Hi there!
On Tue, 4 Jun 2002, Martin Devera wrote:
> This is often discussed and is on "TODO" for someone ;)
>
> >
> > SFQ is connection oriented. right?
> > Would be a good idea to make the queues per ip rather than per tcp flow?
> > So there would be per host fairnes.
I've done some in this direction , probably needs more work, and
it's poorly tested - expect b00ms ;)
This adds a new qdisc for now - esfq which is a 100% clone of
original sfq.
- You can set all sfq parameters: hash table size, queue depths,
queue limits.
- You can choose from 3 hash types: original(classic), dst ip, src
ip.
Things to consider: perturbation with dst and src hashes is not
good IMHO, you can try with perturb 0 if it couses trouble.
Please, see the attached files.
Plaing with it gives interesting results:
higher depth -> makes flows equal slower
small depth -> makes flows equal faster
limit kills big delays when set at about 75-85% of depth.
Needs testings and mesurements - that's why i made it
separate qdisc and not a patch over sfq, i wanted to compare both.
Any feedback good or bad is welcome.
--
have fun,
alex
You need:
iproute2-2.2.4-now-ss001007.tar.gz
linux-2.4.18.tar.gz
This may work with next versions too.
Example Step by Step install
------------------------------------------------------------------
Install kernel:
tar zxvf linux-2.4.18.tar.gz
cd linux
cat linux-2.4.18-esfq.diff | patch -p1
make menuconfig
Now you have it in:
Networking options ---> QoS and/or fair queueing ---> ESFQ queue
Configure and install kernel
make dep clean bzImage modules_install
cp System.map /boot/
cp arch/i386/boot/bzImage /boot/bzImage
Edit lilo.conf and add your new kernel.
------------------------------------------------------------------
Install iproute:
tar zxvf iproute2-2.2.4-now-ss001007.tar.gz
cd iproute2
cat iproute2-2.2.4-now-ss001007-esfq.diff | patch -p1
make
/* Note: If you get an error in lib/ll_proto.c comment _PF(ECHO,echo) */
cp tc/tc your_favourite_iproute_path/tc
cp ip/ip your_favourite_iproute_path/ip
------------------------------------------------------------------
Usage: ... esfq [ perturb SECS ] [ quantum BYTES ] [ depth FLOWS ]
[ divisor HASHBITS ] [ limit PKTS ] [ hash HASHTYPE]
Where:
HASHTYPE := { classic | src | dst }
Examples:
tc qdisc add dev eth0 root esfq limit 128 depth 128 divisor 10 \
hash classic perturb 15
Setups a classic SFQ.
tc qdisc add dev eth0 root esfq limit 64 depth 64 divisor 11 \
hash dst
Setups a dst SFQ with limit and depth of 64 packets and
11bits (2048 rows) hash table. 1:1 with sch_sfq.
You can experiment with the values as you like to find
the best which sfq can do for you.
More can be found in:
linux/net/sched/sch_sfq.c
linux/net/sched/sch_esfq.c
Limits:
- limit must be less than depth
- divisor must be less than 15
diff -urN iproute2.orig/tc/Makefile iproute2/tc/Makefile
--- iproute2.orig/tc/Makefile Sun Apr 16 20:42:53 2000
+++ iproute2/tc/Makefile Tue May 14 23:04:10 2002
@@ -5,6 +5,7 @@
TCMODULES :=
TCMODULES += q_fifo.o
TCMODULES += q_sfq.o
+TCMODULES += q_esfq.o
TCMODULES += q_red.o
TCMODULES += q_prio.o
TCMODULES += q_tbf.o
diff -urN iproute2.orig/tc/q_esfq.c iproute2/tc/q_esfq.c
--- iproute2.orig/tc/q_esfq.c Thu Jan 1 02:00:00 1970
+++ iproute2/tc/q_esfq.c Thu May 16 02:13:30 2002
@@ -0,0 +1,169 @@
+/*
+ * q_esfq.c ESFQ.
+ *
+ * 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.
