]>
Commit | Line | Data |
---|---|---|
0545a303 | 1 | /* |
462dbc91 | 2 | * net/sched/sch_qfq.c Quick Fair Queueing Plus Scheduler. |
0545a303 | 3 | * |
4 | * Copyright (c) 2009 Fabio Checconi, Luigi Rizzo, and Paolo Valente. | |
462dbc91 | 5 | * Copyright (c) 2012 Paolo Valente. |
0545a303 | 6 | * |
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 | ||
462dbc91 PV |
23 | /* Quick Fair Queueing Plus |
24 | ======================== | |
0545a303 | 25 | |
26 | Sources: | |
27 | ||
462dbc91 PV |
28 | [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 | |
0545a303 | 35 | Packet Scheduling with Tight Bandwidth Distribution Guarantees." |
36 | ||
37 | See also: | |
38 | http://retis.sssup.it/~fabio/linux/qfq/ | |
39 | */ | |
40 | ||
41 | /* | |
42 | ||
462dbc91 PV |
43 | 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 | ||
0545a303 | 57 | 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 | /* | |
462dbc91 PV |
100 | * 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 | |
0545a303 | 102 | * group with the smallest index that can support the L_i / r_i configured |
462dbc91 | 103 | * for the classes in the aggregate. |
0545a303 | 104 | * |
105 | * grp->index is the index of the group; and grp->slot_shift | |
106 | * is the shift for the corresponding (scaled) sigma_i. | |
107 | */ | |
3015f3d2 | 108 | #define QFQ_MAX_INDEX 24 |
462dbc91 | 109 | #define QFQ_MAX_WSHIFT 10 |
0545a303 | 110 | |
462dbc91 PV |
111 | #define QFQ_MAX_WEIGHT (1<<QFQ_MAX_WSHIFT) /* see qfq_slot_insert */ |
112 | #define QFQ_MAX_WSUM (64*QFQ_MAX_WEIGHT) | |
0545a303 | 113 | |
114 | #define FRAC_BITS 30 /* fixed point arithmetic */ | |
115 | #define ONE_FP (1UL << FRAC_BITS) | |
116 | #define IWSUM (ONE_FP/QFQ_MAX_WSUM) | |
117 | ||
3015f3d2 | 118 | #define QFQ_MTU_SHIFT 16 /* to support TSO/GSO */ |
462dbc91 PV |
119 | #define QFQ_MIN_LMAX 512 /* see qfq_slot_insert */ |
120 | ||
121 | #define QFQ_MAX_AGG_CLASSES 8 /* max num classes per aggregate allowed */ | |
0545a303 | 122 | |
123 | /* | |
124 | * Possible group states. These values are used as indexes for the bitmaps | |
125 | * array of struct qfq_queue. | |
126 | */ | |
127 | enum qfq_state { ER, IR, EB, IB, QFQ_MAX_STATE }; | |
128 | ||
129 | struct qfq_group; | |
130 | ||
462dbc91 PV |
131 | struct qfq_aggregate; |
132 | ||
0545a303 | 133 | struct qfq_class { |
134 | struct Qdisc_class_common common; | |
135 | ||
136 | unsigned int refcnt; | |
137 | unsigned int filter_cnt; | |
138 | ||
139 | struct gnet_stats_basic_packed bstats; | |
140 | struct gnet_stats_queue qstats; | |
141 | struct gnet_stats_rate_est rate_est; | |
142 | struct Qdisc *qdisc; | |
462dbc91 PV |
143 | struct list_head alist; /* Link for active-classes list. */ |
144 | struct qfq_aggregate *agg; /* Parent aggregate. */ | |
145 | int deficit; /* DRR deficit counter. */ | |
146 | }; | |
0545a303 | 147 | |
462dbc91 | 148 | struct qfq_aggregate { |
0545a303 | 149 | struct hlist_node next; /* Link for the slot list. */ |
150 | u64 S, F; /* flow timestamps (exact) */ | |
151 | ||
152 | /* group we belong to. In principle we would need the index, | |
153 | * which is log_2(lmax/weight), but we never reference it | |
154 | * directly, only the group. | |
155 | */ | |
156 | struct qfq_group *grp; | |
157 | ||
158 | /* these are copied from the flowset. */ | |
462dbc91 PV |
159 | u32 class_weight; /* Weight of each class in this aggregate. */ |
160 | /* Max pkt size for the classes in this aggregate, DRR quantum. */ | |
161 | int lmax; | |
162 | ||
163 | u32 inv_w; /* ONE_FP/(sum of weights of classes in aggr.). */ | |
164 | u32 budgetmax; /* Max budget for this aggregate. */ | |
165 | u32 initial_budget, budget; /* Initial and current budget. */ | |
166 | ||
167 | int num_classes; /* Number of classes in this aggr. */ | |
168 | struct list_head active; /* DRR queue of active classes. */ | |
169 | ||
170 | struct hlist_node nonfull_next; /* See nonfull_aggs in qfq_sched. */ | |
0545a303 | 171 | }; |
172 | ||
173 | struct qfq_group { | |
174 | u64 S, F; /* group timestamps (approx). */ | |
175 | unsigned int slot_shift; /* Slot shift. */ | |
176 | unsigned int index; /* Group index. */ | |
177 | unsigned int front; /* Index of the front slot. */ | |
178 | unsigned long full_slots; /* non-empty slots */ | |
179 | ||
462dbc91 | 180 | /* Array of RR lists of active aggregates. */ |
0545a303 | 181 | struct hlist_head slots[QFQ_MAX_SLOTS]; |
182 | }; | |
183 | ||
184 | struct qfq_sched { | |
185 | struct tcf_proto *filter_list; | |
186 | struct Qdisc_class_hash clhash; | |
187 | ||
462dbc91 PV |
188 | u64 oldV, V; /* Precise virtual times. */ |
189 | struct qfq_aggregate *in_serv_agg; /* Aggregate being served. */ | |
190 | u32 num_active_agg; /* Num. of active aggregates */ | |
191 | u32 wsum; /* weight sum */ | |
0545a303 | 192 | |
193 | unsigned long bitmaps[QFQ_MAX_STATE]; /* Group bitmaps. */ | |
194 | struct qfq_group groups[QFQ_MAX_INDEX + 1]; /* The groups. */ | |
462dbc91 PV |
195 | 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. */ | |
0545a303 | 199 | }; |
200 | ||
462dbc91 PV |
201 | /* |
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 | */ | |
208 | enum update_reason {enqueue, requeue}; | |
209 | ||
0545a303 | 210 | static 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 | ||
221 | static 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 | ||
229 | static 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 | */ | |
462dbc91 | 239 | static int qfq_calc_index(u32 inv_w, unsigned int maxlen, u32 min_slot_shift) |
0545a303 | 240 | { |
241 | u64 slot_size = (u64)maxlen * inv_w; | |
242 | unsigned long size_map; | |
243 | int index = 0; | |
244 | ||
462dbc91 | 245 | size_map = slot_size >> min_slot_shift; |
0545a303 | 246 | if (!size_map) |
247 | goto out; | |
248 | ||
249 | index = __fls(size_map) + 1; /* basically a log_2 */ | |
462dbc91 | 250 | index -= !(slot_size - (1ULL << (index + min_slot_shift - 1))); |
0545a303 | 251 | |
252 | if (index < 0) | |
253 | index = 0; | |
254 | out: | |
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 | ||
462dbc91 PV |
261 | static void qfq_deactivate_agg(struct qfq_sched *, struct qfq_aggregate *); |
262 | static void qfq_activate_agg(struct qfq_sched *, struct qfq_aggregate *, | |
263 | enum update_reason); | |
264 | ||
265 | static void qfq_init_agg(struct qfq_sched *q, struct qfq_aggregate *agg, | |
266 | u32 lmax, u32 weight) | |
be72f63b | 267 | { |
462dbc91 PV |
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; | |
273 | } | |
274 | ||
275 | static struct qfq_aggregate *qfq_find_agg(struct qfq_sched *q, | |
276 | u32 lmax, u32 weight) | |
