mirror of https://gitee.com/openkylin/linux.git
667 lines
18 KiB
C
667 lines
18 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/* Copyright (C) 2013 Cisco Systems, Inc, 2013.
|
|
*
|
|
* Author: Vijay Subramanian <vijaynsu@cisco.com>
|
|
* Author: Mythili Prabhu <mysuryan@cisco.com>
|
|
*
|
|
* ECN support is added by Naeem Khademi <naeemk@ifi.uio.no>
|
|
* University of Oslo, Norway.
|
|
*
|
|
* References:
|
|
* RFC 8033: https://tools.ietf.org/html/rfc8033
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/types.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/skbuff.h>
|
|
#include <net/pkt_sched.h>
|
|
#include <net/inet_ecn.h>
|
|
|
|
#define QUEUE_THRESHOLD 16384
|
|
#define DQCOUNT_INVALID -1
|
|
#define DTIME_INVALID 0xffffffffffffffff
|
|
#define MAX_PROB 0xffffffffffffffff
|
|
#define PIE_SCALE 8
|
|
|
|
/* parameters used */
|
|
struct pie_params {
|
|
psched_time_t target; /* user specified target delay in pschedtime */
|
|
u32 tupdate; /* timer frequency (in jiffies) */
|
|
u32 limit; /* number of packets that can be enqueued */
|
|
u32 alpha; /* alpha and beta are between 0 and 32 */
|
|
u32 beta; /* and are used for shift relative to 1 */
|
|
bool ecn; /* true if ecn is enabled */
|
|
bool bytemode; /* to scale drop early prob based on pkt size */
|
|
u8 dq_rate_estimator; /* to calculate delay using Little's law */
|
|
};
|
|
|
|
/* variables used */
|
|
struct pie_vars {
|
|
u64 prob; /* probability but scaled by u64 limit. */
|
|
psched_time_t burst_time;
|
|
psched_time_t qdelay;
|
|
psched_time_t qdelay_old;
|
|
u64 dq_count; /* measured in bytes */
|
|
psched_time_t dq_tstamp; /* drain rate */
|
|
u64 accu_prob; /* accumulated drop probability */
|
|
u32 avg_dq_rate; /* bytes per pschedtime tick,scaled */
|
|
u32 qlen_old; /* in bytes */
|
|
u8 accu_prob_overflows; /* overflows of accu_prob */
|
|
};
|
|
|
|
/* statistics gathering */
|
|
struct pie_stats {
|
|
u32 packets_in; /* total number of packets enqueued */
|
|
u32 dropped; /* packets dropped due to pie_action */
|
|
u32 overlimit; /* dropped due to lack of space in queue */
|
|
u32 maxq; /* maximum queue size */
|
|
u32 ecn_mark; /* packets marked with ECN */
|
|
};
|
|
|
|
/* private data for the Qdisc */
|
|
struct pie_sched_data {
|
|
struct pie_params params;
|
|
struct pie_vars vars;
|
|
struct pie_stats stats;
|
|
struct timer_list adapt_timer;
|
|
struct Qdisc *sch;
|
|
};
|
|
|
|
static void pie_params_init(struct pie_params *params)
|
|
{
|
|
params->alpha = 2;
|
|
params->beta = 20;
|
|
params->tupdate = usecs_to_jiffies(15 * USEC_PER_MSEC); /* 15 ms */
|
|
params->limit = 1000; /* default of 1000 packets */
|
|
params->target = PSCHED_NS2TICKS(15 * NSEC_PER_MSEC); /* 15 ms */
|
|
params->ecn = false;
|
|
params->bytemode = false;
|
|
params->dq_rate_estimator = false;
|
|
}
|
|
|
|
/* private skb vars */
|
|
struct pie_skb_cb {
|
|
psched_time_t enqueue_time;
|
|
};
|
|
|
|