+ *
+ * Authors: Alexey Kuznetsov, <[EMAIL PROTECTED]>
+ *
+ * Changes: Alexander Atanasov, <[EMAIL PROTECTED]>
+ * Added depth,limit,divisor,hash_kind options.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <syslog.h>
+#include <fcntl.h>
+#include <math.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <string.h>
+
+#include "utils.h"
+#include "tc_util.h"
+
+static void explain(void)
+{
+ fprintf(stderr, "Usage: ... esfq [ perturb SECS ] [ quantum BYTES ] [ depth
+FLOWS ]\n\t[ divisor HASHBITS ] [ limit PKTS ] [ hash HASHTYPE]\n");
+ fprintf(stderr,"Where: \n");
+ fprintf(stderr,"HASHTYPE := { classic | src | dst }\n");
+}
+
+#define usage() return(-1)
+
+static int esfq_parse_opt(struct qdisc_util *qu, int argc, char **argv, struct
+nlmsghdr *n)
+{
+ int ok=0;
+ struct tc_sfq_qopt opt;
+
+ memset(&opt, 0, sizeof(opt));
+
+ opt.hash_kind= TCA_SFQ_HASH_CLASSIC;
+
+ while (argc > 0) {
+ if (strcmp(*argv, "quantum") == 0) {
+ NEXT_ARG();
+ if (get_size(&opt.quantum, *argv)) {
+ fprintf(stderr, "Illegal \"quantum\"\n");
+ return -1;
+ }
+ ok++;
+ } else if (strcmp(*argv, "perturb") == 0) {
+ NEXT_ARG();
+ if (get_integer(&opt.perturb_period, *argv, 0)) {
+ fprintf(stderr, "Illegal \"perturb\"\n");
+ return -1;
+ }
+ ok++;
+ } else if (strcmp(*argv, "depth") == 0) {
+ NEXT_ARG();
+ if (get_integer(&opt.flows, *argv, 0)) {
+ fprintf(stderr, "Illegal \"depth\"\n");
+ return -1;
+ }
+ ok++;
+ } else if (strcmp(*argv, "divisor") == 0) {
+ NEXT_ARG();
+ if (get_integer(&opt.divisor, *argv, 0)) {
+ fprintf(stderr, "Illegal \"divisor\"\n");
+ return -1;
+ }
+ if(opt.divisor >= 15) {
+ fprintf(stderr, "Illegal \"divisor\" must be < 15\n");
+ return -1;
+ }
+ opt.divisor=pow(2,opt.divisor);
+ ok++;
+ } else if (strcmp(*argv, "limit") == 0) {
+ NEXT_ARG();
+ if (get_integer(&opt.limit, *argv, 0)) {
+ fprintf(stderr, "Illegal \"limit\"\n");
+ return -1;
+ }
+ ok++;
+ } else if (strcmp(*argv, "hash") == 0) {
+ NEXT_ARG();
+ if(strcmp(*argv,"classic") == 0) {
+ opt.hash_kind= TCA_SFQ_HASH_CLASSIC;
+ } else
+ if(strcmp(*argv,"dst") == 0) {
+ opt.hash_kind= TCA_SFQ_HASH_DST;
+ } else
+ if(strcmp(*argv,"src") == 0) {
+ opt.hash_kind= TCA_SFQ_HASH_SRC;
+ } else {
+ fprintf(stderr, "Illegal \"hash\"\n");
+ explain();
+ return -1;
+ }
+ ok++;
+ } else if (strcmp(*argv, "help") == 0) {
+ explain();
+ return -1;
+ } else {
+ fprintf(stderr, "What is \"%s\"?\n", *argv);
+ explain();
+ return -1;
+ }
+ argc--; argv++;
+ }
+
+ if (ok)
+ addattr_l(n, 1024, TCA_OPTIONS, &opt, sizeof(opt));
+ return 0;
+}
+
+static int esfq_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
+{
+ struct tc_sfq_qopt *qopt;
+ SPRINT_BUF(b1);
+
+ if (opt == NULL)
+ return 0;
+
+ if (RTA_PAYLOAD(opt) < sizeof(*qopt))
+ return -1;
+ qopt = RTA_DATA(opt);
+ fprintf(f, "quantum %s ", sprint_size(qopt->quantum, b1));
+ if (show_details) {
+ fprintf(f, "limit %up flows %u/%u ",
