--- /dev/null
+--- a/arch/mips/lib/memset.S
++++ b/arch/mips/lib/memset.S
+@@ -19,6 +19,8 @@
+ #define LONG_S_R sdr
+ #endif
+
++#include "prefetch.h"
++
+ #define EX(insn,reg,addr,handler) \
+ 9: insn reg, addr; \
+ .section __ex_table,"a"; \
+@@ -75,6 +77,8 @@ FEXPORT(__bzero)
+ bnez t0, .Lsmall_memset
+ andi t0, a0, LONGMASK /* aligned? */
+
++ prefetch_store a0, a2, t2, t3, t4
++
+ #ifndef CONFIG_CPU_DADDI_WORKAROUNDS
+ beqz t0, 1f
+ PTR_SUBU t0, LONGSIZE /* alignment in bytes */
+--- a/arch/mips/include/asm/processor.h
++++ b/arch/mips/include/asm/processor.h
+@@ -354,7 +354,7 @@ unsigned long get_wchan(struct task_stru
+ #define prefetch(x) __builtin_prefetch((x), 0, 1)
+
+ #define ARCH_HAS_PREFETCHW
+-#define prefetchw(x) __builtin_prefetch((x), 1, 1)
++#define prefetchw(x) do {} while (0)
+
+ #endif
+
+--- /dev/null
++++ b/arch/mips/lib/prefetch.h
+@@ -0,0 +1,35 @@
++/*
++ * This file is subject to the terms and conditions of the GNU General Public
++ * License. See the file "COPYING" in the main directory of this archive
++ * for more details.
++ *
++ * Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
++ */
++
++.macro prefetch_store dst, size, temp1, temp2, temp3
++#ifdef CONFIG_CPU_MIPS32
++ li \temp1, ((1 << CONFIG_MIPS_L1_CACHE_SHIFT) - 1)
++ nor \temp1, \temp1, \temp1
++
++ and \temp2, \size, \temp1
++ beqz \temp2, 2f
++ nop
++
++ move \temp2, \dst
++ PTR_ADDIU \temp2, ((1 << CONFIG_MIPS_L1_CACHE_SHIFT) - 1)
++ and \temp2, \temp2, \temp1
++
++ move \temp3, \dst
++ PTR_ADDU \temp3, \size
++ and \temp3, \temp3, \temp1
++
++1: beq \temp2, \temp3, 2f
++ nop
++
++ pref 30, 0(\temp2)
++
++ b 1b
++ PTR_ADDIU \temp2, (1 << CONFIG_MIPS_L1_CACHE_SHIFT)
++2:
++#endif
++.endm
+--- a/arch/mips/lib/memcpy.S
++++ b/arch/mips/lib/memcpy.S
+@@ -182,6 +182,8 @@
+ .set at=v1
+ #endif
+
++#include "prefetch.h"
++
+ /*
+ * A combined memcpy/__copy_user
+ * __copy_user sets len to 0 for success; else to an upper bound of
+@@ -199,6 +201,8 @@ FEXPORT(__copy_user)
+ */
+ #define rem t8
+
++ prefetch_store a0, a2, t0, t1, t2
++
+ R10KCBARRIER(0(ra))
+ /*
+ * The "issue break"s below are very approximate.
+--- a/arch/mips/lib/memcpy-inatomic.S
++++ b/arch/mips/lib/memcpy-inatomic.S
+@@ -182,6 +182,8 @@
+ .set at=v1
+ #endif
+
++#include "prefetch.h"
++
+ /*
+ * A combined memcpy/__copy_user
+ * __copy_user sets len to 0 for success; else to an upper bound of
+@@ -196,6 +198,8 @@ LEAF(__copy_user_inatomic)
+ */
+ #define rem t8
+
++ prefetch_store dst, len, t0, t1, t2
++
+ /*
+ * The "issue break"s below are very approximate.
+ * Issue delays for dcache fills will perturb the schedule, as will
--- /dev/null
+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");
--- /dev/null
+From 536edd67109df5e0cdb2c4ee759e9bade7976367 Mon Sep 17 00:00:00 2001
+From: Eric Dumazet <edumazet@google.com>
+Date: Sat, 12 May 2012 03:32:13 +0000
+Subject: [PATCH 37/41] codel: use Newton method instead of sqrt() and divides
+
+As Van pointed out, interval/sqrt(count) can be implemented using
+multiplies only.
+
+http://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Iterative_methods_for_reciprocal_square_roots
+
+This patch implements the Newton method and reciprocal divide.
+
+Total cost is 15 cycles instead of 120 on my Corei5 machine (64bit
+kernel).
+
+There is a small 'error' for count values < 5, but we don't really care.
+
+I reuse a hole in struct codel_vars :
+ - pack the dropping boolean into one bit
+ - use 31bit to store the reciprocal value of sqrt(count).