277 | { | |
278 | struct qfq_aggregate *agg; | |
279 | struct hlist_node *n; | |
280 | ||
281 | hlist_for_each_entry(agg, n, &q->nonfull_aggs, nonfull_next) | |
282 | if (agg->lmax == lmax && agg->class_weight == weight) | |
283 | return agg; | |
284 | ||
285 | return NULL; | |
286 | } | |
287 | ||
be72f63b | 288 | |
462dbc91 PV |
289 | /* Update aggregate as a function of the new number of classes. */ |
290 | static void qfq_update_agg(struct qfq_sched *q, struct qfq_aggregate *agg, | |
291 | int new_num_classes) | |
292 | { | |
293 | u32 new_agg_weight; | |
294 | ||
295 | if (new_num_classes == q->max_agg_classes) | |
296 | hlist_del_init(&agg->nonfull_next); | |
297 | ||
298 | if (agg->num_classes > new_num_classes && | |
299 | new_num_classes == q->max_agg_classes - 1) /* agg no more full */ | |
300 | hlist_add_head(&agg->nonfull_next, &q->nonfull_aggs); | |
301 | ||
302 | agg->budgetmax = new_num_classes * agg->lmax; | |
303 | new_agg_weight = agg->class_weight * new_num_classes; | |
304 | agg->inv_w = ONE_FP/new_agg_weight; | |
305 | ||
306 | if (agg->grp == NULL) { | |
307 | int i = qfq_calc_index(agg->inv_w, agg->budgetmax, | |
308 | q->min_slot_shift); | |
309 | agg->grp = &q->groups[i]; | |
310 | } | |
311 | ||
312 | q->wsum += | |
313 | (int) agg->class_weight * (new_num_classes - agg->num_classes); | |
314 | ||
315 | agg->num_classes = new_num_classes; | |
316 | } | |
317 | ||
318 | /* Add class to aggregate. */ | |
319 | static void qfq_add_to_agg(struct qfq_sched *q, | |
320 | struct qfq_aggregate *agg, | |
321 | struct qfq_class *cl) | |
322 | { | |
323 | cl->agg = agg; | |
324 | ||
325 | qfq_update_agg(q, agg, agg->num_classes+1); | |
326 | if (cl->qdisc->q.qlen > 0) { /* adding an active class */ | |
327 | list_add_tail(&cl->alist, &agg->active); | |
328 | if (list_first_entry(&agg->active, struct qfq_class, alist) == | |
329 | cl && q->in_serv_agg != agg) /* agg was inactive */ | |
330 | qfq_activate_agg(q, agg, enqueue); /* schedule agg */ | |
331 | } | |
be72f63b PV |
332 | } |
333 | ||
462dbc91 | 334 | static struct qfq_aggregate *qfq_choose_next_agg(struct qfq_sched *); |
be72f63b | 335 | |
462dbc91 | 336 | static void qfq_destroy_agg(struct qfq_sched *q, struct qfq_aggregate *agg) |
be72f63b | 337 | { |
462dbc91 PV |
338 | if (!hlist_unhashed(&agg->nonfull_next)) |
339 | hlist_del_init(&agg->nonfull_next); | |
340 | if (q->in_serv_agg == agg) | |
341 | q->in_serv_agg = qfq_choose_next_agg(q); | |
342 | kfree(agg); | |
343 | } | |
be72f63b | 344 | |
462dbc91 PV |
345 | /* Deschedule class from within its parent aggregate. */ |
346 | static void qfq_deactivate_class(struct qfq_sched *q, struct qfq_class *cl) | |
347 | { | |
348 | struct qfq_aggregate *agg = cl->agg; | |
be72f63b | 349 | |
be72f63b | 350 | |
462dbc91 PV |
351 | list_del(&cl->alist); /* remove from RR queue of the aggregate */ |
352 | if (list_empty(&agg->active)) /* agg is now inactive */ | |
353 | qfq_deactivate_agg(q, agg); | |
be72f63b PV |
354 | } |
355 | ||
462dbc91 PV |
356 | /* Remove class from its parent aggregate. */ |
357 | static void qfq_rm_from_agg(struct qfq_sched *q, struct qfq_class *cl) | |
3015f3d2 | 358 | { |
462dbc91 | 359 | struct qfq_aggregate *agg = cl->agg; |
3015f3d2 | 360 | |
462dbc91 PV |
361 | cl->agg = NULL; |
362 | if (agg->num_classes == 1) { /* agg being emptied, destroy it */ | |
363 | qfq_destroy_agg(q, agg); | |
364 | return; | |
3015f3d2 | 365 | } |
462dbc91 PV |
366 | qfq_update_agg(q, agg, agg->num_classes-1); |
367 | } | |
3015f3d2 | 368 | |
462dbc91 PV |
369 | /* Deschedule class and remove it from its parent aggregate. */ |
370 | static void qfq_deact_rm_from_agg(struct qfq_sched *q, struct qfq_class *cl) | |
371 | { | |
372 | if (cl->qdisc->q.qlen > 0) /* class is active */ | |
373 | qfq_deactivate_class(q, cl); | |
3015f3d2 | 374 | |
462dbc91 | 375 | qfq_rm_from_agg(q, cl); |
3015f3d2 PV |
376 | } |
377 | ||
462dbc91 PV |
378 | /* Move class to a new aggregate, matching the new class weight and/or lmax */ |
379 | static int qfq_change_agg(struct Qdisc *sch, struct qfq_class *cl, u32 weight, | |
380 | u32 lmax) | |
381 | { | |
382 | struct qfq_sched *q = qdisc_priv(sch); | |
383 | struct qfq_aggregate *new_agg = qfq_find_agg(q, lmax, weight); | |
384 | ||
385 | if (new_agg == NULL) { /* create new aggregate */ | |
386 | new_agg = kzalloc(sizeof(*new_agg), GFP_ATOMIC); | |
387 | if (new_agg == NULL) | |
388 | return -ENOBUFS; | |
389 | qfq_init_agg(q, new_agg, lmax, weight); | |
390 | } | |
391 | qfq_deact_rm_from_agg(q, cl); | |
392 | qfq_add_to_agg(q, new_agg, cl); | |
393 | ||
394 | return 0; | |
395 | } | |
3015f3d2 | 396 | |
0545a303 | 397 | static int qfq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, |
398 | struct nlattr **tca, unsigned long *arg) | |
399 | { | |
400 | struct qfq_sched *q = qdisc_priv(sch); | |
401 | struct qfq_class *cl = (struct qfq_class *)*arg; | |
462dbc91 | 402 | bool existing = false; |
0545a303 | 403 | struct nlattr *tb[TCA_QFQ_MAX + 1]; |
462dbc91 | 404 | struct qfq_aggregate *new_agg = NULL; |
0545a303 | 405 | u32 weight, lmax, inv_w; |
3015f3d2 | 406 | int err; |
d32ae76f | 407 | int delta_w; |
0545a303 | 408 | |
409 | if (tca[TCA_OPTIONS] == NULL) { | |
410 | pr_notice("qfq: no options\n"); | |
411 | return -EINVAL; | |
412 | } | |
413 | ||
414 | err = nla_parse_nested(tb, TCA_QFQ_MAX, tca[TCA_OPTIONS], qfq_policy); | |
415 | if (err < 0) | |
416 | return err; | |
417 | ||
418 | if (tb[TCA_QFQ_WEIGHT]) { | |
419 | weight = nla_get_u32(tb[TCA_QFQ_WEIGHT]); | |
420 | if (!weight || weight > (1UL << QFQ_MAX_WSHIFT)) { | |
421 | pr_notice("qfq: invalid weight %u\n", weight); | |
422 | return -EINVAL; | |
423 | } | |
424 | } else | |
425 | weight = 1; | |
426 | ||
0545a303 | 427 | if (tb[TCA_QFQ_LMAX]) { |
428 | lmax = nla_get_u32(tb[TCA_QFQ_LMAX]); | |
3015f3d2 | 429 | if (lmax < QFQ_MIN_LMAX || lmax > (1UL << QFQ_MTU_SHIFT)) { |
0545a303 | 430 | pr_notice("qfq: invalid max length %u\n", lmax); |
431 | return -EINVAL; | |
432 | } | |
433 | } else | |
3015f3d2 | 434 | lmax = psched_mtu(qdisc_dev(sch)); |
0545a303 | 435 | |
462dbc91 PV |
436 | inv_w = ONE_FP / weight; |
437 | weight = ONE_FP / inv_w; | |
438 | ||
439 | if (cl != NULL && | |
440 | lmax == cl->agg->lmax && | |
441 | weight == cl->agg->class_weight) | |
442 | return 0; /* nothing to change */ | |
443 | ||
444 | delta_w = weight - (cl ? cl->agg->class_weight : 0); | |
445 | ||
446 | if (q->wsum + delta_w > QFQ_MAX_WSUM) { | |
447 | pr_notice("qfq: total weight out of range (%d + %u)\n", | |
448 | delta_w, q->wsum); | |
449 | return -EINVAL; | |
450 | } | |
451 | ||