static struct pie_skb_cb *get_pie_cb(const struct sk_buff *skb)
|
|
{
|
|
qdisc_cb_private_validate(skb, sizeof(struct pie_skb_cb));
|
|
return (struct pie_skb_cb *)qdisc_skb_cb(skb)->data;
|
|
}
|
|
|
|
static psched_time_t pie_get_enqueue_time(const struct sk_buff *skb)
|
|
{
|
|
return get_pie_cb(skb)->enqueue_time;
|
|
}
|
|
|
|
static void pie_set_enqueue_time(struct sk_buff *skb)
|
|
{
|
|
get_pie_cb(skb)->enqueue_time = psched_get_time();
|
|
}
|
|
|
|
static void pie_vars_init(struct pie_vars *vars)
|
|
{
|
|
vars->dq_count = DQCOUNT_INVALID;
|
|
vars->dq_tstamp = DTIME_INVALID;
|
|
vars->accu_prob = 0;
|
|
vars->avg_dq_rate = 0;
|
|
/* default of 150 ms in pschedtime */
|
|
vars->burst_time = PSCHED_NS2TICKS(150 * NSEC_PER_MSEC);
|
|
vars->accu_prob_overflows = 0;
|
|
}
|
|
|
|
static bool drop_early(struct Qdisc *sch, u32 packet_size)
|
|
{
|
|
struct pie_sched_data *q = qdisc_priv(sch);
|
|
u64 rnd;
|
|
u64 local_prob = q->vars.prob;
|
|
u32 mtu = psched_mtu(qdisc_dev(sch));
|
|
|
|
/* If there is still burst allowance left skip random early drop */
|
|
if (q->vars.burst_time > 0)
|
|
return false;
|
|
|
|
/* If current delay is less than half of target, and
|
|
* if drop prob is low already, disable early_drop
|
|
*/
|
|
if ((q->vars.qdelay < q->params.target / 2) &&
|
|
(q->vars.prob < MAX_PROB / 5))
|
|
return false;
|
|
|
|
/* If we have fewer than 2 mtu-sized packets, disable drop_early,
|
|
* similar to min_th in RED
|
|
*/
|
|
if (sch->qstats.backlog < 2 * mtu)
|
|
return false;
|
|
|
|
/* If bytemode is turned on, use packet size to compute new
|
|
* probablity. Smaller packets will have lower drop prob in this case
|
|
*/
|
|
if (q->params.bytemode && packet_size <= mtu)
|
|
local_prob = (u64)packet_size * div_u64(local_prob, mtu);
|
|
else
|
|
local_prob = q->vars.prob;
|
|
|
|
if (local_prob == 0) {
|
|
q->vars.accu_prob = 0;
|
|
q->vars.accu_prob_overflows = 0;
|
|
}
|
|
|
|
if (local_prob > MAX_PROB - q->vars.accu_prob)
|
|
q->vars.accu_prob_overflows++;
|
|
|
|
q->vars.accu_prob += local_prob;
|
|
|
|
if (q->vars.accu_prob_overflows == 0 &&
|
|
q->vars.accu_prob < (MAX_PROB / 100) * 85)
|
|
return false;
|
|
if (q->vars.accu_prob_overflows == 8 &&
|
|
q->vars.accu_prob >= MAX_PROB / 2)
|
|
return true;
|
|
|
|
prandom_bytes(&rnd, 8);
|
|
if (rnd < local_prob) {
|
|
q->vars.accu_prob = 0;
|
|
q->vars.accu_prob_overflows = 0;
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static int pie_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
|
|
struct sk_buff **to_free)
|
|
{
|
|
struct pie_sched_data *q = qdisc_priv(sch);
|
|
bool enqueue = false;
|
|
|
|
if (unlikely(qdisc_qlen(sch) >= sch->limit)) {
|
|
q->stats.overlimit++;
|
|
goto out;
|
|
}
|
|
|
|
if (!drop_early(sch, skb->len)) {
|
|
enqueue = true;
|
|
} else if (q->params.ecn && (q->vars.prob <= MAX_PROB / 10) &&
|
|
INET_ECN_set_ce(skb)) {
|
|
/* If packet is ecn capable, mark it if drop probability
|
|
* is lower than 10%, else drop it.
