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mirror of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-09-04 20:19:47 +08:00

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>
This commit is contained in:
Chia-Yu Chang 2025-07-22 11:59:10 +02:00 committed by Jakub Kicinski
parent 1cdf3f2d8f
commit 320d031ad6
2 changed files with 644 additions and 0 deletions

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@ -1211,4 +1211,57 @@ enum {
#define TCA_ETS_MAX (__TCA_ETS_MAX - 1)
/* DUALPI2 */
enum tc_dualpi2_drop_overload {
TC_DUALPI2_DROP_OVERLOAD_OVERFLOW = 0,
TC_DUALPI2_DROP_OVERLOAD_DROP = 1,
__TCA_DUALPI2_DROP_OVERLOAD_MAX,
};
#define TCA_DUALPI2_DROP_OVERLOAD_MAX (__TCA_DUALPI2_DROP_OVERLOAD_MAX - 1)
enum tc_dualpi2_drop_early {
TC_DUALPI2_DROP_EARLY_DROP_DEQUEUE = 0,
TC_DUALPI2_DROP_EARLY_DROP_ENQUEUE = 1,
__TCA_DUALPI2_DROP_EARLY_MAX,
};
#define TCA_DUALPI2_DROP_EARLY_MAX (__TCA_DUALPI2_DROP_EARLY_MAX - 1)
enum tc_dualpi2_ecn_mask {
TC_DUALPI2_ECN_MASK_L4S_ECT = 1,
TC_DUALPI2_ECN_MASK_CLA_ECT = 2,
TC_DUALPI2_ECN_MASK_ANY_ECT = 3,
__TCA_DUALPI2_ECN_MASK_MAX,
};
#define TCA_DUALPI2_ECN_MASK_MAX (__TCA_DUALPI2_ECN_MASK_MAX - 1)
enum tc_dualpi2_split_gso {
TC_DUALPI2_SPLIT_GSO_NO_SPLIT_GSO = 0,
TC_DUALPI2_SPLIT_GSO_SPLIT_GSO = 1,
__TCA_DUALPI2_SPLIT_GSO_MAX,
};
#define TCA_DUALPI2_SPLIT_GSO_MAX (__TCA_DUALPI2_SPLIT_GSO_MAX - 1)
enum {
TCA_DUALPI2_UNSPEC,
TCA_DUALPI2_LIMIT, /* Packets */
TCA_DUALPI2_MEMORY_LIMIT, /* Bytes */
TCA_DUALPI2_TARGET, /* us */
TCA_DUALPI2_TUPDATE, /* us */
TCA_DUALPI2_ALPHA, /* Hz scaled up by 256 */
TCA_DUALPI2_BETA, /* Hz scaled up by 256 */
TCA_DUALPI2_STEP_THRESH_PKTS, /* Step threshold in packets */
TCA_DUALPI2_STEP_THRESH_US, /* Step threshold in microseconds */
TCA_DUALPI2_MIN_QLEN_STEP, /* Minimum qlen to apply STEP_THRESH */
TCA_DUALPI2_COUPLING, /* Coupling factor between queues */
TCA_DUALPI2_DROP_OVERLOAD, /* Whether to drop on overload */
TCA_DUALPI2_DROP_EARLY, /* Whether to drop on enqueue */
TCA_DUALPI2_C_PROTECTION, /* Percentage */
TCA_DUALPI2_ECN_MASK, /* L4S queue classification mask */
TCA_DUALPI2_SPLIT_GSO, /* Split GSO packets at enqueue */
TCA_DUALPI2_PAD,
__TCA_DUALPI2_MAX
};
#define TCA_DUALPI2_MAX (__TCA_DUALPI2_MAX - 1)
#endif

591
net/sched/sch_dualpi2.c Normal file
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@ -0,0 +1,591 @@
// SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
/* Copyright (C) 2024 Nokia
*
* Author: Koen De Schepper <koen.de_schepper@nokia-bell-labs.com>
* Author: Olga Albisser <olga@albisser.org>
* Author: Henrik Steen <henrist@henrist.net>
* Author: Olivier Tilmans <olivier.tilmans@nokia.com>
* Author: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com>
*
* DualPI Improved with a Square (dualpi2):
* - Supports congestion controls that comply with the Prague requirements
* in RFC9331 (e.g. TCP-Prague)
* - Supports coupled dual-queue with PI2 as defined in RFC9332
* - Supports ECN L4S-identifier (IP.ECN==0b*1)
*
* note: Although DCTCP and BBRv3 can use shallow-threshold ECN marks,
* they do not meet the 'Prague L4S Requirements' listed in RFC 9331
* Section 4, so they can only be used with DualPI2 in a datacenter
* context.