+
+Suggested-by: Van Jacobson <van@pollere.net>
+Signed-off-by: Eric Dumazet <edumazet@google.com>
+Cc: Dave Taht <dave.taht@bufferbloat.net>
+Cc: Kathleen Nichols <nichols@pollere.com>
+Cc: Tom Herbert <therbert@google.com>
+Cc: Matt Mathis <mattmathis@google.com>
+Cc: Yuchung Cheng <ycheng@google.com>
+Cc: Nandita Dukkipati <nanditad@google.com>
+Cc: Stephen Hemminger <shemminger@vyatta.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+ include/net/codel.h | 68 ++++++++++++++++++++++++++++-----------------------
+ 1 file changed, 37 insertions(+), 31 deletions(-)
+
+--- a/include/net/codel.h
++++ b/include/net/codel.h
+@@ -46,6 +46,7 @@
+ #include <linux/skbuff.h>
+ #include <net/pkt_sched.h>
+ #include <net/inet_ecn.h>
++#include <linux/reciprocal_div.h>
+
+ /* Controlling Queue Delay (CoDel) algorithm
+ * =========================================
+@@ -123,6 +124,7 @@ struct codel_params {
+ * entered dropping state
+ * @lastcount: count at entry to dropping state
+ * @dropping: set to true if in dropping state
++ * @rec_inv_sqrt: reciprocal value of sqrt(count) >> 1
+ * @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
+@@ -131,7 +133,8 @@ struct codel_params {
+ struct codel_vars {
+ u32 count;
+ u32 lastcount;
+- bool dropping;
++ bool dropping:1;
++ u32 rec_inv_sqrt:31;
+ codel_time_t first_above_time;
+ codel_time_t drop_next;
+ codel_time_t ldelay;
+@@ -158,11 +161,7 @@ static void codel_params_init(struct cod
+
+ 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;
++ memset(vars, 0, sizeof(*vars));
+ }
+
+ static void codel_stats_init(struct codel_stats *stats)
+@@ -170,38 +169,37 @@ static void codel_stats_init(struct code
+ stats->maxpacket = 256;
+ }
+
+-/* return interval/sqrt(x) with good precision
+- * relies on int_sqrt(unsigned long x) kernel implementation
++/*
++ * http://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Iterative_methods_for_reciprocal_square_roots
++ * new_invsqrt = (invsqrt / 2) * (3 - count * invsqrt^2)
++ *
++ * Here, invsqrt is a fixed point number (< 1.0), 31bit mantissa)
+ */
+-static u32 codel_inv_sqrt(u32 _interval, u32 _x)
++static void codel_Newton_step(struct codel_vars *vars)
+ {
+- u64 interval = _interval;
+- unsigned long x = _x;
+-
+- /* Scale operands for max precision */
++ u32 invsqrt = vars->rec_inv_sqrt;
++ u32 invsqrt2 = ((u64)invsqrt * invsqrt) >> 31;
++ u64 val = (3LL << 31) - ((u64)vars->count * invsqrt2);
+
+-#if BITS_PER_LONG == 64
+- x <<= 32; /* On 64bit arches, we can prescale x by 32bits */
+- interval <<= 16;
+-#endif
++ val = (val * invsqrt) >> 32;
+
+- while (x < (1UL << (BITS_PER_LONG - 2))) {
+- x <<= 2;
+- interval <<= 1;
+- }
+- do_div(interval, int_sqrt(x));
+- return (u32)interval;
++ vars->rec_inv_sqrt = val;
+ }
+
++/*
++ * CoDel control_law is t + interval/sqrt(count)
++ * We maintain in rec_inv_sqrt the reciprocal value of sqrt(count) to avoid
++ * both sqrt() and divide operation.
++ */
+ static codel_time_t codel_control_law(codel_time_t t,
+ codel_time_t interval,
+- u32 count)
++ u32 rec_inv_sqrt)
+ {
+- return t + codel_inv_sqrt(interval, count);
++ return t + reciprocal_divide(interval, rec_inv_sqrt << 1);
+ }
+
+
+-static bool codel_should_drop(struct sk_buff *skb,
++static bool codel_should_drop(const struct sk_buff *skb,
+ unsigned int *backlog,
+ struct codel_vars *vars,
+ struct codel_params *params,
+@@ -274,14 +272,16 @@ static struct sk_buff *codel_dequeue(str
+ */
+ while (vars->dropping &&
+ codel_time_after_eq(now, vars->drop_next)) {
+- if (++vars->count == 0) /* avoid zero divides */
+- vars->count = ~0U;
++ vars->count++; /* dont care of possible wrap
++ * since there is no more divide
++ */
++ codel_Newton_step(vars);
+ if (params->ecn && INET_ECN_set_ce(skb)) {
+ stats->ecn_mark++;
+ vars->drop_next =
+ codel_control_law(vars->drop_next,
+ params->interval,
+- vars->count);
++ vars->rec_inv_sqrt);
+ goto end;
+ }
+ qdisc_drop(skb, sch);
+@@ -296,7 +296,7 @@ static struct sk_buff *codel_dequeue(str
+ vars->drop_next =
+ codel_control_law(vars->drop_next,
+ params->interval,
+- vars->count);
++ vars->rec_inv_sqrt);
+ }
+ }
+ }
+@@ -319,12 +319,18 @@ static struct sk_buff *codel_dequeue(str
+ if (codel_time_before(now - vars->drop_next,
+ 16 * params->interval)) {
+ vars->count = (vars->count - vars->lastcount) | 1;
++ /* we dont care if rec_inv_sqrt approximation
++ * is not very precise :
++ * Next Newton steps will correct it quadratically.
++ */
++ codel_Newton_step(vars);
+ } else {
+ vars->count = 1;
++ vars->rec_inv_sqrt = 0x7fffffff;
+ }
+ vars->lastcount = vars->count;
+ vars->drop_next = codel_control_law(now, params->interval,
+- vars->count);
++ vars->rec_inv_sqrt);
+ }
+ end:
+ return skb;
--- /dev/null
+From 4b549a2ef4bef9965d97cbd992ba67930cd3e0fe Mon Sep 17 00:00:00 2001
+From: Eric Dumazet <edumazet@google.com>
+Date: Fri, 11 May 2012 09:30:50 +0000
+Subject: [PATCH 38/41] fq_codel: Fair Queue Codel AQM
+
+Fair Queue Codel packet scheduler
+
+Principles :
+
+- Packets are classified (internal classifier or external) on flows.
+- This is a Stochastic model (as we use a hash, several flows might
+ be hashed on same slot)
+- Each flow has a CoDel managed queue.
+- Flows are linked onto two (Round Robin) lists,
+ so that new flows have priority on old ones.
+
+- For a given flow, packets are not reordered (CoDel uses a FIFO)
+- head drops only.
+- ECN capability is on by default.