|
|
*/
|
|
q->stats.ecn_mark++;
|
|
enqueue = true;
|
|
}
|
|
|
|
/* we can enqueue the packet */
|
|
if (enqueue) {
|
|
/* Set enqueue time only when dq_rate_estimator is disabled. */
|
|
if (!q->params.dq_rate_estimator)
|
|
pie_set_enqueue_time(skb);
|
|
|
|
q->stats.packets_in++;
|
|
if (qdisc_qlen(sch) > q->stats.maxq)
|
|
q->stats.maxq = qdisc_qlen(sch);
|
|
|
|
return qdisc_enqueue_tail(skb, sch);
|
|
}
|
|
|
|
out:
|
|
q->stats.dropped++;
|
|
q->vars.accu_prob = 0;
|
|
q->vars.accu_prob_overflows = 0;
|
|
return qdisc_drop(skb, sch, to_free);
|
|
}
|
|
|
|
static const struct nla_policy pie_policy[TCA_PIE_MAX + 1] = {
|
|
[TCA_PIE_TARGET] = {.type = NLA_U32},
|
|
[TCA_PIE_LIMIT] = {.type = NLA_U32},
|
|
[TCA_PIE_TUPDATE] = {.type = NLA_U32},
|
|
[TCA_PIE_ALPHA] = {.type = NLA_U32},
|
|
[TCA_PIE_BETA] = {.type = NLA_U32},
|
|
[TCA_PIE_ECN] = {.type = NLA_U32},
|
|
[TCA_PIE_BYTEMODE] = {.type = NLA_U32},
|
|
[TCA_PIE_DQ_RATE_ESTIMATOR] = {.type = NLA_U32},
|
|
};
|
|
|
|
static int pie_change(struct Qdisc *sch, struct nlattr *opt,
|
|
struct netlink_ext_ack *extack)
|
|
{
|
|
struct pie_sched_data *q = qdisc_priv(sch);
|
|
struct nlattr *tb[TCA_PIE_MAX + 1];
|
|
unsigned int qlen, dropped = 0;
|
|
int err;
|
|
|
|
if (!opt)
|
|
return -EINVAL;
|
|
|
|
err = nla_parse_nested_deprecated(tb, TCA_PIE_MAX, opt, pie_policy,
|
|
NULL);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
sch_tree_lock(sch);
|
|
|
|
/* convert from microseconds to pschedtime */
|
|
if (tb[TCA_PIE_TARGET]) {
|
|
/* target is in us */
|
|
u32 target = nla_get_u32(tb[TCA_PIE_TARGET]);
|
|
|
|
/* convert to pschedtime */
|
|
q->params.target = PSCHED_NS2TICKS((u64)target * NSEC_PER_USEC);
|
|
}
|
|
|
|
/* tupdate is in jiffies */
|
|
if (tb[TCA_PIE_TUPDATE])
|
|
q->params.tupdate =
|
|
usecs_to_jiffies(nla_get_u32(tb[TCA_PIE_TUPDATE]));
|
|
|
|
if (tb[TCA_PIE_LIMIT]) {
|
|
u32 limit = nla_get_u32(tb[TCA_PIE_LIMIT]);
|
|
|
|
q->params.limit = limit;
|
|
sch->limit = limit;
|
|
}
|
|
|
|
if (tb[TCA_PIE_ALPHA])
|
|
q->params.alpha = nla_get_u32(tb[TCA_PIE_ALPHA]);
|
|
|
|
if (tb[TCA_PIE_BETA])
|
|
q->params.beta = nla_get_u32(tb[TCA_PIE_BETA]);
|
|
|
|
if (tb[TCA_PIE_ECN])
|
|
q->params.ecn = nla_get_u32(tb[TCA_PIE_ECN]);
|
|
|
|
if (tb[TCA_PIE_BYTEMODE])
|
|
q->params.bytemode = nla_get_u32(tb[TCA_PIE_BYTEMODE]);
|
|
|
|
if (tb[TCA_PIE_DQ_RATE_ESTIMATOR])
|
|
q->params.dq_rate_estimator =
|
|
nla_get_u32(tb[TCA_PIE_DQ_RATE_ESTIMATOR]);
|
|
|
|
/* Drop excess packets if new limit is lower */
|
|
qlen = sch->q.qlen;
|
|
while (sch->q.qlen > sch->limit) {
|
|
struct sk_buff *skb = __qdisc_dequeue_head(&sch->q);
|
|
|
|
dropped += qdisc_pkt_len(skb);
|
|
qdisc_qstats_backlog_dec(sch, skb);
|
|
rtnl_qdisc_drop(skb, sch);
|
|
}
|
|
qdisc_tree_reduce_backlog(sch, qlen - sch->q.qlen, dropped);
|
|
|
|
sch_tree_unlock(sch);
|
|
return 0;
|
|
}
|
|
|
|
static void pie_process_dequeue(struct Qdisc *sch, struct sk_buff *skb)
|
|
{
|
|
struct pie_sched_data *q = qdisc_priv(sch);
|
|
int qlen = sch->qstats.backlog; /* current queue size in bytes */
|
|
psched_time_t now = psched_get_time();
|
|
u32 dtime = 0;
|
|
|
|
/* If dq_rate_estimator is disabled, calculate qdelay using the
|
|
* packet timestamp.