*
* References:
* - RFC9332: https://datatracker.ietf.org/doc/html/rfc9332
* - De Schepper, Koen, et al. "PI 2: A linearized AQM for both classic and
* scalable TCP." in proc. ACM CoNEXT'16, 2016.
*/
#include <linux/errno.h>
#include <linux/hrtimer.h>
#include <linux/if_vlan.h>
#include <linux/kernel.h>
#include <linux/limits.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/types.h>
#include <net/gso.h>
#include <net/inet_ecn.h>
#include <net/pkt_cls.h>
#include <net/pkt_sched.h>
/* 32b enable to support flows with windows up to ~8.6 * 1e9 packets
* i.e., twice the maximal snd_cwnd.
* MAX_PROB must be consistent with the RNG in dualpi2_roll().
*/
#define MAX_PROB U32_MAX
/* alpha/beta values exchanged over netlink are in units of 256ns */
#define ALPHA_BETA_SHIFT 8
/* Scaled values of alpha/beta must fit in 32b to avoid overflow in later
* computations. Consequently (see and dualpi2_scale_alpha_beta()), their
* netlink-provided values can use at most 31b, i.e. be at most (2^23)-1
* (~4MHz) as those are given in 1/256th. This enable to tune alpha/beta to
* control flows whose maximal RTTs can be in usec up to few secs.
*/
#define ALPHA_BETA_MAX ((1U << 31) - 1)
/* Internal alpha/beta are in units of 64ns.
* This enables to use all alpha/beta values in the allowed range without loss
* of precision due to rounding when scaling them internally, e.g.,
* scale_alpha_beta(1) will not round down to 0.
*/
#define ALPHA_BETA_GRANULARITY 6
#define ALPHA_BETA_SCALING (ALPHA_BETA_SHIFT - ALPHA_BETA_GRANULARITY)
/* We express the weights (wc, wl) in %, i.e., wc + wl = 100 */
#define MAX_WC 100
struct dualpi2_sched_data {
struct Qdisc *l_queue; /* The L4S Low latency queue (L-queue) */
struct Qdisc *sch; /* The Classic queue (C-queue) */
/* Registered tc filters */
struct tcf_proto __rcu *tcf_filters;
struct tcf_block *tcf_block;
/* PI2 parameters */
u64 pi2_target; /* Target delay in nanoseconds */
u32 pi2_tupdate; /* Timer frequency in nanoseconds */
u32 pi2_prob; /* Base PI probability */
u32 pi2_alpha; /* Gain factor for the integral rate response */
u32 pi2_beta; /* Gain factor for the proportional response */
struct hrtimer pi2_timer; /* prob update timer */
/* Step AQM (L-queue only) parameters */
u32 step_thresh; /* Step threshold */
bool step_in_packets; /* Step thresh in packets (1) or time (0) */
/* C-queue starvation protection */
s32 c_protection_credit; /* Credit (sign indicates which queue) */
s32 c_protection_init; /* Reset value of the credit */
u8 c_protection_wc; /* C-queue weight (between 0 and MAX_WC) */
u8 c_protection_wl; /* L-queue weight (MAX_WC - wc) */
/* General dualQ parameters */
u32 memory_limit; /* Memory limit of both queues */
u8 coupling_factor;/* Coupling factor (k) between both queues */
u8 ecn_mask; /* Mask to match packets into L-queue */
u32 min_qlen_step; /* Minimum queue length to apply step thresh */
bool drop_early; /* Drop at enqueue (1) instead of dequeue (0) */
bool drop_overload; /* Drop (1) on overload, or overflow (0) */
bool split_gso; /* Split aggregated skb (1) or leave as is (0) */
/* Statistics */
u64 c_head_ts; /* Enqueue timestamp of the C-queue head */
u64 l_head_ts; /* Enqueue timestamp of the L-queue head */
u64 last_qdelay; /* Q delay val at the last probability update */
u32 packets_in_c; /* Enqueue packet counter of the C-queue */
u32 packets_in_l; /* Enqueue packet counter of the L-queue */
u32 maxq; /* Maximum queue size of the C-queue */
u32 ecn_mark; /* ECN mark pkt counter due to PI probability */
u32 step_marks; /* ECN mark pkt counter due to step AQM */
u32 memory_used; /* Memory used of both queues */
u32 max_memory_used;/* Maximum used memory */
};
static u32 dualpi2_scale_alpha_beta(u32 param)
{
u64 tmp = ((u64)param * MAX_PROB >> ALPHA_BETA_SCALING);
do_div(tmp, NSEC_PER_SEC);
return tmp;
}
static ktime_t next_pi2_timeout(struct dualpi2_sched_data *q)
{
return ktime_add_ns(ktime_get_ns(), q->pi2_tupdate);
}
static void dualpi2_reset_c_protection(struct dualpi2_sched_data *q)
{
q->c_protection_credit = q->c_protection_init;
}
/* This computes the initial credit value and WRR weight for the L queue (wl)
* from the weight of the C queue (wc).
