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authorPaul Gortmaker <paul.gortmaker@windriver.com>2012-06-20 09:38:34 -0400
committerPaul Gortmaker <paul.gortmaker@windriver.com>2012-06-20 09:38:34 -0400
commit701905ded521dc4b27fd34a1d97af6317c7403dc (patch)
treef249c1de79d75ba4d600380f12e15be541f4021c
parent3b8cb9e7082e152c6929e1444e3155baa6c5a5ed (diff)
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net_sched: Add CODEL queue management algorithm.
Straightforward backport from v3.5. See http://lwn.net/Articles/496509/ for a nice description of it. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
-rw-r--r--features/net_sched/codel-Controlled-Delay-AQM.patch764
-rw-r--r--features/net_sched/net_sched.cfg1
-rw-r--r--features/net_sched/net_sched.scc2
3 files changed, 767 insertions, 0 deletions
diff --git a/features/net_sched/codel-Controlled-Delay-AQM.patch b/features/net_sched/codel-Controlled-Delay-AQM.patch
new file mode 100644
index 00000000..700c7bf2
--- /dev/null
+++ b/features/net_sched/codel-Controlled-Delay-AQM.patch
@@ -0,0 +1,764 @@
+From 4f84a660ea97014e1293c8690657329e016198a8 Mon Sep 17 00:00:00 2001
+From: Eric Dumazet <edumazet@google.com>
+Date: Thu, 10 May 2012 07:51:25 +0000
+Subject: [PATCH] codel: Controlled Delay AQM
+
+commit 76e3cc126bb223013a6b9a0e2a51238d1ef2e409 upstream.
+
+An implementation of CoDel AQM, from Kathleen Nichols and Van Jacobson.
+
+http://queue.acm.org/detail.cfm?id=2209336
+
+This AQM main input is no longer queue size in bytes or packets, but the
+delay packets stay in (FIFO) queue.
+
+As we don't have infinite memory, we still can drop packets in enqueue()
+in case of massive load, but mean of CoDel is to drop packets in
+dequeue(), using a control law based on two simple parameters :
+
+target : target sojourn time (default 5ms)
+interval : width of moving time window (default 100ms)
+
+Based on initial work from Dave Taht.
+
+Refactored to help future codel inclusion as a plugin for other linux
+qdisc (FQ_CODEL, ...), like RED.
+
+include/net/codel.h contains codel algorithm as close as possible than
+Kathleen reference.
+
+net/sched/sch_codel.c contains the linux qdisc specific glue.
+
+Separate structures permit a memory efficient implementation of fq_codel
+(to be sent as a separate work) : Each flow has its own struct
+codel_vars.
+
+timestamps are taken at enqueue() time with 1024 ns precision, allowing
+a range of 2199 seconds in queue, and 100Gb links support. iproute2 uses
+usec as base unit.
+
+Selected packets are dropped, unless ECN is enabled and packets can get
+ECN mark instead.
+
+Tested from 2Mb to 10Gb speeds with no particular problems, on ixgbe and
+tg3 drivers (BQL enabled).
+
+Usage: tc qdisc ... codel [ limit PACKETS ] [ target TIME ]
+ [ interval TIME ] [ ecn ]
+
+qdisc codel 10: parent 1:1 limit 2000p target 3.0ms interval 60.0ms ecn
+ Sent 13347099587 bytes 8815805 pkt (dropped 0, overlimits 0 requeues 0)
+ rate 202365Kbit 16708pps backlog 113550b 75p requeues 0
+ count 116 lastcount 98 ldelay 4.3ms dropping drop_next 816us
+ maxpacket 1514 ecn_mark 84399 drop_overlimit 0
+
+CoDel must be seen as a base module, and should be used keeping in mind
+there is still a FIFO queue. So a typical setup will probably need a
+hierarchy of several qdiscs and packet classifiers to be able to meet
+whatever constraints a user might have.
+
+One possible example would be to use fq_codel, which combines Fair
+Queueing and CoDel, in replacement of sfq / sfq_red.