|
|
*/
|
|
if (!q->params.dq_rate_estimator) {
|
|
q->vars.qdelay = now - pie_get_enqueue_time(skb);
|
|
|
|
if (q->vars.dq_tstamp != DTIME_INVALID)
|
|
dtime = now - q->vars.dq_tstamp;
|
|
|
|
q->vars.dq_tstamp = now;
|
|
|
|
if (qlen == 0)
|
|
q->vars.qdelay = 0;
|
|
|
|
if (dtime == 0)
|
|
return;
|
|
|
|
goto burst_allowance_reduction;
|
|
}
|
|
|
|
/* If current queue is about 10 packets or more and dq_count is unset
|
|
* we have enough packets to calculate the drain rate. Save
|
|
* current time as dq_tstamp and start measurement cycle.
|
|
*/
|
|
if (qlen >= QUEUE_THRESHOLD && q->vars.dq_count == DQCOUNT_INVALID) {
|
|
q->vars.dq_tstamp = psched_get_time();
|
|
q->vars.dq_count = 0;
|
|
}
|
|
|
|
/* Calculate the average drain rate from this value. If queue length
|
|
* has receded to a small value viz., <= QUEUE_THRESHOLD bytes,reset
|
|
* the dq_count to -1 as we don't have enough packets to calculate the
|
|
* drain rate anymore The following if block is entered only when we
|
|
* have a substantial queue built up (QUEUE_THRESHOLD bytes or more)
|
|
* and we calculate the drain rate for the threshold here. dq_count is
|
|
* in bytes, time difference in psched_time, hence rate is in
|
|
* bytes/psched_time.
|
|
*/
|
|
if (q->vars.dq_count != DQCOUNT_INVALID) {
|
|
q->vars.dq_count += skb->len;
|
|
|
|
if (q->vars.dq_count >= QUEUE_THRESHOLD) {
|
|
u32 count = q->vars.dq_count << PIE_SCALE;
|
|
|
|
dtime = now - q->vars.dq_tstamp;
|
|
|
|
if (dtime == 0)
|
|
return;
|
|
|
|
count = count / dtime;
|
|
|
|
if (q->vars.avg_dq_rate == 0)
|
|
q->vars.avg_dq_rate = count;
|
|
else
|
|
q->vars.avg_dq_rate =
|
|
(q->vars.avg_dq_rate -
|
|
(q->vars.avg_dq_rate >> 3)) + (count >> 3);
|
|
|
|
/* If the queue has receded below the threshold, we hold
|
|
* on to the last drain rate calculated, else we reset
|
|
* dq_count to 0 to re-enter the if block when the next
|
|
* packet is dequeued
|
|
*/
|
|
if (qlen < QUEUE_THRESHOLD) {
|
|
q->vars.dq_count = DQCOUNT_INVALID;
|
|
} else {
|
|
q->vars.dq_count = 0;
|
|
q->vars.dq_tstamp = psched_get_time();
|
|
}
|
|
|
|
goto burst_allowance_reduction;
|
|
}
|
|
}
|
|
|
|
return;
|
|
|
|
burst_allowance_reduction:
|
|
if (q->vars.burst_time > 0) {
|
|
if (q->vars.burst_time > dtime)
|
|
q->vars.burst_time -= dtime;
|
|
else
|
|
q->vars.burst_time = 0;
|
|
}
|
|
}
|
|
|
|
static void calculate_probability(struct Qdisc *sch)
|
|
{
|
|
struct pie_sched_data *q = qdisc_priv(sch);
|
|
u32 qlen = sch->qstats.backlog; /* queue size in bytes */
|
|
psched_time_t qdelay = 0; /* in pschedtime */
|
|
psched_time_t qdelay_old = 0; /* in pschedtime */
