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/init.h>
13 #include <linux/errno.h>
14 #include <linux/netdevice.h>
15 #include <linux/pkt_sched.h>
16 #include <net/sch_generic.h>
17 #include <net/pkt_sched.h>
18 #include <net/pkt_cls.h>
21 struct Qdisc_class_common common;
23 unsigned int filter_cnt;
25 struct gnet_stats_basic bstats;
26 struct gnet_stats_queue qstats;
27 struct gnet_stats_rate_est rate_est;
28 struct list_head alist;
36 struct list_head active;
37 struct tcf_proto *filter_list;
38 struct Qdisc_class_hash clhash;
41 static struct drr_class *drr_find_class(struct Qdisc *sch, u32 classid)
43 struct drr_sched *q = qdisc_priv(sch);
44 struct Qdisc_class_common *clc;
46 clc = qdisc_class_find(&q->clhash, classid);
49 return container_of(clc, struct drr_class, common);
52 static void drr_purge_queue(struct drr_class *cl)
54 unsigned int len = cl->qdisc->q.qlen;
56 qdisc_reset(cl->qdisc);
57 qdisc_tree_decrease_qlen(cl->qdisc, len);
60 static const struct nla_policy drr_policy[TCA_DRR_MAX + 1] = {
61 [TCA_DRR_QUANTUM] = { .type = NLA_U32 },
64 static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
65 struct nlattr **tca, unsigned long *arg)
67 struct drr_sched *q = qdisc_priv(sch);
68 struct drr_class *cl = (struct drr_class *)*arg;
69 struct nlattr *tb[TCA_DRR_MAX + 1];
73 err = nla_parse_nested(tb, TCA_DRR_MAX, tca[TCA_OPTIONS], drr_policy);
77 if (tb[TCA_DRR_QUANTUM]) {
78 quantum = nla_get_u32(tb[TCA_DRR_QUANTUM]);
82 quantum = psched_mtu(qdisc_dev(sch));
86 if (tb[TCA_DRR_QUANTUM])
87 cl->quantum = quantum;
91 gen_replace_estimator(&cl->bstats, &cl->rate_est,
92 qdisc_root_sleeping_lock(sch),
97 cl = kzalloc(sizeof(struct drr_class), GFP_KERNEL);
102 cl->common.classid = classid;
103 cl->quantum = quantum;
104 cl->qdisc = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue,
105 &pfifo_qdisc_ops, classid);
106 if (cl->qdisc == NULL)
107 cl->qdisc = &noop_qdisc;
110 gen_replace_estimator(&cl->bstats, &cl->rate_est,
111 qdisc_root_sleeping_lock(sch),
115 qdisc_class_hash_insert(&q->clhash, &cl->common);
116 sch_tree_unlock(sch);
118 qdisc_class_hash_grow(sch, &q->clhash);
120 *arg = (unsigned long)cl;
124 static void drr_destroy_class(struct Qdisc *sch, struct drr_class *cl)
126 gen_kill_estimator(&cl->bstats, &cl->rate_est);
127 qdisc_destroy(cl->qdisc);
131 static int drr_delete_class(struct Qdisc *sch, unsigned long arg)
133 struct drr_sched *q = qdisc_priv(sch);
134 struct drr_class *cl = (struct drr_class *)arg;
136 if (cl->filter_cnt > 0)
142 qdisc_class_hash_remove(&q->clhash, &cl->common);
144 if (--cl->refcnt == 0)
145 drr_destroy_class(sch, cl);
147 sch_tree_unlock(sch);
151 static unsigned long drr_get_class(struct Qdisc *sch, u32 classid)
153 struct drr_class *cl = drr_find_class(sch, classid);
158 return (unsigned long)cl;
161 static void drr_put_class(struct Qdisc *sch, unsigned long arg)
163 struct drr_class *cl = (struct drr_class *)arg;
165 if (--cl->refcnt == 0)
166 drr_destroy_class(sch, cl);
169 static struct tcf_proto **drr_tcf_chain(struct Qdisc *sch, unsigned long cl)
171 struct drr_sched *q = qdisc_priv(sch);
176 return &q->filter_list;
179 static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent,
182 struct drr_class *cl = drr_find_class(sch, classid);
187 return (unsigned long)cl;
190 static void drr_unbind_tcf(struct Qdisc *sch, unsigned long arg)
192 struct drr_class *cl = (struct drr_class *)arg;
197 static int drr_graft_class(struct Qdisc *sch, unsigned long arg,
198 struct Qdisc *new, struct Qdisc **old)
200 struct drr_class *cl = (struct drr_class *)arg;
203 new = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue,
204 &pfifo_qdisc_ops, cl->common.classid);
211 *old = xchg(&cl->qdisc, new);
212 sch_tree_unlock(sch);
216 static struct Qdisc *drr_class_leaf(struct Qdisc *sch, unsigned long arg)
218 struct drr_class *cl = (struct drr_class *)arg;
223 static void drr_qlen_notify(struct Qdisc *csh, unsigned long arg)
225 struct drr_class *cl = (struct drr_class *)arg;
