blob: 3ec7e88a43cab2df5e012d3c5216bc31b75eafe3 [file] [log] [blame]
stephen hemminger0545a302011-04-04 05:30:58 +00001/*
Paolo Valente462dbc92012-11-23 11:03:19 +00002 * net/sched/sch_qfq.c Quick Fair Queueing Plus Scheduler.
stephen hemminger0545a302011-04-04 05:30:58 +00003 *
4 * Copyright (c) 2009 Fabio Checconi, Luigi Rizzo, and Paolo Valente.
Paolo Valente462dbc92012-11-23 11:03:19 +00005 * Copyright (c) 2012 Paolo Valente.
stephen hemminger0545a302011-04-04 05:30:58 +00006 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * version 2 as published by the Free Software Foundation.
10 */
11
12#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/bitops.h>
15#include <linux/errno.h>
16#include <linux/netdevice.h>
17#include <linux/pkt_sched.h>
18#include <net/sch_generic.h>
19#include <net/pkt_sched.h>
20#include <net/pkt_cls.h>
21
22
Paolo Valente462dbc92012-11-23 11:03:19 +000023/* Quick Fair Queueing Plus
24 ========================
stephen hemminger0545a302011-04-04 05:30:58 +000025
26 Sources:
27
Paolo Valente462dbc92012-11-23 11:03:19 +000028 [1] Paolo Valente,
29 "Reducing the Execution Time of Fair-Queueing Schedulers."
30 http://algo.ing.unimo.it/people/paolo/agg-sched/agg-sched.pdf
31
32 Sources for QFQ:
33
34 [2] Fabio Checconi, Luigi Rizzo, and Paolo Valente: "QFQ: Efficient
stephen hemminger0545a302011-04-04 05:30:58 +000035 Packet Scheduling with Tight Bandwidth Distribution Guarantees."
36
37 See also:
38 http://retis.sssup.it/~fabio/linux/qfq/
39 */
40
41/*
42
Paolo Valente462dbc92012-11-23 11:03:19 +000043 QFQ+ divides classes into aggregates of at most MAX_AGG_CLASSES
44 classes. Each aggregate is timestamped with a virtual start time S
45 and a virtual finish time F, and scheduled according to its
46 timestamps. S and F are computed as a function of a system virtual
47 time function V. The classes within each aggregate are instead
48 scheduled with DRR.
49
50 To speed up operations, QFQ+ divides also aggregates into a limited
51 number of groups. Which group a class belongs to depends on the
52 ratio between the maximum packet length for the class and the weight
53 of the class. Groups have their own S and F. In the end, QFQ+
54 schedules groups, then aggregates within groups, then classes within
55 aggregates. See [1] and [2] for a full description.
56
stephen hemminger0545a302011-04-04 05:30:58 +000057 Virtual time computations.
58
59 S, F and V are all computed in fixed point arithmetic with
60 FRAC_BITS decimal bits.
61
62 QFQ_MAX_INDEX is the maximum index allowed for a group. We need
63 one bit per index.
64 QFQ_MAX_WSHIFT is the maximum power of two supported as a weight.
65
66 The layout of the bits is as below:
67
68 [ MTU_SHIFT ][ FRAC_BITS ]
69 [ MAX_INDEX ][ MIN_SLOT_SHIFT ]
70 ^.__grp->index = 0
71 *.__grp->slot_shift
72
73 where MIN_SLOT_SHIFT is derived by difference from the others.
74
75 The max group index corresponds to Lmax/w_min, where
76 Lmax=1<<MTU_SHIFT, w_min = 1 .
77 From this, and knowing how many groups (MAX_INDEX) we want,
78 we can derive the shift corresponding to each group.
79
80 Because we often need to compute
81 F = S + len/w_i and V = V + len/wsum
82 instead of storing w_i store the value
83 inv_w = (1<<FRAC_BITS)/w_i
84 so we can do F = S + len * inv_w * wsum.
85 We use W_TOT in the formulas so we can easily move between
86 static and adaptive weight sum.
87
88 The per-scheduler-instance data contain all the data structures
89 for the scheduler: bitmaps and bucket lists.
90
91 */
92
93/*
94 * Maximum number of consecutive slots occupied by backlogged classes
95 * inside a group.
96 */
97#define QFQ_MAX_SLOTS 32
98
99/*
Paolo Valente462dbc92012-11-23 11:03:19 +0000100 * Shifts used for aggregate<->group mapping. We allow class weights that are
101 * in the range [1, 2^MAX_WSHIFT], and we try to map each aggregate i to the
stephen hemminger0545a302011-04-04 05:30:58 +0000102 * group with the smallest index that can support the L_i / r_i configured
Paolo Valente462dbc92012-11-23 11:03:19 +0000103 * for the classes in the aggregate.
stephen hemminger0545a302011-04-04 05:30:58 +0000104 *
105 * grp->index is the index of the group; and grp->slot_shift
106 * is the shift for the corresponding (scaled) sigma_i.
107 */
Paolo Valente3015f3d2012-11-05 20:29:24 +0000108#define QFQ_MAX_INDEX 24
Paolo Valente462dbc92012-11-23 11:03:19 +0000109#define QFQ_MAX_WSHIFT 10
stephen hemminger0545a302011-04-04 05:30:58 +0000110
Paolo Valente462dbc92012-11-23 11:03:19 +0000111#define QFQ_MAX_WEIGHT (1<<QFQ_MAX_WSHIFT) /* see qfq_slot_insert */
112#define QFQ_MAX_WSUM (64*QFQ_MAX_WEIGHT)
stephen hemminger0545a302011-04-04 05:30:58 +0000113
114#define FRAC_BITS 30 /* fixed point arithmetic */
115#define ONE_FP (1UL << FRAC_BITS)
stephen hemminger0545a302011-04-04 05:30:58 +0000116
Paolo Valente3015f3d2012-11-05 20:29:24 +0000117#define QFQ_MTU_SHIFT 16 /* to support TSO/GSO */
Paolo Valente462dbc92012-11-23 11:03:19 +0000118#define QFQ_MIN_LMAX 512 /* see qfq_slot_insert */
119
120#define QFQ_MAX_AGG_CLASSES 8 /* max num classes per aggregate allowed */
stephen hemminger0545a302011-04-04 05:30:58 +0000121
122/*
123 * Possible group states. These values are used as indexes for the bitmaps
124 * array of struct qfq_queue.
125 */
126enum qfq_state { ER, IR, EB, IB, QFQ_MAX_STATE };
127
128struct qfq_group;
129
Paolo Valente462dbc92012-11-23 11:03:19 +0000130struct qfq_aggregate;
131
stephen hemminger0545a302011-04-04 05:30:58 +0000132struct qfq_class {
133 struct Qdisc_class_common common;
134
135 unsigned int refcnt;
136 unsigned int filter_cnt;
137
138 struct gnet_stats_basic_packed bstats;
139 struct gnet_stats_queue qstats;
Eric Dumazet45203a32013-06-06 08:43:22 -0700140 struct gnet_stats_rate_est64 rate_est;
stephen hemminger0545a302011-04-04 05:30:58 +0000141 struct Qdisc *qdisc;
Paolo Valente462dbc92012-11-23 11:03:19 +0000142 struct list_head alist; /* Link for active-classes list. */
143 struct qfq_aggregate *agg; /* Parent aggregate. */
144 int deficit; /* DRR deficit counter. */
145};
stephen hemminger0545a302011-04-04 05:30:58 +0000146
Paolo Valente462dbc92012-11-23 11:03:19 +0000147struct qfq_aggregate {
stephen hemminger0545a302011-04-04 05:30:58 +0000148 struct hlist_node next; /* Link for the slot list. */
149 u64 S, F; /* flow timestamps (exact) */
150
151 /* group we belong to. In principle we would need the index,
152 * which is log_2(lmax/weight), but we never reference it
153 * directly, only the group.
154 */
155 struct qfq_group *grp;
156
157 /* these are copied from the flowset. */
Paolo Valente462dbc92012-11-23 11:03:19 +0000158 u32 class_weight; /* Weight of each class in this aggregate. */
159 /* Max pkt size for the classes in this aggregate, DRR quantum. */
160 int lmax;
161
162 u32 inv_w; /* ONE_FP/(sum of weights of classes in aggr.). */
163 u32 budgetmax; /* Max budget for this aggregate. */
164 u32 initial_budget, budget; /* Initial and current budget. */
165
166 int num_classes; /* Number of classes in this aggr. */
167 struct list_head active; /* DRR queue of active classes. */
168
169 struct hlist_node nonfull_next; /* See nonfull_aggs in qfq_sched. */
stephen hemminger0545a302011-04-04 05:30:58 +0000170};
171
172struct qfq_group {
173 u64 S, F; /* group timestamps (approx). */
174 unsigned int slot_shift; /* Slot shift. */
175 unsigned int index; /* Group index. */
176 unsigned int front; /* Index of the front slot. */
177 unsigned long full_slots; /* non-empty slots */
178
Paolo Valente462dbc92012-11-23 11:03:19 +0000179 /* Array of RR lists of active aggregates. */
stephen hemminger0545a302011-04-04 05:30:58 +0000180 struct hlist_head slots[QFQ_MAX_SLOTS];
181};
182
183struct qfq_sched {
John Fastabend25d8c0d2014-09-12 20:05:27 -0700184 struct tcf_proto __rcu *filter_list;
stephen hemminger0545a302011-04-04 05:30:58 +0000185 struct Qdisc_class_hash clhash;
186
Paolo Valente462dbc92012-11-23 11:03:19 +0000187 u64 oldV, V; /* Precise virtual times. */
188 struct qfq_aggregate *in_serv_agg; /* Aggregate being served. */
189 u32 num_active_agg; /* Num. of active aggregates */
190 u32 wsum; /* weight sum */
Paolo Valente87f40dd2013-07-16 08:52:30 +0200191 u32 iwsum; /* inverse weight sum */
stephen hemminger0545a302011-04-04 05:30:58 +0000192
193 unsigned long bitmaps[QFQ_MAX_STATE]; /* Group bitmaps. */
194 struct qfq_group groups[QFQ_MAX_INDEX + 1]; /* The groups. */
Paolo Valente462dbc92012-11-23 11:03:19 +0000195 u32 min_slot_shift; /* Index of the group-0 bit in the bitmaps. */
196
197 u32 max_agg_classes; /* Max number of classes per aggr. */
198 struct hlist_head nonfull_aggs; /* Aggs with room for more classes. */
stephen hemminger0545a302011-04-04 05:30:58 +0000199};
200
Paolo Valente462dbc92012-11-23 11:03:19 +0000201/*
202 * Possible reasons why the timestamps of an aggregate are updated
203 * enqueue: the aggregate switches from idle to active and must scheduled
204 * for service
205 * requeue: the aggregate finishes its budget, so it stops being served and
206 * must be rescheduled for service
207 */
208enum update_reason {enqueue, requeue};
209
stephen hemminger0545a302011-04-04 05:30:58 +0000210static struct qfq_class *qfq_find_class(struct Qdisc *sch, u32 classid)
211{
212 struct qfq_sched *q = qdisc_priv(sch);
213 struct Qdisc_class_common *clc;
214
215 clc = qdisc_class_find(&q->clhash, classid);
216 if (clc == NULL)
217 return NULL;
218 return container_of(clc, struct qfq_class, common);
219}
220
221static void qfq_purge_queue(struct qfq_class *cl)
222{
223 unsigned int len = cl->qdisc->q.qlen;
224
225 qdisc_reset(cl->qdisc);
226 qdisc_tree_decrease_qlen(cl->qdisc, len);
227}
228
229static const struct nla_policy qfq_policy[TCA_QFQ_MAX + 1] = {
230 [TCA_QFQ_WEIGHT] = { .type = NLA_U32 },
231 [TCA_QFQ_LMAX] = { .type = NLA_U32 },
232};
233
234/*
235 * Calculate a flow index, given its weight and maximum packet length.