|
|
s64 delta = 0; /* determines the change in probability */
|
|
u64 oldprob;
|
|
u64 alpha, beta;
|
|
u32 power;
|
|
bool update_prob = true;
|
|
|
|
if (q->params.dq_rate_estimator) {
|
|
qdelay_old = q->vars.qdelay;
|
|
q->vars.qdelay_old = q->vars.qdelay;
|
|
|
|
if (q->vars.avg_dq_rate > 0)
|
|
qdelay = (qlen << PIE_SCALE) / q->vars.avg_dq_rate;
|
|
else
|
|
qdelay = 0;
|
|
} else {
|
|
qdelay = q->vars.qdelay;
|
|
qdelay_old = q->vars.qdelay_old;
|
|
}
|
|
|
|
/* If qdelay is zero and qlen is not, it means qlen is very small, less
|
|
* than dequeue_rate, so we do not update probabilty in this round
|
|
*/
|
|
if (qdelay == 0 && qlen != 0)
|
|
update_prob = false;
|
|
|
|
/* In the algorithm, alpha and beta are between 0 and 2 with typical
|
|
* value for alpha as 0.125. In this implementation, we use values 0-32
|
|
* passed from user space to represent this. Also, alpha and beta have
|
|
* unit of HZ and need to be scaled before they can used to update
|
|
* probability. alpha/beta are updated locally below by scaling down
|
|
* by 16 to come to 0-2 range.
|
|
*/
|
|
alpha = ((u64)q->params.alpha * (MAX_PROB / PSCHED_TICKS_PER_SEC)) >> 4;
|
|
beta = ((u64)q->params.beta * (MAX_PROB / PSCHED_TICKS_PER_SEC)) >> 4;
|
|
|
|
/* We scale alpha and beta differently depending on how heavy the
|
|
* congestion is. Please see RFC 8033 for details.
|
|
*/
|
|
if (q->vars.prob < MAX_PROB / 10) {
|
|
alpha >>= 1;
|
|
beta >>= 1;
|
|
|
|
power = 100;
|
|
while (q->vars.prob < div_u64(MAX_PROB, power) &&
|
|
power <= 1000000) {
|
|
alpha >>= 2;
|
|
beta >>= 2;
|
|
power *= 10;
|
|
}
|
|
}
|
|
|
|
/* alpha and beta should be between 0 and 32, in multiples of 1/16 */
|
|
delta += alpha * (u64)(qdelay - q->params.target);
|
|
delta += beta * (u64)(qdelay - qdelay_old);
|
|
|
|
oldprob = q->vars.prob;
|
|
|
|
/* to ensure we increase probability in steps of no more than 2% */
|
|
if (delta > (s64)(MAX_PROB / (100 / 2)) &&
|
|
q->vars.prob >= MAX_PROB / 10)
|
|
delta = (MAX_PROB / 100) * 2;
|
|
|
|
/* Non-linear drop:
|
|
* Tune drop probability to increase quickly for high delays(>= 250ms)
|
|
* 250ms is derived through experiments and provides error protection
|
|
*/
|
|
|
|
if (qdelay > (PSCHED_NS2TICKS(250 * NSEC_PER_MSEC)))
|
|
delta += MAX_PROB / (100 / 2);
|
|
|
|
q->vars.prob += delta;
|
|
|
|
if (delta > 0) {
|
|
/* prevent overflow */
|
|
if (q->vars.prob < oldprob) {
|
|
q->vars.prob = MAX_PROB;
|
|
/* Prevent normalization error. If probability is at
|
|
* maximum value already, we normalize it here, and
|
|
* skip the check to do a non-linear drop in the next
|
|
* section.