+
+Signed-off-by: Eric Dumazet <edumazet@google.com>
+Signed-off-by: Dave Taht <dave.taht@bufferbloat.net>
+Cc: Kathleen Nichols <nichols@pollere.com>
+Cc: Van Jacobson <van@pollere.net>
+Cc: Tom Herbert <therbert@google.com>
+Cc: Matt Mathis <mattmathis@google.com>
+Cc: Yuchung Cheng <ycheng@google.com>
+Cc: Stephen Hemminger <shemminger@vyatta.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
+
+diff --git a/include/linux/pkt_sched.h b/include/linux/pkt_sched.h
+index 410b33d..382e695 100644
+--- a/include/linux/pkt_sched.h
++++ b/include/linux/pkt_sched.h
+@@ -654,4 +654,30 @@ struct tc_qfq_stats {
+ __u32 lmax;
+ };
+
++/* CODEL */
++
++enum {
++ TCA_CODEL_UNSPEC,
++ TCA_CODEL_TARGET,
++ TCA_CODEL_LIMIT,
++ TCA_CODEL_INTERVAL,
++ TCA_CODEL_ECN,
++ __TCA_CODEL_MAX
++};
++
++#define TCA_CODEL_MAX (__TCA_CODEL_MAX - 1)
++
++struct tc_codel_xstats {
++ __u32 maxpacket; /* largest packet we've seen so far */
++ __u32 count; /* how many drops we've done since the last time we
++ * entered dropping state
++ */
++ __u32 lastcount; /* count at entry to dropping state */
++ __u32 ldelay; /* in-queue delay seen by most recently dequeued packet */
++ __s32 drop_next; /* time to drop next packet */
++ __u32 drop_overlimit; /* number of time max qdisc packet limit was hit */
++ __u32 ecn_mark; /* number of packets we ECN marked instead of dropped */
++ __u32 dropping; /* are we in dropping state ? */
++};
++
+ #endif
+diff --git a/include/net/codel.h b/include/net/codel.h
+new file mode 100644
+index 0000000..bce2cef
+--- /dev/null
++++ b/include/net/codel.h
+@@ -0,0 +1,332 @@
++#ifndef __NET_SCHED_CODEL_H
++#define __NET_SCHED_CODEL_H
++
++/*
++ * Codel - The Controlled-Delay Active Queue Management algorithm
++ *
++ * Copyright (C) 2011-2012 Kathleen Nichols <nichols@pollere.com>
++ * Copyright (C) 2011-2012 Van Jacobson <van@pollere.net>
++ * Copyright (C) 2012 Michael D. Taht <dave.taht@bufferbloat.net>
++ * Copyright (C) 2012 Eric Dumazet <edumazet@google.com>
++ *
++ * Redistribution and use in source and binary forms, with or without
++ * modification, are permitted provided that the following conditions
++ * are met:
++ * 1. Redistributions of source code must retain the above copyright
++ * notice, this list of conditions, and the following disclaimer,
++ * without modification.
++ * 2. Redistributions in binary form must reproduce the above copyright
++ * notice, this list of conditions and the following disclaimer in the
++ * documentation and/or other materials provided with the distribution.
++ * 3. The names of the authors may not be used to endorse or promote products
++ * derived from this software without specific prior written permission.
++ *
++ * Alternatively, provided that this notice is retained in full, this
++ * software may be distributed under the terms of the GNU General
++ * Public License ("GPL") version 2, in which case the provisions of the
++ * GPL apply INSTEAD OF those given above.
++ *
++ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
++ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
++ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
++ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
++ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
++ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
++ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
++ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
++ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
++ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
++ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
++ * DAMAGE.