236 * index = log_2(maxlen/weight) but we need to apply the scaling.
237 * This is used only once at flow creation.
238 */
Paolo Valente462dbc92012-11-23 11:03:19 +0000239static int qfq_calc_index(u32 inv_w, unsigned int maxlen, u32 min_slot_shift)
stephen hemminger0545a302011-04-04 05:30:58 +0000240{
241 u64 slot_size = (u64)maxlen * inv_w;
242 unsigned long size_map;
243 int index = 0;
244
Paolo Valente462dbc92012-11-23 11:03:19 +0000245 size_map = slot_size >> min_slot_shift;
stephen hemminger0545a302011-04-04 05:30:58 +0000246 if (!size_map)
247 goto out;
248
249 index = __fls(size_map) + 1; /* basically a log_2 */
Paolo Valente462dbc92012-11-23 11:03:19 +0000250 index -= !(slot_size - (1ULL << (index + min_slot_shift - 1)));
stephen hemminger0545a302011-04-04 05:30:58 +0000251
252 if (index < 0)
253 index = 0;
254out:
255 pr_debug("qfq calc_index: W = %lu, L = %u, I = %d\n",
256 (unsigned long) ONE_FP/inv_w, maxlen, index);
257
258 return index;
259}
260
Paolo Valente462dbc92012-11-23 11:03:19 +0000261static void qfq_deactivate_agg(struct qfq_sched *, struct qfq_aggregate *);
262static void qfq_activate_agg(struct qfq_sched *, struct qfq_aggregate *,
263 enum update_reason);
Paolo Valentebe72f632012-08-07 07:27:25 +0000264
Paolo Valente462dbc92012-11-23 11:03:19 +0000265static void qfq_init_agg(struct qfq_sched *q, struct qfq_aggregate *agg,
266 u32 lmax, u32 weight)
267{
268 INIT_LIST_HEAD(&agg->active);
269 hlist_add_head(&agg->nonfull_next, &q->nonfull_aggs);
270
271 agg->lmax = lmax;
272 agg->class_weight = weight;
Paolo Valentebe72f632012-08-07 07:27:25 +0000273}
274
Paolo Valente462dbc92012-11-23 11:03:19 +0000275static struct qfq_aggregate *qfq_find_agg(struct qfq_sched *q,
276 u32 lmax, u32 weight)
Paolo Valentebe72f632012-08-07 07:27:25 +0000277{
Paolo Valente462dbc92012-11-23 11:03:19 +0000278 struct qfq_aggregate *agg;
Paolo Valentebe72f632012-08-07 07:27:25 +0000279
Sasha Levinb67bfe02013-02-27 17:06:00 -0800280 hlist_for_each_entry(agg, &q->nonfull_aggs, nonfull_next)
Paolo Valente462dbc92012-11-23 11:03:19 +0000281 if (agg->lmax == lmax && agg->class_weight == weight)
282 return agg;
Paolo Valentebe72f632012-08-07 07:27:25 +0000283
Paolo Valente462dbc92012-11-23 11:03:19 +0000284 return NULL;
Paolo Valentebe72f632012-08-07 07:27:25 +0000285}
286
Paolo Valente3015f3d2012-11-05 20:29:24 +0000287
Paolo Valente462dbc92012-11-23 11:03:19 +0000288/* Update aggregate as a function of the new number of classes. */
289static void qfq_update_agg(struct qfq_sched *q, struct qfq_aggregate *agg,
290 int new_num_classes)
291{
292 u32 new_agg_weight;
293
294 if (new_num_classes == q->max_agg_classes)
295 hlist_del_init(&agg->nonfull_next);
296
297 if (agg->num_classes > new_num_classes &&
298 new_num_classes == q->max_agg_classes - 1) /* agg no more full */
299 hlist_add_head(&agg->nonfull_next, &q->nonfull_aggs);
300
Paolo Valente9b99b7e2013-03-05 08:04:57 +0000301 /* The next assignment may let
302 * agg->initial_budget > agg->budgetmax
303 * hold, we will take it into account in charge_actual_service().
304 */
Paolo Valente462dbc92012-11-23 11:03:19 +0000305 agg->budgetmax = new_num_classes * agg->lmax;
306 new_agg_weight = agg->class_weight * new_num_classes;
307 agg->inv_w = ONE_FP/new_agg_weight;
308
309 if (agg->grp == NULL) {
310 int i = qfq_calc_index(agg->inv_w, agg->budgetmax,
311 q->min_slot_shift);
312 agg->grp = &q->groups[i];
Paolo Valente3015f3d2012-11-05 20:29:24 +0000313 }
314
Paolo Valente462dbc92012-11-23 11:03:19 +0000315 q->wsum +=
316 (int) agg->class_weight * (new_num_classes - agg->num_classes);
Paolo Valente87f40dd2013-07-16 08:52:30 +0200317 q->iwsum = ONE_FP / q->wsum;
Paolo Valente3015f3d2012-11-05 20:29:24 +0000318
Paolo Valente462dbc92012-11-23 11:03:19 +0000319 agg->num_classes = new_num_classes;
Paolo Valente3015f3d2012-11-05 20:29:24 +0000320}
321
Paolo Valente462dbc92012-11-23 11:03:19 +0000322/* Add class to aggregate. */
323static void qfq_add_to_agg(struct qfq_sched *q,
324 struct qfq_aggregate *agg,
325 struct qfq_class *cl)
326{
327 cl->agg = agg;
328
329 qfq_update_agg(q, agg, agg->num_classes+1);
330 if (cl->qdisc->q.qlen > 0) { /* adding an active class */
331 list_add_tail(&cl->alist, &agg->active);
332 if (list_first_entry(&agg->active, struct qfq_class, alist) ==
333 cl && q->in_serv_agg != agg) /* agg was inactive */
334 qfq_activate_agg(q, agg, enqueue); /* schedule agg */
335 }
336}
337
338static struct qfq_aggregate *qfq_choose_next_agg(struct qfq_sched *);
339
340static void qfq_destroy_agg(struct qfq_sched *q, struct qfq_aggregate *agg)
341{
342 if (!hlist_unhashed(&agg->nonfull_next))
343 hlist_del_init(&agg->nonfull_next);
Paolo Valente87f40dd2013-07-16 08:52:30 +0200344 q->wsum -= agg->class_weight;
345 if (q->wsum != 0)
346 q->iwsum = ONE_FP / q->wsum;
347
Paolo Valente462dbc92012-11-23 11:03:19 +0000348 if (q->in_serv_agg == agg)
349 q->in_serv_agg = qfq_choose_next_agg(q);
350 kfree(agg);
351}
352
353/* Deschedule class from within its parent aggregate. */
354static void qfq_deactivate_class(struct qfq_sched *q, struct qfq_class *cl)
355{
356 struct qfq_aggregate *agg = cl->agg;
357
358
359 list_del(&cl->alist); /* remove from RR queue of the aggregate */
360 if (list_empty(&agg->active)) /* agg is now inactive */
361 qfq_deactivate_agg(q, agg);
362}
363
364/* Remove class from its parent aggregate. */
365static void qfq_rm_from_agg(struct qfq_sched *q, struct qfq_class *cl)
366{
367 struct qfq_aggregate *agg = cl->agg;
368
369 cl->agg = NULL;
370 if (agg->num_classes == 1) { /* agg being emptied, destroy it */
371 qfq_destroy_agg(q, agg);
372 return;
373 }
374 qfq_update_agg(q, agg, agg->num_classes-1);
375}
376
377/* Deschedule class and remove it from its parent aggregate. */
378static void qfq_deact_rm_from_agg(struct qfq_sched *q, struct qfq_class *cl)
379{
380 if (cl->qdisc->q.qlen > 0) /* class is active */
381 qfq_deactivate_class(q, cl);
382
383 qfq_rm_from_agg(q, cl);
384}
385
386/* Move class to a new aggregate, matching the new class weight and/or lmax */
387static int qfq_change_agg(struct Qdisc *sch, struct qfq_class *cl, u32 weight,