|
|
*/
|
|
update_prob = false;
|
|
}
|
|
} else {
|
|
/* prevent underflow */
|
|
if (q->vars.prob > oldprob)
|
|
q->vars.prob = 0;
|
|
}
|
|
|
|
/* Non-linear drop in probability: Reduce drop probability quickly if
|
|
* delay is 0 for 2 consecutive Tupdate periods.
|
|
*/
|
|
|
|
if (qdelay == 0 && qdelay_old == 0 && update_prob)
|
|
/* Reduce drop probability to 98.4% */
|
|
q->vars.prob -= q->vars.prob / 64u;
|
|
|
|
q->vars.qdelay = qdelay;
|
|
q->vars.qlen_old = qlen;
|
|
|
|
/* We restart the measurement cycle if the following conditions are met
|
|
* 1. If the delay has been low for 2 consecutive Tupdate periods
|
|
* 2. Calculated drop probability is zero
|
|
* 3. If average dq_rate_estimator is enabled, we have atleast one
|
|
* estimate for the avg_dq_rate ie., is a non-zero value
|
|
*/
|
|
if ((q->vars.qdelay < q->params.target / 2) &&
|
|
(q->vars.qdelay_old < q->params.target / 2) &&
|
|
q->vars.prob == 0 &&
|
|
(!q->params.dq_rate_estimator || q->vars.avg_dq_rate > 0)) {
|
|
pie_vars_init(&q->vars);
|
|
}
|
|
|
|
if (!q->params.dq_rate_estimator)
|
|
q->vars.qdelay_old = qdelay;
|
|
}
|
|
|
|
static void pie_timer(struct timer_list *t)
|
|
{
|
|
struct pie_sched_data *q = from_timer(q, t, adapt_timer);
|
|
struct Qdisc *sch = q->sch;
|
|
spinlock_t *root_lock = qdisc_lock(qdisc_root_sleeping(sch));
|
|
|
|
spin_lock(root_lock);
|
|
calculate_probability(sch);
|
|
|
|
/* reset the timer to fire after 'tupdate'. tupdate is in jiffies. */
|
|
if (q->params.tupdate)
|
|
mod_timer(&q->adapt_timer, jiffies + q->params.tupdate);
|
|
spin_unlock(root_lock);
|
|
}
|
|
|
|
static int pie_init(struct Qdisc *sch, struct nlattr *opt,
|
|
struct netlink_ext_ack *extack)
|
|
{
|
|
struct pie_sched_data *q = qdisc_priv(sch);
|
|
|
|
pie_params_init(&q->params);
|
|
pie_vars_init(&q->vars);
|
|
sch->limit = q->params.limit;
|
|
|
|
q->sch = sch;
|
|
timer_setup(&q->adapt_timer, pie_timer, 0);
|
|
|
|
if (opt) {
|
|
int err = pie_change(sch, opt, extack);
|
|
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
mod_timer(&q->adapt_timer, jiffies + HZ / 2);
|
|
return 0;
|
|
}
|
|
|
|
static int pie_dump(struct Qdisc *sch, struct sk_buff *skb)
|
|
{
|
|
struct pie_sched_data *q = qdisc_priv(sch);
|
|
struct nlattr *opts;
|
|
|
|
opts = nla_nest_start_noflag(skb, TCA_OPTIONS);
|
|
if (!opts)
|
|
goto nla_put_failure;
|
|
|
|
/* convert target from pschedtime to us */
|
|
if (nla_put_u32(skb, TCA_PIE_TARGET,
|
|
((u32)PSCHED_TICKS2NS(q->params.target)) /
|
|
NSEC_PER_USEC) ||
|
|
nla_put_u32(skb, TCA_PIE_LIMIT, sch->limit) ||
|
|
nla_put_u32(skb, TCA_PIE_TUPDATE,
|
|
jiffies_to_usecs(q->params.tupdate)) ||
|
|
nla_put_u32(skb, TCA_PIE_ALPHA, q->params.alpha) ||