++ *
++ */
++
++#include <linux/types.h>
++#include <linux/ktime.h>
++#include <linux/skbuff.h>
++#include <net/pkt_sched.h>
++#include <net/inet_ecn.h>
++
++/* Controlling Queue Delay (CoDel) algorithm
++ * =========================================
++ * Source : Kathleen Nichols and Van Jacobson
++ * http://queue.acm.org/detail.cfm?id=2209336
++ *
++ * Implemented on linux by Dave Taht and Eric Dumazet
++ */
++
++
++/* CoDel uses a 1024 nsec clock, encoded in u32
++ * This gives a range of 2199 seconds, because of signed compares
++ */
++typedef u32 codel_time_t;
++typedef s32 codel_tdiff_t;
++#define CODEL_SHIFT 10
++#define MS2TIME(a) ((a * NSEC_PER_MSEC) >> CODEL_SHIFT)
++
++static inline codel_time_t codel_get_time(void)
++{
++ u64 ns = ktime_to_ns(ktime_get());
++
++ return ns >> CODEL_SHIFT;
++}
++
++#define codel_time_after(a, b) ((s32)(a) - (s32)(b) > 0)
++#define codel_time_after_eq(a, b) ((s32)(a) - (s32)(b) >= 0)
++#define codel_time_before(a, b) ((s32)(a) - (s32)(b) < 0)
++#define codel_time_before_eq(a, b) ((s32)(a) - (s32)(b) <= 0)
++
++/* Qdiscs using codel plugin must use codel_skb_cb in their own cb[] */
++struct codel_skb_cb {
++ codel_time_t enqueue_time;
++};
++
++static struct codel_skb_cb *get_codel_cb(const struct sk_buff *skb)
++{
++ qdisc_cb_private_validate(skb, sizeof(struct codel_skb_cb));
++ return (struct codel_skb_cb *)qdisc_skb_cb(skb)->data;
++}
++
++static codel_time_t codel_get_enqueue_time(const struct sk_buff *skb)
++{
++ return get_codel_cb(skb)->enqueue_time;
++}
++
++static void codel_set_enqueue_time(struct sk_buff *skb)
++{
++ get_codel_cb(skb)->enqueue_time = codel_get_time();
++}
++
++static inline u32 codel_time_to_us(codel_time_t val)
++{
++ u64 valns = ((u64)val << CODEL_SHIFT);
++
++ do_div(valns, NSEC_PER_USEC);
++ return (u32)valns;
++}
++
++/**
++ * struct codel_params - contains codel parameters
++ * @target: target queue size (in time units)
++ * @interval: width of moving time window
++ * @ecn: is Explicit Congestion Notification enabled
++ */
++struct codel_params {
++ codel_time_t target;
++ codel_time_t interval;
++ bool ecn;
++};
++
++/**
++ * struct codel_vars - contains codel variables
++ * @count: how many drops we've done since the last time we
++ * entered dropping state
++ * @lastcount: count at entry to dropping state
++ * @dropping: set to true if in dropping state
++ * @first_above_time: when we went (or will go) continuously above target
++ * for interval
++ * @drop_next: time to drop next packet, or when we dropped last
++ * @ldelay: sojourn time of last dequeued packet
++ */
++struct codel_vars {
++ u32 count;
++ u32 lastcount;
++ bool dropping;
++ codel_time_t first_above_time;
++ codel_time_t drop_next;
++ codel_time_t ldelay;
++};
++
++/**
++ * struct codel_stats - contains codel shared variables and stats
++ * @maxpacket: largest packet we've seen so far
++ * @drop_count: temp count of dropped packets in dequeue()
++ * ecn_mark: number of packets we ECN marked instead of dropping
++ */
++struct codel_stats {
++ u32 maxpacket;
++ u32 drop_count;
++ u32 ecn_mark;
++};
++
++static void codel_params_init(struct codel_params *params)
++{
++ params->interval = MS2TIME(100);
++ params->target = MS2TIME(5);
++ params->ecn = false;
++}
++
++static void codel_vars_init(struct codel_vars *vars)
++{
++ vars->drop_next = 0;
++ vars->first_above_time = 0;
++ vars->dropping = false; /* exit dropping state */
++ vars->count = 0;
++ vars->lastcount = 0;
++}
++
++static void codel_stats_init(struct codel_stats *stats)
++{
++ stats->maxpacket = 256;
++}
++
++/* return interval/sqrt(x) with good precision
++ * relies on int_sqrt(unsigned long x) kernel implementation
++ */
++static u32 codel_inv_sqrt(u32 _interval, u32 _x)
++{
++ u64 interval = _interval;