+ qopt->limit, qopt->flows, qopt->divisor);
+ }
+ if (qopt->perturb_period)
+ fprintf(f, "perturb %dsec ", qopt->perturb_period);
+
+ fprintf(f,"hash: ");
+ switch(qopt->hash_kind)
+ {
+ case TCA_SFQ_HASH_CLASSIC:
+ fprintf(f,"classic");
+ break;
+ case TCA_SFQ_HASH_DST:
+ fprintf(f,"dst");
+ break;
+ case TCA_SFQ_HASH_SRC:
+ fprintf(f,"src");
+ break;
+ default:
+ fprintf(f,"Unknown");
+ }
+ return 0;
+}
+
+static int esfq_print_xstats(struct qdisc_util *qu, FILE *f, struct rtattr *xstats)
+{
+ return 0;
+}
+
+
+struct qdisc_util esfq_util = {
+ NULL,
+ "esfq",
+ esfq_parse_opt,
+ esfq_print_opt,
+ esfq_print_xstats,
+};
--- linux-2.4.18/include/linux/pkt_sched.h.orig Tue May 14 23:25:13 2002
+++ linux-2.4.18/include/linux/pkt_sched.h Tue May 14 23:34:57 2002
@@ -157,6 +157,13 @@
/* SFQ section */
+enum
+{
+ TCA_SFQ_HASH_CLASSIC,
+ TCA_SFQ_HASH_DST,
+ TCA_SFQ_HASH_SRC,
+};
+
struct tc_sfq_qopt
{
unsigned quantum; /* Bytes per round allocated to flow */
@@ -164,6 +171,7 @@
__u32 limit; /* Maximal packets in queue */
unsigned divisor; /* Hash divisor */
unsigned flows; /* Maximal number of flows */
+ unsigned hash_kind; /* Hash function to use for flow
+identification */
};
/*
@@ -173,6 +181,8 @@
*
* The only reason for this is efficiency, it is possible
* to change these parameters in compile time.
+ *
+ * If you need to play with this values use esfq.
*/
/* RED section */
--- linux-2.4.18/net/ipv4/netfilter/ipchains_core.c.orig Fri May 24 19:27:01
2002
+++ linux-2.4.18/net/ipv4/netfilter/ipchains_core.c Fri May 24 19:31:24 2002
@@ -723,6 +723,7 @@
src_port, dst_port,
count, tcpsyn)) {
ret = FW_BLOCK;
+ cleanup(chain, 0, slot);
goto out;
}
break;
--- linux-2.4.18/net/sched/Makefile.orig Tue May 14 23:06:55 2002
+++ linux-2.4.18/net/sched/Makefile Tue May 14 23:07:08 2002
@@ -17,6 +17,7 @@
obj-$(CONFIG_NET_SCH_HPFQ) += sch_hpfq.o
obj-$(CONFIG_NET_SCH_HFSC) += sch_hfsc.o
obj-$(CONFIG_NET_SCH_SFQ) += sch_sfq.o
+obj-$(CONFIG_NET_SCH_ESFQ) += sch_esfq.o
obj-$(CONFIG_NET_SCH_RED) += sch_red.o
obj-$(CONFIG_NET_SCH_TBF) += sch_tbf.o
obj-$(CONFIG_NET_SCH_PRIO) += sch_prio.o
--- linux-2.4.18/net/sched/Config.in.orig Tue May 14 23:07:15 2002
+++ linux-2.4.18/net/sched/Config.in Tue May 14 23:09:03 2002
@@ -11,6 +11,7 @@
tristate ' The simplest PRIO pseudoscheduler' CONFIG_NET_SCH_PRIO
tristate ' RED queue' CONFIG_NET_SCH_RED
tristate ' SFQ queue' CONFIG_NET_SCH_SFQ
+tristate ' ESFQ queue' CONFIG_NET_SCH_ESFQ
tristate ' TEQL queue' CONFIG_NET_SCH_TEQL
tristate ' TBF queue' CONFIG_NET_SCH_TBF
tristate ' GRED queue' CONFIG_NET_SCH_GRED
--- linux-2.4.18/Documentation/Configure.help.orig Thu May 16 01:37:22 2002
+++ linux-2.4.18/Documentation/Configure.help Mon May 27 01:09:03 2002
@@ -9433,6 +9433,24 @@
whenever you want). If you want to compile it as a module, say M
here and read <file:Documentation/modules.txt>.
