aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/generic-2.6/patches/200-sched_esfq.patch
blob: 6830b833ad786d8384fb5006cb0faf91bd8ca02e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
diff -urN linux-2.6.19.old/include/linux/pkt_sched.h linux-2.6.19.dev/include/linux/pkt_sched.h
--- linux-2.6.19.old/include/linux/pkt_sched.h	2006-11-29 22:57:37.000000000 +0100
+++ linux-2.6.19.dev/include/linux/pkt_sched.h	2006-12-14 03:13:51.000000000 +0100
@@ -146,8 +146,35 @@
  *
  *	The only reason for this is efficiency, it is possible
  *	to change these parameters in compile time.
+ *	
+ *	If you need to play with these values use esfq instead.
  */
 
+/* ESFQ section */
+
+enum
+{
+        /* traditional */
+	TCA_SFQ_HASH_CLASSIC,
+	TCA_SFQ_HASH_DST,
+	TCA_SFQ_HASH_SRC,
+	TCA_SFQ_HASH_FWMARK,
+        /* direct */
+	TCA_SFQ_HASH_DSTDIR,
+	TCA_SFQ_HASH_SRCDIR,
+	TCA_SFQ_HASH_FWMARKDIR,
+};
+
+struct tc_esfq_qopt
+{
+	unsigned	quantum;	/* Bytes per round allocated to flow */
+	int		perturb_period;	/* Period of hash perturbation */
+	__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 */
+};
+
 /* RED section */
 
 enum
diff -urN linux-2.6.19.old/net/sched/Kconfig linux-2.6.19.dev/net/sched/Kconfig
--- linux-2.6.19.old/net/sched/Kconfig	2006-11-29 22:57:37.000000000 +0100
+++ linux-2.6.19.dev/net/sched/Kconfig	2006-12-14 03:13:51.000000000 +0100
@@ -185,6 +185,28 @@
 	  To compile this code as a module, choose M here: the
 	  module will be called sch_sfq.
 
+config NET_SCH_ESFQ
+	tristate "ESFQ queue"
+	depends on NET_SCHED
+	---help---
+	  Say Y here if you want to use the Enhanced Stochastic Fairness
+	  Queueing (ESFQ) packet scheduling algorithm for some of your network
+	  devices or as a leaf discipline for a classful qdisc such as HTB or
+	  CBQ (see the top of <file:net/sched/sch_esfq.c> for details and
+	  references to the SFQ algorithm).
+	  
+	  This is an enchanced SFQ version which allows you to control some
+	  hardcoded values in the SFQ scheduler: queue depth, hash table size,
+	  and queues limit.
+	  
+	  ESFQ also adds control to the hash function used to identify packet
+	  flows. The original SFQ hashes by individual flow (TCP session or UDP
+	  stream); ESFQ can hash by src or dst IP as well, which can be more
+	  fair to users in some networking situations.
+	  
+	  To compile this code as a module, choose M here: the
+	  module will be called sch_esfq.
+
 config NET_SCH_TEQL
 	tristate "True Link Equalizer (TEQL)"
 	---help---
diff -urN linux-2.6.19.old/net/sched/Makefile linux-2.6.19.dev/net/sched/Makefile
--- linux-2.6.19.old/net/sched/Makefile	2006-11-29 22:57:37.000000000 +0100
+++ linux-2.6.19.dev/net/sched/Makefile	2006-12-14 03:13:51.000000000 +0100
@@ -23,6 +23,7 @@
 obj-$(CONFIG_NET_SCH_INGRESS)	+= sch_ingress.o 
 obj-$(CONFIG_NET_SCH_DSMARK)	+= sch_dsmark.o
 obj-$(CONFIG_NET_SCH_SFQ)	+= sch_sfq.o
+obj-$(CONFIG_NET_SCH_ESFQ)	+= sch_esfq.o
 obj-$(CONFIG_NET_SCH_TBF)	+= sch_tbf.o
 obj-$(CONFIG_NET_SCH_TEQL)	+= sch_teql.o
 obj-$(CONFIG_NET_SCH_PRIO)	+= sch_prio.o
diff -urN linux-2.6.19.old/net/sched/sch_esfq.c linux-2.6.19.dev/net/sched/sch_esfq.c
--- linux-2.6.19.old/net/sched/sch_esfq.c	1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.19.dev/net/sched/sch_esfq.c	2006-12-14 03:13:51.000000000 +0100
@@ -0,0 +1,644 @@
+/*
+ * 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, <kuznet@ms2.inr.ac.ru>
+ *
+ * Changes:	Alexander Atanasov, <alex@ssi.bg>
+ *		Added dynamic depth,limit,divisor,hash_kind options.