++ unsigned long x = _x;
++
++ /* Scale operands for max precision */
++
++#if BITS_PER_LONG == 64
++ x <<= 32; /* On 64bit arches, we can prescale x by 32bits */
++ interval <<= 16;
++#endif
++
++ while (x < (1UL << (BITS_PER_LONG - 2))) {
++ x <<= 2;
++ interval <<= 1;
++ }
++ do_div(interval, int_sqrt(x));
++ return (u32)interval;
++}
++
++static codel_time_t codel_control_law(codel_time_t t,
++ codel_time_t interval,
++ u32 count)
++{
++ return t + codel_inv_sqrt(interval, count);
++}
++
++
++static bool codel_should_drop(struct sk_buff *skb,
++ unsigned int *backlog,
++ struct codel_vars *vars,
++ struct codel_params *params,
++ struct codel_stats *stats,
++ codel_time_t now)
++{
++ bool ok_to_drop;
++
++ if (!skb) {
++ vars->first_above_time = 0;
++ return false;
++ }
++
++ vars->ldelay = now - codel_get_enqueue_time(skb);
++ *backlog -= qdisc_pkt_len(skb);
++
++ if (unlikely(qdisc_pkt_len(skb) > stats->maxpacket))
++ stats->maxpacket = qdisc_pkt_len(skb);
++
++ if (codel_time_before(vars->ldelay, params->target) ||
++ *backlog <= stats->maxpacket) {
++ /* went below - stay below for at least interval */
++ vars->first_above_time = 0;
++ return false;
++ }
++ ok_to_drop = false;
++ if (vars->first_above_time == 0) {
++ /* just went above from below. If we stay above
++ * for at least interval we'll say it's ok to drop
++ */
++ vars->first_above_time = now + params->interval;
++ } else if (codel_time_after(now, vars->first_above_time)) {
++ ok_to_drop = true;
++ }
++ return ok_to_drop;
++}
++
++typedef struct sk_buff * (*codel_skb_dequeue_t)(struct codel_vars *vars,
++ struct Qdisc *sch);
++
++static struct sk_buff *codel_dequeue(struct Qdisc *sch,
++ struct codel_params *params,
++ struct codel_vars *vars,
++ struct codel_stats *stats,
++ codel_skb_dequeue_t dequeue_func,
++ u32 *backlog)
++{
++ struct sk_buff *skb = dequeue_func(vars, sch);
++ codel_time_t now;
++ bool drop;
++
++ if (!skb) {
++ vars->dropping = false;
++ return skb;
++ }
++ now = codel_get_time();
++ drop = codel_should_drop(skb, backlog, vars, params, stats, now);
++ if (vars->dropping) {
++ if (!drop) {
++ /* sojourn time below target - leave dropping state */
++ vars->dropping = false;
++ } else if (codel_time_after_eq(now, vars->drop_next)) {
++ /* It's time for the next drop. Drop the current
++ * packet and dequeue the next. The dequeue might
++ * take us out of dropping state.
++ * If not, schedule the next drop.
++ * A large backlog might result in drop rates so high
++ * that the next drop should happen now,
++ * hence the while loop.
++ */
++ while (vars->dropping &&
++ codel_time_after_eq(now, vars->drop_next)) {
++ if (++vars->count == 0) /* avoid zero divides */
++ vars->count = ~0U;
++ if (params->ecn && INET_ECN_set_ce(skb)) {
++ stats->ecn_mark++;
++ vars->drop_next =
++ codel_control_law(vars->drop_next,
++ params->interval,
++ vars->count);
++ goto end;
++ }
++ qdisc_drop(skb, sch);
++ stats->drop_count++;
++ skb = dequeue_func(vars, sch);
++ if (!codel_should_drop(skb, backlog,
++ vars, params, stats, now)) {
++ /* leave dropping state */
++ vars->dropping = false;
++ } else {
++ /* and schedule the next drop */
++ vars->drop_next =
++ codel_control_law(vars->drop_next,
++ params->interval,
++ vars->count);
++ }
++ }
++ }
++ } else if (drop) {
++ if (params->ecn && INET_ECN_set_ce(skb)) {
++ stats->ecn_mark++;
++ } else {
++ qdisc_drop(skb, sch);
++ stats->drop_count++;
++
++ skb = dequeue_func(vars, sch);
++ drop = codel_should_drop(skb, backlog, vars, params,
++ stats, now);
++ }
++ vars->dropping = true;
++ /* if min went above target close to when we last went below it
++ * assume that the drop rate that controlled the queue on the
++ * last cycle is a good starting point to control it now.