452 | if (cl != NULL) { /* modify existing class */ | |
0545a303 | 453 | if (tca[TCA_RATE]) { |
454 | err = gen_replace_estimator(&cl->bstats, &cl->rate_est, | |
455 | qdisc_root_sleeping_lock(sch), | |
456 | tca[TCA_RATE]); | |
457 | if (err) | |
458 | return err; | |
459 | } | |
462dbc91 PV |
460 | existing = true; |
461 | goto set_change_agg; | |
0545a303 | 462 | } |
463 | ||
462dbc91 | 464 | /* create and init new class */ |
0545a303 | 465 | cl = kzalloc(sizeof(struct qfq_class), GFP_KERNEL); |
466 | if (cl == NULL) | |
467 | return -ENOBUFS; | |
468 | ||
469 | cl->refcnt = 1; | |
470 | cl->common.classid = classid; | |
462dbc91 | 471 | cl->deficit = lmax; |
0545a303 | 472 | |
473 | cl->qdisc = qdisc_create_dflt(sch->dev_queue, | |
474 | &pfifo_qdisc_ops, classid); | |
475 | if (cl->qdisc == NULL) | |
476 | cl->qdisc = &noop_qdisc; | |
477 | ||
478 | if (tca[TCA_RATE]) { | |
479 | err = gen_new_estimator(&cl->bstats, &cl->rate_est, | |
480 | qdisc_root_sleeping_lock(sch), | |
481 | tca[TCA_RATE]); | |
462dbc91 PV |
482 | if (err) |
483 | goto destroy_class; | |
0545a303 | 484 | } |
485 | ||
486 | sch_tree_lock(sch); | |
487 | qdisc_class_hash_insert(&q->clhash, &cl->common); | |
488 | sch_tree_unlock(sch); | |
489 | ||
490 | qdisc_class_hash_grow(sch, &q->clhash); | |
491 | ||
462dbc91 PV |
492 | set_change_agg: |
493 | sch_tree_lock(sch); | |
494 | new_agg = qfq_find_agg(q, lmax, weight); | |
495 | if (new_agg == NULL) { /* create new aggregate */ | |
496 | sch_tree_unlock(sch); | |
497 | new_agg = kzalloc(sizeof(*new_agg), GFP_KERNEL); | |
498 | if (new_agg == NULL) { | |
499 | err = -ENOBUFS; | |
500 | gen_kill_estimator(&cl->bstats, &cl->rate_est); | |
501 | goto destroy_class; | |
502 | } | |
503 | sch_tree_lock(sch); | |
504 | qfq_init_agg(q, new_agg, lmax, weight); | |
505 | } | |
506 | if (existing) | |
507 | qfq_deact_rm_from_agg(q, cl); | |
508 | qfq_add_to_agg(q, new_agg, cl); | |
509 | sch_tree_unlock(sch); | |
510 | ||
0545a303 | 511 | *arg = (unsigned long)cl; |
512 | return 0; | |
462dbc91 PV |
513 | |
514 | destroy_class: | |
515 | qdisc_destroy(cl->qdisc); | |
516 | kfree(cl); | |
517 | return err; | |
0545a303 | 518 | } |
519 | ||
520 | static void qfq_destroy_class(struct Qdisc *sch, struct qfq_class *cl) | |
521 | { | |
522 | struct qfq_sched *q = qdisc_priv(sch); | |
523 | ||
462dbc91 | 524 | qfq_rm_from_agg(q, cl); |
0545a303 | 525 | gen_kill_estimator(&cl->bstats, &cl->rate_est); |
526 | qdisc_destroy(cl->qdisc); | |
527 | kfree(cl); | |
528 | } | |
529 | ||
530 | static int qfq_delete_class(struct Qdisc *sch, unsigned long arg) | |
531 | { | |
532 | struct qfq_sched *q = qdisc_priv(sch); | |
533 | struct qfq_class *cl = (struct qfq_class *)arg; | |
534 | ||
535 | if (cl->filter_cnt > 0) | |
536 | return -EBUSY; | |
537 | ||
538 | sch_tree_lock(sch); | |
539 | ||
540 | qfq_purge_queue(cl); | |
541 | qdisc_class_hash_remove(&q->clhash, &cl->common); | |
542 | ||
543 | BUG_ON(--cl->refcnt == 0); | |
544 | /* | |
545 | * This shouldn't happen: we "hold" one cops->get() when called | |
546 | * from tc_ctl_tclass; the destroy method is done from cops->put(). | |
547 | */ | |
548 | ||
549 | sch_tree_unlock(sch); | |
550 | return 0; | |
551 | } | |
552 | ||
553 | static unsigned long qfq_get_class(struct Qdisc *sch, u32 classid) | |
554 | { | |
555 | struct qfq_class *cl = qfq_find_class(sch, classid); | |
556 | ||
557 | if (cl != NULL) | |
558 | cl->refcnt++; | |
559 | ||
560 | return (unsigned long)cl; | |
561 | } | |
562 | ||
563 | static void qfq_put_class(struct Qdisc *sch, unsigned long arg) | |
564 | { | |
565 | struct qfq_class *cl = (struct qfq_class *)arg; | |
566 | ||
567 | if (--cl->refcnt == 0) | |
568 | qfq_destroy_class(sch, cl); | |
569 | } | |
570 | ||
571 | static struct tcf_proto **qfq_tcf_chain(struct Qdisc *sch, unsigned long cl) | |
572 | { | |
573 | struct qfq_sched *q = qdisc_priv(sch); | |
574 | ||
575 | if (cl) | |
576 | return NULL; | |
577 | ||
578 | return &q->filter_list; | |
579 | } | |
580 | ||
581 | static unsigned long qfq_bind_tcf(struct Qdisc *sch, unsigned long parent, | |
582 | u32 classid) | |
583 | { | |
584 | struct qfq_class *cl = qfq_find_class(sch, classid); | |
585 | ||
586 | if (cl != NULL) | |
587 | cl->filter_cnt++; | |
588 | ||
589 | return (unsigned long)cl; | |
590 | } | |
591 | ||
592 | static void qfq_unbind_tcf(struct Qdisc *sch, unsigned long arg) | |
593 | { | |
594 | struct qfq_class *cl = (struct qfq_class *)arg; | |
595 | ||
596 | cl->filter_cnt--; | |
597 | } | |
598 | ||
599 | static int qfq_graft_class(struct Qdisc *sch, unsigned long arg, | |
600 | struct Qdisc *new, struct Qdisc **old) | |
601 | { | |
602 | struct qfq_class *cl = (struct qfq_class *)arg; | |
603 | ||
604 | if (new == NULL) { | |
605 | new = qdisc_create_dflt(sch->dev_queue, | |
606 | &pfifo_qdisc_ops, cl->common.classid); | |
607 | if (new == NULL) | |
608 | new = &noop_qdisc; | |
609 | } | |
610 | ||
611 | sch_tree_lock(sch); | |
612 | qfq_purge_queue(cl); | |
613 | *old = cl->qdisc; | |
614 | cl->qdisc = new; | |
615 | sch_tree_unlock(sch); | |
616 | return 0; | |
617 | } | |
618 | ||
619 | static struct Qdisc *qfq_class_leaf(struct Qdisc *sch, unsigned long arg) | |
620 | { | |
621 | struct qfq_class *cl = (struct qfq_class *)arg; | |
622 | ||
623 | return cl->qdisc; | |
624 | } | |
625 | ||
626 | static int qfq_dump_class(struct Qdisc *sch, unsigned long arg, | |
627 | struct sk_buff *skb, struct tcmsg *tcm) | |
628 | { | |
629 | struct qfq_class *cl = (struct qfq_class *)arg; | |
630 | struct nlattr *nest; | |
631 | ||
632 | tcm->tcm_parent = TC_H_ROOT; | |
633 | tcm->tcm_handle = cl->common.classid; | |
634 | tcm->tcm_info = cl->qdisc->handle; | |
635 | ||
636 | nest = nla_nest_start(skb, TCA_OPTIONS); | |
637 | if (nest == NULL) | |
638 | goto nla_put_failure; | |
462dbc91 PV |
639 | if (nla_put_u32(skb, TCA_QFQ_WEIGHT, cl->agg->class_weight) || |
640 | nla_put_u32(skb, TCA_QFQ_LMAX, cl->agg->lmax)) | |
1b34ec43 | 641 | goto nla_put_failure; |
0545a303 | 642 | return nla_nest_end(skb, nest); |
643 | ||
644 | nla_put_failure: | |
645 | nla_nest_cancel(skb, nest); | |
646 | return -EMSGSIZE; | |
647 | } | |
648 | ||
649 | static int qfq_dump_class_stats(struct Qdisc *sch, unsigned long arg, | |
650 | struct gnet_dump *d) | |
651 | { | |
652 | struct qfq_class *cl = (struct qfq_class *)arg; | |
653 | struct tc_qfq_stats xstats; | |
654 | ||
655 | memset(&xstats, 0, sizeof(xstats)); | |
656 | cl->qdisc->qstats.qlen = cl->qdisc->q.qlen; | |
657 | ||
462dbc91 PV |
658 | xstats.weight = cl->agg->class_weight; |
659 | xstats.lmax = cl->agg->lmax; | |
0545a303 | 660 | |