+- Very low memory footprint (64 bytes per flow)
+
+tc qdisc ... fq_codel [ limit PACKETS ] [ flows number ]
+ [ target TIME ] [ interval TIME ] [ noecn ]
+ [ quantum BYTES ]
+
+defaults : 1024 flows, 10240 packets limit, quantum : device MTU
+ target : 5ms (CoDel default)
+ interval : 100ms (CoDel default)
+
+Impressive results on load :
+
+class htb 1:1 root leaf 10: prio 0 quantum 1514 rate 200000Kbit ceil 200000Kbit burst 1475b/8 mpu 0b overhead 0b cburst 1475b/8 mpu 0b overhead 0b level 0
+ Sent 43304920109 bytes 33063109 pkt (dropped 0, overlimits 0 requeues 0)
+ rate 201691Kbit 28595pps backlog 0b 312p requeues 0
+ lended: 33063109 borrowed: 0 giants: 0
+ tokens: -912 ctokens: -912
+
+class fq_codel 10:1735 parent 10:
+ (dropped 1292, overlimits 0 requeues 0)
+ backlog 15140b 10p requeues 0
+ deficit 1514 count 1 lastcount 1 ldelay 7.1ms
+class fq_codel 10:4524 parent 10:
+ (dropped 1291, overlimits 0 requeues 0)
+ backlog 16654b 11p requeues 0
+ deficit 1514 count 1 lastcount 1 ldelay 7.1ms
+class fq_codel 10:4e74 parent 10:
+ (dropped 1290, overlimits 0 requeues 0)
+ backlog 6056b 4p requeues 0
+ deficit 1514 count 1 lastcount 1 ldelay 6.4ms dropping drop_next 92.0ms
+class fq_codel 10:628a parent 10:
+ (dropped 1289, overlimits 0 requeues 0)
+ backlog 7570b 5p requeues 0
+ deficit 1514 count 1 lastcount 1 ldelay 5.4ms dropping drop_next 90.9ms
+class fq_codel 10:a4b3 parent 10:
+ (dropped 302, overlimits 0 requeues 0)
+ backlog 16654b 11p requeues 0
+ deficit 1514 count 1 lastcount 1 ldelay 7.1ms
+class fq_codel 10:c3c2 parent 10:
+ (dropped 1284, overlimits 0 requeues 0)
+ backlog 13626b 9p requeues 0
+ deficit 1514 count 1 lastcount 1 ldelay 5.9ms
+class fq_codel 10:d331 parent 10:
+ (dropped 299, overlimits 0 requeues 0)
+ backlog 15140b 10p requeues 0
+ deficit 1514 count 1 lastcount 1 ldelay 7.0ms
+class fq_codel 10:d526 parent 10:
+ (dropped 12160, overlimits 0 requeues 0)
+ backlog 35870b 211p requeues 0
+ deficit 1508 count 12160 lastcount 1 ldelay 15.3ms dropping drop_next 247us
+class fq_codel 10:e2c6 parent 10:
+ (dropped 1288, overlimits 0 requeues 0)
+ backlog 15140b 10p requeues 0
+ deficit 1514 count 1 lastcount 1 ldelay 7.1ms
+class fq_codel 10:eab5 parent 10:
+ (dropped 1285, overlimits 0 requeues 0)
+ backlog 16654b 11p requeues 0
+ deficit 1514 count 1 lastcount 1 ldelay 5.9ms
+class fq_codel 10:f220 parent 10:
+ (dropped 1289, overlimits 0 requeues 0)
+ backlog 15140b 10p requeues 0
+ deficit 1514 count 1 lastcount 1 ldelay 7.1ms
+
+qdisc htb 1: root refcnt 6 r2q 10 default 1 direct_packets_stat 0 ver 3.17
+ Sent 43331086547 bytes 33092812 pkt (dropped 0, overlimits 66063544 requeues 71)
+ rate 201697Kbit 28602pps backlog 0b 260p requeues 71
+qdisc fq_codel 10: parent 1:1 limit 10240p flows 65536 target 5.0ms interval 100.0ms ecn
+ Sent 43331086547 bytes 33092812 pkt (dropped 949359, overlimits 0 requeues 0)
+ rate 201697Kbit 28602pps backlog 189352b 260p requeues 0
+ maxpacket 1514 drop_overlimit 0 new_flow_count 5582 ecn_mark 125593
+ new_flows_len 0 old_flows_len 11
+
+PING 172.30.42.18 (172.30.42.18) 56(84) bytes of data.
+64 bytes from 172.30.42.18: icmp_req=1 ttl=64 time=0.227 ms
+64 bytes from 172.30.42.18: icmp_req=2 ttl=64 time=0.165 ms
+64 bytes from 172.30.42.18: icmp_req=3 ttl=64 time=0.166 ms
+64 bytes from 172.30.42.18: icmp_req=4 ttl=64 time=0.151 ms
+64 bytes from 172.30.42.18: icmp_req=5 ttl=64 time=0.164 ms
+64 bytes from 172.30.42.18: icmp_req=6 ttl=64 time=0.172 ms
+64 bytes from 172.30.42.18: icmp_req=7 ttl=64 time=0.175 ms
+64 bytes from 172.30.42.18: icmp_req=8 ttl=64 time=0.183 ms
+64 bytes from 172.30.42.18: icmp_req=9 ttl=64 time=0.158 ms
+64 bytes from 172.30.42.18: icmp_req=10 ttl=64 time=0.200 ms
+
+10 packets transmitted, 10 received, 0% packet loss, time 8999ms
+rtt min/avg/max/mdev = 0.151/0.176/0.227/0.022 ms
+
+Much better than SFQ because of priority given to new flows, and fast
+path dirtying less cache lines.
+
+Signed-off-by: Eric Dumazet <edumazet@google.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+ include/linux/pkt_sched.h | 54 ++++
+ net/sched/Kconfig | 11 +
+ net/sched/Makefile | 1 +
+ net/sched/sch_fq_codel.c | 624 +++++++++++++++++++++++++++++++++++++++++++++
+ 4 files changed, 690 insertions(+)
+ create mode 100644 net/sched/sch_fq_codel.c
+
+--- a/include/linux/pkt_sched.h
++++ b/include/linux/pkt_sched.h
+@@ -659,4 +659,58 @@ struct tc_codel_xstats {
+ __u32 dropping; /* are we in dropping state ? */
+ };
+
++/* FQ_CODEL */
++
++enum {
++ TCA_FQ_CODEL_UNSPEC,
++ TCA_FQ_CODEL_TARGET,
++ TCA_FQ_CODEL_LIMIT,
++ TCA_FQ_CODEL_INTERVAL,
++ TCA_FQ_CODEL_ECN,
++ TCA_FQ_CODEL_FLOWS,
++ TCA_FQ_CODEL_QUANTUM,
++ __TCA_FQ_CODEL_MAX
++};
++
++#define TCA_FQ_CODEL_MAX (__TCA_FQ_CODEL_MAX - 1)
++
++enum {
++ TCA_FQ_CODEL_XSTATS_QDISC,
++ TCA_FQ_CODEL_XSTATS_CLASS,
++};
++
++struct tc_fq_codel_qd_stats {
++ __u32 maxpacket; /* largest packet we've seen so far */
++ __u32 drop_overlimit; /* number of time max qdisc
++ * packet limit was hit
++ */
++ __u32 ecn_mark; /* number of packets we ECN marked
++ * instead of being dropped
++ */
++ __u32 new_flow_count; /* number of time packets
++ * created a 'new flow'
++ */
++ __u32 new_flows_len; /* count of flows in new list */
++ __u32 old_flows_len; /* count of flows in old list */
++};
++
++struct tc_fq_codel_cl_stats {
++ __s32 deficit;
++ __u32 ldelay; /* in-queue delay seen by most recently
++ * dequeued packet
++ */
++ __u32 count;
++ __u32 lastcount;
++ __u32 dropping;
++ __s32 drop_next;
++};
++
++struct tc_fq_codel_xstats {
++ __u32 type;
++ union {
++ struct tc_fq_codel_qd_stats qdisc_stats;
++ struct tc_fq_codel_cl_stats class_stats;
++ };
++};
++
+ #endif
+--- a/net/sched/Kconfig
++++ b/net/sched/Kconfig
+@@ -261,6 +261,17 @@ config NET_SCH_CODEL
+
+ If unsure, say N.
