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13d2a1d2 PM |
1 | /* |
2 | * net/sched/sch_drr.c Deficit Round Robin scheduler | |
3 | * | |
4 | * Copyright (c) 2008 Patrick McHardy <kaber@trash.net> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * version 2 as published by the Free Software Foundation. | |
9 | */ | |
10 | ||
11 | #include <linux/module.h> | |
5a0e3ad6 | 12 | #include <linux/slab.h> |
13d2a1d2 PM |
13 | #include <linux/init.h> |
14 | #include <linux/errno.h> | |
15 | #include <linux/netdevice.h> | |
16 | #include <linux/pkt_sched.h> | |
17 | #include <net/sch_generic.h> | |
18 | #include <net/pkt_sched.h> | |
19 | #include <net/pkt_cls.h> | |
20 | ||
21 | struct drr_class { | |
22 | struct Qdisc_class_common common; | |
13d2a1d2 PM |
23 | unsigned int filter_cnt; |
24 | ||
c1a8f1f1 | 25 | struct gnet_stats_basic_packed bstats; |
13d2a1d2 | 26 | struct gnet_stats_queue qstats; |
1c0d32fd | 27 | struct net_rate_estimator __rcu *rate_est; |
13d2a1d2 PM |
28 | struct list_head alist; |
29 | struct Qdisc *qdisc; | |
30 | ||
31 | u32 quantum; | |
32 | u32 deficit; | |
33 | }; | |
34 | ||
35 | struct drr_sched { | |
36 | struct list_head active; | |
25d8c0d5 | 37 | struct tcf_proto __rcu *filter_list; |
6529eaba | 38 | struct tcf_block *block; |
13d2a1d2 PM |
39 | struct Qdisc_class_hash clhash; |
40 | }; | |
41 | ||
42 | static struct drr_class *drr_find_class(struct Qdisc *sch, u32 classid) | |
43 | { | |
44 | struct drr_sched *q = qdisc_priv(sch); | |
45 | struct Qdisc_class_common *clc; | |
46 | ||
47 | clc = qdisc_class_find(&q->clhash, classid); | |
48 | if (clc == NULL) | |
49 | return NULL; | |
50 | return container_of(clc, struct drr_class, common); | |
51 | } | |
52 | ||
53 | static void drr_purge_queue(struct drr_class *cl) | |
54 | { | |
55 | unsigned int len = cl->qdisc->q.qlen; | |
2ccccf5f | 56 | unsigned int backlog = cl->qdisc->qstats.backlog; |
13d2a1d2 PM |
57 | |
58 | qdisc_reset(cl->qdisc); | |
2ccccf5f | 59 | qdisc_tree_reduce_backlog(cl->qdisc, len, backlog); |
13d2a1d2 PM |
60 | } |
61 | ||
62 | static const struct nla_policy drr_policy[TCA_DRR_MAX + 1] = { | |
63 | [TCA_DRR_QUANTUM] = { .type = NLA_U32 }, | |
64 | }; | |
65 | ||
66 | static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid, | |
67 | struct nlattr **tca, unsigned long *arg) | |
68 | { | |
69 | struct drr_sched *q = qdisc_priv(sch); | |
70 | struct drr_class *cl = (struct drr_class *)*arg; | |
1844f747 | 71 | struct nlattr *opt = tca[TCA_OPTIONS]; |
13d2a1d2 PM |
72 | struct nlattr *tb[TCA_DRR_MAX + 1]; |
73 | u32 quantum; | |
74 | int err; | |
75 | ||
1844f747 JP |
76 | if (!opt) |
77 | return -EINVAL; | |
78 | ||
fceb6435 | 79 | err = nla_parse_nested(tb, TCA_DRR_MAX, opt, drr_policy, NULL); |
13d2a1d2 PM |
80 | if (err < 0) |
81 | return err; | |
82 | ||
83 | if (tb[TCA_DRR_QUANTUM]) { | |
84 | quantum = nla_get_u32(tb[TCA_DRR_QUANTUM]); | |
85 | if (quantum == 0) | |
86 | return -EINVAL; | |
87 | } else | |
88 | quantum = psched_mtu(qdisc_dev(sch)); | |
89 | ||
90 | if (cl != NULL) { | |
71bcb09a | 91 | if (tca[TCA_RATE]) { |
22e0f8b9 JF |
92 | err = gen_replace_estimator(&cl->bstats, NULL, |
93 | &cl->rate_est, | |
edb09eb1 ED |
94 | NULL, |
95 | qdisc_root_sleeping_running(sch), | |
71bcb09a SH |
96 | tca[TCA_RATE]); |