+ESFQ queue
+CONFIG_NET_SCH_ESFQ
+ Say Y here if you want to use the Stochastic Fairness Queueing (SFQ)
+ packet scheduling algorithm for some of your network devices or as a
+ leaf discipline for the CBQ scheduling algorithm (see the top of
+ <file:net/sched/sch_esfq.c> for details and references about the SFQ
+ algorithm).
+
+ This is an enchanced SFQ version which allows you to control the
+ hardcoded values in the SFQ scheduler: queue depth, hash table size,
+ queues limit. Also adds control to the hash function used to identify
+ packet flows. Hash by src or dst ip and original sfq hash.
+
+ This code is also available as a module called sch_esfq.o ( = code
+ which can be inserted in and removed from the running kernel
+ whenever you want). If you want to compile it as a module, say M
+ here and read <file:Documentation/modules.txt>.
+
TEQL queue
CONFIG_NET_SCH_TEQL
Say Y here if you want to use the True Link Equalizer (TLE) packet
--- /dev/null Mon Jul 18 02:46:18 1994
+++ linux-2.4.18/net/sched/sch_esfq.c Mon May 27 01:49:19 2002
@@ -0,0 +1,591 @@
+/*
+ * net/sched/sch_esfq.c Extended Stochastic Fairness Queueing 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.
+ *
+ * Authors: Alexey Kuznetsov, <[EMAIL PROTECTED]>
+ *
+ * Changes: Alexander Atanasov, <[EMAIL PROTECTED]>
+ * Added dynamic depth,limit,divisor,hash_kind options.
+ * Added dst and src hashes.
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <asm/bitops.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/in.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/if_ether.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/notifier.h>
+#include <linux/init.h>
+#include <net/ip.h>
+#include <linux/ipv6.h>
+#include <net/route.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <net/pkt_sched.h>
+
+
+/* Stochastic Fairness Queuing algorithm.
+ For more comments look at sch_sfq.c.
+ The difference is that you can change limit, depth,
+ hash table size and choose 3 hash types.
+
+ classic: same as in sch_sfq.c
+ dst: destination IP address
+ src: source IP address
+
+ TODO:
+ make sfq_change work.
+*/
+
+
+/* This type should contain at least SFQ_DEPTH*2 values */
+typedef unsigned int esfq_index;
+
+struct esfq_head
+{
+ esfq_index next;
+ esfq_index prev;
+};
+
+struct esfq_sched_data
+{
+/* Parameters */
+ int perturb_period;
+ unsigned quantum; /* Allotment per round: MUST BE >= MTU */
+ int limit;
+ unsigned depth;
+ unsigned hash_divisor;
+ unsigned hash_kind;
+/* Variables */
+ struct timer_list perturb_timer;
+ int perturbation;
+ esfq_index tail; /* Index of current slot in round */
+ esfq_index max_depth; /* Maximal depth */
+
+ esfq_index *ht; /* Hash table */
+ esfq_index *next; /* Active slots link */
+ short *allot; /* Current allotment per slot */