388 u32 lmax)
389{
390 struct qfq_sched *q = qdisc_priv(sch);
391 struct qfq_aggregate *new_agg = qfq_find_agg(q, lmax, weight);
392
393 if (new_agg == NULL) { /* create new aggregate */
394 new_agg = kzalloc(sizeof(*new_agg), GFP_ATOMIC);
395 if (new_agg == NULL)
396 return -ENOBUFS;
397 qfq_init_agg(q, new_agg, lmax, weight);
398 }
399 qfq_deact_rm_from_agg(q, cl);
400 qfq_add_to_agg(q, new_agg, cl);
401
402 return 0;
403}
Paolo Valente3015f3d2012-11-05 20:29:24 +0000404
stephen hemminger0545a302011-04-04 05:30:58 +0000405static int qfq_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
406 struct nlattr **tca, unsigned long *arg)
407{
408 struct qfq_sched *q = qdisc_priv(sch);
409 struct qfq_class *cl = (struct qfq_class *)*arg;
Paolo Valente462dbc92012-11-23 11:03:19 +0000410 bool existing = false;
stephen hemminger0545a302011-04-04 05:30:58 +0000411 struct nlattr *tb[TCA_QFQ_MAX + 1];
Paolo Valente462dbc92012-11-23 11:03:19 +0000412 struct qfq_aggregate *new_agg = NULL;
stephen hemminger0545a302011-04-04 05:30:58 +0000413 u32 weight, lmax, inv_w;
Paolo Valente3015f3d2012-11-05 20:29:24 +0000414 int err;
Eric Dumazetd32ae76f2012-01-02 11:47:50 +0000415 int delta_w;
stephen hemminger0545a302011-04-04 05:30:58 +0000416
417 if (tca[TCA_OPTIONS] == NULL) {
418 pr_notice("qfq: no options\n");
419 return -EINVAL;
420 }
421
422 err = nla_parse_nested(tb, TCA_QFQ_MAX, tca[TCA_OPTIONS], qfq_policy);
423 if (err < 0)
424 return err;
425
426 if (tb[TCA_QFQ_WEIGHT]) {
427 weight = nla_get_u32(tb[TCA_QFQ_WEIGHT]);
428 if (!weight || weight > (1UL << QFQ_MAX_WSHIFT)) {
429 pr_notice("qfq: invalid weight %u\n", weight);
430 return -EINVAL;
431 }
432 } else
433 weight = 1;
434
stephen hemminger0545a302011-04-04 05:30:58 +0000435 if (tb[TCA_QFQ_LMAX]) {
436 lmax = nla_get_u32(tb[TCA_QFQ_LMAX]);
Paolo Valente3015f3d2012-11-05 20:29:24 +0000437 if (lmax < QFQ_MIN_LMAX || lmax > (1UL << QFQ_MTU_SHIFT)) {
stephen hemminger0545a302011-04-04 05:30:58 +0000438 pr_notice("qfq: invalid max length %u\n", lmax);
439 return -EINVAL;
440 }
441 } else
Paolo Valente3015f3d2012-11-05 20:29:24 +0000442 lmax = psched_mtu(qdisc_dev(sch));
stephen hemminger0545a302011-04-04 05:30:58 +0000443
Paolo Valente462dbc92012-11-23 11:03:19 +0000444 inv_w = ONE_FP / weight;
445 weight = ONE_FP / inv_w;
446
447 if (cl != NULL &&
448 lmax == cl->agg->lmax &&
449 weight == cl->agg->class_weight)
450 return 0; /* nothing to change */
451
452 delta_w = weight - (cl ? cl->agg->class_weight : 0);
453
454 if (q->wsum + delta_w > QFQ_MAX_WSUM) {
455 pr_notice("qfq: total weight out of range (%d + %u)\n",
456 delta_w, q->wsum);
457 return -EINVAL;
458 }
459
460 if (cl != NULL) { /* modify existing class */
stephen hemminger0545a302011-04-04 05:30:58 +0000461 if (tca[TCA_RATE]) {
John Fastabend22e0f8b2014-09-28 11:52:56 -0700462 err = gen_replace_estimator(&cl->bstats, NULL,
463 &cl->rate_est,
stephen hemminger0545a302011-04-04 05:30:58 +0000464 qdisc_root_sleeping_lock(sch),
465 tca[TCA_RATE]);
466 if (err)
467 return err;
468 }
Paolo Valente462dbc92012-11-23 11:03:19 +0000469 existing = true;
470 goto set_change_agg;
stephen hemminger0545a302011-04-04 05:30:58 +0000471 }
472
Paolo Valente462dbc92012-11-23 11:03:19 +0000473 /* create and init new class */
stephen hemminger0545a302011-04-04 05:30:58 +0000474 cl = kzalloc(sizeof(struct qfq_class), GFP_KERNEL);
475 if (cl == NULL)
476 return -ENOBUFS;
477
478 cl->refcnt = 1;
479 cl->common.classid = classid;
Paolo Valente462dbc92012-11-23 11:03:19 +0000480 cl->deficit = lmax;
stephen hemminger0545a302011-04-04 05:30:58 +0000481
482 cl->qdisc = qdisc_create_dflt(sch->dev_queue,
483 &pfifo_qdisc_ops, classid);
484 if (cl->qdisc == NULL)
485 cl->qdisc = &noop_qdisc;
486
487 if (tca[TCA_RATE]) {
John Fastabend22e0f8b2014-09-28 11:52:56 -0700488 err = gen_new_estimator(&cl->bstats, NULL,
489 &cl->rate_est,
stephen hemminger0545a302011-04-04 05:30:58 +0000490 qdisc_root_sleeping_lock(sch),
491 tca[TCA_RATE]);
Paolo Valente462dbc92012-11-23 11:03:19 +0000492 if (err)
493 goto destroy_class;
stephen hemminger0545a302011-04-04 05:30:58 +0000494 }
stephen hemminger0545a302011-04-04 05:30:58 +0000495
496 sch_tree_lock(sch);
497 qdisc_class_hash_insert(&q->clhash, &cl->common);
498 sch_tree_unlock(sch);
499
500 qdisc_class_hash_grow(sch, &q->clhash);
501
Paolo Valente462dbc92012-11-23 11:03:19 +0000502set_change_agg:
503 sch_tree_lock(sch);
504 new_agg = qfq_find_agg(q, lmax, weight);
505 if (new_agg == NULL) { /* create new aggregate */
506 sch_tree_unlock(sch);
507 new_agg = kzalloc(sizeof(*new_agg), GFP_KERNEL);
508 if (new_agg == NULL) {
509 err = -ENOBUFS;
510 gen_kill_estimator(&cl->bstats, &cl->rate_est);
511 goto destroy_class;
512 }
513 sch_tree_lock(sch);
514 qfq_init_agg(q, new_agg, lmax, weight);
515 }
516 if (existing)
517 qfq_deact_rm_from_agg(q, cl);
518 qfq_add_to_agg(q, new_agg, cl);
519 sch_tree_unlock(sch);
520
stephen hemminger0545a302011-04-04 05:30:58 +0000521 *arg = (unsigned long)cl;
522 return 0;
Paolo Valente462dbc92012-11-23 11:03:19 +0000523
524destroy_class:
525 qdisc_destroy(cl->qdisc);
526 kfree(cl);
527 return err;
stephen hemminger0545a302011-04-04 05:30:58 +0000528}
529
530static void qfq_destroy_class(struct Qdisc *sch, struct qfq_class *cl)
531{
532 struct qfq_sched *q = qdisc_priv(sch);
533
Paolo Valente462dbc92012-11-23 11:03:19 +0000534 qfq_rm_from_agg(q, cl);
stephen hemminger0545a302011-04-04 05:30:58 +0000535 gen_kill_estimator(&cl->bstats, &cl->rate_est);
536 qdisc_destroy(cl->qdisc);
537 kfree(cl);
538}
539
540static int qfq_delete_class(struct Qdisc *sch, unsigned long arg)
541{
542 struct qfq_sched *q = qdisc_priv(sch);
543 struct qfq_class *cl = (struct qfq_class *)arg;
544
545 if (cl->filter_cnt > 0)
546 return -EBUSY;
547
548 sch_tree_lock(sch);
549
550 qfq_purge_queue(cl);
551 qdisc_class_hash_remove(&q->clhash, &cl->common);
552
553 BUG_ON(--cl->refcnt == 0);
554 /*
555 * This shouldn't happen: we "hold" one cops->get() when called
556 * from tc_ctl_tclass; the destroy method is done from cops->put().