+
++config NET_SCH_FQ_CODEL
++ tristate "Fair Queue Controlled Delay AQM (FQ_CODEL)"
++ help
++ Say Y here if you want to use the FQ Controlled Delay (FQ_CODEL)
++ packet scheduling algorithm.
++
++ To compile this driver as a module, choose M here: the module
++ will be called sch_fq_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
+@@ -37,6 +37,7 @@ obj-$(CONFIG_NET_SCH_MQPRIO) += sch_mqpr
+ 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_SCH_FQ_CODEL) += sch_fq_codel.o
+
+ obj-$(CONFIG_NET_CLS_U32) += cls_u32.o
+ obj-$(CONFIG_NET_CLS_ROUTE4) += cls_route.o
+--- /dev/null
++++ b/net/sched/sch_fq_codel.c
+@@ -0,0 +1,624 @@
++/*
++ * Fair Queue CoDel discipline
++ *
++ * This program is free software; you can redistribute it and/or
++ * modify it under the terms of the GNU General Public License
++ * as published by the Free Software Foundation; either version
++ * 2 of the License, or (at your option) any later version.
++ *
++ * Copyright (C) 2012 Eric Dumazet <edumazet@google.com>
++ */
++
++#include <linux/module.h>
++#include <linux/types.h>
++#include <linux/kernel.h>
++#include <linux/jiffies.h>
++#include <linux/string.h>
++#include <linux/in.h>
++#include <linux/errno.h>
++#include <linux/init.h>
++#include <linux/skbuff.h>
++#include <linux/jhash.h>
++#include <linux/slab.h>
++#include <linux/vmalloc.h>
++#include <net/netlink.h>
++#include <net/pkt_sched.h>
++#include <net/flow_keys.h>
++#include <net/codel.h>
++
++/* Fair Queue CoDel.
++ *
++ * Principles :
++ * Packets are classified (internal classifier or external) on flows.
++ * This is a Stochastic model (as we use a hash, several flows
++ * might be hashed on same slot)
++ * Each flow has a CoDel managed queue.
++ * Flows are linked onto two (Round Robin) lists,
++ * so that new flows have priority on old ones.
++ *
++ * For a given flow, packets are not reordered (CoDel uses a FIFO)
++ * head drops only.
++ * ECN capability is on by default.
++ * Low memory footprint (64 bytes per flow)
++ */
++
++struct fq_codel_flow {
++ struct sk_buff *head;
++ struct sk_buff *tail;
++ struct list_head flowchain;
++ int deficit;
++ u32 dropped; /* number of drops (or ECN marks) on this flow */
++ struct codel_vars cvars;
++}; /* please try to keep this structure <= 64 bytes */
++
++struct fq_codel_sched_data {
++ struct tcf_proto *filter_list; /* optional external classifier */
++ struct fq_codel_flow *flows; /* Flows table [flows_cnt] */
++ u32 *backlogs; /* backlog table [flows_cnt] */
++ u32 flows_cnt; /* number of flows */
++ u32 perturbation; /* hash perturbation */
++ u32 quantum; /* psched_mtu(qdisc_dev(sch)); */
++ struct codel_params cparams;
++ struct codel_stats cstats;
++ u32 drop_overlimit;
++ u32 new_flow_count;
++
++ struct list_head new_flows; /* list of new flows */
++ struct list_head old_flows; /* list of old flows */
++};
++
++static unsigned int fq_codel_hash(const struct fq_codel_sched_data *q,
++ const struct sk_buff *skb)
++{
++ struct flow_keys keys;
++ unsigned int hash;
++
++ skb_flow_dissect(skb, &keys);
++ hash = jhash_3words((__force u32)keys.dst,
++ (__force u32)keys.src ^ keys.ip_proto,
++ (__force u32)keys.ports, q->perturbation);
++ return ((u64)hash * q->flows_cnt) >> 32;
++}
++
++static unsigned int fq_codel_classify(struct sk_buff *skb, struct Qdisc *sch,
++ int *qerr)
++{
++ struct fq_codel_sched_data *q = qdisc_priv(sch);
++ struct tcf_result res;
++ int result;
++
++ if (TC_H_MAJ(skb->priority) == sch->handle &&
++ TC_H_MIN(skb->priority) > 0 &&
++ TC_H_MIN(skb->priority) <= q->flows_cnt)
++ return TC_H_MIN(skb->priority);
++
++ if (!q->filter_list)
++ return fq_codel_hash(q, skb) + 1;
++
++ *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
++ result = tc_classify(skb, q->filter_list, &res);
++ if (result >= 0) {
++#ifdef CONFIG_NET_CLS_ACT
++ switch (result) {
++ case TC_ACT_STOLEN:
++ case TC_ACT_QUEUED:
++ *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
++ case TC_ACT_SHOT:
++ return 0;
++ }
++#endif
++ if (TC_H_MIN(res.classid) <= q->flows_cnt)
++ return TC_H_MIN(res.classid);
++ }
++ return 0;
++}
++
++/* helper functions : might be changed when/if skb use a standard list_head */
++
++/* remove one skb from head of slot queue */
++static inline struct sk_buff *dequeue_head(struct fq_codel_flow *flow)
++{
++ struct sk_buff *skb = flow->head;
++
++ flow->head = skb->next;
++ skb->next = NULL;
++ return skb;
++}
++
++/* add skb to flow queue (tail add) */
++static inline void flow_queue_add(struct fq_codel_flow *flow,
++ struct sk_buff *skb)
++{
++ if (flow->head == NULL)
++ flow->head = skb;
++ else
++ flow->tail->next = skb;
++ flow->tail = skb;
++ skb->next = NULL;
++}
++
++static unsigned int fq_codel_drop(struct Qdisc *sch)
++{
++ struct fq_codel_sched_data *q = qdisc_priv(sch);
++ struct sk_buff *skb;
++ unsigned int maxbacklog = 0, idx = 0, i, len;
++ struct fq_codel_flow *flow;
++
++ /* Queue is full! Find the fat flow and drop packet from it.