661 | if (gnet_stats_copy_basic(d, &cl->bstats) < 0 || | |
662 | gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 || | |
663 | gnet_stats_copy_queue(d, &cl->qdisc->qstats) < 0) | |
664 | return -1; | |
665 | ||
666 | return gnet_stats_copy_app(d, &xstats, sizeof(xstats)); | |
667 | } | |
668 | ||
669 | static void qfq_walk(struct Qdisc *sch, struct qdisc_walker *arg) | |
670 | { | |
671 | struct qfq_sched *q = qdisc_priv(sch); | |
672 | struct qfq_class *cl; | |
673 | struct hlist_node *n; | |
674 | unsigned int i; | |
675 | ||
676 | if (arg->stop) | |
677 | return; | |
678 | ||
679 | for (i = 0; i < q->clhash.hashsize; i++) { | |
680 | hlist_for_each_entry(cl, n, &q->clhash.hash[i], common.hnode) { | |
681 | if (arg->count < arg->skip) { | |
682 | arg->count++; | |
683 | continue; | |
684 | } | |
685 | if (arg->fn(sch, (unsigned long)cl, arg) < 0) { | |
686 | arg->stop = 1; | |
687 | return; | |
688 | } | |
689 | arg->count++; | |
690 | } | |
691 | } | |
692 | } | |
693 | ||
694 | static struct qfq_class *qfq_classify(struct sk_buff *skb, struct Qdisc *sch, | |
695 | int *qerr) | |
696 | { | |
697 | struct qfq_sched *q = qdisc_priv(sch); | |
698 | struct qfq_class *cl; | |
699 | struct tcf_result res; | |
700 | int result; | |
701 | ||
702 | if (TC_H_MAJ(skb->priority ^ sch->handle) == 0) { | |
703 | pr_debug("qfq_classify: found %d\n", skb->priority); | |
704 | cl = qfq_find_class(sch, skb->priority); | |
705 | if (cl != NULL) | |
706 | return cl; | |
707 | } | |
708 | ||
709 | *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; | |
710 | result = tc_classify(skb, q->filter_list, &res); | |
711 | if (result >= 0) { | |
712 | #ifdef CONFIG_NET_CLS_ACT | |
713 | switch (result) { | |
714 | case TC_ACT_QUEUED: | |
715 | case TC_ACT_STOLEN: | |
716 | *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN; | |
717 | case TC_ACT_SHOT: | |
718 | return NULL; | |
719 | } | |
720 | #endif | |
721 | cl = (struct qfq_class *)res.class; | |
722 | if (cl == NULL) | |
723 | cl = qfq_find_class(sch, res.classid); | |
724 | return cl; | |
725 | } | |
726 | ||
727 | return NULL; | |
728 | } | |
729 | ||
730 | /* Generic comparison function, handling wraparound. */ | |
731 | static inline int qfq_gt(u64 a, u64 b) | |
732 | { | |
733 | return (s64)(a - b) > 0; | |
734 | } | |
735 | ||
736 | /* Round a precise timestamp to its slotted value. */ | |
737 | static inline u64 qfq_round_down(u64 ts, unsigned int shift) | |
738 | { | |
739 | return ts & ~((1ULL << shift) - 1); | |
740 | } | |
741 | ||
742 | /* return the pointer to the group with lowest index in the bitmap */ | |
743 | static inline struct qfq_group *qfq_ffs(struct qfq_sched *q, | |
744 | unsigned long bitmap) | |
745 | { | |
746 | int index = __ffs(bitmap); | |
747 | return &q->groups[index]; | |
748 | } | |
749 | /* Calculate a mask to mimic what would be ffs_from(). */ | |
750 | static inline unsigned long mask_from(unsigned long bitmap, int from) | |
751 | { | |
752 | return bitmap & ~((1UL << from) - 1); | |
753 | } | |
754 | ||
755 | /* | |
756 | * The state computation relies on ER=0, IR=1, EB=2, IB=3 | |
757 | * First compute eligibility comparing grp->S, q->V, | |
758 | * then check if someone is blocking us and possibly add EB | |
759 | */ | |
760 | static int qfq_calc_state(struct qfq_sched *q, const struct qfq_group *grp) | |
761 | { | |
762 | /* if S > V we are not eligible */ | |
763 | unsigned int state = qfq_gt(grp->S, q->V); | |
764 | unsigned long mask = mask_from(q->bitmaps[ER], grp->index); | |
765 | struct qfq_group *next; | |
766 | ||
767 | if (mask) { | |
768 | next = qfq_ffs(q, mask); | |
769 | if (qfq_gt(grp->F, next->F)) | |
770 | state |= EB; | |
771 | } | |
772 | ||
773 | return state; | |
774 | } | |
775 | ||
776 | ||
777 | /* | |
778 | * In principle | |
779 | * q->bitmaps[dst] |= q->bitmaps[src] & mask; | |
780 | * q->bitmaps[src] &= ~mask; | |
781 | * but we should make sure that src != dst | |
782 | */ | |
783 | static inline void qfq_move_groups(struct qfq_sched *q, unsigned long mask, | |
784 | int src, int dst) | |
785 | { | |
786 | q->bitmaps[dst] |= q->bitmaps[src] & mask; | |
787 | q->bitmaps[src] &= ~mask; | |
788 | } | |
789 | ||
790 | static void qfq_unblock_groups(struct qfq_sched *q, int index, u64 old_F) | |
791 | { | |
792 | unsigned long mask = mask_from(q->bitmaps[ER], index + 1); | |
793 | struct qfq_group *next; | |
794 | ||
795 | if (mask) { | |
796 | next = qfq_ffs(q, mask); | |
797 | if (!qfq_gt(next->F, old_F)) | |
798 | return; | |
799 | } | |
800 | ||
801 | mask = (1UL << index) - 1; | |
802 | qfq_move_groups(q, mask, EB, ER); | |
803 | qfq_move_groups(q, mask, IB, IR); | |
804 | } | |
805 | ||
806 | /* | |
807 | * perhaps | |
808 | * | |
809 | old_V ^= q->V; | |
462dbc91 | 810 | old_V >>= q->min_slot_shift; |
0545a303 | 811 | if (old_V) { |
812 | ... | |
813 | } | |
814 | * | |
815 | */ | |
462dbc91 | 816 | static void qfq_make_eligible(struct qfq_sched *q) |
0545a303 | 817 | { |
462dbc91 PV |
818 | unsigned long vslot = q->V >> q->min_slot_shift; |
819 | unsigned long old_vslot = q->oldV >> q->min_slot_shift; | |
0545a303 | 820 | |
821 | if (vslot != old_vslot) { | |
822 | unsigned long mask = (1UL << fls(vslot ^ old_vslot)) - 1; | |
823 | qfq_move_groups(q, mask, IR, ER); | |
824 | qfq_move_groups(q, mask, IB, EB); | |
825 | } | |
826 | } | |
827 | ||
828 | ||
829 | /* | |
462dbc91 PV |
830 | * The index of the slot in which the aggregate is to be inserted must |
831 | * not be higher than QFQ_MAX_SLOTS-2. There is a '-2' and not a '-1' | |
832 | * because the start time of the group may be moved backward by one | |
833 | * slot after the aggregate has been inserted, and this would cause | |
834 | * non-empty slots to be right-shifted by one position. | |
3015f3d2 | 835 | * |
462dbc91 PV |
836 | * If the weight and lmax (max_pkt_size) of the classes do not change, |
837 | * then QFQ+ does meet the above contraint according to the current | |
838 | * values of its parameters. In fact, if the weight and lmax of the | |
839 | * classes do not change, then, from the theory, QFQ+ guarantees that | |
840 | * the slot index is never higher than | |
841 | * 2 + QFQ_MAX_AGG_CLASSES * ((1<<QFQ_MTU_SHIFT)/QFQ_MIN_LMAX) * | |
842 | * (QFQ_MAX_WEIGHT/QFQ_MAX_WSUM) = 2 + 8 * 128 * (1 / 64) = 18 | |
3015f3d2 PV |
843 | * |
844 | * When the weight of a class is increased or the lmax of the class is | |
462dbc91 PV |
845 | * decreased, a new aggregate with smaller slot size than the original |
846 | * parent aggregate of the class may happen to be activated. The | |