557 */
558
559 sch_tree_unlock(sch);
560 return 0;
561}
562
563static unsigned long qfq_get_class(struct Qdisc *sch, u32 classid)
564{
565 struct qfq_class *cl = qfq_find_class(sch, classid);
566
567 if (cl != NULL)
568 cl->refcnt++;
569
570 return (unsigned long)cl;
571}
572
573static void qfq_put_class(struct Qdisc *sch, unsigned long arg)
574{
575 struct qfq_class *cl = (struct qfq_class *)arg;
576
577 if (--cl->refcnt == 0)
578 qfq_destroy_class(sch, cl);
579}
580
John Fastabend25d8c0d2014-09-12 20:05:27 -0700581static struct tcf_proto __rcu **qfq_tcf_chain(struct Qdisc *sch,
582 unsigned long cl)
stephen hemminger0545a302011-04-04 05:30:58 +0000583{
584 struct qfq_sched *q = qdisc_priv(sch);
585
586 if (cl)
587 return NULL;
588
589 return &q->filter_list;
590}
591
592static unsigned long qfq_bind_tcf(struct Qdisc *sch, unsigned long parent,
593 u32 classid)
594{
595 struct qfq_class *cl = qfq_find_class(sch, classid);
596
597 if (cl != NULL)
598 cl->filter_cnt++;
599
600 return (unsigned long)cl;
601}
602
603static void qfq_unbind_tcf(struct Qdisc *sch, unsigned long arg)
604{
605 struct qfq_class *cl = (struct qfq_class *)arg;
606
607 cl->filter_cnt--;
608}
609
610static int qfq_graft_class(struct Qdisc *sch, unsigned long arg,
611 struct Qdisc *new, struct Qdisc **old)
612{
613 struct qfq_class *cl = (struct qfq_class *)arg;
614
615 if (new == NULL) {
616 new = qdisc_create_dflt(sch->dev_queue,
617 &pfifo_qdisc_ops, cl->common.classid);
618 if (new == NULL)
619 new = &noop_qdisc;
620 }
621
622 sch_tree_lock(sch);
623 qfq_purge_queue(cl);
624 *old = cl->qdisc;
625 cl->qdisc = new;
626 sch_tree_unlock(sch);
627 return 0;
628}
629
630static struct Qdisc *qfq_class_leaf(struct Qdisc *sch, unsigned long arg)
631{
632 struct qfq_class *cl = (struct qfq_class *)arg;
633
634 return cl->qdisc;
635}
636
637static int qfq_dump_class(struct Qdisc *sch, unsigned long arg,
638 struct sk_buff *skb, struct tcmsg *tcm)
639{
640 struct qfq_class *cl = (struct qfq_class *)arg;
641 struct nlattr *nest;
642
643 tcm->tcm_parent = TC_H_ROOT;
644 tcm->tcm_handle = cl->common.classid;
645 tcm->tcm_info = cl->qdisc->handle;
646
647 nest = nla_nest_start(skb, TCA_OPTIONS);
648 if (nest == NULL)
649 goto nla_put_failure;
Paolo Valente462dbc92012-11-23 11:03:19 +0000650 if (nla_put_u32(skb, TCA_QFQ_WEIGHT, cl->agg->class_weight) ||
651 nla_put_u32(skb, TCA_QFQ_LMAX, cl->agg->lmax))
David S. Miller1b34ec42012-03-29 05:11:39 -0400652 goto nla_put_failure;
stephen hemminger0545a302011-04-04 05:30:58 +0000653 return nla_nest_end(skb, nest);
654
655nla_put_failure:
656 nla_nest_cancel(skb, nest);
657 return -EMSGSIZE;
658}
659
660static int qfq_dump_class_stats(struct Qdisc *sch, unsigned long arg,
661 struct gnet_dump *d)
662{
663 struct qfq_class *cl = (struct qfq_class *)arg;
664 struct tc_qfq_stats xstats;
665
666 memset(&xstats, 0, sizeof(xstats));
stephen hemminger0545a302011-04-04 05:30:58 +0000667
Paolo Valente462dbc92012-11-23 11:03:19 +0000668 xstats.weight = cl->agg->class_weight;
669 xstats.lmax = cl->agg->lmax;
stephen hemminger0545a302011-04-04 05:30:58 +0000670
John Fastabend22e0f8b2014-09-28 11:52:56 -0700671 if (gnet_stats_copy_basic(d, NULL, &cl->bstats) < 0 ||
stephen hemminger0545a302011-04-04 05:30:58 +0000672 gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 ||
John Fastabendb0ab6f92014-09-28 11:54:24 -0700673 gnet_stats_copy_queue(d, NULL,
674 &cl->qdisc->qstats, cl->qdisc->q.qlen) < 0)
stephen hemminger0545a302011-04-04 05:30:58 +0000675 return -1;
676
677 return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
678}
679
680static void qfq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
681{
682 struct qfq_sched *q = qdisc_priv(sch);
683 struct qfq_class *cl;
stephen hemminger0545a302011-04-04 05:30:58 +0000684 unsigned int i;
685
686 if (arg->stop)
687 return;
688
689 for (i = 0; i < q->clhash.hashsize; i++) {
Sasha Levinb67bfe02013-02-27 17:06:00 -0800690 hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
stephen hemminger0545a302011-04-04 05:30:58 +0000691 if (arg->count < arg->skip) {
692 arg->count++;
693 continue;
694 }
695 if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
696 arg->stop = 1;
697 return;
698 }
699 arg->count++;
700 }
701 }
702}
703
704static struct qfq_class *qfq_classify(struct sk_buff *skb, struct Qdisc *sch,
705 int *qerr)
706{
707 struct qfq_sched *q = qdisc_priv(sch);
708 struct qfq_class *cl;
709 struct tcf_result res;
John Fastabend25d8c0d2014-09-12 20:05:27 -0700710 struct tcf_proto *fl;
stephen hemminger0545a302011-04-04 05:30:58 +0000711 int result;
712
713 if (TC_H_MAJ(skb->priority ^ sch->handle) == 0) {
714 pr_debug("qfq_classify: found %d\n", skb->priority);
715 cl = qfq_find_class(sch, skb->priority);
716 if (cl != NULL)
717 return cl;
718 }
719
720 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
John Fastabend25d8c0d2014-09-12 20:05:27 -0700721 fl = rcu_dereference_bh(q->filter_list);
722 result = tc_classify(skb, fl, &res);
stephen hemminger0545a302011-04-04 05:30:58 +0000723 if (result >= 0) {
724#ifdef CONFIG_NET_CLS_ACT
725 switch (result) {
726 case TC_ACT_QUEUED:
727 case TC_ACT_STOLEN:
728 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
729 case TC_ACT_SHOT:
730 return NULL;
731 }
732#endif
733 cl = (struct qfq_class *)res.class;
734 if (cl == NULL)
735 cl = qfq_find_class(sch, res.classid);
736 return cl;
737 }
738
739 return NULL;
740}
741
742/* Generic comparison function, handling wraparound. */
743static inline int qfq_gt(u64 a, u64 b)
744{
745 return (s64)(a - b) > 0;
746}
747
748/* Round a precise timestamp to its slotted value. */
749static inline u64 qfq_round_down(u64 ts, unsigned int shift)
750{
751 return ts & ~((1ULL << shift) - 1);
752}
753
754/* return the pointer to the group with lowest index in the bitmap */
755static inline struct qfq_group *qfq_ffs(struct qfq_sched *q,
756 unsigned long bitmap)
757{
758 int index = __ffs(bitmap);
759 return &q->groups[index];
760}
761/* Calculate a mask to mimic what would be ffs_from(). */
762static inline unsigned long mask_from(unsigned long bitmap, int from)
763{
764 return bitmap & ~((1UL << from) - 1);
765}
766
767/*
768 * The state computation relies on ER=0, IR=1, EB=2, IB=3
769 * First compute eligibility comparing grp->S, q->V,
770 * then check if someone is blocking us and possibly add EB
771 */
772static int qfq_calc_state(struct qfq_sched *q, const struct qfq_group *grp)
773{
774 /* if S > V we are not eligible */
775 unsigned int state = qfq_gt(grp->S, q->V);
776 unsigned long mask = mask_from(q->bitmaps[ER], grp->index);
777 struct qfq_group *next;
778
779 if (mask) {
780 next = qfq_ffs(q, mask);
781 if (qfq_gt(grp->F, next->F))
782 state |= EB;
783 }
784
785 return state;
786}
787
788
789/*
790 * In principle
791 * q->bitmaps[dst] |= q->bitmaps[src] & mask;
792 * q->bitmaps[src] &= ~mask;
793 * but we should make sure that src != dst
794 */
795static inline void qfq_move_groups(struct qfq_sched *q, unsigned long mask,
796 int src, int dst)
797{
798 q->bitmaps[dst] |= q->bitmaps[src] & mask;
799 q->bitmaps[src] &= ~mask;
800}
801
802static void qfq_unblock_groups(struct qfq_sched *q, int index, u64 old_F)
803{
804 unsigned long mask = mask_from(q->bitmaps[ER], index + 1);
805 struct qfq_group *next;
806
807 if (mask) {
808 next = qfq_ffs(q, mask);
809 if (!qfq_gt(next->F, old_F))
810 return;
811 }
812
813 mask = (1UL << index) - 1;
814 qfq_move_groups(q, mask, EB, ER);
815 qfq_move_groups(q, mask, IB, IR);
816}
817
818/*
819 * perhaps
820 *
821 old_V ^= q->V;
Paolo Valente462dbc92012-11-23 11:03:19 +0000822 old_V >>= q->min_slot_shift;
stephen hemminger0545a302011-04-04 05:30:58 +0000823 if (old_V) {
824 ...
825 }
826 *
827 */
Paolo Valente462dbc92012-11-23 11:03:19 +0000828static void qfq_make_eligible(struct qfq_sched *q)
stephen hemminger0545a302011-04-04 05:30:58 +0000829{
Paolo Valente462dbc92012-11-23 11:03:19 +0000830 unsigned long vslot = q->V >> q->min_slot_shift;
831 unsigned long old_vslot = q->oldV >> q->min_slot_shift;
stephen hemminger0545a302011-04-04 05:30:58 +0000832
833 if (vslot != old_vslot) {
Paolo Valente87f13692013-07-10 15:46:08 +0200834 unsigned long mask;
835 int last_flip_pos = fls(vslot ^ old_vslot);
836
837 if (last_flip_pos > 31) /* higher than the number of groups */
838 mask = ~0UL; /* make all groups eligible */
839 else
840 mask = (1UL << last_flip_pos) - 1;
841
stephen hemminger0545a302011-04-04 05:30:58 +0000842 qfq_move_groups(q, mask, IR, ER);
843 qfq_move_groups(q, mask, IB, EB);
844 }
845}
846
stephen hemminger0545a302011-04-04 05:30:58 +0000847/*
Paolo Valente87f40dd2013-07-16 08:52:30 +0200848 * The index of the slot in which the input aggregate agg is to be
849 * inserted must not be higher than QFQ_MAX_SLOTS-2. There is a '-2'
850 * and not a '-1' because the start time of the group may be moved
851 * backward by one slot after the aggregate has been inserted, and
852 * this would cause non-empty slots to be right-shifted by one
853 * position.