++ * This might sound expensive, but with 1024 flows, we scan
++ * 4KB of memory, and we dont need to handle a complex tree
++ * in fast path (packet queue/enqueue) with many cache misses.
++ */
++ for (i = 0; i < q->flows_cnt; i++) {
++ if (q->backlogs[i] > maxbacklog) {
++ maxbacklog = q->backlogs[i];
++ idx = i;
++ }
++ }
++ flow = &q->flows[idx];
++ skb = dequeue_head(flow);
++ len = qdisc_pkt_len(skb);
++ q->backlogs[idx] -= len;
++ kfree_skb(skb);
++ sch->q.qlen--;
++ sch->qstats.drops++;
++ sch->qstats.backlog -= len;
++ flow->dropped++;
++ return idx;
++}
++
++static int fq_codel_enqueue(struct sk_buff *skb, struct Qdisc *sch)
++{
++ struct fq_codel_sched_data *q = qdisc_priv(sch);
++ unsigned int idx;
++ struct fq_codel_flow *flow;
++ int uninitialized_var(ret);
++
++ idx = fq_codel_classify(skb, sch, &ret);
++ if (idx == 0) {
++ if (ret & __NET_XMIT_BYPASS)
++ sch->qstats.drops++;
++ kfree_skb(skb);
++ return ret;
++ }
++ idx--;
++
++ codel_set_enqueue_time(skb);
++ flow = &q->flows[idx];
++ flow_queue_add(flow, skb);
++ q->backlogs[idx] += qdisc_pkt_len(skb);
++ sch->qstats.backlog += qdisc_pkt_len(skb);
++
++ if (list_empty(&flow->flowchain)) {
++ list_add_tail(&flow->flowchain, &q->new_flows);
++ codel_vars_init(&flow->cvars);
++ q->new_flow_count++;
++ flow->deficit = q->quantum;
++ flow->dropped = 0;
++ }
++ if (++sch->q.qlen < sch->limit)
++ return NET_XMIT_SUCCESS;
++
++ q->drop_overlimit++;
++ /* Return Congestion Notification only if we dropped a packet
++ * from this flow.
++ */
++ if (fq_codel_drop(sch) == idx)
++ return NET_XMIT_CN;
++
++ /* As we dropped a packet, better let upper stack know this */
++ qdisc_tree_decrease_qlen(sch, 1);
++ return NET_XMIT_SUCCESS;
++}
++
++/* 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 fq_codel_flow *flow;
++ struct sk_buff *skb = NULL;
++
++ flow = container_of(vars, struct fq_codel_flow, cvars);
++ if (flow->head) {
++ skb = dequeue_head(flow);
++ sch->qstats.backlog -= qdisc_pkt_len(skb);
++ sch->q.qlen--;
++ }
++ return skb;
++}
++
++static struct sk_buff *fq_codel_dequeue(struct Qdisc *sch)
++{
++ struct fq_codel_sched_data *q = qdisc_priv(sch);
++ struct sk_buff *skb;
++ struct fq_codel_flow *flow;
++ struct list_head *head;
++ u32 prev_drop_count, prev_ecn_mark;
++
++begin:
++ head = &q->new_flows;
++ if (list_empty(head)) {
++ head = &q->old_flows;
++ if (list_empty(head))
++ return NULL;
++ }
++ flow = list_first_entry(head, struct fq_codel_flow, flowchain);
++
++ if (flow->deficit <= 0) {
++ flow->deficit += q->quantum;
++ list_move_tail(&flow->flowchain, &q->old_flows);
++ goto begin;
++ }
++
++ prev_drop_count = q->cstats.drop_count;
++ prev_ecn_mark = q->cstats.ecn_mark;
++
++ skb = codel_dequeue(sch, &q->cparams, &flow->cvars, &q->cstats,
++ dequeue, &q->backlogs[flow - q->flows]);
++
++ flow->dropped += q->cstats.drop_count - prev_drop_count;
++ flow->dropped += q->cstats.ecn_mark - prev_ecn_mark;
++
++ if (!skb) {
++ /* force a pass through old_flows to prevent starvation */
++ if ((head == &q->new_flows) && !list_empty(&q->old_flows))
++ list_move_tail(&flow->flowchain, &q->old_flows);
++ else
++ list_del_init(&flow->flowchain);
++ goto begin;
++ }
++ qdisc_bstats_update(sch, skb);
++ flow->deficit -= qdisc_pkt_len(skb);
++ /* We cant call qdisc_tree_decrease_qlen() if our qlen is 0,
++ * or HTB crashes. Defer it for next round.
