if (!q->l_queue)
|
||||
return -ENOMEM;
|
||||
|
||||
err = tcf_block_get(&q->tcf_block, &q->tcf_filters, sch, extack);
|
||||
if (err)
|
||||
return err;
|
||||
|
||||
q->sch = sch;
|
||||
dualpi2_reset_default(sch);
|
||||
hrtimer_setup(&q->pi2_timer, dualpi2_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
|
||||
|
||||
if (opt && nla_len(opt)) {
|
||||
err = dualpi2_change(sch, opt, extack);
|
||||
|
||||
if (err)
|
||||
return err;
|
||||
}
|
||||
|
||||
hrtimer_start(&q->pi2_timer, next_pi2_timeout(q),
|
||||
HRTIMER_MODE_ABS_PINNED);
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* Reset both L-queue and C-queue, internal packet counters, PI probability,
|
||||
* C-queue protection credit, and timestamps, while preserving current
|
||||
* configuration of DUALPI2.
|
||||
*/
|
||||
static void dualpi2_reset(struct Qdisc *sch)
|
||||
{
|
||||
struct dualpi2_sched_data *q = qdisc_priv(sch);
|
||||
|
||||
qdisc_reset_queue(sch);
|
||||
qdisc_reset_queue(q->l_queue);
|
||||
q->c_head_ts = 0;
|
||||
q->l_head_ts = 0;
|
||||
q->pi2_prob = 0;
|
||||
q->packets_in_c = 0;
|
||||
q->packets_in_l = 0;
|
||||
q->maxq = 0;
|
||||
q->ecn_mark = 0;
|
||||
q->step_marks = 0;
|
||||
q->memory_used = 0;
|
||||
q->max_memory_used = 0;
|
||||
dualpi2_reset_c_protection(q);
|
||||
}
|
||||
|
||||
static void dualpi2_destroy(struct Qdisc *sch)
|
||||
{
|
||||
struct dualpi2_sched_data *q = qdisc_priv(sch);
|
||||
|
||||
q->pi2_tupdate = 0;
|
||||
hrtimer_cancel(&q->pi2_timer);
|
||||
if (q->l_queue)
|
||||
qdisc_put(q->l_queue);
|
||||
tcf_block_put(q->tcf_block);
|
||||
}
|
||||
|
||||
static struct Qdisc *dualpi2_leaf(struct Qdisc *sch, unsigned long arg)
|
||||
{
|
||||
return NULL;
|
||||
}
|
||||
|
||||
static unsigned long dualpi2_find(struct Qdisc *sch, u32 classid)
|
||||
{
|
||||
return 0;
|
||||
}
|
||||
|
||||
static unsigned long dualpi2_bind(struct Qdisc *sch, unsigned long parent,
|
||||
u32 classid)
|
||||
{
|
||||
return 0;
|
||||
}
|
||||
|
||||
static void dualpi2_unbind(struct Qdisc *q, unsigned long cl)
|
||||
{
|
||||
}
|
||||
|
||||
static struct tcf_block *dualpi2_tcf_block(struct Qdisc *sch, unsigned long cl,
|
||||
struct netlink_ext_ack *extack)
|
||||
{
|
||||
struct dualpi2_sched_data *q = qdisc_priv(sch);
|
||||
|
||||
if (cl)
|
||||
return NULL;
|
||||
return q->tcf_block;
|
||||
}
|
||||
|
||||
static void dualpi2_walk(struct Qdisc *sch, struct qdisc_walker *arg)
|
||||
{
|
||||
unsigned int i;
|
||||
|
||||
if (arg->stop)
|
||||
return;
|
||||
|
||||
/* We statically define only 2 queues */
|
||||
for (i = 0; i < 2; i++) {
|
||||
if (arg->count < arg->skip) {
|
||||
arg->count++;
|
||||
continue;
|
||||
}
|
||||
if (arg->fn(sch, i + 1, arg) < 0) {
|
||||
arg->stop = 1;
|
||||
break;
|
||||
}
|
||||
arg->count++;
|
||||
}
|
||||
}
|
||||
|
||||
/* Minimal class support to handle tc filters */
|
||||
static const struct Qdisc_class_ops dualpi2_class_ops = {
|
||||
.leaf = dualpi2_leaf,
|
||||
.find = dualpi2_find,
|
||||
.tcf_block = dualpi2_tcf_block,
|
||||
.bind_tcf = dualpi2_bind,
|
||||
.unbind_tcf = dualpi2_unbind,
|
||||
.walk = dualpi2_walk,
|
||||
};
|
||||
|
||||
static struct Qdisc_ops dualpi2_qdisc_ops __read_mostly = {
|
||||
.id = "dualpi2",
|
||||
.cl_ops = &dualpi2_class_ops,
|
||||
.priv_size = sizeof(struct dualpi2_sched_data),
|
||||
.peek = qdisc_peek_dequeued,
|
||||
.init = dualpi2_init,
|
||||
.destroy = dualpi2_destroy,
|
||||
.reset = dualpi2_reset,
|
||||
.change = dualpi2_change,
|
||||
.owner = THIS_MODULE,
|
||||
};
|
||||
|
||||
static int __init dualpi2_module_init(void)
|
||||
{
|
||||
return register_qdisc(&dualpi2_qdisc_ops);
|
||||
}
|
||||
|
||||
static void __exit dualpi2_module_exit(void)
|
||||
{
|
||||
unregister_qdisc(&dualpi2_qdisc_ops);
|
||||
}
|
||||
|
||||
module_init(dualpi2_module_init);
|
||||
module_exit(dualpi2_module_exit);
|
||||
|
||||
MODULE_DESCRIPTION("Dual Queue with Proportional Integral controller Improved with a Square (dualpi2) scheduler");
|
||||
MODULE_AUTHOR("Koen De Schepper <koen.de_schepper@nokia-bell-labs.com>");
|
||||
MODULE_AUTHOR("Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com>");
|
||||
MODULE_AUTHOR("Olga Albisser <olga@albisser.org>");
|
||||
MODULE_AUTHOR("Henrik Steen <henrist@henrist.net>");
|
||||
MODULE_AUTHOR("Olivier Tilmans <olivier.tilmans@nokia.com>");
|
||||
|
||||
MODULE_LICENSE("Dual BSD/GPL");
|
||||
MODULE_VERSION("1.0");
|
Loading…
Reference in New Issue
Block a user