847 | * activation of this aggregate should be properly delayed to when the | |
848 | * service of the class has finished in the ideal system tracked by | |
849 | * QFQ+. If the activation of the aggregate is not delayed to this | |
850 | * reference time instant, then this aggregate may be unjustly served | |
851 | * before other aggregates waiting for service. This may cause the | |
852 | * above bound to the slot index to be violated for some of these | |
853 | * unlucky aggregates. | |
3015f3d2 | 854 | * |
462dbc91 PV |
855 | * Instead of delaying the activation of the new aggregate, which is |
856 | * quite complex, the following inaccurate but simple solution is used: | |
857 | * if the slot index is higher than QFQ_MAX_SLOTS-2, then the | |
858 | * timestamps of the aggregate are shifted backward so as to let the | |
859 | * slot index become equal to QFQ_MAX_SLOTS-2. | |
0545a303 | 860 | */ |
462dbc91 | 861 | static void qfq_slot_insert(struct qfq_group *grp, struct qfq_aggregate *agg, |
0545a303 | 862 | u64 roundedS) |
863 | { | |
864 | u64 slot = (roundedS - grp->S) >> grp->slot_shift; | |
3015f3d2 PV |
865 | unsigned int i; /* slot index in the bucket list */ |
866 | ||
867 | if (unlikely(slot > QFQ_MAX_SLOTS - 2)) { | |
868 | u64 deltaS = roundedS - grp->S - | |
869 | ((u64)(QFQ_MAX_SLOTS - 2)<<grp->slot_shift); | |
462dbc91 PV |
870 | agg->S -= deltaS; |
871 | agg->F -= deltaS; | |
3015f3d2 PV |
872 | slot = QFQ_MAX_SLOTS - 2; |
873 | } | |
874 | ||
875 | i = (grp->front + slot) % QFQ_MAX_SLOTS; | |
0545a303 | 876 | |
462dbc91 | 877 | hlist_add_head(&agg->next, &grp->slots[i]); |
0545a303 | 878 | __set_bit(slot, &grp->full_slots); |
879 | } | |
880 | ||
881 | /* Maybe introduce hlist_first_entry?? */ | |
462dbc91 | 882 | static struct qfq_aggregate *qfq_slot_head(struct qfq_group *grp) |
0545a303 | 883 | { |
884 | return hlist_entry(grp->slots[grp->front].first, | |
462dbc91 | 885 | struct qfq_aggregate, next); |
0545a303 | 886 | } |
887 | ||
888 | /* | |
889 | * remove the entry from the slot | |
890 | */ | |
891 | static void qfq_front_slot_remove(struct qfq_group *grp) | |
892 | { | |
462dbc91 | 893 | struct qfq_aggregate *agg = qfq_slot_head(grp); |
0545a303 | 894 | |
462dbc91 PV |
895 | BUG_ON(!agg); |
896 | hlist_del(&agg->next); | |
0545a303 | 897 | if (hlist_empty(&grp->slots[grp->front])) |
898 | __clear_bit(0, &grp->full_slots); | |
899 | } | |
900 | ||
901 | /* | |
462dbc91 PV |
902 | * Returns the first aggregate in the first non-empty bucket of the |
903 | * group. As a side effect, adjusts the bucket list so the first | |
904 | * non-empty bucket is at position 0 in full_slots. | |
0545a303 | 905 | */ |
462dbc91 | 906 | static struct qfq_aggregate *qfq_slot_scan(struct qfq_group *grp) |
0545a303 | 907 | { |
908 | unsigned int i; | |
909 | ||
910 | pr_debug("qfq slot_scan: grp %u full %#lx\n", | |
911 | grp->index, grp->full_slots); | |
912 | ||
913 | if (grp->full_slots == 0) | |
914 | return NULL; | |
915 | ||
916 | i = __ffs(grp->full_slots); /* zero based */ | |
917 | if (i > 0) { | |
918 | grp->front = (grp->front + i) % QFQ_MAX_SLOTS; | |
919 | grp->full_slots >>= i; | |
920 | } | |
921 | ||
922 | return qfq_slot_head(grp); | |
923 | } | |
924 | ||
925 | /* | |
926 | * adjust the bucket list. When the start time of a group decreases, | |
927 | * we move the index down (modulo QFQ_MAX_SLOTS) so we don't need to | |
928 | * move the objects. The mask of occupied slots must be shifted | |
929 | * because we use ffs() to find the first non-empty slot. | |
930 | * This covers decreases in the group's start time, but what about | |
931 | * increases of the start time ? | |
932 | * Here too we should make sure that i is less than 32 | |
933 | */ | |
934 | static void qfq_slot_rotate(struct qfq_group *grp, u64 roundedS) | |
935 | { | |
936 | unsigned int i = (grp->S - roundedS) >> grp->slot_shift; | |
937 | ||
938 | grp->full_slots <<= i; | |
939 | grp->front = (grp->front - i) % QFQ_MAX_SLOTS; | |
940 | } | |
941 | ||
462dbc91 | 942 | static void qfq_update_eligible(struct qfq_sched *q) |
0545a303 | 943 | { |
944 | struct qfq_group *grp; | |
945 | unsigned long ineligible; | |
946 | ||
947 | ineligible = q->bitmaps[IR] | q->bitmaps[IB]; | |
948 | if (ineligible) { | |
949 | if (!q->bitmaps[ER]) { | |
950 | grp = qfq_ffs(q, ineligible); | |
951 | if (qfq_gt(grp->S, q->V)) | |
952 | q->V = grp->S; | |
953 | } | |
462dbc91 | 954 | qfq_make_eligible(q); |
0545a303 | 955 | } |
956 | } | |
957 | ||
462dbc91 PV |
958 | /* Dequeue head packet of the head class in the DRR queue of the aggregate. */ |
959 | static void agg_dequeue(struct qfq_aggregate *agg, | |
960 | struct qfq_class *cl, unsigned int len) | |
0545a303 | 961 | { |
462dbc91 | 962 | qdisc_dequeue_peeked(cl->qdisc); |
0545a303 | 963 | |
462dbc91 | 964 | cl->deficit -= (int) len; |
0545a303 | 965 | |
462dbc91 PV |
966 | if (cl->qdisc->q.qlen == 0) /* no more packets, remove from list */ |
967 | list_del(&cl->alist); | |
968 | else if (cl->deficit < qdisc_pkt_len(cl->qdisc->ops->peek(cl->qdisc))) { | |
969 | cl->deficit += agg->lmax; | |
970 | list_move_tail(&cl->alist, &agg->active); | |
0545a303 | 971 | } |
462dbc91 PV |
972 | } |
973 | ||
974 | static inline struct sk_buff *qfq_peek_skb(struct qfq_aggregate *agg, | |
975 | struct qfq_class **cl, | |
976 | unsigned int *len) | |
977 | { | |
978 | struct sk_buff *skb; | |
0545a303 | 979 | |
462dbc91 PV |
980 | *cl = list_first_entry(&agg->active, struct qfq_class, alist); |
981 | skb = (*cl)->qdisc->ops->peek((*cl)->qdisc); | |
982 | if (skb == NULL) | |
983 | WARN_ONCE(1, "qfq_dequeue: non-workconserving leaf\n"); | |
984 | else | |
985 | *len = qdisc_pkt_len(skb); | |
986 | ||
987 | return skb; | |
988 | } | |
989 | ||
990 | /* Update F according to the actual service received by the aggregate. */ | |
991 | static inline void charge_actual_service(struct qfq_aggregate *agg) | |
992 | { | |
993 | /* compute the service received by the aggregate */ | |
994 | u32 service_received = agg->initial_budget - agg->budget; | |
995 | ||
996 | agg->F = agg->S + (u64)service_received * agg->inv_w; | |
0545a303 | 997 | } |
998 | ||
999 | static struct sk_buff *qfq_dequeue(struct Qdisc *sch) | |
1000 | { | |
1001 | struct qfq_sched *q = qdisc_priv(sch); | |
462dbc91 | 1002 | struct qfq_aggregate *in_serv_agg = q->in_serv_agg; |
0545a303 | 1003 | struct qfq_class *cl; |
462dbc91 PV |
1004 | struct sk_buff *skb = NULL; |
1005 | /* next-packet len, 0 means no more active classes in in-service agg */ | |
1006 | unsigned int len = 0; | |
0545a303 | 1007 | |
462dbc91 | 1008 | if (in_serv_agg == NULL) |
0545a303 | 1009 | return NULL; |