+ unsigned short *hash; /* Hash value indexed by slots */
+ struct sk_buff_head *qs; /* Slot queue */
+ struct esfq_head *dep; /* Linked list of slots, indexed by
+depth */
+};
+
+static __inline__ unsigned esfq_hash_u32(struct esfq_sched_data *q,u32 h)
+{
+ int pert = q->perturbation;
+
+ if (pert)
+ h = (h<<pert) ^ (h>>(0x1F - pert));
+ h = ntohl(h) * 2654435761UL;
+ return h & (q->hash_divisor-1);
+}
+
+static __inline__ unsigned esfq_fold_hash_classic(struct esfq_sched_data *q, u32 h,
+u32 h1)
+{
+ int pert = q->perturbation;
+
+ /* Have we any rotation primitives? If not, WHY? */
+ h ^= (h1<<pert) ^ (h1>>(0x1F - pert));
+ h ^= h>>10;
+ return h & (q->hash_divisor-1);
+}
+
+#ifndef IPPROTO_ESP
+#define IPPROTO_ESP 50
+#endif
+
+static unsigned esfq_hash(struct esfq_sched_data *q, struct sk_buff *skb)
+{
+ u32 h, h2;
+ u32 hs;
+
+ switch (skb->protocol) {
+ case __constant_htons(ETH_P_IP):
+ {
+ struct iphdr *iph = skb->nh.iph;
+ h = iph->daddr;
+ hs = iph->saddr;
+ h2 = hs^iph->protocol;
+ if (!(iph->frag_off&htons(IP_MF|IP_OFFSET)) &&
+ (iph->protocol == IPPROTO_TCP ||
+ iph->protocol == IPPROTO_UDP ||
+ iph->protocol == IPPROTO_ESP))
+ h2 ^= *(((u32*)iph) + iph->ihl);
+ break;
+ }
+ case __constant_htons(ETH_P_IPV6):
+ {
+ struct ipv6hdr *iph = skb->nh.ipv6h;
+ h = iph->daddr.s6_addr32[3];
+ hs = iph->saddr.s6_addr32[3];
+ h2 = hs^iph->nexthdr;
+ if (iph->nexthdr == IPPROTO_TCP ||
+ iph->nexthdr == IPPROTO_UDP ||
+ iph->nexthdr == IPPROTO_ESP)
+ h2 ^= *(u32*)&iph[1];
+ break;
+ }
+ default:
+ h = (u32)(unsigned long)skb->dst;
+ hs = (u32)(unsigned long)skb->sk;
+ h2 = hs^skb->protocol;
+ }
+ switch(q->hash_kind)
+ {
+ case TCA_SFQ_HASH_CLASSIC:
+ return esfq_fold_hash_classic(q, h, h2);
+ case TCA_SFQ_HASH_DST:
+ return esfq_hash_u32(q,h);
+ case TCA_SFQ_HASH_SRC:
+ return esfq_hash_u32(q,hs);
+ default:
+ if (net_ratelimit())
+ printk(KERN_DEBUG "esfq unknown hash method, fallback to
+classic\n");
+ }
+ return esfq_fold_hash_classic(q, h, h2);
+}
+
+extern __inline__ void esfq_link(struct esfq_sched_data *q, esfq_index x)
+{
+ esfq_index p, n;
+ int d = q->qs[x].qlen + q->depth;
+
+ p = d;
+ n = q->dep[d].next;
+ q->dep[x].next = n;
+ q->dep[x].prev = p;
+ q->dep[p].next = q->dep[n].prev = x;
+}
+
+extern __inline__ void esfq_dec(struct esfq_sched_data *q, esfq_index x)
+{
+ esfq_index p, n;
+
+ n = q->dep[x].next;
+ p = q->dep[x].prev;
+ q->dep[p].next = n;
+ q->dep[n].prev = p;
+
+ if (n == p && q->max_depth == q->qs[x].qlen + 1)
+ q->max_depth--;
+
+ esfq_link(q, x);
+}
+
+extern __inline__ void esfq_inc(struct esfq_sched_data *q, esfq_index x)
+{
+ esfq_index p, n;
+ int d;
+
+ n = q->dep[x].next;
+ p = q->dep[x].prev;
+ q->dep[p].next = n;
+ q->dep[n].prev = p;
+ d = q->qs[x].qlen;
+ if (q->max_depth < d)
+ q->max_depth = d;
+
+ esfq_link(q, x);