++ */
++ if (codel_time_before(now - vars->drop_next,
++ 16 * params->interval)) {
++ vars->count = (vars->count - vars->lastcount) | 1;
++ } else {
++ vars->count = 1;
++ }
++ vars->lastcount = vars->count;
++ vars->drop_next = codel_control_law(now, params->interval,
++ vars->count);
++ }
++end:
++ return skb;
++}
++#endif
+diff --git a/net/sched/Kconfig b/net/sched/Kconfig
+index 75b58f8..fadd252 100644
+--- a/net/sched/Kconfig
++++ b/net/sched/Kconfig
+@@ -250,6 +250,17 @@ config NET_SCH_QFQ
+
+ If unsure, say N.
+
++config NET_SCH_CODEL
++ tristate "Controlled Delay AQM (CODEL)"
++ help
++ Say Y here if you want to use the Controlled Delay (CODEL)
++ packet scheduling algorithm.
++
++ To compile this driver as a module, choose M here: the module
++ will be called sch_codel.
++
++ If unsure, say N.
++
+ config NET_SCH_INGRESS
+ tristate "Ingress Qdisc"
+ depends on NET_CLS_ACT
+diff --git a/net/sched/Makefile b/net/sched/Makefile
+index 8cdf4e2..30fab03 100644
+--- a/net/sched/Makefile
++++ b/net/sched/Makefile
+@@ -37,6 +37,7 @@ obj-$(CONFIG_NET_SCH_PLUG) += sch_plug.o
+ obj-$(CONFIG_NET_SCH_MQPRIO) += sch_mqprio.o
+ obj-$(CONFIG_NET_SCH_CHOKE) += sch_choke.o
+ obj-$(CONFIG_NET_SCH_QFQ) += sch_qfq.o
++obj-$(CONFIG_NET_SCH_CODEL) += sch_codel.o
+
+ obj-$(CONFIG_NET_CLS_U32) += cls_u32.o
+ obj-$(CONFIG_NET_CLS_ROUTE4) += cls_route.o
+diff --git a/net/sched/sch_codel.c b/net/sched/sch_codel.c
+new file mode 100644
+index 0000000..b4a1a81
+--- /dev/null
++++ b/net/sched/sch_codel.c
+@@ -0,0 +1,275 @@
++/*
++ * Codel - The Controlled-Delay Active Queue Management algorithm
++ *
++ * Copyright (C) 2011-2012 Kathleen Nichols <nichols@pollere.com>
++ * Copyright (C) 2011-2012 Van Jacobson <van@pollere.net>
++ *
++ * Implemented on linux by :
++ * Copyright (C) 2012 Michael D. Taht <dave.taht@bufferbloat.net>
++ * Copyright (C) 2012 Eric Dumazet <edumazet@google.com>
++ *
++ * Redistribution and use in source and binary forms, with or without
++ * modification, are permitted provided that the following conditions
++ * are met:
++ * 1. Redistributions of source code must retain the above copyright
++ * notice, this list of conditions, and the following disclaimer,
++ * without modification.
++ * 2. Redistributions in binary form must reproduce the above copyright
++ * notice, this list of conditions and the following disclaimer in the
++ * documentation and/or other materials provided with the distribution.
++ * 3. The names of the authors may not be used to endorse or promote products
++ * derived from this software without specific prior written permission.
++ *
++ * Alternatively, provided that this notice is retained in full, this
++ * software may be distributed under the terms of the GNU General
++ * Public License ("GPL") version 2, in which case the provisions of the
++ * GPL apply INSTEAD OF those given above.
++ *
++ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
++ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
++ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
++ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
++ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
++ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
++ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
++ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
++ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
++ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
++ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
++ * DAMAGE.
++ *
++ */
++
++#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/codel.h>
++
++
++#define DEFAULT_CODEL_LIMIT 1000
++
++struct codel_sched_data {
++ struct codel_params params;
++ struct codel_vars vars;
++ struct codel_stats stats;
++ u32 drop_overlimit;
++};
++
++/* This is the specific function called from codel_dequeue()
++ * to dequeue a packet from queue. Note: backlog is handled in
++ * codel, we dont need to reduce it here.
