2 * net/sched/sch_drr.c Deficit Round Robin scheduler
4 * Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
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.
11 #include <linux/module.h>
12 #include <linux/slab.h>
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>
22 struct Qdisc_class_common common;
24 unsigned int filter_cnt;
26 struct gnet_stats_basic_packed bstats;
27 struct gnet_stats_queue qstats;
28 struct gnet_stats_rate_est rate_est;
29 struct list_head alist;
37 struct list_head active;
38 struct tcf_proto *filter_list;
39 struct Qdisc_class_hash clhash;
42 static struct drr_class *drr_find_class(struct Qdisc *sch, u32 classid)
44 struct drr_sched *q = qdisc_priv(sch);
45 struct Qdisc_class_common *clc;
47 clc = qdisc_class_find(&q->clhash, classid);
50 return container_of(clc, struct drr_class, common);
53 static void drr_purge_queue(struct drr_class *cl)
55 unsigned int len = cl->qdisc->q.qlen;
57 qdisc_reset(cl->qdisc);
58 qdisc_tree_decrease_qlen(cl->qdisc, len);
61 static const struct nla_policy drr_policy[TCA_DRR_MAX + 1] = {
62 [TCA_DRR_QUANTUM] = { .type = NLA_U32 },
65 static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
66 struct nlattr **tca, unsigned long *arg)
68 struct drr_sched *q = qdisc_priv(sch);
69 struct drr_class *cl = (struct drr_class *)*arg;
70 struct nlattr *opt = tca[TCA_OPTIONS];
71 struct nlattr *tb[TCA_DRR_MAX + 1];
78 err = nla_parse_nested(tb, TCA_DRR_MAX, opt, drr_policy);
82 if (tb[TCA_DRR_QUANTUM]) {
83 quantum = nla_get_u32(tb[TCA_DRR_QUANTUM]);
87 quantum = psched_mtu(qdisc_dev(sch));
91 err = gen_replace_estimator(&cl->bstats, &cl->rate_est,
92 qdisc_root_sleeping_lock(sch),
99 if (tb[TCA_DRR_QUANTUM])
100 cl->quantum = quantum;
101 sch_tree_unlock(sch);
106 cl = kzalloc(sizeof(struct drr_class), GFP_KERNEL);
111 cl->common.classid = classid;
112 cl->quantum = quantum;
113 cl->qdisc = qdisc_create_dflt(sch->dev_queue,
114 &pfifo_qdisc_ops, classid);
115 if (cl->qdisc == NULL)
116 cl->qdisc = &noop_qdisc;
119 err = gen_replace_estimator(&cl->bstats, &cl->rate_est,
120 qdisc_root_sleeping_lock(sch),
123 qdisc_destroy(cl->qdisc);
130 qdisc_class_hash_insert(&q->clhash, &cl->common);
131 sch_tree_unlock(sch);
133 qdisc_class_hash_grow(sch, &q->clhash);
135 *arg = (unsigned long)cl;
139 static void drr_destroy_class(struct Qdisc *sch, struct drr_class *cl)
141 gen_kill_estimator(&cl->bstats, &cl->rate_est);
142 qdisc_destroy(cl->qdisc);
146 static int drr_delete_class(struct Qdisc *sch, unsigned long arg)
148 struct drr_sched *q = qdisc_priv(sch);
149 struct drr_class *cl = (struct drr_class *)arg;
151 if (cl->filter_cnt > 0)
157 qdisc_class_hash_remove(&q->clhash, &cl->common);
159 BUG_ON(--cl->refcnt == 0);
161 * This shouldn't happen: we "hold" one cops->get() when called
162 * from tc_ctl_tclass; the destroy method is done from cops->put().