+}
+
+static int esfq_drop(struct Qdisc *sch)
+{
+ struct esfq_sched_data *q = (struct esfq_sched_data *)sch->data;
+ esfq_index d = q->max_depth;
+ struct sk_buff *skb;
+
+ /* Queue is full! Find the longest slot and
+ drop a packet from it */
+
+ if (d > 1) {
+ esfq_index x = q->dep[d+q->depth].next;
+ skb = q->qs[x].prev;
+ __skb_unlink(skb, &q->qs[x]);
+ kfree_skb(skb);
+ esfq_dec(q, x);
+ sch->q.qlen--;
+ sch->stats.drops++;
+ return 1;
+ }
+
+ if (d == 1) {
+ /* It is difficult to believe, but ALL THE SLOTS HAVE LENGTH 1. */
+ d = q->next[q->tail];
+ q->next[q->tail] = q->next[d];
+ q->allot[q->next[d]] += q->quantum;
+ skb = q->qs[d].prev;
+ __skb_unlink(skb, &q->qs[d]);
+ kfree_skb(skb);
+ esfq_dec(q, d);
+ sch->q.qlen--;
+ q->ht[q->hash[d]] = q->depth;
+ sch->stats.drops++;
+ return 1;
+ }
+
+ return 0;
+}
+
+static int
+esfq_enqueue(struct sk_buff *skb, struct Qdisc* sch)
+{
+ struct esfq_sched_data *q = (struct esfq_sched_data *)sch->data;
+ unsigned hash = esfq_hash(q, skb);
+ unsigned depth = q->depth;
+ esfq_index x;
+
+ x = q->ht[hash];
+ if (x == depth) {
+ q->ht[hash] = x = q->dep[depth].next;
+ q->hash[x] = hash;
+ }
+ __skb_queue_tail(&q->qs[x], skb);
+ esfq_inc(q, x);
+ if (q->qs[x].qlen == 1) { /* The flow is new */
+ if (q->tail == depth) { /* It is the first flow */
+ q->tail = x;
+ q->next[x] = x;
+ q->allot[x] = q->quantum;
+ } else {
+ q->next[x] = q->next[q->tail];
+ q->next[q->tail] = x;
+ q->tail = x;
+ }
+ }
+ if (++sch->q.qlen < q->limit-1) {
+ sch->stats.bytes += skb->len;
+ sch->stats.packets++;
+ return 0;
+ }
+
+ esfq_drop(sch);
+ return NET_XMIT_CN;
+}
+
+static int
+esfq_requeue(struct sk_buff *skb, struct Qdisc* sch)
+{
+ struct esfq_sched_data *q = (struct esfq_sched_data *)sch->data;
+ unsigned hash = esfq_hash(q, skb);
+ unsigned depth = q->depth;
+ esfq_index x;
+
+ x = q->ht[hash];
+ if (x == depth) {
+ q->ht[hash] = x = q->dep[depth].next;
+ q->hash[x] = hash;
+ }
+ __skb_queue_head(&q->qs[x], skb);
+ esfq_inc(q, x);
+ if (q->qs[x].qlen == 1) { /* The flow is new */
+ if (q->tail == depth) { /* It is the first flow */
+ q->tail = x;
+ q->next[x] = x;
+ q->allot[x] = q->quantum;
+ } else {
+ q->next[x] = q->next[q->tail];
+ q->next[q->tail] = x;
+ q->tail = x;
+ }
+ }
+ if (++sch->q.qlen < q->limit - 1)
+ return 0;
+
+ sch->stats.drops++;
+ esfq_drop(sch);
+ return NET_XMIT_CN;
+}
+
+
+
+
+static struct sk_buff *
+esfq_dequeue(struct Qdisc* sch)
+{
+ struct esfq_sched_data *q = (struct esfq_sched_data *)sch->data;
+ struct sk_buff *skb;
+ unsigned depth = q->depth;
+ esfq_index a, old_a;
+
+ /* No active slots */
+ if (q->tail == depth)
+ return NULL;
+
+ a = old_a = q->next[q->tail];
+
+ /* Grab packet */
+ skb = __skb_dequeue(&q->qs[a]);
+ esfq_dec(q, a);
+ sch->q.qlen--;
+
+ /* Is the slot empty? */