++ */
++ if (q->cstats.drop_count && sch->q.qlen) {
++ qdisc_tree_decrease_qlen(sch, q->cstats.drop_count);
++ q->cstats.drop_count = 0;
++ }
++ return skb;
++}
++
++static void fq_codel_reset(struct Qdisc *sch)
++{
++ struct sk_buff *skb;
++
++ while ((skb = fq_codel_dequeue(sch)) != NULL)
++ kfree_skb(skb);
++}
++
++static const struct nla_policy fq_codel_policy[TCA_FQ_CODEL_MAX + 1] = {
++ [TCA_FQ_CODEL_TARGET] = { .type = NLA_U32 },
++ [TCA_FQ_CODEL_LIMIT] = { .type = NLA_U32 },
++ [TCA_FQ_CODEL_INTERVAL] = { .type = NLA_U32 },
++ [TCA_FQ_CODEL_ECN] = { .type = NLA_U32 },
++ [TCA_FQ_CODEL_FLOWS] = { .type = NLA_U32 },
++ [TCA_FQ_CODEL_QUANTUM] = { .type = NLA_U32 },
++};
++
++static int fq_codel_change(struct Qdisc *sch, struct nlattr *opt)
++{
++ struct fq_codel_sched_data *q = qdisc_priv(sch);
++ struct nlattr *tb[TCA_FQ_CODEL_MAX + 1];
++ int err;
++
++ if (!opt)
++ return -EINVAL;
++
++ err = nla_parse_nested(tb, TCA_FQ_CODEL_MAX, opt, fq_codel_policy);
++ if (err < 0)
++ return err;
++ if (tb[TCA_FQ_CODEL_FLOWS]) {
++ if (q->flows)
++ return -EINVAL;
++ q->flows_cnt = nla_get_u32(tb[TCA_FQ_CODEL_FLOWS]);
++ if (!q->flows_cnt ||
++ q->flows_cnt > 65536)
++ return -EINVAL;
++ }
++ sch_tree_lock(sch);
++
++ if (tb[TCA_FQ_CODEL_TARGET]) {
++ u64 target = nla_get_u32(tb[TCA_FQ_CODEL_TARGET]);
++
++ q->cparams.target = (target * NSEC_PER_USEC) >> CODEL_SHIFT;
++ }
++
++ if (tb[TCA_FQ_CODEL_INTERVAL]) {
++ u64 interval = nla_get_u32(tb[TCA_FQ_CODEL_INTERVAL]);
++
++ q->cparams.interval = (interval * NSEC_PER_USEC) >> CODEL_SHIFT;
++ }
++
++ if (tb[TCA_FQ_CODEL_LIMIT])
++ sch->limit = nla_get_u32(tb[TCA_FQ_CODEL_LIMIT]);
++
++ if (tb[TCA_FQ_CODEL_ECN])
++ q->cparams.ecn = !!nla_get_u32(tb[TCA_FQ_CODEL_ECN]);
++
++ if (tb[TCA_FQ_CODEL_QUANTUM])
++ q->quantum = max(256U, nla_get_u32(tb[TCA_FQ_CODEL_QUANTUM]));
++
++ while (sch->q.qlen > sch->limit) {
++ struct sk_buff *skb = fq_codel_dequeue(sch);
++
++ kfree_skb(skb);
++ q->cstats.drop_count++;
++ }
++ qdisc_tree_decrease_qlen(sch, q->cstats.drop_count);
++ q->cstats.drop_count = 0;
++
++ sch_tree_unlock(sch);
++ return 0;
++}
++
++static void *fq_codel_zalloc(size_t sz)
++{
++ void *ptr = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN);
++
++ if (!ptr)
++ ptr = vzalloc(sz);
++ return ptr;
++}
++
++static void fq_codel_free(void *addr)
++{
++ if (addr) {
++ if (is_vmalloc_addr(addr))
++ vfree(addr);
++ else
++ kfree(addr);
++ }
++}
++
++static void fq_codel_destroy(struct Qdisc *sch)
++{
++ struct fq_codel_sched_data *q = qdisc_priv(sch);
++
++ tcf_destroy_chain(&q->filter_list);
++ fq_codel_free(q->backlogs);
++ fq_codel_free(q->flows);
++}
++
++static int fq_codel_init(struct Qdisc *sch, struct nlattr *opt)
++{
++ struct fq_codel_sched_data *q = qdisc_priv(sch);
++ int i;
++
++ sch->limit = 10*1024;
++ q->flows_cnt = 1024;
++ q->quantum = psched_mtu(qdisc_dev(sch));
++ q->perturbation = net_random();
++ INIT_LIST_HEAD(&q->new_flows);
++ INIT_LIST_HEAD(&q->old_flows);
++ codel_params_init(&q->cparams);
++ codel_stats_init(&q->cstats);
++ q->cparams.ecn = true;
++
++ if (opt) {
++ int err = fq_codel_change(sch, opt);
++ if (err)
++ return err;
++ }
++
++ if (!q->flows) {
++ q->flows = fq_codel_zalloc(q->flows_cnt *
++ sizeof(struct fq_codel_flow));
++ if (!q->flows)
++ return -ENOMEM;
++ q->backlogs = fq_codel_zalloc(q->flows_cnt * sizeof(u32));
++ if (!q->backlogs) {
++ fq_codel_free(q->flows);
++ return -ENOMEM;
++ }
++ for (i = 0; i < q->flows_cnt; i++) {
++ struct fq_codel_flow *flow = q->flows + i;
++
++ INIT_LIST_HEAD(&flow->flowchain);
++ }
++ }
++ if (sch->limit >= 1)
++ sch->flags |= TCQ_F_CAN_BYPASS;
++ else
++ sch->flags &= ~TCQ_F_CAN_BYPASS;
++ return 0;
++}
++
++static int fq_codel_dump(struct Qdisc *sch, struct sk_buff *skb)
++{
++ struct fq_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_FQ_CODEL_TARGET,
++ codel_time_to_us(q->cparams.target)) ||
++ nla_put_u32(skb, TCA_FQ_CODEL_LIMIT,
++ sch->limit) ||
++ nla_put_u32(skb, TCA_FQ_CODEL_INTERVAL,
++ codel_time_to_us(q->cparams.interval)) ||
++ nla_put_u32(skb, TCA_FQ_CODEL_ECN,
++ q->cparams.ecn) ||
++ nla_put_u32(skb, TCA_FQ_CODEL_QUANTUM,
++ q->quantum) ||
++ nla_put_u32(skb, TCA_FQ_CODEL_FLOWS,
++ q->flows_cnt))
++ goto nla_put_failure;
++
++ nla_nest_end(skb, opts);
++ return skb->len;
++
++nla_put_failure:
++ return -1;
++}
++
++static int fq_codel_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
++{
++ struct fq_codel_sched_data *q = qdisc_priv(sch);
++ struct tc_fq_codel_xstats st = {
++ .type = TCA_FQ_CODEL_XSTATS_QDISC,
++ .qdisc_stats.maxpacket = q->cstats.maxpacket,
++ .qdisc_stats.drop_overlimit = q->drop_overlimit,
++ .qdisc_stats.ecn_mark = q->cstats.ecn_mark,
++ .qdisc_stats.new_flow_count = q->new_flow_count,
++ };
++ struct list_head *pos;
++
++ list_for_each(pos, &q->new_flows)
++ st.qdisc_stats.new_flows_len++;
++
++ list_for_each(pos, &q->old_flows)
++ st.qdisc_stats.old_flows_len++;
++
++ return gnet_stats_copy_app(d, &st, sizeof(st));
++}
++
++static struct Qdisc *fq_codel_leaf(struct Qdisc *sch, unsigned long arg)
++{
++ return NULL;
++}
++
++static unsigned long fq_codel_get(struct Qdisc *sch, u32 classid)
++{
++ return 0;
++}
++
++static unsigned long fq_codel_bind(struct Qdisc *sch, unsigned long parent,
++ u32 classid)
++{
++ /* we cannot bypass queue discipline anymore */
++ sch->flags &= ~TCQ_F_CAN_BYPASS;
++ return 0;
++}
++
++static void fq_codel_put(struct Qdisc *q, unsigned long cl)
++{
++}
++
++static struct tcf_proto **fq_codel_find_tcf(struct Qdisc *sch, unsigned long cl)
++{
++ struct fq_codel_sched_data *q = qdisc_priv(sch);
++
++ if (cl)
++ return NULL;
++ return &q->filter_list;
++}
++
++static int fq_codel_dump_class(struct Qdisc *sch, unsigned long cl,
++ struct sk_buff *skb, struct tcmsg *tcm)
++{
++ tcm->tcm_handle |= TC_H_MIN(cl);
++ return 0;
++}
++
++static int fq_codel_dump_class_stats(struct Qdisc *sch, unsigned long cl,
++ struct gnet_dump *d)
++{
++ struct fq_codel_sched_data *q = qdisc_priv(sch);
++ u32 idx = cl - 1;
++ struct gnet_stats_queue qs = { 0 };
++ struct tc_fq_codel_xstats xstats;
++
++ if (idx < q->flows_cnt) {
++ const struct fq_codel_flow *flow = &q->flows[idx];
++ const struct sk_buff *skb = flow->head;
++
++ memset(&xstats, 0, sizeof(xstats));
++ xstats.type = TCA_FQ_CODEL_XSTATS_CLASS;
++ xstats.class_stats.deficit = flow->deficit;
++ xstats.class_stats.ldelay =
++ codel_time_to_us(flow->cvars.ldelay);
++ xstats.class_stats.count = flow->cvars.count;
++ xstats.class_stats.lastcount = flow->cvars.lastcount;
++ xstats.class_stats.dropping = flow->cvars.dropping;
++ if (flow->cvars.dropping) {
++ codel_tdiff_t delta = flow->cvars.drop_next -
++ codel_get_time();
++
++ xstats.class_stats.drop_next = (delta >= 0) ?