++ */
++static struct sk_buff *dequeue(struct codel_vars *vars, struct Qdisc *sch)
++{
++ struct sk_buff *skb = __skb_dequeue(&sch->q);
++
++ prefetch(&skb->end); /* we'll need skb_shinfo() */
++ return skb;
++}
++
++static struct sk_buff *codel_qdisc_dequeue(struct Qdisc *sch)
++{
++ struct codel_sched_data *q = qdisc_priv(sch);
++ struct sk_buff *skb;
++
++ skb = codel_dequeue(sch, &q->params, &q->vars, &q->stats,
++ dequeue, &sch->qstats.backlog);
++ /* We cant call qdisc_tree_decrease_qlen() if our qlen is 0,
++ * or HTB crashes. Defer it for next round.
++ */
++ if (q->stats.drop_count && sch->q.qlen) {
++ qdisc_tree_decrease_qlen(sch, q->stats.drop_count);
++ q->stats.drop_count = 0;
++ }
++ if (skb)
++ qdisc_bstats_update(sch, skb);
++ return skb;
++}
++
++static int codel_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch)
++{
++ struct codel_sched_data *q;
++
++ if (likely(qdisc_qlen(sch) < sch->limit)) {
++ codel_set_enqueue_time(skb);
++ return qdisc_enqueue_tail(skb, sch);
++ }
++ q = qdisc_priv(sch);
++ q->drop_overlimit++;
++ return qdisc_drop(skb, sch);
++}
++
++static const struct nla_policy codel_policy[TCA_CODEL_MAX + 1] = {
++ [TCA_CODEL_TARGET] = { .type = NLA_U32 },
++ [TCA_CODEL_LIMIT] = { .type = NLA_U32 },
++ [TCA_CODEL_INTERVAL] = { .type = NLA_U32 },
++ [TCA_CODEL_ECN] = { .type = NLA_U32 },
++};
++
++static int codel_change(struct Qdisc *sch, struct nlattr *opt)
++{
++ struct codel_sched_data *q = qdisc_priv(sch);
++ struct nlattr *tb[TCA_CODEL_MAX + 1];
++ unsigned int qlen;
++ int err;
++
++ if (!opt)
++ return -EINVAL;
++
++ err = nla_parse_nested(tb, TCA_CODEL_MAX, opt, codel_policy);
++ if (err < 0)
++ return err;
++
++ sch_tree_lock(sch);
++
++ if (tb[TCA_CODEL_TARGET]) {
++ u32 target = nla_get_u32(tb[TCA_CODEL_TARGET]);
++
++ q->params.target = ((u64)target * NSEC_PER_USEC) >> CODEL_SHIFT;
++ }
++
++ if (tb[TCA_CODEL_INTERVAL]) {
++ u32 interval = nla_get_u32(tb[TCA_CODEL_INTERVAL]);
++
++ q->params.interval = ((u64)interval * NSEC_PER_USEC) >> CODEL_SHIFT;
++ }
++
++ if (tb[TCA_CODEL_LIMIT])
++ sch->limit = nla_get_u32(tb[TCA_CODEL_LIMIT]);
++
++ if (tb[TCA_CODEL_ECN])
++ q->params.ecn = !!nla_get_u32(tb[TCA_CODEL_ECN]);
++
++ qlen = sch->q.qlen;
++ while (sch->q.qlen > sch->limit) {
++ struct sk_buff *skb = __skb_dequeue(&sch->q);
++
++ sch->qstats.backlog -= qdisc_pkt_len(skb);
++ qdisc_drop(skb, sch);
++ }
++ qdisc_tree_decrease_qlen(sch, qlen - sch->q.qlen);
++
++ sch_tree_unlock(sch);
++ return 0;
++}
++
++static int codel_init(struct Qdisc *sch, struct nlattr *opt)
++{
++ struct codel_sched_data *q = qdisc_priv(sch);
++
++ sch->limit = DEFAULT_CODEL_LIMIT;
++
++ codel_params_init(&q->params);
++ codel_vars_init(&q->vars);
++ codel_stats_init(&q->stats);
++
++ if (opt) {
++ int err = codel_change(sch, opt);
++
++ if (err)
++ return err;
++ }
++
++ if (sch->limit >= 1)
++ sch->flags |= TCQ_F_CAN_BYPASS;
++ else
++ sch->flags &= ~TCQ_F_CAN_BYPASS;
++
++ return 0;
++}
++