Paolo Valente3015f3d2012-11-05 20:29:24 +0000854 *
Paolo Valente87f40dd2013-07-16 08:52:30 +0200855 * QFQ+ fully satisfies this bound to the slot index if the parameters
856 * of the classes are not changed dynamically, and if QFQ+ never
857 * happens to postpone the service of agg unjustly, i.e., it never
858 * happens that the aggregate becomes backlogged and eligible, or just
859 * eligible, while an aggregate with a higher approximated finish time
860 * is being served. In particular, in this case QFQ+ guarantees that
861 * the timestamps of agg are low enough that the slot index is never
862 * higher than 2. Unfortunately, QFQ+ cannot provide the same
863 * guarantee if it happens to unjustly postpone the service of agg, or
864 * if the parameters of some class are changed.
Paolo Valente3015f3d2012-11-05 20:29:24 +0000865 *
Paolo Valente87f40dd2013-07-16 08:52:30 +0200866 * As for the first event, i.e., an out-of-order service, the
867 * upper bound to the slot index guaranteed by QFQ+ grows to
868 * 2 +
869 * QFQ_MAX_AGG_CLASSES * ((1<<QFQ_MTU_SHIFT)/QFQ_MIN_LMAX) *
870 * (current_max_weight/current_wsum) <= 2 + 8 * 128 * 1.
871 *
872 * The following function deals with this problem by backward-shifting
873 * the timestamps of agg, if needed, so as to guarantee that the slot
874 * index is never higher than QFQ_MAX_SLOTS-2. This backward-shift may
875 * cause the service of other aggregates to be postponed, yet the
876 * worst-case guarantees of these aggregates are not violated. In
877 * fact, in case of no out-of-order service, the timestamps of agg
878 * would have been even lower than they are after the backward shift,
879 * because QFQ+ would have guaranteed a maximum value equal to 2 for
880 * the slot index, and 2 < QFQ_MAX_SLOTS-2. Hence the aggregates whose
881 * service is postponed because of the backward-shift would have
882 * however waited for the service of agg before being served.
883 *
884 * The other event that may cause the slot index to be higher than 2
885 * for agg is a recent change of the parameters of some class. If the
886 * weight of a class is increased or the lmax (max_pkt_size) of the
887 * class is decreased, then a new aggregate with smaller slot size
888 * than the original parent aggregate of the class may happen to be
889 * activated. The activation of this aggregate should be properly
890 * delayed to when the service of the class has finished in the ideal
891 * system tracked by QFQ+. If the activation of the aggregate is not
892 * delayed to this reference time instant, then this aggregate may be
893 * unjustly served before other aggregates waiting for service. This
894 * may cause the above bound to the slot index to be violated for some
895 * of these unlucky aggregates.
Paolo Valente3015f3d2012-11-05 20:29:24 +0000896 *
Paolo Valente462dbc92012-11-23 11:03:19 +0000897 * Instead of delaying the activation of the new aggregate, which is
Paolo Valente87f40dd2013-07-16 08:52:30 +0200898 * quite complex, the above-discussed capping of the slot index is
899 * used to handle also the consequences of a change of the parameters
900 * of a class.
stephen hemminger0545a302011-04-04 05:30:58 +0000901 */
Paolo Valente462dbc92012-11-23 11:03:19 +0000902static void qfq_slot_insert(struct qfq_group *grp, struct qfq_aggregate *agg,
stephen hemminger0545a302011-04-04 05:30:58 +0000903 u64 roundedS)
904{
905 u64 slot = (roundedS - grp->S) >> grp->slot_shift;
Paolo Valente3015f3d2012-11-05 20:29:24 +0000906 unsigned int i; /* slot index in the bucket list */
907
908 if (unlikely(slot > QFQ_MAX_SLOTS - 2)) {
909 u64 deltaS = roundedS - grp->S -
910 ((u64)(QFQ_MAX_SLOTS - 2)<<grp->slot_shift);
Paolo Valente462dbc92012-11-23 11:03:19 +0000911 agg->S -= deltaS;
912 agg->F -= deltaS;
Paolo Valente3015f3d2012-11-05 20:29:24 +0000913 slot = QFQ_MAX_SLOTS - 2;
914 }
915
916 i = (grp->front + slot) % QFQ_MAX_SLOTS;
stephen hemminger0545a302011-04-04 05:30:58 +0000917
Paolo Valente462dbc92012-11-23 11:03:19 +0000918 hlist_add_head(&agg->next, &grp->slots[i]);
stephen hemminger0545a302011-04-04 05:30:58 +0000919 __set_bit(slot, &grp->full_slots);
920}
921
922/* Maybe introduce hlist_first_entry?? */
Paolo Valente462dbc92012-11-23 11:03:19 +0000923static struct qfq_aggregate *qfq_slot_head(struct qfq_group *grp)
stephen hemminger0545a302011-04-04 05:30:58 +0000924{
925 return hlist_entry(grp->slots[grp->front].first,
Paolo Valente462dbc92012-11-23 11:03:19 +0000926 struct qfq_aggregate, next);
stephen hemminger0545a302011-04-04 05:30:58 +0000927}
928
929/*
930 * remove the entry from the slot
931 */
932static void qfq_front_slot_remove(struct qfq_group *grp)
933{
Paolo Valente462dbc92012-11-23 11:03:19 +0000934 struct qfq_aggregate *agg = qfq_slot_head(grp);
stephen hemminger0545a302011-04-04 05:30:58 +0000935
Paolo Valente462dbc92012-11-23 11:03:19 +0000936 BUG_ON(!agg);
937 hlist_del(&agg->next);
stephen hemminger0545a302011-04-04 05:30:58 +0000938 if (hlist_empty(&grp->slots[grp->front]))
939 __clear_bit(0, &grp->full_slots);
940}
941
942/*
Paolo Valente462dbc92012-11-23 11:03:19 +0000943 * Returns the first aggregate in the first non-empty bucket of the
944 * group. As a side effect, adjusts the bucket list so the first
945 * non-empty bucket is at position 0 in full_slots.
stephen hemminger0545a302011-04-04 05:30:58 +0000946 */
Paolo Valente462dbc92012-11-23 11:03:19 +0000947static struct qfq_aggregate *qfq_slot_scan(struct qfq_group *grp)
stephen hemminger0545a302011-04-04 05:30:58 +0000948{
949 unsigned int i;
950
951 pr_debug("qfq slot_scan: grp %u full %#lx\n",
952 grp->index, grp->full_slots);
953
954 if (grp->full_slots == 0)
955 return NULL;
956
957 i = __ffs(grp->full_slots); /* zero based */
958 if (i > 0) {
959 grp->front = (grp->front + i) % QFQ_MAX_SLOTS;
960 grp->full_slots >>= i;
961 }
962
963 return qfq_slot_head(grp);
964}
965
966/*
967 * adjust the bucket list. When the start time of a group decreases,
968 * we move the index down (modulo QFQ_MAX_SLOTS) so we don't need to
969 * move the objects. The mask of occupied slots must be shifted
970 * because we use ffs() to find the first non-empty slot.
971 * This covers decreases in the group's start time, but what about
972 * increases of the start time ?
973 * Here too we should make sure that i is less than 32
974 */
975static void qfq_slot_rotate(struct qfq_group *grp, u64 roundedS)
976{
977 unsigned int i = (grp->S - roundedS) >> grp->slot_shift;
978
979 grp->full_slots <<= i;
980 grp->front = (grp->front - i) % QFQ_MAX_SLOTS;
981}
982
Paolo Valente462dbc92012-11-23 11:03:19 +0000983static void qfq_update_eligible(struct qfq_sched *q)
stephen hemminger0545a302011-04-04 05:30:58 +0000984{
985 struct qfq_group *grp;
986 unsigned long ineligible;
987
988 ineligible = q->bitmaps[IR] | q->bitmaps[IB];
989 if (ineligible) {
990 if (!q->bitmaps[ER]) {
991 grp = qfq_ffs(q, ineligible);
992 if (qfq_gt(grp->S, q->V))
993 q->V = grp->S;
994 }
Paolo Valente462dbc92012-11-23 11:03:19 +0000995 qfq_make_eligible(q);
stephen hemminger0545a302011-04-04 05:30:58 +0000996 }
997}
998
Paolo Valente462dbc92012-11-23 11:03:19 +0000999/* Dequeue head packet of the head class in the DRR queue of the aggregate. */
1000static void agg_dequeue(struct qfq_aggregate *agg,
1001 struct qfq_class *cl, unsigned int len)
stephen hemminger0545a302011-04-04 05:30:58 +00001002{
Paolo Valente462dbc92012-11-23 11:03:19 +00001003 qdisc_dequeue_peeked(cl->qdisc);
stephen hemminger0545a302011-04-04 05:30:58 +00001004
Paolo Valente462dbc92012-11-23 11:03:19 +00001005 cl->deficit -= (int) len;
stephen hemminger0545a302011-04-04 05:30:58 +00001006
Paolo Valente462dbc92012-11-23 11:03:19 +00001007 if (cl->qdisc->q.qlen == 0) /* no more packets, remove from list */
1008 list_del(&cl->alist);
1009 else if (cl->deficit < qdisc_pkt_len(cl->qdisc->ops->peek(cl->qdisc))) {
1010 cl->deficit += agg->lmax;
1011 list_move_tail(&cl->alist, &agg->active);
stephen hemminger0545a302011-04-04 05:30:58 +00001012 }
Paolo Valente462dbc92012-11-23 11:03:19 +00001013}
stephen hemminger0545a302011-04-04 05:30:58 +00001014
Paolo Valente462dbc92012-11-23 11:03:19 +00001015static inline struct sk_buff *qfq_peek_skb(struct qfq_aggregate *agg,
1016 struct qfq_class **cl,
1017 unsigned int *len)
1018{
1019 struct sk_buff *skb;
1020
1021 *cl = list_first_entry(&agg->active, struct qfq_class, alist);
1022 skb = (*cl)->qdisc->ops->peek((*cl)->qdisc);
1023 if (skb == NULL)
1024 WARN_ONCE(1, "qfq_dequeue: non-workconserving leaf\n");
1025 else
1026 *len = qdisc_pkt_len(skb);
1027
1028 return skb;
1029}
1030
1031/* Update F according to the actual service received by the aggregate. */
1032static inline void charge_actual_service(struct qfq_aggregate *agg)
1033{
Paolo Valente9b99b7e2013-03-05 08:04:57 +00001034 /* Compute the service received by the aggregate, taking into
1035 * account that, after decreasing the number of classes in
1036 * agg, it may happen that
1037 * agg->initial_budget - agg->budget > agg->bugdetmax
1038 */
1039 u32 service_received = min(agg->budgetmax,
1040 agg->initial_budget - agg->budget);
Paolo Valente462dbc92012-11-23 11:03:19 +00001041
1042 agg->F = agg->S + (u64)service_received * agg->inv_w;
stephen hemminger0545a302011-04-04 05:30:58 +00001043}
1044
Paolo Valente88d4f412013-07-10 15:46:09 +02001045/* Assign a reasonable start time for a new aggregate in group i.