|
|
nla_put_u32(skb, TCA_PIE_BETA, q->params.beta) ||
|
|
nla_put_u32(skb, TCA_PIE_ECN, q->params.ecn) ||
|
|
nla_put_u32(skb, TCA_PIE_BYTEMODE, q->params.bytemode) ||
|
|
nla_put_u32(skb, TCA_PIE_DQ_RATE_ESTIMATOR,
|
|
q->params.dq_rate_estimator))
|
|
goto nla_put_failure;
|
|
|
|
return nla_nest_end(skb, opts);
|
|
|
|
nla_put_failure:
|
|
nla_nest_cancel(skb, opts);
|
|
return -1;
|
|
}
|
|
|
|
static int pie_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
|
|
{
|
|
struct pie_sched_data *q = qdisc_priv(sch);
|
|
struct tc_pie_xstats st = {
|
|
.prob = q->vars.prob,
|
|
.delay = ((u32)PSCHED_TICKS2NS(q->vars.qdelay)) /
|
|
NSEC_PER_USEC,
|
|
.packets_in = q->stats.packets_in,
|
|
.overlimit = q->stats.overlimit,
|
|
.maxq = q->stats.maxq,
|
|
.dropped = q->stats.dropped,
|
|
.ecn_mark = q->stats.ecn_mark,
|
|
};
|
|
|
|
/* avg_dq_rate is only valid if dq_rate_estimator is enabled */
|
|
st.dq_rate_estimating = q->params.dq_rate_estimator;
|
|
|
|
/* unscale and return dq_rate in bytes per sec */
|
|
if (q->params.dq_rate_estimator)
|
|
st.avg_dq_rate = q->vars.avg_dq_rate *
|
|
(PSCHED_TICKS_PER_SEC) >> PIE_SCALE;
|
|
|
|
return gnet_stats_copy_app(d, &st, sizeof(st));
|
|
}
|
|
|
|
static struct sk_buff *pie_qdisc_dequeue(struct Qdisc *sch)
|
|
{
|
|
struct sk_buff *skb = qdisc_dequeue_head(sch);
|
|
|
|
if (!skb)
|
|
return NULL;
|
|
|
|
pie_process_dequeue(sch, skb);
|
|
return skb;
|
|
}
|
|
|
|
static void pie_reset(struct Qdisc *sch)
|
|
{
|
|
struct pie_sched_data *q = qdisc_priv(sch);
|
|
|
|
qdisc_reset_queue(sch);
|
|
pie_vars_init(&q->vars);
|
|
}
|
|
|
|
static void pie_destroy(struct Qdisc *sch)
|
|
{
|
|
struct pie_sched_data *q = qdisc_priv(sch);
|
|
|
|
q->params.tupdate = 0;
|
|
del_timer_sync(&q->adapt_timer);
|
|
}
|
|
|
|
static struct Qdisc_ops pie_qdisc_ops __read_mostly = {
|
|
.id = "pie",
|
|
.priv_size = sizeof(struct pie_sched_data),
|
|
.enqueue = pie_qdisc_enqueue,
|
|
.dequeue = pie_qdisc_dequeue,
|
|
.peek = qdisc_peek_dequeued,
|
|
.init = pie_init,
|
|
.destroy = pie_destroy,
|
|
.reset = pie_reset,
|
|
.change = pie_change,
|
|
.dump = pie_dump,
|
|
.dump_stats = pie_dump_stats,
|
|
.owner = THIS_MODULE,
|
|
};
|
|
|
|
static int __init pie_module_init(void)
|
|
{
|
|
return register_qdisc(&pie_qdisc_ops);
|
|
}
|
|
|
|
static void __exit pie_module_exit(void)
|
|
{
|
|
unregister_qdisc(&pie_qdisc_ops);
|
|
}
|
|
|
|
module_init(pie_module_init);
|
|
module_exit(pie_module_exit);
|
|
|
|
MODULE_DESCRIPTION("Proportional Integral controller Enhanced (PIE) scheduler");
|
|
MODULE_AUTHOR("Vijay Subramanian");
|
|
MODULE_AUTHOR("Mythili Prabhu");
|
|
MODULE_LICENSE("GPL");
|