++ codel_time_to_us(delta) :
++ -codel_time_to_us(-delta);
++ }
++ while (skb) {
++ qs.qlen++;
++ skb = skb->next;
++ }
++ qs.backlog = q->backlogs[idx];
++ qs.drops = flow->dropped;
++ }
++ if (gnet_stats_copy_queue(d, &qs) < 0)
++ return -1;
++ if (idx < q->flows_cnt)
++ return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
++ return 0;
++}
++
++static void fq_codel_walk(struct Qdisc *sch, struct qdisc_walker *arg)
++{
++ struct fq_codel_sched_data *q = qdisc_priv(sch);
++ unsigned int i;
++
++ if (arg->stop)
++ return;
++
++ for (i = 0; i < q->flows_cnt; i++) {
++ if (list_empty(&q->flows[i].flowchain) ||
++ arg->count < arg->skip) {
++ arg->count++;
++ continue;
++ }
++ if (arg->fn(sch, i + 1, arg) < 0) {
++ arg->stop = 1;
++ break;
++ }
++ arg->count++;
++ }
++}
++
++static const struct Qdisc_class_ops fq_codel_class_ops = {
++ .leaf = fq_codel_leaf,
++ .get = fq_codel_get,
++ .put = fq_codel_put,
++ .tcf_chain = fq_codel_find_tcf,
++ .bind_tcf = fq_codel_bind,
++ .unbind_tcf = fq_codel_put,
++ .dump = fq_codel_dump_class,
++ .dump_stats = fq_codel_dump_class_stats,
++ .walk = fq_codel_walk,
++};
++
++static struct Qdisc_ops fq_codel_qdisc_ops __read_mostly = {
++ .cl_ops = &fq_codel_class_ops,
++ .id = "fq_codel",
++ .priv_size = sizeof(struct fq_codel_sched_data),
++ .enqueue = fq_codel_enqueue,
++ .dequeue = fq_codel_dequeue,
++ .peek = qdisc_peek_dequeued,
++ .drop = fq_codel_drop,
++ .init = fq_codel_init,
++ .reset = fq_codel_reset,
++ .destroy = fq_codel_destroy,
++ .change = fq_codel_change,
++ .dump = fq_codel_dump,
++ .dump_stats = fq_codel_dump_stats,
++ .owner = THIS_MODULE,
++};
++
++static int __init fq_codel_module_init(void)
++{
++ return register_qdisc(&fq_codel_qdisc_ops);
++}
++
++static void __exit fq_codel_module_exit(void)
++{
++ unregister_qdisc(&fq_codel_qdisc_ops);
++}
++
++module_init(fq_codel_module_init)
++module_exit(fq_codel_module_exit)
++MODULE_AUTHOR("Eric Dumazet");
++MODULE_LICENSE("GPL");
--- /dev/null
+From ce5b4b977127ee20c3f9c3fd3637cd3796f649f5 Mon Sep 17 00:00:00 2001
+From: Geert Uytterhoeven <geert@linux-m68k.org>
+Date: Mon, 14 May 2012 09:47:05 +0000
+Subject: [PATCH 44/50] net/codel: Add missing #include <linux/prefetch.h>
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+m68k allmodconfig:
+
+net/sched/sch_codel.c: In function ‘dequeue’:
+net/sched/sch_codel.c:70: error: implicit declaration of function ‘prefetch’
+make[1]: *** [net/sched/sch_codel.o] Error 1
+
+Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
+Acked-by: Eric Dumazet <edumazet@google.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+ net/sched/sch_codel.c | 1 +
+ 1 file changed, 1 insertion(+)
+
+--- a/net/sched/sch_codel.c
++++ b/net/sched/sch_codel.c
+@@ -46,6 +46,7 @@
+ #include <linux/kernel.h>
+ #include <linux/errno.h>
+ #include <linux/skbuff.h>
++#include <linux/prefetch.h>
+ #include <net/pkt_sched.h>
+ #include <net/codel.h>
+
--- /dev/null
+From 669d67bf777def468970f2dcba1537edf3b2d329 Mon Sep 17 00:00:00 2001
+From: Sasha Levin <levinsasha928@gmail.com>
+Date: Mon, 14 May 2012 11:57:06 +0000
+Subject: [PATCH 45/50] net: codel: fix build errors
+
+Fix the following build error:
+
+net/sched/sch_fq_codel.c: In function 'fq_codel_dump_stats':
+net/sched/sch_fq_codel.c:464:3: error: unknown field 'qdisc_stats' specified in initializer
+net/sched/sch_fq_codel.c:464:3: warning: missing braces around initializer
+net/sched/sch_fq_codel.c:464:3: warning: (near initialization for 'st.<anonymous>')
+net/sched/sch_fq_codel.c:465:3: error: unknown field 'qdisc_stats' specified in initializer
+net/sched/sch_fq_codel.c:465:3: warning: excess elements in struct initializer
+net/sched/sch_fq_codel.c:465:3: warning: (near initialization for 'st')
+net/sched/sch_fq_codel.c:466:3: error: unknown field 'qdisc_stats' specified in initializer
+net/sched/sch_fq_codel.c:466:3: warning: excess elements in struct initializer
+net/sched/sch_fq_codel.c:466:3: warning: (near initialization for 'st')
+net/sched/sch_fq_codel.c:467:3: error: unknown field 'qdisc_stats' specified in initializer
+net/sched/sch_fq_codel.c:467:3: warning: excess elements in struct initializer
+net/sched/sch_fq_codel.c:467:3: warning: (near initialization for 'st')