1046 * Admissible values for \hat(F) are multiples of \sigma_i
1047 * no greater than V+\sigma_i . Larger values mean that
1048 * we had a wraparound so we consider the timestamp to be stale.
1049 *
1050 * If F is not stale and F >= V then we set S = F.
1051 * Otherwise we should assign S = V, but this may violate
1052 * the ordering in EB (see [2]). So, if we have groups in ER,
1053 * set S to the F_j of the first group j which would be blocking us.
1054 * We are guaranteed not to move S backward because
1055 * otherwise our group i would still be blocked.
1056 */
1057static void qfq_update_start(struct qfq_sched *q, struct qfq_aggregate *agg)
1058{
1059 unsigned long mask;
1060 u64 limit, roundedF;
1061 int slot_shift = agg->grp->slot_shift;
1062
1063 roundedF = qfq_round_down(agg->F, slot_shift);
1064 limit = qfq_round_down(q->V, slot_shift) + (1ULL << slot_shift);
1065
1066 if (!qfq_gt(agg->F, q->V) || qfq_gt(roundedF, limit)) {
1067 /* timestamp was stale */
1068 mask = mask_from(q->bitmaps[ER], agg->grp->index);
1069 if (mask) {
1070 struct qfq_group *next = qfq_ffs(q, mask);
1071 if (qfq_gt(roundedF, next->F)) {
1072 if (qfq_gt(limit, next->F))
1073 agg->S = next->F;
1074 else /* preserve timestamp correctness */
1075 agg->S = limit;
1076 return;
1077 }
1078 }
1079 agg->S = q->V;
1080 } else /* timestamp is not stale */
1081 agg->S = agg->F;
1082}
1083
1084/* Update the timestamps of agg before scheduling/rescheduling it for
1085 * service. In particular, assign to agg->F its maximum possible
1086 * value, i.e., the virtual finish time with which the aggregate
1087 * should be labeled if it used all its budget once in service.
1088 */
1089static inline void
1090qfq_update_agg_ts(struct qfq_sched *q,
1091 struct qfq_aggregate *agg, enum update_reason reason)
1092{
1093 if (reason != requeue)
1094 qfq_update_start(q, agg);
1095 else /* just charge agg for the service received */
1096 agg->S = agg->F;
1097
1098 agg->F = agg->S + (u64)agg->budgetmax * agg->inv_w;
1099}
Paolo Valente2f3b89a2013-03-05 08:04:59 +00001100
1101static void qfq_schedule_agg(struct qfq_sched *q, struct qfq_aggregate *agg);
1102
stephen hemminger0545a302011-04-04 05:30:58 +00001103static struct sk_buff *qfq_dequeue(struct Qdisc *sch)
1104{
1105 struct qfq_sched *q = qdisc_priv(sch);
Paolo Valente462dbc92012-11-23 11:03:19 +00001106 struct qfq_aggregate *in_serv_agg = q->in_serv_agg;
stephen hemminger0545a302011-04-04 05:30:58 +00001107 struct qfq_class *cl;
Paolo Valente462dbc92012-11-23 11:03:19 +00001108 struct sk_buff *skb = NULL;
1109 /* next-packet len, 0 means no more active classes in in-service agg */
1110 unsigned int len = 0;
1111
1112 if (in_serv_agg == NULL)
1113 return NULL;
1114
1115 if (!list_empty(&in_serv_agg->active))
1116 skb = qfq_peek_skb(in_serv_agg, &cl, &len);
1117
1118 /*
1119 * If there are no active classes in the in-service aggregate,
1120 * or if the aggregate has not enough budget to serve its next
1121 * class, then choose the next aggregate to serve.
1122 */
1123 if (len == 0 || in_serv_agg->budget < len) {
1124 charge_actual_service(in_serv_agg);
1125
1126 /* recharge the budget of the aggregate */
1127 in_serv_agg->initial_budget = in_serv_agg->budget =
1128 in_serv_agg->budgetmax;
1129
Paolo Valente2f3b89a2013-03-05 08:04:59 +00001130 if (!list_empty(&in_serv_agg->active)) {
Paolo Valente462dbc92012-11-23 11:03:19 +00001131 /*
1132 * Still active: reschedule for
1133 * service. Possible optimization: if no other
1134 * aggregate is active, then there is no point
1135 * in rescheduling this aggregate, and we can
1136 * just keep it as the in-service one. This
1137 * should be however a corner case, and to
1138 * handle it, we would need to maintain an
1139 * extra num_active_aggs field.
1140 */
Paolo Valente2f3b89a2013-03-05 08:04:59 +00001141 qfq_update_agg_ts(q, in_serv_agg, requeue);
1142 qfq_schedule_agg(q, in_serv_agg);
1143 } else if (sch->q.qlen == 0) { /* no aggregate to serve */
Paolo Valente462dbc92012-11-23 11:03:19 +00001144 q->in_serv_agg = NULL;
1145 return NULL;
1146 }
1147
1148 /*
1149 * If we get here, there are other aggregates queued:
1150 * choose the new aggregate to serve.
1151 */
1152 in_serv_agg = q->in_serv_agg = qfq_choose_next_agg(q);
1153 skb = qfq_peek_skb(in_serv_agg, &cl, &len);
1154 }
1155 if (!skb)
1156 return NULL;
1157
1158 sch->q.qlen--;
1159 qdisc_bstats_update(sch, skb);
1160
1161 agg_dequeue(in_serv_agg, cl, len);
Paolo Valentea0143ef2013-03-05 08:05:00 +00001162 /* If lmax is lowered, through qfq_change_class, for a class
1163 * owning pending packets with larger size than the new value
1164 * of lmax, then the following condition may hold.
1165 */
1166 if (unlikely(in_serv_agg->budget < len))
1167 in_serv_agg->budget = 0;
1168 else
1169 in_serv_agg->budget -= len;
1170
Paolo Valente87f40dd2013-07-16 08:52:30 +02001171 q->V += (u64)len * q->iwsum;
Paolo Valente462dbc92012-11-23 11:03:19 +00001172 pr_debug("qfq dequeue: len %u F %lld now %lld\n",
1173 len, (unsigned long long) in_serv_agg->F,
1174 (unsigned long long) q->V);
1175
1176 return skb;
1177}
1178
1179static struct qfq_aggregate *qfq_choose_next_agg(struct qfq_sched *q)
1180{
1181 struct qfq_group *grp;
1182 struct qfq_aggregate *agg, *new_front_agg;
1183 u64 old_F;
1184
1185 qfq_update_eligible(q);
1186 q->oldV = q->V;
stephen hemminger0545a302011-04-04 05:30:58 +00001187
1188 if (!q->bitmaps[ER])
1189 return NULL;
1190
1191 grp = qfq_ffs(q, q->bitmaps[ER]);
Paolo Valente462dbc92012-11-23 11:03:19 +00001192 old_F = grp->F;
stephen hemminger0545a302011-04-04 05:30:58 +00001193
Paolo Valente462dbc92012-11-23 11:03:19 +00001194 agg = qfq_slot_head(grp);
1195
1196 /* agg starts to be served, remove it from schedule */
1197 qfq_front_slot_remove(grp);
1198
1199 new_front_agg = qfq_slot_scan(grp);
1200
1201 if (new_front_agg == NULL) /* group is now inactive, remove from ER */
1202 __clear_bit(grp->index, &q->bitmaps[ER]);
1203 else {
1204 u64 roundedS = qfq_round_down(new_front_agg->S,
1205 grp->slot_shift);
1206 unsigned int s;
1207
1208 if (grp->S == roundedS)
1209 return agg;
1210 grp->S = roundedS;
1211 grp->F = roundedS + (2ULL << grp->slot_shift);
1212 __clear_bit(grp->index, &q->bitmaps[ER]);
1213 s = qfq_calc_state(q, grp);
1214 __set_bit(grp->index, &q->bitmaps[s]);
stephen hemminger0545a302011-04-04 05:30:58 +00001215 }
1216
Paolo Valente462dbc92012-11-23 11:03:19 +00001217 qfq_unblock_groups(q, grp->index, old_F);
stephen hemminger0545a302011-04-04 05:30:58 +00001218
Paolo Valente462dbc92012-11-23 11:03:19 +00001219 return agg;
stephen hemminger0545a302011-04-04 05:30:58 +00001220}
1221
stephen hemminger0545a302011-04-04 05:30:58 +00001222static int qfq_enqueue(struct sk_buff *skb, struct Qdisc *sch)
1223{
1224 struct qfq_sched *q = qdisc_priv(sch);
stephen hemminger0545a302011-04-04 05:30:58 +00001225 struct qfq_class *cl;
Paolo Valente462dbc92012-11-23 11:03:19 +00001226 struct qfq_aggregate *agg;
David S. Millerf54ba772012-09-27 18:35:47 -04001227 int err = 0;