1010 | ||
462dbc91 PV |
1011 | if (!list_empty(&in_serv_agg->active)) |
1012 | skb = qfq_peek_skb(in_serv_agg, &cl, &len); | |
0545a303 | 1013 | |
462dbc91 PV |
1014 | /* |
1015 | * If there are no active classes in the in-service aggregate, | |
1016 | * or if the aggregate has not enough budget to serve its next | |
1017 | * class, then choose the next aggregate to serve. | |
1018 | */ | |
1019 | if (len == 0 || in_serv_agg->budget < len) { | |
1020 | charge_actual_service(in_serv_agg); | |
1021 | ||
1022 | /* recharge the budget of the aggregate */ | |
1023 | in_serv_agg->initial_budget = in_serv_agg->budget = | |
1024 | in_serv_agg->budgetmax; | |
1025 | ||
1026 | if (!list_empty(&in_serv_agg->active)) | |
1027 | /* | |
1028 | * Still active: reschedule for | |
1029 | * service. Possible optimization: if no other | |
1030 | * aggregate is active, then there is no point | |
1031 | * in rescheduling this aggregate, and we can | |
1032 | * just keep it as the in-service one. This | |
1033 | * should be however a corner case, and to | |
1034 | * handle it, we would need to maintain an | |
1035 | * extra num_active_aggs field. | |
1036 | */ | |
1037 | qfq_activate_agg(q, in_serv_agg, requeue); | |
1038 | else if (sch->q.qlen == 0) { /* no aggregate to serve */ | |
1039 | q->in_serv_agg = NULL; | |
1040 | return NULL; | |
1041 | } | |
1042 | ||
1043 | /* | |
1044 | * If we get here, there are other aggregates queued: | |
1045 | * choose the new aggregate to serve. | |
1046 | */ | |
1047 | in_serv_agg = q->in_serv_agg = qfq_choose_next_agg(q); | |
1048 | skb = qfq_peek_skb(in_serv_agg, &cl, &len); | |
0545a303 | 1049 | } |
462dbc91 PV |
1050 | if (!skb) |
1051 | return NULL; | |
0545a303 | 1052 | |
1053 | sch->q.qlen--; | |
1054 | qdisc_bstats_update(sch, skb); | |
1055 | ||
462dbc91 PV |
1056 | agg_dequeue(in_serv_agg, cl, len); |
1057 | in_serv_agg->budget -= len; | |
0545a303 | 1058 | q->V += (u64)len * IWSUM; |
1059 | pr_debug("qfq dequeue: len %u F %lld now %lld\n", | |
462dbc91 PV |
1060 | len, (unsigned long long) in_serv_agg->F, |
1061 | (unsigned long long) q->V); | |
0545a303 | 1062 | |
462dbc91 PV |
1063 | return skb; |
1064 | } | |
0545a303 | 1065 | |
462dbc91 PV |
1066 | static struct qfq_aggregate *qfq_choose_next_agg(struct qfq_sched *q) |
1067 | { | |
1068 | struct qfq_group *grp; | |
1069 | struct qfq_aggregate *agg, *new_front_agg; | |
1070 | u64 old_F; | |
0545a303 | 1071 | |
462dbc91 PV |
1072 | qfq_update_eligible(q); |
1073 | q->oldV = q->V; | |
1074 | ||
1075 | if (!q->bitmaps[ER]) | |
1076 | return NULL; | |
1077 | ||
1078 | grp = qfq_ffs(q, q->bitmaps[ER]); | |
1079 | old_F = grp->F; | |
1080 | ||
1081 | agg = qfq_slot_head(grp); | |
0545a303 | 1082 | |
462dbc91 PV |
1083 | /* agg starts to be served, remove it from schedule */ |
1084 | qfq_front_slot_remove(grp); | |
1085 | ||
1086 | new_front_agg = qfq_slot_scan(grp); | |
1087 | ||
1088 | if (new_front_agg == NULL) /* group is now inactive, remove from ER */ | |
1089 | __clear_bit(grp->index, &q->bitmaps[ER]); | |
1090 | else { | |
1091 | u64 roundedS = qfq_round_down(new_front_agg->S, | |
1092 | grp->slot_shift); | |
1093 | unsigned int s; | |
1094 | ||
1095 | if (grp->S == roundedS) | |
1096 | return agg; | |
1097 | grp->S = roundedS; | |
1098 | grp->F = roundedS + (2ULL << grp->slot_shift); | |
1099 | __clear_bit(grp->index, &q->bitmaps[ER]); | |
1100 | s = qfq_calc_state(q, grp); | |
1101 | __set_bit(grp->index, &q->bitmaps[s]); | |
0545a303 | 1102 | } |
1103 | ||
462dbc91 | 1104 | qfq_unblock_groups(q, grp->index, old_F); |
0545a303 | 1105 | |
462dbc91 | 1106 | return agg; |
0545a303 | 1107 | } |
1108 | ||
1109 | /* | |
462dbc91 | 1110 | * Assign a reasonable start time for a new aggregate in group i. |
0545a303 | 1111 | * Admissible values for \hat(F) are multiples of \sigma_i |
1112 | * no greater than V+\sigma_i . Larger values mean that | |
1113 | * we had a wraparound so we consider the timestamp to be stale. | |
1114 | * | |
1115 | * If F is not stale and F >= V then we set S = F. | |
1116 | * Otherwise we should assign S = V, but this may violate | |
462dbc91 PV |
1117 | * the ordering in EB (see [2]). So, if we have groups in ER, |
1118 | * set S to the F_j of the first group j which would be blocking us. | |
0545a303 | 1119 | * We are guaranteed not to move S backward because |
1120 | * otherwise our group i would still be blocked. | |
1121 | */ | |
462dbc91 | 1122 | static void qfq_update_start(struct qfq_sched *q, struct qfq_aggregate *agg) |
0545a303 | 1123 | { |
1124 | unsigned long mask; | |
6bafcac3 | 1125 | u64 limit, roundedF; |
462dbc91 | 1126 | int slot_shift = agg->grp->slot_shift; |
0545a303 | 1127 | |
462dbc91 | 1128 | roundedF = qfq_round_down(agg->F, slot_shift); |
6bafcac3 | 1129 | limit = qfq_round_down(q->V, slot_shift) + (1ULL << slot_shift); |
0545a303 | 1130 | |
462dbc91 | 1131 | if (!qfq_gt(agg->F, q->V) || qfq_gt(roundedF, limit)) { |
0545a303 | 1132 | /* timestamp was stale */ |
462dbc91 | 1133 | mask = mask_from(q->bitmaps[ER], agg->grp->index); |
0545a303 | 1134 | if (mask) { |
1135 | struct qfq_group *next = qfq_ffs(q, mask); | |
1136 | if (qfq_gt(roundedF, next->F)) { | |
71261956 | 1137 | if (qfq_gt(limit, next->F)) |
462dbc91 | 1138 | agg->S = next->F; |
71261956 | 1139 | else /* preserve timestamp correctness */ |
462dbc91 | 1140 | agg->S = limit; |
0545a303 | 1141 | return; |
1142 | } | |
1143 | } | |
462dbc91 | 1144 | agg->S = q->V; |
0545a303 | 1145 | } else /* timestamp is not stale */ |
462dbc91 | 1146 | agg->S = agg->F; |
0545a303 | 1147 | } |
1148 | ||
462dbc91 PV |
1149 | /* |
1150 | * Update the timestamps of agg before scheduling/rescheduling it for | |
1151 | * service. In particular, assign to agg->F its maximum possible | |
1152 | * value, i.e., the virtual finish time with which the aggregate | |
1153 | * should be labeled if it used all its budget once in service. | |
1154 | */ | |
1155 | static inline void | |
1156 | qfq_update_agg_ts(struct qfq_sched *q, | |
1157 | struct qfq_aggregate *agg, enum update_reason reason) | |
1158 | { | |
1159 | if (reason != requeue) | |
1160 | qfq_update_start(q, agg); | |
1161 | else /* just charge agg for the service received */ | |
1162 | agg->S = agg->F; | |
1163 | ||
1164 | agg->F = agg->S + (u64)agg->budgetmax * agg->inv_w; | |
1165 | } | |
1166 | ||
1167 | static void qfq_schedule_agg(struct qfq_sched *, struct qfq_aggregate *); | |
1168 | ||
0545a303 | 1169 | static int qfq_enqueue(struct sk_buff *skb, struct Qdisc *sch) |
1170 | { | |
1171 | struct qfq_sched *q = qdisc_priv(sch); | |
0545a303 | 1172 | struct qfq_class *cl; |