+ *		Added dst and src hashes.
+ *
+ * 		Alexander Clouter, <alex@digriz.org.uk>
+ *		Ported ESFQ to Linux 2.6.
+ *
+ * 		Corey Hickey, <bugfood-c@fatooh.org>
+ *		Maintenance of the Linux 2.6 port.
+ *		Added fwmark hash (thanks to Robert Kurjata)
+ *		Added direct hashing for src, dst, and fwmark.
+ *		
+ */
+
+#include <linux/autoconf.h>
+#include <linux/module.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <linux/bitops.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/jiffies.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 7 hash types.
+	
+	classic:	same as in sch_sfq.c
+	dst:		destination IP address
+	src:		source IP address
+	fwmark:         netfilter mark value
+	dst_direct:
+	src_direct:
+	fwmark_direct:  direct hashing of the above sources
+	
+	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 */
+	unsigned	dyn_min;	/* For dynamic divisor adjustment; minimum value seen */
+	unsigned	dyn_max;	/*                                 maximum value seen */
+	unsigned	dyn_range;	/*	        		   saved range */
+};
+
+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);
+}
+
+/* Hash input values directly into the "nearest" slot, taking into account the
+ * range of input values seen. This is most useful when the hash table is at
+ * least as large as the range of possible values. */
+static __inline__ unsigned esfq_hash_direct(struct esfq_sched_data *q, u32 h)
+{
+	/* adjust minimum and maximum */
+	if (h < q->dyn_min || h > q->dyn_max) {
+		q->dyn_min = h < q->dyn_min ? h : q->dyn_min;
+		q->dyn_max = h > q->dyn_max ? h : q->dyn_max;
+	
+		/* find new range */
+		if ((q->dyn_range = q->dyn_max - q->dyn_min) >= q->hash_divisor)
+			printk(KERN_WARNING "ESFQ: (direct hash) Input range %u is larger than hash "
+					"table. See ESFQ README for details.\n", q->dyn_range);
+	}
+	
+	/* hash input values into slot numbers */
+	if (q->dyn_min == q->dyn_max)
+		return 0; /* only one value seen; avoid division by 0 */
+	else
+		return (h - q->dyn_min) * (q->hash_divisor - 1) / q->dyn_range;
+}
+
+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);
+}
+
+static unsigned esfq_hash(struct esfq_sched_data *q, struct sk_buff *skb)
+{
+	u32 h, h2;
+	u32 hs;
+	u32 nfm;
+
+	switch (skb->protocol) {
+	case __constant_htons(ETH_P_IP):
+	{
+		struct iphdr *iph = skb->nh.iph;
+		h = iph->daddr;
+		hs = iph->saddr;
+		nfm = skb->nfmark;
+		h2 = hs^iph->protocol;
+		if (!(iph->frag_off&htons(IP_MF|IP_OFFSET)) &&
+		    (iph->protocol == IPPROTO_TCP ||
+		     iph->protocol == IPPROTO_UDP ||
+		     iph->protocol == IPPROTO_SCTP ||
+		     iph->protocol == IPPROTO_DCCP ||
+		     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];
+		nfm = skb->nfmark;
+		h2 = hs^iph->nexthdr;
+		if (iph->nexthdr == IPPROTO_TCP ||
+		    iph->nexthdr == IPPROTO_UDP ||
+		    iph->nexthdr == IPPROTO_SCTP ||
+		    iph->nexthdr == IPPROTO_DCCP ||
+		    iph->nexthdr == IPPROTO_ESP)
+			h2 ^= *(u32*)&iph[1];
+		break;
+	}
+	default:
+		h = (u32)(unsigned long)skb->dst;
+		hs = (u32)(unsigned long)skb->sk;
+		nfm = skb->nfmark;
+		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_DSTDIR:
+		return esfq_hash_direct(q, ntohl(h));
+	case TCA_SFQ_HASH_SRC:
+		return esfq_hash_u32(q,hs);
+	case TCA_SFQ_HASH_SRCDIR:
+		return esfq_hash_direct(q, ntohl(hs));
+#ifdef CONFIG_NETFILTER
+	case TCA_SFQ_HASH_FWMARK:
+		return esfq_hash_u32(q,nfm);
+	case TCA_SFQ_HASH_FWMARKDIR:
+		return esfq_hash_direct(q,nfm);
+#endif
+	default:
+		if (net_ratelimit())
+			printk(KERN_WARNING "ESFQ: Unknown hash method. Falling back to classic.\n");
+	}
+	return esfq_fold_hash_classic(q, h, h2);
+}
+