+make[1]: *** [net/sched/sch_fq_codel.o] Error 1
+
+Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+ net/sched/sch_fq_codel.c | 9 +++++----
+ 1 file changed, 5 insertions(+), 4 deletions(-)
+
+--- a/net/sched/sch_fq_codel.c
++++ b/net/sched/sch_fq_codel.c
+@@ -461,13 +461,14 @@ static int fq_codel_dump_stats(struct Qd
+ struct fq_codel_sched_data *q = qdisc_priv(sch);
+ struct tc_fq_codel_xstats st = {
+ .type = TCA_FQ_CODEL_XSTATS_QDISC,
+- .qdisc_stats.maxpacket = q->cstats.maxpacket,
+- .qdisc_stats.drop_overlimit = q->drop_overlimit,
+- .qdisc_stats.ecn_mark = q->cstats.ecn_mark,
+- .qdisc_stats.new_flow_count = q->new_flow_count,
+ };
+ struct list_head *pos;
+
++ st.qdisc_stats.maxpacket = q->cstats.maxpacket;
++ st.qdisc_stats.drop_overlimit = q->drop_overlimit;
++ st.qdisc_stats.ecn_mark = q->cstats.ecn_mark;
++ st.qdisc_stats.new_flow_count = q->new_flow_count;
++
+ list_for_each(pos, &q->new_flows)
+ st.qdisc_stats.new_flows_len++;
+
--- /dev/null
+From 6ff272c9ad65eda219cd975b9da2dbc31cc812ee Mon Sep 17 00:00:00 2001
+From: Eric Dumazet <eric.dumazet@gmail.com>
+Date: Sat, 12 May 2012 21:23:23 +0000
+Subject: [PATCH 46/50] codel: use u16 field instead of 31bits for
+ rec_inv_sqrt
+
+David pointed out gcc might generate poor code with 31bit fields.
+
+Using u16 is more than enough and permits a better code output.
+
+Also make the code intent more readable using constants, fixed point arithmetic
+not being trivial for everybody.
+
+Suggested-by: David Miller <davem@davemloft.net>
+Signed-off-by: Eric Dumazet <edumazet@google.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+ include/net/codel.h | 25 +++++++++++++++----------
+ 1 file changed, 15 insertions(+), 10 deletions(-)
+
+--- a/include/net/codel.h
++++ b/include/net/codel.h
+@@ -133,13 +133,17 @@ struct codel_params {
+ struct codel_vars {
+ u32 count;
+ u32 lastcount;
+- bool dropping:1;
+- u32 rec_inv_sqrt:31;
++ bool dropping;
++ u16 rec_inv_sqrt;
+ codel_time_t first_above_time;
+ codel_time_t drop_next;
+ codel_time_t ldelay;
+ };
+
++#define REC_INV_SQRT_BITS (8 * sizeof(u16)) /* or sizeof_in_bits(rec_inv_sqrt) */
++/* needed shift to get a Q0.32 number from rec_inv_sqrt */
++#define REC_INV_SQRT_SHIFT (32 - REC_INV_SQRT_BITS)
++
+ /**
+ * struct codel_stats - contains codel shared variables and stats
+ * @maxpacket: largest packet we've seen so far
+@@ -173,17 +177,18 @@ static void codel_stats_init(struct code
+ * http://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Iterative_methods_for_reciprocal_square_roots
+ * new_invsqrt = (invsqrt / 2) * (3 - count * invsqrt^2)
+ *
+- * Here, invsqrt is a fixed point number (< 1.0), 31bit mantissa)
++ * Here, invsqrt is a fixed point number (< 1.0), 32bit mantissa, aka Q0.32
+ */
+ static void codel_Newton_step(struct codel_vars *vars)
+ {
+- u32 invsqrt = vars->rec_inv_sqrt;
+- u32 invsqrt2 = ((u64)invsqrt * invsqrt) >> 31;
+- u64 val = (3LL << 31) - ((u64)vars->count * invsqrt2);
++ u32 invsqrt = ((u32)vars->rec_inv_sqrt) << REC_INV_SQRT_SHIFT;
++ u32 invsqrt2 = ((u64)invsqrt * invsqrt) >> 32;
++ u64 val = (3LL << 32) - ((u64)vars->count * invsqrt2);
+
+- val = (val * invsqrt) >> 32;
++ val >>= 2; /* avoid overflow in following multiply */
++ val = (val * invsqrt) >> (32 - 2 + 1);
+
+- vars->rec_inv_sqrt = val;
++ vars->rec_inv_sqrt = val >> REC_INV_SQRT_SHIFT;
+ }
+
+ /*
+@@ -195,7 +200,7 @@ static codel_time_t codel_control_law(co
+ codel_time_t interval,
+ u32 rec_inv_sqrt)
+ {
+- return t + reciprocal_divide(interval, rec_inv_sqrt << 1);
++ return t + reciprocal_divide(interval, rec_inv_sqrt << REC_INV_SQRT_SHIFT);
+ }
+
+
+@@ -326,7 +331,7 @@ static struct sk_buff *codel_dequeue(str
+ codel_Newton_step(vars);
+ } else {
+ vars->count = 1;
+- vars->rec_inv_sqrt = 0x7fffffff;
++ vars->rec_inv_sqrt = ~0U >> REC_INV_SQRT_SHIFT;
+ }
+ vars->lastcount = vars->count;
+ vars->drop_next = codel_control_law(now, params->interval,
+module_exit(connmark_cleanup_module);
--- a/net/sched/Kconfig
+++ b/net/sched/Kconfig
-@@ -602,6 +602,19 @@ config NET_ACT_CSUM
+@@ -624,6 +624,19 @@ config NET_ACT_CSUM
To compile this code as a module, choose M here: the
module will be called act_csum.
projects / openwrt / svn-archive / archive.git / commitdiff