+ if (q->qs[a].qlen == 0) {
+ a = q->next[a];
+ if (a == old_a) {
+ q->tail = depth;
+ return skb;
+ }
+ q->next[q->tail] = a;
+ q->allot[a] += q->quantum;
+ } else if ((q->allot[a] -= skb->len) <= 0) {
+ q->tail = a;
+ a = q->next[a];
+ q->allot[a] += q->quantum;
+ }
+
+ return skb;
+}
+
+static void
+esfq_reset(struct Qdisc* sch)
+{
+ struct sk_buff *skb;
+
+ while ((skb = esfq_dequeue(sch)) != NULL)
+ kfree_skb(skb);
+}
+
+static void esfq_perturbation(unsigned long arg)
+{
+ struct Qdisc *sch = (struct Qdisc*)arg;
+ struct esfq_sched_data *q = (struct esfq_sched_data *)sch->data;
+
+ q->perturbation = net_random()&0x1F;
+ q->perturb_timer.expires = jiffies + q->perturb_period;
+
+ if (q->perturb_period) {
+ q->perturb_timer.expires = jiffies + q->perturb_period;
+ add_timer(&q->perturb_timer);
+ }
+}
+
+static int esfq_change(struct Qdisc *sch, struct rtattr *opt)
+{
+ struct esfq_sched_data *q = (struct esfq_sched_data *)sch->data;
+ struct tc_sfq_qopt *ctl = RTA_DATA(opt);
+ int old_perturb = q->perturb_period;
+
+ if (opt->rta_len < RTA_LENGTH(sizeof(*ctl)))
+ return -EINVAL;
+
+ sch_tree_lock(sch);
+ q->quantum = ctl->quantum ? : psched_mtu(sch->dev);
+ q->perturb_period = ctl->perturb_period*HZ;
+// q->hash_divisor = ctl->divisor;
+// q->tail = q->limit = q->depth = ctl->flows;
+
+ if (ctl->limit)
+ q->limit = min_t(u32, ctl->limit, q->depth);
+
+ if (ctl->hash_kind) {
+ q->hash_kind = ctl->hash_kind;
+ if (q->hash_kind != TCA_SFQ_HASH_CLASSIC)
+ q->perturb_period = 0;
+ }
+
+ // is sch_tree_lock enough to do this ?
+ while (sch->q.qlen >= q->limit-1)
+ esfq_drop(sch);
+
+ if (old_perturb)
+ del_timer(&q->perturb_timer);
+ if (q->perturb_period) {
+ q->perturb_timer.expires = jiffies + q->perturb_period;
+ add_timer(&q->perturb_timer);
+ } else {
+ q->perturbation = 0;
+ }
+ sch_tree_unlock(sch);
+ return 0;
+}
+
+static int esfq_init(struct Qdisc *sch, struct rtattr *opt)
+{
+ struct esfq_sched_data *q = (struct esfq_sched_data *)sch->data;
+ struct tc_sfq_qopt *ctl;
+ esfq_index p = ~0UL/2;
+ int i;
+
+ if (opt && opt->rta_len < RTA_LENGTH(sizeof(*ctl)))
+ return -EINVAL;
+ q->perturb_timer.data = (unsigned long)sch;
+ q->perturb_timer.function = esfq_perturbation;
+ init_timer(&q->perturb_timer);
+ q->perturbation = 0;
+ q->hash_kind = TCA_SFQ_HASH_CLASSIC;
+ q->max_depth = 0;
+ if (opt == NULL) {
+ q->quantum = psched_mtu(sch->dev);
+ q->perturb_period = 0;
+ q->hash_divisor = 1024;
+ q->tail = q->limit = q->depth = 128;
+
+ } else {
+ ctl = RTA_DATA(opt);
+ q->quantum = ctl->quantum ? : psched_mtu(sch->dev);
+ q->perturb_period = ctl->perturb_period*HZ;
+ q->hash_divisor = ctl->divisor;
+ q->tail = q->limit = q->depth = ctl->flows;
+
+ if ( q->depth > p - 1 )
+ return -EINVAL;
+
+ if (ctl->limit)
+ q->limit = min_t(u32, ctl->limit, q->depth);