++static int codel_dump(struct Qdisc *sch, struct sk_buff *skb)
++{
++ struct codel_sched_data *q = qdisc_priv(sch);
++ struct nlattr *opts;
++
++ opts = nla_nest_start(skb, TCA_OPTIONS);
++ if (opts == NULL)
++ goto nla_put_failure;
++
++ if (nla_put_u32(skb, TCA_CODEL_TARGET,
++ codel_time_to_us(q->params.target)) ||
++ nla_put_u32(skb, TCA_CODEL_LIMIT,
++ sch->limit) ||
++ nla_put_u32(skb, TCA_CODEL_INTERVAL,
++ codel_time_to_us(q->params.interval)) ||
++ nla_put_u32(skb, TCA_CODEL_ECN,
++ q->params.ecn))
++ goto nla_put_failure;
++
++ return nla_nest_end(skb, opts);
++
++nla_put_failure:
++ nla_nest_cancel(skb, opts);
++ return -1;
++}
++
++static int codel_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
++{
++ const struct codel_sched_data *q = qdisc_priv(sch);
++ struct tc_codel_xstats st = {
++ .maxpacket = q->stats.maxpacket,
++ .count = q->vars.count,
++ .lastcount = q->vars.lastcount,
++ .drop_overlimit = q->drop_overlimit,
++ .ldelay = codel_time_to_us(q->vars.ldelay),
++ .dropping = q->vars.dropping,
++ .ecn_mark = q->stats.ecn_mark,
++ };
++
++ if (q->vars.dropping) {
++ codel_tdiff_t delta = q->vars.drop_next - codel_get_time();
++
++ if (delta >= 0)
++ st.drop_next = codel_time_to_us(delta);
++ else
++ st.drop_next = -codel_time_to_us(-delta);
++ }
++
++ return gnet_stats_copy_app(d, &st, sizeof(st));
++}
++
++static void codel_reset(struct Qdisc *sch)
++{
++ struct codel_sched_data *q = qdisc_priv(sch);
++
++ qdisc_reset_queue(sch);
++ codel_vars_init(&q->vars);
++}
++
++static struct Qdisc_ops codel_qdisc_ops __read_mostly = {
++ .id = "codel",
++ .priv_size = sizeof(struct codel_sched_data),
++
++ .enqueue = codel_qdisc_enqueue,
++ .dequeue = codel_qdisc_dequeue,
++ .peek = qdisc_peek_dequeued,
++ .init = codel_init,
++ .reset = codel_reset,
++ .change = codel_change,
++ .dump = codel_dump,
++ .dump_stats = codel_dump_stats,
++ .owner = THIS_MODULE,
++};
++
++static int __init codel_module_init(void)
++{
++ return register_qdisc(&codel_qdisc_ops);
++}
++
++static void __exit codel_module_exit(void)
++{
++ unregister_qdisc(&codel_qdisc_ops);
++}
++
++module_init(codel_module_init)
++module_exit(codel_module_exit)
++
++MODULE_DESCRIPTION("Controlled Delay queue discipline");
++MODULE_AUTHOR("Dave Taht");
++MODULE_AUTHOR("Eric Dumazet");
++MODULE_LICENSE("Dual BSD/GPL");
+--
+1.7.9.1
+
diff --git a/features/net_sched/net_sched.cfg b/features/net_sched/net_sched.cfg
index ae5f7726..8a45e593 100644
--- a/features/net_sched/net_sched.cfg
+++ b/features/net_sched/net_sched.cfg
@@ -22,6 +22,7 @@ CONFIG_NET_SCH_GRED=m
CONFIG_NET_SCH_DSMARK=m
CONFIG_NET_SCH_NETEM=m
CONFIG_NET_SCH_INGRESS=m
+CONFIG_NET_SCH_CODEL=m
#
# Classification
diff --git a/features/net_sched/net_sched.scc b/features/net_sched/net_sched.scc
index 8ccea1cb..df576d83 100644
--- a/features/net_sched/net_sched.scc
+++ b/features/net_sched/net_sched.scc
@@ -1 +1,3 @@
+patch codel-Controlled-Delay-AQM.patch
+
kconf non-hardware net_traffic_controller.cfg