stephen hemminger0545a302011-04-04 05:30:58 +00001228
1229 cl = qfq_classify(skb, sch, &err);
1230 if (cl == NULL) {
1231 if (err & __NET_XMIT_BYPASS)
John Fastabend25331d62014-09-28 11:53:29 -07001232 qdisc_qstats_drop(sch);
stephen hemminger0545a302011-04-04 05:30:58 +00001233 kfree_skb(skb);
1234 return err;
1235 }
1236 pr_debug("qfq_enqueue: cl = %x\n", cl->common.classid);
1237
Paolo Valente462dbc92012-11-23 11:03:19 +00001238 if (unlikely(cl->agg->lmax < qdisc_pkt_len(skb))) {
Paolo Valente3015f3d2012-11-05 20:29:24 +00001239 pr_debug("qfq: increasing maxpkt from %u to %u for class %u",
Paolo Valente462dbc92012-11-23 11:03:19 +00001240 cl->agg->lmax, qdisc_pkt_len(skb), cl->common.classid);
1241 err = qfq_change_agg(sch, cl, cl->agg->class_weight,
1242 qdisc_pkt_len(skb));
1243 if (err)
1244 return err;
Paolo Valente3015f3d2012-11-05 20:29:24 +00001245 }
1246
stephen hemminger0545a302011-04-04 05:30:58 +00001247 err = qdisc_enqueue(skb, cl->qdisc);
1248 if (unlikely(err != NET_XMIT_SUCCESS)) {
1249 pr_debug("qfq_enqueue: enqueue failed %d\n", err);
1250 if (net_xmit_drop_count(err)) {
1251 cl->qstats.drops++;
John Fastabend25331d62014-09-28 11:53:29 -07001252 qdisc_qstats_drop(sch);
stephen hemminger0545a302011-04-04 05:30:58 +00001253 }
1254 return err;
1255 }
1256
1257 bstats_update(&cl->bstats, skb);
1258 ++sch->q.qlen;
1259
Paolo Valente462dbc92012-11-23 11:03:19 +00001260 agg = cl->agg;
1261 /* if the queue was not empty, then done here */
1262 if (cl->qdisc->q.qlen != 1) {
1263 if (unlikely(skb == cl->qdisc->ops->peek(cl->qdisc)) &&
1264 list_first_entry(&agg->active, struct qfq_class, alist)
1265 == cl && cl->deficit < qdisc_pkt_len(skb))
1266 list_move_tail(&cl->alist, &agg->active);
stephen hemminger0545a302011-04-04 05:30:58 +00001267
Paolo Valente462dbc92012-11-23 11:03:19 +00001268 return err;
1269 }
1270
1271 /* schedule class for service within the aggregate */
1272 cl->deficit = agg->lmax;
1273 list_add_tail(&cl->alist, &agg->active);
1274
Paolo Valente2f3b89a2013-03-05 08:04:59 +00001275 if (list_first_entry(&agg->active, struct qfq_class, alist) != cl ||
1276 q->in_serv_agg == agg)
1277 return err; /* non-empty or in service, nothing else to do */
Paolo Valente462dbc92012-11-23 11:03:19 +00001278
Paolo Valente2f3b89a2013-03-05 08:04:59 +00001279 qfq_activate_agg(q, agg, enqueue);
Paolo Valentebe72f632012-08-07 07:27:25 +00001280
1281 return err;
1282}
1283
1284/*
Paolo Valente462dbc92012-11-23 11:03:19 +00001285 * Schedule aggregate according to its timestamps.
Paolo Valentebe72f632012-08-07 07:27:25 +00001286 */
Paolo Valente462dbc92012-11-23 11:03:19 +00001287static void qfq_schedule_agg(struct qfq_sched *q, struct qfq_aggregate *agg)
Paolo Valentebe72f632012-08-07 07:27:25 +00001288{
Paolo Valente462dbc92012-11-23 11:03:19 +00001289 struct qfq_group *grp = agg->grp;
Paolo Valentebe72f632012-08-07 07:27:25 +00001290 u64 roundedS;
1291 int s;
1292
Paolo Valente462dbc92012-11-23 11:03:19 +00001293 roundedS = qfq_round_down(agg->S, grp->slot_shift);
stephen hemminger0545a302011-04-04 05:30:58 +00001294
1295 /*
Paolo Valente462dbc92012-11-23 11:03:19 +00001296 * Insert agg in the correct bucket.
1297 * If agg->S >= grp->S we don't need to adjust the
stephen hemminger0545a302011-04-04 05:30:58 +00001298 * bucket list and simply go to the insertion phase.
1299 * Otherwise grp->S is decreasing, we must make room
1300 * in the bucket list, and also recompute the group state.
1301 * Finally, if there were no flows in this group and nobody
1302 * was in ER make sure to adjust V.
1303 */
1304 if (grp->full_slots) {
Paolo Valente462dbc92012-11-23 11:03:19 +00001305 if (!qfq_gt(grp->S, agg->S))
stephen hemminger0545a302011-04-04 05:30:58 +00001306 goto skip_update;
1307
Paolo Valente462dbc92012-11-23 11:03:19 +00001308 /* create a slot for this agg->S */
stephen hemminger0545a302011-04-04 05:30:58 +00001309 qfq_slot_rotate(grp, roundedS);
1310 /* group was surely ineligible, remove */
1311 __clear_bit(grp->index, &q->bitmaps[IR]);
1312 __clear_bit(grp->index, &q->bitmaps[IB]);
Paolo Valente40dd2d52013-03-05 08:05:01 +00001313 } else if (!q->bitmaps[ER] && qfq_gt(roundedS, q->V) &&
1314 q->in_serv_agg == NULL)
stephen hemminger0545a302011-04-04 05:30:58 +00001315 q->V = roundedS;
1316
1317 grp->S = roundedS;
1318 grp->F = roundedS + (2ULL << grp->slot_shift);
1319 s = qfq_calc_state(q, grp);
1320 __set_bit(grp->index, &q->bitmaps[s]);
1321
1322 pr_debug("qfq enqueue: new state %d %#lx S %lld F %lld V %lld\n",
1323 s, q->bitmaps[s],
Paolo Valente462dbc92012-11-23 11:03:19 +00001324 (unsigned long long) agg->S,
1325 (unsigned long long) agg->F,
stephen hemminger0545a302011-04-04 05:30:58 +00001326 (unsigned long long) q->V);
1327
1328skip_update:
Paolo Valente462dbc92012-11-23 11:03:19 +00001329 qfq_slot_insert(grp, agg, roundedS);
stephen hemminger0545a302011-04-04 05:30:58 +00001330}
1331
1332
Paolo Valente462dbc92012-11-23 11:03:19 +00001333/* Update agg ts and schedule agg for service */
1334static void qfq_activate_agg(struct qfq_sched *q, struct qfq_aggregate *agg,
1335 enum update_reason reason)
1336{
Paolo Valente2f3b89a2013-03-05 08:04:59 +00001337 agg->initial_budget = agg->budget = agg->budgetmax; /* recharge budg. */
1338
Paolo Valente462dbc92012-11-23 11:03:19 +00001339 qfq_update_agg_ts(q, agg, reason);
Paolo Valente2f3b89a2013-03-05 08:04:59 +00001340 if (q->in_serv_agg == NULL) { /* no aggr. in service or scheduled */
1341 q->in_serv_agg = agg; /* start serving this aggregate */
1342 /* update V: to be in service, agg must be eligible */
1343 q->oldV = q->V = agg->S;
1344 } else if (agg != q->in_serv_agg)
1345 qfq_schedule_agg(q, agg);
Paolo Valente462dbc92012-11-23 11:03:19 +00001346}
1347
stephen hemminger0545a302011-04-04 05:30:58 +00001348static void qfq_slot_remove(struct qfq_sched *q, struct qfq_group *grp,
Paolo Valente462dbc92012-11-23 11:03:19 +00001349 struct qfq_aggregate *agg)
stephen hemminger0545a302011-04-04 05:30:58 +00001350{
1351 unsigned int i, offset;
1352 u64 roundedS;
1353
Paolo Valente462dbc92012-11-23 11:03:19 +00001354 roundedS = qfq_round_down(agg->S, grp->slot_shift);
stephen hemminger0545a302011-04-04 05:30:58 +00001355 offset = (roundedS - grp->S) >> grp->slot_shift;
Paolo Valente462dbc92012-11-23 11:03:19 +00001356
stephen hemminger0545a302011-04-04 05:30:58 +00001357 i = (grp->front + offset) % QFQ_MAX_SLOTS;
1358
Paolo Valente462dbc92012-11-23 11:03:19 +00001359 hlist_del(&agg->next);
stephen hemminger0545a302011-04-04 05:30:58 +00001360 if (hlist_empty(&grp->slots[i]))
1361 __clear_bit(offset, &grp->full_slots);
1362}
1363
1364/*
Paolo Valente462dbc92012-11-23 11:03:19 +00001365 * Called to forcibly deschedule an aggregate. If the aggregate is
1366 * not in the front bucket, or if the latter has other aggregates in
1367 * the front bucket, we can simply remove the aggregate with no other
1368 * side effects.
stephen hemminger0545a302011-04-04 05:30:58 +00001369 * Otherwise we must propagate the event up.