+
+ if (ctl->hash_kind) {
+ q->hash_kind = ctl->hash_kind;
+ if (q->hash_kind != TCA_SFQ_HASH_CLASSIC)
+ q->perturb_period = 0;
+ }
+
+ while (sch->q.qlen >= q->limit-1)
+ esfq_drop(sch);
+
+ if (q->perturb_period) {
+ q->perturb_timer.expires = jiffies + q->perturb_period;
+ add_timer(&q->perturb_timer);
+ }
+ }
+
+ q->ht = kmalloc(q->hash_divisor*sizeof(esfq_index), GFP_KERNEL);
+ if (!q->ht)
+ goto err_case;
+
+ q->dep = kmalloc((1+q->depth*2)*sizeof(struct esfq_head), GFP_KERNEL);
+ if (!q->dep)
+ goto err_case;
+ q->next = kmalloc(q->depth*sizeof(esfq_index), GFP_KERNEL);
+ if (!q->next)
+ goto err_case;
+
+ q->allot = kmalloc(q->depth*sizeof(short), GFP_KERNEL);
+ if (!q->allot)
+ goto err_case;
+ q->hash = kmalloc(q->depth*sizeof(unsigned short), GFP_KERNEL);
+ if (!q->hash)
+ goto err_case;
+ q->qs = kmalloc(q->depth*sizeof(struct sk_buff_head), GFP_KERNEL);
+ if (!q->qs)
+ goto err_case;
+
+ for (i=0; i< q->hash_divisor; i++)
+ q->ht[i] = q->depth;
+ for (i=0; i<q->depth; i++) {
+ skb_queue_head_init(&q->qs[i]);
+ q->dep[i+q->depth].next = i+q->depth;
+ q->dep[i+q->depth].prev = i+q->depth;
+ }
+
+ for (i=0; i<q->depth; i++)
+ esfq_link(q, i);
+ MOD_INC_USE_COUNT;
+ return 0;
+err_case:
+ if (q->ht)
+ kfree(q->ht);
+ if (q->dep)
+ kfree(q->dep);
+ if (q->next)
+ kfree(q->next);
+ if (q->allot)
+ kfree(q->allot);
+ if (q->hash)
+ kfree(q->hash);
+ if (q->qs)
+ kfree(q->qs);
+ return -ENOBUFS;
+}
+
+static void esfq_destroy(struct Qdisc *sch)
+{
+ struct esfq_sched_data *q = (struct esfq_sched_data *)sch->data;
+ del_timer(&q->perturb_timer);
+ if(q->ht)
+ kfree(q->ht);
+ if(q->dep)
+ kfree(q->dep);
+ if(q->next)
+ kfree(q->next);
+ if(q->allot)
+ kfree(q->allot);
+ if(q->hash)
+ kfree(q->hash);
+ if(q->qs)
+ kfree(q->qs);
+ MOD_DEC_USE_COUNT;
+}
+
+static int esfq_dump(struct Qdisc *sch, struct sk_buff *skb)
+{
+ struct esfq_sched_data *q = (struct esfq_sched_data *)sch->data;
+ unsigned char *b = skb->tail;
+ struct tc_sfq_qopt opt;
+
+ opt.quantum = q->quantum;
+ opt.perturb_period = q->perturb_period/HZ;
+
+ opt.limit = q->limit;
+ opt.divisor = q->hash_divisor;
+ opt.flows = q->depth;
+ opt.hash_kind = q->hash_kind;
+
+ RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
+
+ return skb->len;
+
+rtattr_failure:
+ skb_trim(skb, b - skb->data);
+ return -1;
+}
+
+struct Qdisc_ops esfq_qdisc_ops =
+{
+ NULL,
+ NULL,
+ "esfq",
+ sizeof(struct esfq_sched_data),
+
+ esfq_enqueue,
+ esfq_dequeue,
+ esfq_requeue,
+ esfq_drop,
+
+ esfq_init,
+ esfq_reset,
+ esfq_destroy,
+ NULL, /* esfq_change - needs more work */
+
+ esfq_dump,
+};
+
+#ifdef MODULE
+int init_module(void)
+{
+ return register_qdisc(&esfq_qdisc_ops);
+}
+
+void cleanup_module(void)
+{
+ unregister_qdisc(&esfq_qdisc_ops);
+}
+#endif
+MODULE_LICENSE("GPL");