462dbc91 | 1173 | struct qfq_aggregate *agg; |
f54ba779 | 1174 | int err = 0; |
0545a303 | 1175 | |
1176 | cl = qfq_classify(skb, sch, &err); | |
1177 | if (cl == NULL) { | |
1178 | if (err & __NET_XMIT_BYPASS) | |
1179 | sch->qstats.drops++; | |
1180 | kfree_skb(skb); | |
1181 | return err; | |
1182 | } | |
1183 | pr_debug("qfq_enqueue: cl = %x\n", cl->common.classid); | |
1184 | ||
462dbc91 | 1185 | if (unlikely(cl->agg->lmax < qdisc_pkt_len(skb))) { |
3015f3d2 | 1186 | pr_debug("qfq: increasing maxpkt from %u to %u for class %u", |
462dbc91 PV |
1187 | cl->agg->lmax, qdisc_pkt_len(skb), cl->common.classid); |
1188 | err = qfq_change_agg(sch, cl, cl->agg->class_weight, | |
1189 | qdisc_pkt_len(skb)); | |
1190 | if (err) | |
1191 | return err; | |
3015f3d2 PV |
1192 | } |
1193 | ||
0545a303 | 1194 | err = qdisc_enqueue(skb, cl->qdisc); |
1195 | if (unlikely(err != NET_XMIT_SUCCESS)) { | |
1196 | pr_debug("qfq_enqueue: enqueue failed %d\n", err); | |
1197 | if (net_xmit_drop_count(err)) { | |
1198 | cl->qstats.drops++; | |
1199 | sch->qstats.drops++; | |
1200 | } | |
1201 | return err; | |
1202 | } | |
1203 | ||
1204 | bstats_update(&cl->bstats, skb); | |
1205 | ++sch->q.qlen; | |
1206 | ||
462dbc91 PV |
1207 | agg = cl->agg; |
1208 | /* if the queue was not empty, then done here */ | |
1209 | if (cl->qdisc->q.qlen != 1) { | |
1210 | if (unlikely(skb == cl->qdisc->ops->peek(cl->qdisc)) && | |
1211 | list_first_entry(&agg->active, struct qfq_class, alist) | |
1212 | == cl && cl->deficit < qdisc_pkt_len(skb)) | |
1213 | list_move_tail(&cl->alist, &agg->active); | |
1214 | ||
0545a303 | 1215 | return err; |
462dbc91 PV |
1216 | } |
1217 | ||
1218 | /* schedule class for service within the aggregate */ | |
1219 | cl->deficit = agg->lmax; | |
1220 | list_add_tail(&cl->alist, &agg->active); | |
0545a303 | 1221 | |
462dbc91 PV |
1222 | if (list_first_entry(&agg->active, struct qfq_class, alist) != cl) |
1223 | return err; /* aggregate was not empty, nothing else to do */ | |
1224 | ||
1225 | /* recharge budget */ | |
1226 | agg->initial_budget = agg->budget = agg->budgetmax; | |
1227 | ||
1228 | qfq_update_agg_ts(q, agg, enqueue); | |
1229 | if (q->in_serv_agg == NULL) | |
1230 | q->in_serv_agg = agg; | |
1231 | else if (agg != q->in_serv_agg) | |
1232 | qfq_schedule_agg(q, agg); | |
be72f63b PV |
1233 | |
1234 | return err; | |
1235 | } | |
1236 | ||
1237 | /* | |
462dbc91 | 1238 | * Schedule aggregate according to its timestamps. |
be72f63b | 1239 | */ |
462dbc91 | 1240 | static void qfq_schedule_agg(struct qfq_sched *q, struct qfq_aggregate *agg) |
be72f63b | 1241 | { |
462dbc91 | 1242 | struct qfq_group *grp = agg->grp; |
be72f63b PV |
1243 | u64 roundedS; |
1244 | int s; | |
1245 | ||
462dbc91 | 1246 | roundedS = qfq_round_down(agg->S, grp->slot_shift); |
0545a303 | 1247 | |
1248 | /* | |
462dbc91 PV |
1249 | * Insert agg in the correct bucket. |
1250 | * If agg->S >= grp->S we don't need to adjust the | |
0545a303 | 1251 | * bucket list and simply go to the insertion phase. |
1252 | * Otherwise grp->S is decreasing, we must make room | |
1253 | * in the bucket list, and also recompute the group state. | |
1254 | * Finally, if there were no flows in this group and nobody | |
1255 | * was in ER make sure to adjust V. | |
1256 | */ | |
1257 | if (grp->full_slots) { | |
462dbc91 | 1258 | if (!qfq_gt(grp->S, agg->S)) |
0545a303 | 1259 | goto skip_update; |
1260 | ||
462dbc91 | 1261 | /* create a slot for this agg->S */ |
0545a303 | 1262 | qfq_slot_rotate(grp, roundedS); |
1263 | /* group was surely ineligible, remove */ | |
1264 | __clear_bit(grp->index, &q->bitmaps[IR]); | |
1265 | __clear_bit(grp->index, &q->bitmaps[IB]); | |
1266 | } else if (!q->bitmaps[ER] && qfq_gt(roundedS, q->V)) | |
1267 | q->V = roundedS; | |
1268 | ||
1269 | grp->S = roundedS; | |
1270 | grp->F = roundedS + (2ULL << grp->slot_shift); | |
1271 | s = qfq_calc_state(q, grp); | |
1272 | __set_bit(grp->index, &q->bitmaps[s]); | |
1273 | ||
1274 | pr_debug("qfq enqueue: new state %d %#lx S %lld F %lld V %lld\n", | |
1275 | s, q->bitmaps[s], | |
462dbc91 PV |
1276 | (unsigned long long) agg->S, |
1277 | (unsigned long long) agg->F, | |
0545a303 | 1278 | (unsigned long long) q->V); |
1279 | ||
1280 | skip_update: | |
462dbc91 | 1281 | qfq_slot_insert(grp, agg, roundedS); |
0545a303 | 1282 | } |
1283 | ||
1284 | ||
462dbc91 PV |
1285 | /* Update agg ts and schedule agg for service */ |
1286 | static void qfq_activate_agg(struct qfq_sched *q, struct qfq_aggregate *agg, | |
1287 | enum update_reason reason) | |
1288 | { | |
1289 | qfq_update_agg_ts(q, agg, reason); | |
1290 | qfq_schedule_agg(q, agg); | |
1291 | } | |
1292 | ||
0545a303 | 1293 | static void qfq_slot_remove(struct qfq_sched *q, struct qfq_group *grp, |
462dbc91 | 1294 | struct qfq_aggregate *agg) |
0545a303 | 1295 | { |
1296 | unsigned int i, offset; | |
1297 | u64 roundedS; | |
1298 | ||
462dbc91 | 1299 | roundedS = qfq_round_down(agg->S, grp->slot_shift); |
0545a303 | 1300 | offset = (roundedS - grp->S) >> grp->slot_shift; |
462dbc91 | 1301 | |
0545a303 | 1302 | i = (grp->front + offset) % QFQ_MAX_SLOTS; |
1303 | ||
462dbc91 | 1304 | hlist_del(&agg->next); |
0545a303 | 1305 | if (hlist_empty(&grp->slots[i])) |
1306 | __clear_bit(offset, &grp->full_slots); | |
1307 | } | |
1308 | ||
1309 | /* | |
462dbc91 PV |
1310 | * Called to forcibly deschedule an aggregate. If the aggregate is |
1311 | * not in the front bucket, or if the latter has other aggregates in | |
1312 | * the front bucket, we can simply remove the aggregate with no other | |
1313 | * side effects. | |
0545a303 | 1314 | * Otherwise we must propagate the event up. |
1315 | */ | |
462dbc91 | 1316 | static void qfq_deactivate_agg(struct qfq_sched *q, struct qfq_aggregate *agg) |
0545a303 | 1317 | { |
462dbc91 | 1318 | struct qfq_group *grp = agg->grp; |
0545a303 | 1319 | unsigned long mask; |
1320 | u64 roundedS; | |
1321 | int s; | |
1322 | ||
462dbc91 PV |
1323 | if (agg == q->in_serv_agg) { |
1324 | charge_actual_service(agg); | |
1325 | q->in_serv_agg = qfq_choose_next_agg(q); | |
1326 | return; | |
1327 | } | |
1328 | ||
1329 | agg->F = agg->S; | |
1330 | qfq_slot_remove(q, grp, agg); | |
0545a303 | 1331 | |
1332 | if (!grp->full_slots) { | |
1333 | __clear_bit(grp->index, &q->bitmaps[IR]); | |
1334 | __clear_bit(grp->index, &q->bitmaps[EB]); | |
1335 | __clear_bit(grp->index, &q->bitmaps[IB]); | |
1336 | ||
1337 | if (test_bit(grp->index, &q->bitmaps[ER]) && | |
1338 | !(q->bitmaps[ER] & ~((1UL << grp->index) - 1))) { | |
1339 | mask = q->bitmaps[ER] & ((1UL << grp->index) - 1); | |
1340 | if (mask) | |
1341 | mask = ~((1UL << __fls(mask)) - 1); | |