* If wl > wc, the scheduler will start with the L queue when reset.
*/
static void dualpi2_calculate_c_protection(struct Qdisc *sch,
struct dualpi2_sched_data *q, u32 wc)
{
q->c_protection_wc = wc;
q->c_protection_wl = MAX_WC - wc;
q->c_protection_init = (s32)psched_mtu(qdisc_dev(sch)) *
((int)q->c_protection_wc - (int)q->c_protection_wl);
dualpi2_reset_c_protection(q);
}
static s64 __scale_delta(u64 diff)
{
do_div(diff, 1 << ALPHA_BETA_GRANULARITY);
return diff;
}
static void get_queue_delays(struct dualpi2_sched_data *q, u64 *qdelay_c,
u64 *qdelay_l)
{
u64 now, qc, ql;
now = ktime_get_ns();
qc = q->c_head_ts;
ql = q->l_head_ts;
*qdelay_c = qc ? now - qc : 0;
*qdelay_l = ql ? now - ql : 0;
}
static u32 calculate_probability(struct Qdisc *sch)
{
struct dualpi2_sched_data *q = qdisc_priv(sch);
u32 new_prob;
u64 qdelay_c;
u64 qdelay_l;
u64 qdelay;
s64 delta;
get_queue_delays(q, &qdelay_c, &qdelay_l);
qdelay = max(qdelay_l, qdelay_c);
/* Alpha and beta take at most 32b, i.e, the delay difference would
* overflow for queuing delay differences > ~4.2sec.
*/
delta = ((s64)qdelay - (s64)q->pi2_target) * q->pi2_alpha;
delta += ((s64)qdelay - (s64)q->last_qdelay) * q->pi2_beta;
q->last_qdelay = qdelay;
/* Bound new_prob between 0 and MAX_PROB */
if (delta > 0) {
new_prob = __scale_delta(delta) + q->pi2_prob;
if (new_prob < q->pi2_prob)
new_prob = MAX_PROB;
} else {
new_prob = q->pi2_prob - __scale_delta(~delta + 1);
if (new_prob > q->pi2_prob)
new_prob = 0;
}
/* If we do not drop on overload, ensure we cap the L4S probability to
* 100% to keep window fairness when overflowing.
*/
if (!q->drop_overload)
return min_t(u32, new_prob, MAX_PROB / q->coupling_factor);
return new_prob;
}
static u32 get_memory_limit(struct Qdisc *sch, u32 limit)
{
/* Apply rule of thumb, i.e., doubling the packet length,
* to further include per packet overhead in memory_limit.
