diff options
Diffstat (limited to 'target/linux/generic/patches-3.3/040-Controlled-Delay-AQM.patch')
| -rw-r--r-- | target/linux/generic/patches-3.3/040-Controlled-Delay-AQM.patch | 755 |
1 files changed, 755 insertions, 0 deletions
diff --git a/target/linux/generic/patches-3.3/040-Controlled-Delay-AQM.patch b/target/linux/generic/patches-3.3/040-Controlled-Delay-AQM.patch new file mode 100644 index 0000000..5848d2f --- /dev/null +++ b/target/linux/generic/patches-3.3/040-Controlled-Delay-AQM.patch @@ -0,0 +1,755 @@ +From 76e3cc126bb223013a6b9a0e2a51238d1ef2e409 Mon Sep 17 00:00:00 2001 +From: Eric Dumazet <edumazet@google.com> +Date: Thu, 10 May 2012 07:51:25 +0000 +Subject: [PATCH 01/41] codel: Controlled Delay AQM + +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> +--- + include/linux/pkt_sched.h | 26 ++++ + include/net/codel.h | 332 +++++++++++++++++++++++++++++++++++++++++++++ + net/sched/Kconfig | 11 ++ + net/sched/Makefile | 1 + + net/sched/sch_codel.c | 275 +++++++++++++++++++++++++++++++++++++ + 5 files changed, 645 insertions(+) + create mode 100644 include/net/codel.h + create mode 100644 net/sched/sch_codel.c + +--- a/include/linux/pkt_sched.h ++++ b/include/linux/pkt_sched.h +@@ -633,4 +633,30 @@ 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 +--- /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 +--- 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 +--- a/net/sched/Makefile ++++ b/net/sched/Makefile +@@ -36,6 +36,7 @@ obj-$(CONFIG_NET_SCH_DRR) += sch_drr.o + obj-$(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 +--- /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"); |