1342 | else | |
1343 | mask = ~0UL; | |
1344 | qfq_move_groups(q, mask, EB, ER); | |
1345 | qfq_move_groups(q, mask, IB, IR); | |
1346 | } | |
1347 | __clear_bit(grp->index, &q->bitmaps[ER]); | |
1348 | } else if (hlist_empty(&grp->slots[grp->front])) { | |
462dbc91 PV |
1349 | agg = qfq_slot_scan(grp); |
1350 | roundedS = qfq_round_down(agg->S, grp->slot_shift); | |
0545a303 | 1351 | if (grp->S != roundedS) { |
1352 | __clear_bit(grp->index, &q->bitmaps[ER]); | |
1353 | __clear_bit(grp->index, &q->bitmaps[IR]); | |
1354 | __clear_bit(grp->index, &q->bitmaps[EB]); | |
1355 | __clear_bit(grp->index, &q->bitmaps[IB]); | |
1356 | grp->S = roundedS; | |
1357 | grp->F = roundedS + (2ULL << grp->slot_shift); | |
1358 | s = qfq_calc_state(q, grp); | |
1359 | __set_bit(grp->index, &q->bitmaps[s]); | |
1360 | } | |
1361 | } | |
1362 | ||
462dbc91 | 1363 | qfq_update_eligible(q); |
0545a303 | 1364 | } |
1365 | ||
1366 | static void qfq_qlen_notify(struct Qdisc *sch, unsigned long arg) | |
1367 | { | |
1368 | struct qfq_sched *q = qdisc_priv(sch); | |
1369 | struct qfq_class *cl = (struct qfq_class *)arg; | |
1370 | ||
1371 | if (cl->qdisc->q.qlen == 0) | |
1372 | qfq_deactivate_class(q, cl); | |
1373 | } | |
1374 | ||
462dbc91 PV |
1375 | static unsigned int qfq_drop_from_slot(struct qfq_sched *q, |
1376 | struct hlist_head *slot) | |
1377 | { | |
1378 | struct qfq_aggregate *agg; | |
1379 | struct hlist_node *n; | |
1380 | struct qfq_class *cl; | |
1381 | unsigned int len; | |
1382 | ||
1383 | hlist_for_each_entry(agg, n, slot, next) { | |
1384 | list_for_each_entry(cl, &agg->active, alist) { | |
1385 | ||
1386 | if (!cl->qdisc->ops->drop) | |
1387 | continue; | |
1388 | ||
1389 | len = cl->qdisc->ops->drop(cl->qdisc); | |
1390 | if (len > 0) { | |
1391 | if (cl->qdisc->q.qlen == 0) | |
1392 | qfq_deactivate_class(q, cl); | |
1393 | ||
1394 | return len; | |
1395 | } | |
1396 | } | |
1397 | } | |
1398 | return 0; | |
1399 | } | |
1400 | ||
0545a303 | 1401 | static unsigned int qfq_drop(struct Qdisc *sch) |
1402 | { | |
1403 | struct qfq_sched *q = qdisc_priv(sch); | |
1404 | struct qfq_group *grp; | |
1405 | unsigned int i, j, len; | |
1406 | ||
1407 | for (i = 0; i <= QFQ_MAX_INDEX; i++) { | |
1408 | grp = &q->groups[i]; | |
1409 | for (j = 0; j < QFQ_MAX_SLOTS; j++) { | |
462dbc91 PV |
1410 | len = qfq_drop_from_slot(q, &grp->slots[j]); |
1411 | if (len > 0) { | |
1412 | sch->q.qlen--; | |
1413 | return len; | |
0545a303 | 1414 | } |
1415 | } | |
462dbc91 | 1416 | |
0545a303 | 1417 | } |
1418 | ||
1419 | return 0; | |
1420 | } | |
1421 | ||
1422 | static int qfq_init_qdisc(struct Qdisc *sch, struct nlattr *opt) | |
1423 | { | |
1424 | struct qfq_sched *q = qdisc_priv(sch); | |
1425 | struct qfq_group *grp; | |
1426 | int i, j, err; | |
462dbc91 | 1427 | u32 max_cl_shift, maxbudg_shift, max_classes; |
0545a303 | 1428 | |
1429 | err = qdisc_class_hash_init(&q->clhash); | |
1430 | if (err < 0) | |
1431 | return err; | |
1432 | ||
462dbc91 PV |
1433 | if (qdisc_dev(sch)->tx_queue_len + 1 > QFQ_MAX_AGG_CLASSES) |
1434 | max_classes = QFQ_MAX_AGG_CLASSES; | |
1435 | else | |
1436 | max_classes = qdisc_dev(sch)->tx_queue_len + 1; | |
1437 | /* max_cl_shift = floor(log_2(max_classes)) */ | |
1438 | max_cl_shift = __fls(max_classes); | |
1439 | q->max_agg_classes = 1<<max_cl_shift; | |
1440 | ||
1441 | /* maxbudg_shift = log2(max_len * max_classes_per_agg) */ | |
1442 | maxbudg_shift = QFQ_MTU_SHIFT + max_cl_shift; | |
1443 | q->min_slot_shift = FRAC_BITS + maxbudg_shift - QFQ_MAX_INDEX; | |
1444 | ||
0545a303 | 1445 | for (i = 0; i <= QFQ_MAX_INDEX; i++) { |
1446 | grp = &q->groups[i]; | |
1447 | grp->index = i; | |
462dbc91 | 1448 | grp->slot_shift = q->min_slot_shift + i; |
0545a303 | 1449 | for (j = 0; j < QFQ_MAX_SLOTS; j++) |
1450 | INIT_HLIST_HEAD(&grp->slots[j]); | |
1451 | } | |
1452 | ||
462dbc91 PV |
1453 | INIT_HLIST_HEAD(&q->nonfull_aggs); |
1454 | ||
0545a303 | 1455 | return 0; |
1456 | } | |
1457 | ||
1458 | static void qfq_reset_qdisc(struct Qdisc *sch) | |
1459 | { | |
1460 | struct qfq_sched *q = qdisc_priv(sch); | |
0545a303 | 1461 | struct qfq_class *cl; |
462dbc91 PV |
1462 | struct hlist_node *n; |
1463 | unsigned int i; | |
0545a303 | 1464 | |
462dbc91 PV |
1465 | for (i = 0; i < q->clhash.hashsize; i++) { |
1466 | hlist_for_each_entry(cl, n, &q->clhash.hash[i], common.hnode) { | |
1467 | if (cl->qdisc->q.qlen > 0) | |
0545a303 | 1468 | qfq_deactivate_class(q, cl); |
0545a303 | 1469 | |
0545a303 | 1470 | qdisc_reset(cl->qdisc); |
462dbc91 | 1471 | } |
0545a303 | 1472 | } |
1473 | sch->q.qlen = 0; | |
1474 | } | |
1475 | ||
1476 | static void qfq_destroy_qdisc(struct Qdisc *sch) | |
1477 | { | |
1478 | struct qfq_sched *q = qdisc_priv(sch); | |
1479 | struct qfq_class *cl; | |
1480 | struct hlist_node *n, *next; | |
1481 | unsigned int i; | |
1482 | ||
1483 | tcf_destroy_chain(&q->filter_list); | |
1484 | ||
1485 | for (i = 0; i < q->clhash.hashsize; i++) { | |
1486 | hlist_for_each_entry_safe(cl, n, next, &q->clhash.hash[i], | |
1487 | common.hnode) { | |
1488 | qfq_destroy_class(sch, cl); | |
1489 | } | |
1490 | } | |
1491 | qdisc_class_hash_destroy(&q->clhash); | |
1492 | } | |
1493 | ||
1494 | static const struct Qdisc_class_ops qfq_class_ops = { | |
1495 | .change = qfq_change_class, | |
1496 | .delete = qfq_delete_class, | |
1497 | .get = qfq_get_class, | |
1498 | .put = qfq_put_class, | |
1499 | .tcf_chain = qfq_tcf_chain, | |
1500 | .bind_tcf = qfq_bind_tcf, | |
1501 | .unbind_tcf = qfq_unbind_tcf, | |
1502 | .graft = qfq_graft_class, | |
1503 | .leaf = qfq_class_leaf, | |
1504 | .qlen_notify = qfq_qlen_notify, | |
1505 | .dump = qfq_dump_class, | |
1506 | .dump_stats = qfq_dump_class_stats, | |
1507 | .walk = qfq_walk, | |
1508 | }; | |
1509 | ||
1510 | static struct Qdisc_ops qfq_qdisc_ops __read_mostly = { | |
1511 | .cl_ops = &qfq_class_ops, | |
1512 | .id = "qfq", | |
1513 | .priv_size = sizeof(struct qfq_sched), | |
1514 | .enqueue = qfq_enqueue, | |
1515 | .dequeue = qfq_dequeue, | |
1516 | .peek = qdisc_peek_dequeued, | |
1517 | .drop = qfq_drop, | |
1518 | .init = qfq_init_qdisc, | |
1519 | .reset = qfq_reset_qdisc, | |
1520 | .destroy = qfq_destroy_qdisc, | |
1521 | .owner = THIS_MODULE, | |
1522 | }; | |
1523 | ||
1524 | static int __init qfq_init(void) | |
1525 | { | |
1526 | return register_qdisc(&qfq_qdisc_ops); | |
1527 | } | |
1528 | ||
1529 | static void __exit qfq_exit(void) | |
1530 | { | |
1531 | unregister_qdisc(&qfq_qdisc_ops); | |
1532 | } | |
1533 | ||
1534 | module_init(qfq_init); | |
1535 | module_exit(qfq_exit); | |
1536 | MODULE_LICENSE("GPL"); |