97 | if (err) | |
98 | return err; | |
99 | } | |
100 | ||
13d2a1d2 PM |
101 | sch_tree_lock(sch); |
102 | if (tb[TCA_DRR_QUANTUM]) | |
103 | cl->quantum = quantum; | |
104 | sch_tree_unlock(sch); | |
105 | ||
13d2a1d2 PM |
106 | return 0; |
107 | } | |
108 | ||
109 | cl = kzalloc(sizeof(struct drr_class), GFP_KERNEL); | |
110 | if (cl == NULL) | |
111 | return -ENOBUFS; | |
112 | ||
13d2a1d2 PM |
113 | cl->common.classid = classid; |
114 | cl->quantum = quantum; | |
3511c913 | 115 | cl->qdisc = qdisc_create_dflt(sch->dev_queue, |
13d2a1d2 PM |
116 | &pfifo_qdisc_ops, classid); |
117 | if (cl->qdisc == NULL) | |
118 | cl->qdisc = &noop_qdisc; | |
49b49971 JK |
119 | else |
120 | qdisc_hash_add(cl->qdisc, true); | |
13d2a1d2 | 121 | |
71bcb09a | 122 | if (tca[TCA_RATE]) { |
22e0f8b9 | 123 | err = gen_replace_estimator(&cl->bstats, NULL, &cl->rate_est, |
edb09eb1 ED |
124 | NULL, |
125 | qdisc_root_sleeping_running(sch), | |
71bcb09a SH |
126 | tca[TCA_RATE]); |
127 | if (err) { | |
128 | qdisc_destroy(cl->qdisc); | |
129 | kfree(cl); | |
130 | return err; | |
131 | } | |
132 | } | |
13d2a1d2 PM |
133 | |
134 | sch_tree_lock(sch); | |
135 | qdisc_class_hash_insert(&q->clhash, &cl->common); | |
136 | sch_tree_unlock(sch); | |
137 | ||
138 | qdisc_class_hash_grow(sch, &q->clhash); | |
139 | ||
140 | *arg = (unsigned long)cl; | |
141 | return 0; | |
142 | } | |
143 | ||
144 | static void drr_destroy_class(struct Qdisc *sch, struct drr_class *cl) | |
145 | { | |
1c0d32fd | 146 | gen_kill_estimator(&cl->rate_est); |
13d2a1d2 PM |
147 | qdisc_destroy(cl->qdisc); |
148 | kfree(cl); | |
149 | } | |
150 | ||
151 | static int drr_delete_class(struct Qdisc *sch, unsigned long arg) | |
152 | { | |
153 | struct drr_sched *q = qdisc_priv(sch); | |
154 | struct drr_class *cl = (struct drr_class *)arg; | |
155 | ||
156 | if (cl->filter_cnt > 0) | |
157 | return -EBUSY; | |
158 | ||
159 | sch_tree_lock(sch); | |
160 | ||
161 | drr_purge_queue(cl); | |
162 | qdisc_class_hash_remove(&q->clhash, &cl->common); | |
163 | ||
13d2a1d2 | 164 | sch_tree_unlock(sch); |
13d2a1d2 | 165 | |
143976ce WC |
166 | drr_destroy_class(sch, cl); |
167 | return 0; | |
13d2a1d2 PM |
168 | } |
169 | ||
143976ce | 170 | static unsigned long drr_search_class(struct Qdisc *sch, u32 classid) |
13d2a1d2 | 171 | { |
143976ce | 172 | return (unsigned long)drr_find_class(sch, classid); |
13d2a1d2 PM |
173 | } |
174 | ||
6529eaba | 175 | static struct tcf_block *drr_tcf_block(struct Qdisc *sch, unsigned long cl) |
13d2a1d2 PM |
176 | { |
177 | struct drr_sched *q = qdisc_priv(sch); | |
178 | ||
179 | if (cl) | |
180 | return NULL; | |
181 | ||
6529eaba | 182 | return q->block; |
13d2a1d2 PM |
183 | } |
184 | ||
185 | static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent, | |
186 | u32 classid) | |
187 | { | |
188 | struct drr_class *cl = drr_find_class(sch, classid); | |
189 | ||
190 | if (cl != NULL) | |
191 | cl->filter_cnt++; | |
192 | ||
193 | return (unsigned long)cl; | |
194 | } | |
195 | ||
196 | static void drr_unbind_tcf(struct Qdisc *sch, unsigned long arg) | |
197 | { | |
198 | struct drr_class *cl = (struct drr_class *)arg; | |
199 | ||
200 | cl->filter_cnt--; | |
201 | } | |
202 | ||
203 | static int drr_graft_class(struct Qdisc *sch, unsigned long arg, | |