1370 */
Paolo Valente462dbc92012-11-23 11:03:19 +00001371static void qfq_deactivate_agg(struct qfq_sched *q, struct qfq_aggregate *agg)
stephen hemminger0545a302011-04-04 05:30:58 +00001372{
Paolo Valente462dbc92012-11-23 11:03:19 +00001373 struct qfq_group *grp = agg->grp;
stephen hemminger0545a302011-04-04 05:30:58 +00001374 unsigned long mask;
1375 u64 roundedS;
1376 int s;
1377
Paolo Valente462dbc92012-11-23 11:03:19 +00001378 if (agg == q->in_serv_agg) {
1379 charge_actual_service(agg);
1380 q->in_serv_agg = qfq_choose_next_agg(q);
1381 return;
1382 }
1383
1384 agg->F = agg->S;
1385 qfq_slot_remove(q, grp, agg);
stephen hemminger0545a302011-04-04 05:30:58 +00001386
1387 if (!grp->full_slots) {
1388 __clear_bit(grp->index, &q->bitmaps[IR]);
1389 __clear_bit(grp->index, &q->bitmaps[EB]);
1390 __clear_bit(grp->index, &q->bitmaps[IB]);
1391
1392 if (test_bit(grp->index, &q->bitmaps[ER]) &&
1393 !(q->bitmaps[ER] & ~((1UL << grp->index) - 1))) {
1394 mask = q->bitmaps[ER] & ((1UL << grp->index) - 1);
1395 if (mask)
1396 mask = ~((1UL << __fls(mask)) - 1);
1397 else
1398 mask = ~0UL;
1399 qfq_move_groups(q, mask, EB, ER);
1400 qfq_move_groups(q, mask, IB, IR);
1401 }
1402 __clear_bit(grp->index, &q->bitmaps[ER]);
1403 } else if (hlist_empty(&grp->slots[grp->front])) {
Paolo Valente462dbc92012-11-23 11:03:19 +00001404 agg = qfq_slot_scan(grp);
1405 roundedS = qfq_round_down(agg->S, grp->slot_shift);
stephen hemminger0545a302011-04-04 05:30:58 +00001406 if (grp->S != roundedS) {
1407 __clear_bit(grp->index, &q->bitmaps[ER]);
1408 __clear_bit(grp->index, &q->bitmaps[IR]);
1409 __clear_bit(grp->index, &q->bitmaps[EB]);
1410 __clear_bit(grp->index, &q->bitmaps[IB]);
1411 grp->S = roundedS;
1412 grp->F = roundedS + (2ULL << grp->slot_shift);
1413 s = qfq_calc_state(q, grp);
1414 __set_bit(grp->index, &q->bitmaps[s]);
1415 }
1416 }
stephen hemminger0545a302011-04-04 05:30:58 +00001417}
1418
1419static void qfq_qlen_notify(struct Qdisc *sch, unsigned long arg)
1420{
1421 struct qfq_sched *q = qdisc_priv(sch);
1422 struct qfq_class *cl = (struct qfq_class *)arg;
1423
1424 if (cl->qdisc->q.qlen == 0)
1425 qfq_deactivate_class(q, cl);
1426}
1427
Paolo Valente462dbc92012-11-23 11:03:19 +00001428static unsigned int qfq_drop_from_slot(struct qfq_sched *q,
1429 struct hlist_head *slot)
1430{
1431 struct qfq_aggregate *agg;
Paolo Valente462dbc92012-11-23 11:03:19 +00001432 struct qfq_class *cl;
1433 unsigned int len;
1434
Sasha Levinb67bfe02013-02-27 17:06:00 -08001435 hlist_for_each_entry(agg, slot, next) {
Paolo Valente462dbc92012-11-23 11:03:19 +00001436 list_for_each_entry(cl, &agg->active, alist) {
1437
1438 if (!cl->qdisc->ops->drop)
1439 continue;
1440
1441 len = cl->qdisc->ops->drop(cl->qdisc);
1442 if (len > 0) {
1443 if (cl->qdisc->q.qlen == 0)
1444 qfq_deactivate_class(q, cl);
1445
1446 return len;
1447 }
1448 }
1449 }
1450 return 0;
1451}
1452
stephen hemminger0545a302011-04-04 05:30:58 +00001453static unsigned int qfq_drop(struct Qdisc *sch)
1454{
1455 struct qfq_sched *q = qdisc_priv(sch);
1456 struct qfq_group *grp;
1457 unsigned int i, j, len;
1458
1459 for (i = 0; i <= QFQ_MAX_INDEX; i++) {
1460 grp = &q->groups[i];
1461 for (j = 0; j < QFQ_MAX_SLOTS; j++) {
Paolo Valente462dbc92012-11-23 11:03:19 +00001462 len = qfq_drop_from_slot(q, &grp->slots[j]);
1463 if (len > 0) {
1464 sch->q.qlen--;
1465 return len;
stephen hemminger0545a302011-04-04 05:30:58 +00001466 }
1467 }
Paolo Valente462dbc92012-11-23 11:03:19 +00001468
stephen hemminger0545a302011-04-04 05:30:58 +00001469 }
1470
1471 return 0;
1472}
1473
1474static int qfq_init_qdisc(struct Qdisc *sch, struct nlattr *opt)
1475{
1476 struct qfq_sched *q = qdisc_priv(sch);
1477 struct qfq_group *grp;
1478 int i, j, err;
Paolo Valente462dbc92012-11-23 11:03:19 +00001479 u32 max_cl_shift, maxbudg_shift, max_classes;
stephen hemminger0545a302011-04-04 05:30:58 +00001480
1481 err = qdisc_class_hash_init(&q->clhash);
1482 if (err < 0)
1483 return err;
1484
Paolo Valente462dbc92012-11-23 11:03:19 +00001485 if (qdisc_dev(sch)->tx_queue_len + 1 > QFQ_MAX_AGG_CLASSES)
1486 max_classes = QFQ_MAX_AGG_CLASSES;
1487 else
1488 max_classes = qdisc_dev(sch)->tx_queue_len + 1;
1489 /* max_cl_shift = floor(log_2(max_classes)) */
1490 max_cl_shift = __fls(max_classes);
1491 q->max_agg_classes = 1<<max_cl_shift;
1492
1493 /* maxbudg_shift = log2(max_len * max_classes_per_agg) */
1494 maxbudg_shift = QFQ_MTU_SHIFT + max_cl_shift;
1495 q->min_slot_shift = FRAC_BITS + maxbudg_shift - QFQ_MAX_INDEX;
1496
stephen hemminger0545a302011-04-04 05:30:58 +00001497 for (i = 0; i <= QFQ_MAX_INDEX; i++) {
1498 grp = &q->groups[i];
1499 grp->index = i;
Paolo Valente462dbc92012-11-23 11:03:19 +00001500 grp->slot_shift = q->min_slot_shift + i;
stephen hemminger0545a302011-04-04 05:30:58 +00001501 for (j = 0; j < QFQ_MAX_SLOTS; j++)
1502 INIT_HLIST_HEAD(&grp->slots[j]);
1503 }
1504
Paolo Valente462dbc92012-11-23 11:03:19 +00001505 INIT_HLIST_HEAD(&q->nonfull_aggs);
1506
stephen hemminger0545a302011-04-04 05:30:58 +00001507 return 0;
1508}
1509
1510static void qfq_reset_qdisc(struct Qdisc *sch)
1511{
1512 struct qfq_sched *q = qdisc_priv(sch);
stephen hemminger0545a302011-04-04 05:30:58 +00001513 struct qfq_class *cl;
Paolo Valente462dbc92012-11-23 11:03:19 +00001514 unsigned int i;
stephen hemminger0545a302011-04-04 05:30:58 +00001515
1516 for (i = 0; i < q->clhash.hashsize; i++) {
Sasha Levinb67bfe02013-02-27 17:06:00 -08001517 hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
Paolo Valente462dbc92012-11-23 11:03:19 +00001518 if (cl->qdisc->q.qlen > 0)
1519 qfq_deactivate_class(q, cl);
1520
stephen hemminger0545a302011-04-04 05:30:58 +00001521 qdisc_reset(cl->qdisc);
Paolo Valente462dbc92012-11-23 11:03:19 +00001522 }
stephen hemminger0545a302011-04-04 05:30:58 +00001523 }
1524 sch->q.qlen = 0;
1525}
1526
1527static void qfq_destroy_qdisc(struct Qdisc *sch)
1528{
1529 struct qfq_sched *q = qdisc_priv(sch);
1530 struct qfq_class *cl;
Sasha Levinb67bfe02013-02-27 17:06:00 -08001531 struct hlist_node *next;
stephen hemminger0545a302011-04-04 05:30:58 +00001532 unsigned int i;
1533
1534 tcf_destroy_chain(&q->filter_list);
1535
1536 for (i = 0; i < q->clhash.hashsize; i++) {
Sasha Levinb67bfe02013-02-27 17:06:00 -08001537 hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
stephen hemminger0545a302011-04-04 05:30:58 +00001538 common.hnode) {
1539 qfq_destroy_class(sch, cl);
1540 }
1541 }
1542 qdisc_class_hash_destroy(&q->clhash);
1543}
1544
1545static const struct Qdisc_class_ops qfq_class_ops = {
1546 .change = qfq_change_class,
1547 .delete = qfq_delete_class,
1548 .get = qfq_get_class,
1549 .put = qfq_put_class,
1550 .tcf_chain = qfq_tcf_chain,
1551 .bind_tcf = qfq_bind_tcf,
1552 .unbind_tcf = qfq_unbind_tcf,
1553 .graft = qfq_graft_class,
1554 .leaf = qfq_class_leaf,
1555 .qlen_notify = qfq_qlen_notify,
1556 .dump = qfq_dump_class,
1557 .dump_stats = qfq_dump_class_stats,
1558 .walk = qfq_walk,
1559};
1560
1561static struct Qdisc_ops qfq_qdisc_ops __read_mostly = {
1562 .cl_ops = &qfq_class_ops,
1563 .id = "qfq",
1564 .priv_size = sizeof(struct qfq_sched),
1565 .enqueue = qfq_enqueue,
1566 .dequeue = qfq_dequeue,
1567 .peek = qdisc_peek_dequeued,
1568 .drop = qfq_drop,
1569 .init = qfq_init_qdisc,
1570 .reset = qfq_reset_qdisc,
1571 .destroy = qfq_destroy_qdisc,
1572 .owner = THIS_MODULE,
1573};
1574
1575static int __init qfq_init(void)
1576{
1577 return register_qdisc(&qfq_qdisc_ops);
1578}
1579
1580static void __exit qfq_exit(void)
1581{
1582 unregister_qdisc(&qfq_qdisc_ops);
1583}
1584
1585module_init(qfq_init);
1586module_exit(qfq_exit);
1587MODULE_LICENSE("GPL");