165 sch_tree_unlock(sch);
169 static unsigned long drr_get_class(struct Qdisc *sch, u32 classid)
171 struct drr_class *cl = drr_find_class(sch, classid);
176 return (unsigned long)cl;
179 static void drr_put_class(struct Qdisc *sch, unsigned long arg)
181 struct drr_class *cl = (struct drr_class *)arg;
183 if (--cl->refcnt == 0)
184 drr_destroy_class(sch, cl);
187 static struct tcf_proto **drr_tcf_chain(struct Qdisc *sch, unsigned long cl)
189 struct drr_sched *q = qdisc_priv(sch);
194 return &q->filter_list;
197 static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent,
200 struct drr_class *cl = drr_find_class(sch, classid);
205 return (unsigned long)cl;
208 static void drr_unbind_tcf(struct Qdisc *sch, unsigned long arg)
210 struct drr_class *cl = (struct drr_class *)arg;
215 static int drr_graft_class(struct Qdisc *sch, unsigned long arg,
216 struct Qdisc *new, struct Qdisc **old)
218 struct drr_class *cl = (struct drr_class *)arg;
221 new = qdisc_create_dflt(sch->dev_queue,
222 &pfifo_qdisc_ops, cl->common.classid);
231 sch_tree_unlock(sch);
235 static struct Qdisc *drr_class_leaf(struct Qdisc *sch, unsigned long arg)
237 struct drr_class *cl = (struct drr_class *)arg;
242 static void drr_qlen_notify(struct Qdisc *csh, unsigned long arg)
244 struct drr_class *cl = (struct drr_class *)arg;
246 if (cl->qdisc->q.qlen == 0)
247 list_del(&cl->alist);
250 static int drr_dump_class(struct Qdisc *sch, unsigned long arg,
251 struct sk_buff *skb, struct tcmsg *tcm)
253 struct drr_class *cl = (struct drr_class *)arg;
256 tcm->tcm_parent = TC_H_ROOT;
257 tcm->tcm_handle = cl->common.classid;
258 tcm->tcm_info = cl->qdisc->handle;
260 nest = nla_nest_start(skb, TCA_OPTIONS);
262 goto nla_put_failure;
263 NLA_PUT_U32(skb, TCA_DRR_QUANTUM, cl->quantum);
264 return nla_nest_end(skb, nest);
267 nla_nest_cancel(skb, nest);
271 static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg,
274 struct drr_class *cl = (struct drr_class *)arg;
275 struct tc_drr_stats xstats;
277 memset(&xstats, 0, sizeof(xstats));
278 if (cl->qdisc->q.qlen) {
279 xstats.deficit = cl->deficit;
280 cl->qdisc->qstats.qlen = cl->qdisc->q.qlen;
283 if (gnet_stats_copy_basic(d, &cl->bstats) < 0 ||
284 gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 ||
285 gnet_stats_copy_queue(d, &cl->qdisc->qstats) < 0)
288 return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
291 static void drr_walk(struct Qdisc *sch, struct qdisc_walker *arg)
293 struct drr_sched *q = qdisc_priv(sch);
294 struct drr_class *cl;
295 struct hlist_node *n;
301 for (i = 0; i < q->clhash.hashsize; i++) {
302 hlist_for_each_entry(cl, n, &q->clhash.hash[i], common.hnode) {
303 if (arg->count < arg->skip) {
307 if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
316 static struct drr_class *drr_classify(struct sk_buff *skb, struct Qdisc *sch,
319 struct drr_sched *q = qdisc_priv(sch);
320 struct drr_class *cl;
321 struct tcf_result res;
324 if (TC_H_MAJ(skb->priority ^ sch->handle) == 0) {
325 cl = drr_find_class(sch, skb->priority);
330 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
331 result = tc_classify(skb, q->filter_list, &res);
333 #ifdef CONFIG_NET_CLS_ACT
337 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
342 cl = (struct drr_class *)res.class;