204 | struct Qdisc *new, struct Qdisc **old) | |
205 | { | |
206 | struct drr_class *cl = (struct drr_class *)arg; | |
207 | ||
208 | if (new == NULL) { | |
3511c913 | 209 | new = qdisc_create_dflt(sch->dev_queue, |
13d2a1d2 PM |
210 | &pfifo_qdisc_ops, cl->common.classid); |
211 | if (new == NULL) | |
212 | new = &noop_qdisc; | |
213 | } | |
214 | ||
86a7996c | 215 | *old = qdisc_replace(sch, new, &cl->qdisc); |
13d2a1d2 PM |
216 | return 0; |
217 | } | |
218 | ||
219 | static struct Qdisc *drr_class_leaf(struct Qdisc *sch, unsigned long arg) | |
220 | { | |
221 | struct drr_class *cl = (struct drr_class *)arg; | |
222 | ||
223 | return cl->qdisc; | |
224 | } | |
225 | ||
226 | static void drr_qlen_notify(struct Qdisc *csh, unsigned long arg) | |
227 | { | |
228 | struct drr_class *cl = (struct drr_class *)arg; | |
229 | ||
95946658 | 230 | list_del(&cl->alist); |
13d2a1d2 PM |
231 | } |
232 | ||
233 | static int drr_dump_class(struct Qdisc *sch, unsigned long arg, | |
234 | struct sk_buff *skb, struct tcmsg *tcm) | |
235 | { | |
236 | struct drr_class *cl = (struct drr_class *)arg; | |
237 | struct nlattr *nest; | |
238 | ||
239 | tcm->tcm_parent = TC_H_ROOT; | |
240 | tcm->tcm_handle = cl->common.classid; | |
241 | tcm->tcm_info = cl->qdisc->handle; | |
242 | ||
243 | nest = nla_nest_start(skb, TCA_OPTIONS); | |
244 | if (nest == NULL) | |
245 | goto nla_put_failure; | |
1b34ec43 DM |
246 | if (nla_put_u32(skb, TCA_DRR_QUANTUM, cl->quantum)) |
247 | goto nla_put_failure; | |
13d2a1d2 PM |
248 | return nla_nest_end(skb, nest); |
249 | ||
250 | nla_put_failure: | |
251 | nla_nest_cancel(skb, nest); | |
252 | return -EMSGSIZE; | |
253 | } | |
254 | ||
255 | static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg, | |
256 | struct gnet_dump *d) | |
257 | { | |
258 | struct drr_class *cl = (struct drr_class *)arg; | |
64015853 | 259 | __u32 qlen = cl->qdisc->q.qlen; |
13d2a1d2 PM |
260 | struct tc_drr_stats xstats; |
261 | ||
262 | memset(&xstats, 0, sizeof(xstats)); | |
64015853 | 263 | if (qlen) |
13d2a1d2 PM |
264 | xstats.deficit = cl->deficit; |
265 | ||
edb09eb1 ED |
266 | if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch), |
267 | d, NULL, &cl->bstats) < 0 || | |
1c0d32fd | 268 | gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 || |
b0ab6f92 | 269 | gnet_stats_copy_queue(d, NULL, &cl->qdisc->qstats, qlen) < 0) |
13d2a1d2 PM |
270 | return -1; |
271 | ||
272 | return gnet_stats_copy_app(d, &xstats, sizeof(xstats)); | |
273 | } | |
274 | ||
275 | static void drr_walk(struct Qdisc *sch, struct qdisc_walker *arg) | |
276 | { | |
277 | struct drr_sched *q = qdisc_priv(sch); | |
278 | struct drr_class *cl; | |
13d2a1d2 PM |
279 | unsigned int i; |
280 | ||
281 | if (arg->stop) | |
282 | return; | |
283 | ||
284 | for (i = 0; i < q->clhash.hashsize; i++) { | |
b67bfe0d | 285 | hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) { |
13d2a1d2 PM |
286 | if (arg->count < arg->skip) { |
287 | arg->count++; | |
288 | continue; | |
289 | } | |
290 | if (arg->fn(sch, (unsigned long)cl, arg) < 0) { | |
291 | arg->stop = 1; | |
292 | return; | |
293 | } | |
294 | arg->count++; | |
295 | } | |
296 | } | |
297 | } | |
298 | ||
299 | static struct drr_class *drr_classify(struct sk_buff *skb, struct Qdisc *sch, | |
300 | int *qerr) | |
301 | { | |