*/
u64 memlim = mul_u32_u32(limit, 2 * psched_mtu(qdisc_dev(sch)));
if (upper_32_bits(memlim))
return U32_MAX;
else
return lower_32_bits(memlim);
}
static u32 convert_us_to_nsec(u32 us)
{
u64 ns = mul_u32_u32(us, NSEC_PER_USEC);
if (upper_32_bits(ns))
return U32_MAX;
return lower_32_bits(ns);
}
static enum hrtimer_restart dualpi2_timer(struct hrtimer *timer)
{
struct dualpi2_sched_data *q = timer_container_of(q, timer, pi2_timer);
struct Qdisc *sch = q->sch;
spinlock_t *root_lock; /* to lock qdisc for probability calculations */
rcu_read_lock();
root_lock = qdisc_lock(qdisc_root_sleeping(sch));
spin_lock(root_lock);
q->pi2_prob = calculate_probability(sch);
hrtimer_set_expires(&q->pi2_timer, next_pi2_timeout(q));
spin_unlock(root_lock);
rcu_read_unlock();
return HRTIMER_RESTART;
}
static struct netlink_range_validation dualpi2_alpha_beta_range = {
.min = 1,
.max = ALPHA_BETA_MAX,
};
static const struct nla_policy dualpi2_policy[TCA_DUALPI2_MAX + 1] = {
[TCA_DUALPI2_LIMIT] = NLA_POLICY_MIN(NLA_U32, 1),
[TCA_DUALPI2_MEMORY_LIMIT] = NLA_POLICY_MIN(NLA_U32, 1),
[TCA_DUALPI2_TARGET] = { .type = NLA_U32 },
[TCA_DUALPI2_TUPDATE] = NLA_POLICY_MIN(NLA_U32, 1),
[TCA_DUALPI2_ALPHA] =
NLA_POLICY_FULL_RANGE(NLA_U32, &dualpi2_alpha_beta_range),
[TCA_DUALPI2_BETA] =
NLA_POLICY_FULL_RANGE(NLA_U32, &dualpi2_alpha_beta_range),
[TCA_DUALPI2_STEP_THRESH_PKTS] = { .type = NLA_U32 },
[TCA_DUALPI2_STEP_THRESH_US] = { .type = NLA_U32 },
[TCA_DUALPI2_MIN_QLEN_STEP] = { .type = NLA_U32 },
[TCA_DUALPI2_COUPLING] = NLA_POLICY_MIN(NLA_U8, 1),
[TCA_DUALPI2_DROP_OVERLOAD] =
NLA_POLICY_MAX(NLA_U8, TCA_DUALPI2_DROP_OVERLOAD_MAX),
[TCA_DUALPI2_DROP_EARLY] =
NLA_POLICY_MAX(NLA_U8, TCA_DUALPI2_DROP_EARLY_MAX),
[TCA_DUALPI2_C_PROTECTION] =
NLA_POLICY_RANGE(NLA_U8, 0, MAX_WC),
[TCA_DUALPI2_ECN_MASK] =
NLA_POLICY_RANGE(NLA_U8, TC_DUALPI2_ECN_MASK_L4S_ECT,
TCA_DUALPI2_ECN_MASK_MAX),
[TCA_DUALPI2_SPLIT_GSO] =
NLA_POLICY_MAX(NLA_U8, TCA_DUALPI2_SPLIT_GSO_MAX),
};
static int dualpi2_change(struct Qdisc *sch, struct nlattr *opt,
struct netlink_ext_ack *extack)
{
struct nlattr *tb[TCA_DUALPI2_MAX + 1];
struct dualpi2_sched_data *q;
int old_backlog;
int old_qlen;
int err;
if (!opt || !nla_len(opt)) {
NL_SET_ERR_MSG_MOD(extack, "Dualpi2 options are required");
return -EINVAL;
}
err = nla_parse_nested(tb, TCA_DUALPI2_MAX, opt, dualpi2_policy,
extack);
if (err < 0)
return err;
if (tb[TCA_DUALPI2_STEP_THRESH_PKTS] && tb[TCA_DUALPI2_STEP_THRESH_US]) {
NL_SET_ERR_MSG_MOD(extack, "multiple step thresh attributes");
return -EINVAL;
}
q = qdisc_priv(sch);
sch_tree_lock(sch);
if (tb[TCA_DUALPI2_LIMIT]) {
u32 limit = nla_get_u32(tb[TCA_DUALPI2_LIMIT]);
sch->limit = limit;
q->memory_limit = get_memory_limit(sch, limit);
}
if (tb[TCA_DUALPI2_MEMORY_LIMIT])
q->memory_limit = nla_get_u32(tb[TCA_DUALPI2_MEMORY_LIMIT]);
if (tb[TCA_DUALPI2_TARGET]) {
u64 target = nla_get_u32(tb[TCA_DUALPI2_TARGET]);
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");