344 cl = drr_find_class(sch, res.classid);
350 static int drr_enqueue(struct sk_buff *skb, struct Qdisc *sch)
352 struct drr_sched *q = qdisc_priv(sch);
353 struct drr_class *cl;
356 cl = drr_classify(skb, sch, &err);
358 if (err & __NET_XMIT_BYPASS)
364 err = qdisc_enqueue(skb, cl->qdisc);
365 if (unlikely(err != NET_XMIT_SUCCESS)) {
366 if (net_xmit_drop_count(err)) {
373 if (cl->qdisc->q.qlen == 1) {
374 list_add_tail(&cl->alist, &q->active);
375 cl->deficit = cl->quantum;
378 bstats_update(&cl->bstats, skb);
384 static struct sk_buff *drr_dequeue(struct Qdisc *sch)
386 struct drr_sched *q = qdisc_priv(sch);
387 struct drr_class *cl;
391 if (list_empty(&q->active))
394 cl = list_first_entry(&q->active, struct drr_class, alist);
395 skb = cl->qdisc->ops->peek(cl->qdisc);
399 len = qdisc_pkt_len(skb);
400 if (len <= cl->deficit) {
402 skb = qdisc_dequeue_peeked(cl->qdisc);
403 if (cl->qdisc->q.qlen == 0)
404 list_del(&cl->alist);
405 qdisc_bstats_update(sch, skb);
410 cl->deficit += cl->quantum;
411 list_move_tail(&cl->alist, &q->active);
417 static unsigned int drr_drop(struct Qdisc *sch)
419 struct drr_sched *q = qdisc_priv(sch);
420 struct drr_class *cl;
423 list_for_each_entry(cl, &q->active, alist) {
424 if (cl->qdisc->ops->drop) {
425 len = cl->qdisc->ops->drop(cl->qdisc);
428 if (cl->qdisc->q.qlen == 0)
429 list_del(&cl->alist);
437 static int drr_init_qdisc(struct Qdisc *sch, struct nlattr *opt)
439 struct drr_sched *q = qdisc_priv(sch);
442 err = qdisc_class_hash_init(&q->clhash);
445 INIT_LIST_HEAD(&q->active);
449 static void drr_reset_qdisc(struct Qdisc *sch)
451 struct drr_sched *q = qdisc_priv(sch);
452 struct drr_class *cl;
453 struct hlist_node *n;
456 for (i = 0; i < q->clhash.hashsize; i++) {
457 hlist_for_each_entry(cl, n, &q->clhash.hash[i], common.hnode) {
458 if (cl->qdisc->q.qlen)
459 list_del(&cl->alist);
460 qdisc_reset(cl->qdisc);
466 static void drr_destroy_qdisc(struct Qdisc *sch)
468 struct drr_sched *q = qdisc_priv(sch);
469 struct drr_class *cl;
470 struct hlist_node *n, *next;
473 tcf_destroy_chain(&q->filter_list);
475 for (i = 0; i < q->clhash.hashsize; i++) {
476 hlist_for_each_entry_safe(cl, n, next, &q->clhash.hash[i],
478 drr_destroy_class(sch, cl);
480 qdisc_class_hash_destroy(&q->clhash);
483 static const struct Qdisc_class_ops drr_class_ops = {
484 .change = drr_change_class,
485 .delete = drr_delete_class,
486 .get = drr_get_class,
487 .put = drr_put_class,
488 .tcf_chain = drr_tcf_chain,
489 .bind_tcf = drr_bind_tcf,
490 .unbind_tcf = drr_unbind_tcf,
491 .graft = drr_graft_class,
492 .leaf = drr_class_leaf,
493 .qlen_notify = drr_qlen_notify,
494 .dump = drr_dump_class,
495 .dump_stats = drr_dump_class_stats,
499 static struct Qdisc_ops drr_qdisc_ops __read_mostly = {
500 .cl_ops = &drr_class_ops,
502 .priv_size = sizeof(struct drr_sched),
503 .enqueue = drr_enqueue,
504 .dequeue = drr_dequeue,
505 .peek = qdisc_peek_dequeued,
507 .init = drr_init_qdisc,
508 .reset = drr_reset_qdisc,
509 .destroy = drr_destroy_qdisc,
510 .owner = THIS_MODULE,
513 static int __init drr_init(void)
515 return register_qdisc(&drr_qdisc_ops);
518 static void __exit drr_exit(void)
520 unregister_qdisc(&drr_qdisc_ops);
523 module_init(drr_init);
524 module_exit(drr_exit);
525 MODULE_LICENSE("GPL");