302 | struct drr_sched *q = qdisc_priv(sch); | |
303 | struct drr_class *cl; | |
304 | struct tcf_result res; | |
25d8c0d5 | 305 | struct tcf_proto *fl; |
13d2a1d2 PM |
306 | int result; |
307 | ||
308 | if (TC_H_MAJ(skb->priority ^ sch->handle) == 0) { | |
309 | cl = drr_find_class(sch, skb->priority); | |
310 | if (cl != NULL) | |
311 | return cl; | |
312 | } | |
313 | ||
314 | *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; | |
25d8c0d5 | 315 | fl = rcu_dereference_bh(q->filter_list); |
87d83093 | 316 | result = tcf_classify(skb, fl, &res, false); |
13d2a1d2 PM |
317 | if (result >= 0) { |
318 | #ifdef CONFIG_NET_CLS_ACT | |
319 | switch (result) { | |
320 | case TC_ACT_QUEUED: | |
321 | case TC_ACT_STOLEN: | |
e25ea21f | 322 | case TC_ACT_TRAP: |
13d2a1d2 PM |
323 | *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN; |
324 | case TC_ACT_SHOT: | |
325 | return NULL; | |
326 | } | |
327 | #endif | |
328 | cl = (struct drr_class *)res.class; | |
329 | if (cl == NULL) | |
330 | cl = drr_find_class(sch, res.classid); | |
331 | return cl; | |
332 | } | |
333 | return NULL; | |
334 | } | |
335 | ||
520ac30f ED |
336 | static int drr_enqueue(struct sk_buff *skb, struct Qdisc *sch, |
337 | struct sk_buff **to_free) | |
13d2a1d2 PM |
338 | { |
339 | struct drr_sched *q = qdisc_priv(sch); | |
340 | struct drr_class *cl; | |
f54ba779 | 341 | int err = 0; |
13d2a1d2 PM |
342 | |
343 | cl = drr_classify(skb, sch, &err); | |
344 | if (cl == NULL) { | |
345 | if (err & __NET_XMIT_BYPASS) | |
25331d6c | 346 | qdisc_qstats_drop(sch); |
520ac30f | 347 | __qdisc_drop(skb, to_free); |
13d2a1d2 PM |
348 | return err; |
349 | } | |
350 | ||
520ac30f | 351 | err = qdisc_enqueue(skb, cl->qdisc, to_free); |
13d2a1d2 PM |
352 | if (unlikely(err != NET_XMIT_SUCCESS)) { |
353 | if (net_xmit_drop_count(err)) { | |
354 | cl->qstats.drops++; | |
25331d6c | 355 | qdisc_qstats_drop(sch); |
13d2a1d2 PM |
356 | } |
357 | return err; | |
358 | } | |
359 | ||
360 | if (cl->qdisc->q.qlen == 1) { | |
361 | list_add_tail(&cl->alist, &q->active); | |
362 | cl->deficit = cl->quantum; | |
363 | } | |
364 | ||
6a73b571 | 365 | qdisc_qstats_backlog_inc(sch, skb); |
13d2a1d2 PM |
366 | sch->q.qlen++; |
367 | return err; | |
368 | } | |
369 | ||
370 | static struct sk_buff *drr_dequeue(struct Qdisc *sch) | |
371 | { | |
372 | struct drr_sched *q = qdisc_priv(sch); | |
373 | struct drr_class *cl; | |
374 | struct sk_buff *skb; | |
375 | unsigned int len; | |
376 | ||
3f0947c3 PM |
377 | if (list_empty(&q->active)) |
378 | goto out; | |
379 | while (1) { | |
13d2a1d2 PM |
380 | cl = list_first_entry(&q->active, struct drr_class, alist); |
381 | skb = cl->qdisc->ops->peek(cl->qdisc); | |
6e765a00 FW |
382 | if (skb == NULL) { |
383 | qdisc_warn_nonwc(__func__, cl->qdisc); | |
3f0947c3 | 384 | goto out; |
6e765a00 | 385 | } |
13d2a1d2 PM |
386 | |
387 | len = qdisc_pkt_len(skb); | |
388 | if (len <= cl->deficit) { | |
389 | cl->deficit -= len; | |
390 | skb = qdisc_dequeue_peeked(cl->qdisc); | |
df3eb6cd BH |
391 | if (unlikely(skb == NULL)) |
392 | goto out; | |
13d2a1d2 PM |
393 | if (cl->qdisc->q.qlen == 0) |
394 | list_del(&cl->alist); | |
2dd875ff ED |
395 | |
396 | bstats_update(&cl->bstats, skb); | |
9190b3b3 | 397 | qdisc_bstats_update(sch, skb); |
6a73b571 | 398 | qdisc_qstats_backlog_dec(sch, skb); |