+static 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;
+}
+
+static 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);
+}
+
+static 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 unsigned int esfq_drop(struct Qdisc *sch)
+{
+	struct esfq_sched_data *q = qdisc_priv(sch);
+	esfq_index d = q->max_depth;
+	struct sk_buff *skb;
+	unsigned int len;
+
+	/* 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;
+		len = skb->len;
+		__skb_unlink(skb, &q->qs[x]);
+		kfree_skb(skb);
+		esfq_dec(q, x);
+		sch->q.qlen--;
+		sch->qstats.drops++;
+		return len;
+	}
+
+	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;
+		len = skb->len;
+		__skb_unlink(skb, &q->qs[d]);
+		kfree_skb(skb);
+		esfq_dec(q, d);
+		sch->q.qlen--;
+		q->ht[q->hash[d]] = q->depth;
+		sch->qstats.drops++;
+		return len;
+	}
+
+	return 0;
+}
+
+static int
+esfq_enqueue(struct sk_buff *skb, struct Qdisc* sch)
+{
+	struct esfq_sched_data *q = qdisc_priv(sch);
+	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->bstats.bytes += skb->len;
+		sch->bstats.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 = qdisc_priv(sch);
+	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) {
+		sch->qstats.requeues++;
+		return 0;
+	}
+
+	sch->qstats.drops++;
+	esfq_drop(sch);
+	return NET_XMIT_CN;
+}
+
+
+
+
+static struct sk_buff *
+esfq_dequeue(struct Qdisc* sch)
+{
+	struct esfq_sched_data *q = qdisc_priv(sch);
+	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) {
+		q->ht[q->hash[a]] = depth;
+		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 = qdisc_priv(sch);
+
+	q->perturbation = net_random()&0x1F;
+
+	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 = qdisc_priv(sch);
+	struct tc_esfq_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 = qdisc_priv(sch);
+	struct tc_esfq_qopt *ctl;
+	esfq_index p = ~0UL/2;
+	int i;
+	
+	if (opt && opt->rta_len < RTA_LENGTH(sizeof(*ctl)))
+		return -EINVAL;
+
+	init_timer(&q->perturb_timer);
+	q->perturb_timer.data = (unsigned long)sch;
+	q->perturb_timer.function = esfq_perturbation;
+	q->perturbation = 0;
+	q->hash_kind = TCA_SFQ_HASH_CLASSIC;
+	q->max_depth = 0;
+	q->dyn_min = ~0U; /* maximum value for this type */
+	q->dyn_max = 0;  /* dyn_min/dyn_max will be set properly upon first packet */
+	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 ? : 1024;
+		q->tail = q->limit = q->depth = ctl->flows ? : 128;
+		
+		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->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);
+	return 0;
+err_case:
+	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);
+	return -ENOBUFS;
+}
+
+static void esfq_destroy(struct Qdisc *sch)
+{
+	struct esfq_sched_data *q = qdisc_priv(sch);
+	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);
+}
+
+static int esfq_dump(struct Qdisc *sch, struct sk_buff *skb)
+{
+	struct esfq_sched_data *q = qdisc_priv(sch);
+	unsigned char	 *b = skb->tail;
+	struct tc_esfq_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;
+}
+
+static struct Qdisc_ops esfq_qdisc_ops =
+{
+	.next		=	NULL,
+	.cl_ops		=	NULL,
+	.id		=	"esfq",
+	.priv_size	=	sizeof(struct esfq_sched_data),
+	.enqueue	=	esfq_enqueue,
+	.dequeue	=	esfq_dequeue,
+	.requeue	=	esfq_requeue,
+	.drop		=	esfq_drop,
+	.init		=	esfq_init,
+	.reset		=	esfq_reset,
+	.destroy	=	esfq_destroy,
+	.change		=	NULL, /* esfq_change - needs more work */
+	.dump		=	esfq_dump,
+	.owner		=	THIS_MODULE,
+};
+
+static int __init esfq_module_init(void)
+{
+	return register_qdisc(&esfq_qdisc_ops);
+}
+static void __exit esfq_module_exit(void) 
+{
+	unregister_qdisc(&esfq_qdisc_ops);
+}
+module_init(esfq_module_init)
+module_exit(esfq_module_exit)
+MODULE_LICENSE("GPL");