13d2a1d2 PM |
399 | sch->q.qlen--; |
400 | return skb; | |
401 | } | |
402 | ||
403 | cl->deficit += cl->quantum; | |
13d2a1d2 PM |
404 | list_move_tail(&cl->alist, &q->active); |
405 | } | |
3f0947c3 | 406 | out: |
13d2a1d2 PM |
407 | return NULL; |
408 | } | |
409 | ||
13d2a1d2 PM |
410 | static int drr_init_qdisc(struct Qdisc *sch, struct nlattr *opt) |
411 | { | |
412 | struct drr_sched *q = qdisc_priv(sch); | |
413 | int err; | |
414 | ||
69d78ef2 | 415 | err = tcf_block_get(&q->block, &q->filter_list, sch); |
6529eaba JP |
416 | if (err) |
417 | return err; | |
13d2a1d2 PM |
418 | err = qdisc_class_hash_init(&q->clhash); |
419 | if (err < 0) | |
420 | return err; | |
421 | INIT_LIST_HEAD(&q->active); | |
422 | return 0; | |
423 | } | |
424 | ||
425 | static void drr_reset_qdisc(struct Qdisc *sch) | |
426 | { | |
427 | struct drr_sched *q = qdisc_priv(sch); | |
428 | struct drr_class *cl; | |
13d2a1d2 PM |
429 | unsigned int i; |
430 | ||
431 | for (i = 0; i < q->clhash.hashsize; i++) { | |
b67bfe0d | 432 | hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) { |
13d2a1d2 PM |
433 | if (cl->qdisc->q.qlen) |
434 | list_del(&cl->alist); | |
435 | qdisc_reset(cl->qdisc); | |
436 | } | |
437 | } | |
6a73b571 | 438 | sch->qstats.backlog = 0; |
13d2a1d2 PM |
439 | sch->q.qlen = 0; |
440 | } | |
441 | ||
442 | static void drr_destroy_qdisc(struct Qdisc *sch) | |
443 | { | |
444 | struct drr_sched *q = qdisc_priv(sch); | |
445 | struct drr_class *cl; | |
b67bfe0d | 446 | struct hlist_node *next; |
13d2a1d2 PM |
447 | unsigned int i; |
448 | ||
6529eaba | 449 | tcf_block_put(q->block); |
13d2a1d2 PM |
450 | |
451 | for (i = 0; i < q->clhash.hashsize; i++) { | |
b67bfe0d | 452 | hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i], |
13d2a1d2 PM |
453 | common.hnode) |
454 | drr_destroy_class(sch, cl); | |
455 | } | |
456 | qdisc_class_hash_destroy(&q->clhash); | |
457 | } | |
458 | ||
459 | static const struct Qdisc_class_ops drr_class_ops = { | |
460 | .change = drr_change_class, | |
461 | .delete = drr_delete_class, | |
143976ce | 462 | .find = drr_search_class, |
6529eaba | 463 | .tcf_block = drr_tcf_block, |
13d2a1d2 PM |
464 | .bind_tcf = drr_bind_tcf, |
465 | .unbind_tcf = drr_unbind_tcf, | |
466 | .graft = drr_graft_class, | |
467 | .leaf = drr_class_leaf, | |
468 | .qlen_notify = drr_qlen_notify, | |
469 | .dump = drr_dump_class, | |
470 | .dump_stats = drr_dump_class_stats, | |
471 | .walk = drr_walk, | |
472 | }; | |
473 | ||
474 | static struct Qdisc_ops drr_qdisc_ops __read_mostly = { | |
475 | .cl_ops = &drr_class_ops, | |
476 | .id = "drr", | |
477 | .priv_size = sizeof(struct drr_sched), | |
478 | .enqueue = drr_enqueue, | |
479 | .dequeue = drr_dequeue, | |
480 | .peek = qdisc_peek_dequeued, | |
13d2a1d2 PM |
481 | .init = drr_init_qdisc, |
482 | .reset = drr_reset_qdisc, | |
483 | .destroy = drr_destroy_qdisc, | |
484 | .owner = THIS_MODULE, | |
485 | }; | |
486 | ||
487 | static int __init drr_init(void) | |
488 | { | |
489 | return register_qdisc(&drr_qdisc_ops); | |
490 | } | |
491 | ||
492 | static void __exit drr_exit(void) | |
493 | { | |
494 | unregister_qdisc(&drr_qdisc_ops); | |
495 | } | |
496 | ||
497 | module_init(drr_init); | |
498 | module_exit(drr_exit); | |
499 | MODULE_LICENSE("GPL"); |