227 if (cl->qdisc->q.qlen == 0)
228 list_del(&cl->alist);
231 static int drr_dump_class(struct Qdisc *sch, unsigned long arg,
232 struct sk_buff *skb, struct tcmsg *tcm)
234 struct drr_class *cl = (struct drr_class *)arg;
237 tcm->tcm_parent = TC_H_ROOT;
238 tcm->tcm_handle = cl->common.classid;
239 tcm->tcm_info = cl->qdisc->handle;
241 nest = nla_nest_start(skb, TCA_OPTIONS);
243 goto nla_put_failure;
244 NLA_PUT_U32(skb, TCA_DRR_QUANTUM, cl->quantum);
245 return nla_nest_end(skb, nest);
248 nla_nest_cancel(skb, nest);
252 static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg,
255 struct drr_class *cl = (struct drr_class *)arg;
256 struct tc_drr_stats xstats;
258 memset(&xstats, 0, sizeof(xstats));
259 if (cl->qdisc->q.qlen)
260 xstats.deficit = cl->deficit;
262 if (gnet_stats_copy_basic(d, &cl->bstats) < 0 ||
263 gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
264 gnet_stats_copy_queue(d, &cl->qdisc->qstats) < 0)
267 return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
270 static void drr_walk(struct Qdisc *sch, struct qdisc_walker *arg)
272 struct drr_sched *q = qdisc_priv(sch);
273 struct drr_class *cl;
274 struct hlist_node *n;
280 for (i = 0; i < q->clhash.hashsize; i++) {
281 hlist_for_each_entry(cl, n, &q->clhash.hash[i], common.hnode) {
282 if (arg->count < arg->skip) {
286 if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
295 static struct drr_class *drr_classify(struct sk_buff *skb, struct Qdisc *sch,
298 struct drr_sched *q = qdisc_priv(sch);
299 struct drr_class *cl;
300 struct tcf_result res;
303 if (TC_H_MAJ(skb->priority ^ sch->handle) == 0) {
304 cl = drr_find_class(sch, skb->priority);
309 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
310 result = tc_classify(skb, q->filter_list, &res);
312 #ifdef CONFIG_NET_CLS_ACT
316 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
321 cl = (struct drr_class *)res.class;
323 cl = drr_find_class(sch, res.classid);
329 static int drr_enqueue(struct sk_buff *skb, struct Qdisc *sch)
331 struct drr_sched *q = qdisc_priv(sch);
332 struct drr_class *cl;
336 cl = drr_classify(skb, sch, &err);
338 if (err & __NET_XMIT_BYPASS)
344 len = qdisc_pkt_len(skb);
345 err = qdisc_enqueue(skb, cl->qdisc);
346 if (unlikely(err != NET_XMIT_SUCCESS)) {
347 if (net_xmit_drop_count(err)) {
354 if (cl->qdisc->q.qlen == 1) {
355 list_add_tail(&cl->alist, &q->active);
356 cl->deficit = cl->quantum;
359 cl->bstats.packets++;
360 cl->bstats.bytes += len;
361 sch->bstats.packets++;
362 sch->bstats.bytes += len;
368 static struct sk_buff *drr_dequeue(struct Qdisc *sch)
370 struct drr_sched *q = qdisc_priv(sch);
371 struct drr_class *cl;
375 while (!list_empty(&q->active)) {
376 cl = list_first_entry(&q->active, struct drr_class, alist);
377 skb = cl->qdisc->ops->peek(cl->qdisc);
381 len = qdisc_pkt_len(skb);
382 if (len <= cl->deficit) {
384 skb = qdisc_dequeue_peeked(cl->qdisc);
385 if (cl->qdisc->q.qlen == 0)
386 list_del(&cl->alist);
391 cl->deficit += cl->quantum;
393 list_move_tail(&cl->alist, &q->active);
398 static unsigned int drr_drop(struct Qdisc *sch)
400 struct drr_sched *q = qdisc_priv(sch);
401 struct drr_class *cl;
404 list_for_each_entry(cl, &q->active, alist) {
405 if (cl->qdisc->ops->drop) {
406 len = cl->qdisc->ops->drop(cl->qdisc);
408 if (cl->qdisc->q.qlen == 0)
409 list_del(&cl->alist);
417 static int drr_init_qdisc(struct Qdisc *sch, struct nlattr *opt)
419 struct drr_sched *q = qdisc_priv(sch);
422 err = qdisc_class_hash_init(&q->clhash);
425 INIT_LIST_HEAD(&q->active);
429 static void drr_reset_qdisc(struct Qdisc *sch)
431 struct drr_sched *q = qdisc_priv(sch);
432 struct drr_class *cl;
433 struct hlist_node *n;
436 for (i = 0; i < q->clhash.hashsize; i++) {
437 hlist_for_each_entry(cl, n, &q->clhash.hash[i], common.hnode) {
438 if (cl->qdisc->q.qlen)
439 list_del(&cl->alist);
440 qdisc_reset(cl->qdisc);
446 static void drr_destroy_qdisc(struct Qdisc *sch)
448 struct drr_sched *q = qdisc_priv(sch);
449 struct drr_class *cl;
450 struct hlist_node *n, *next;
453 tcf_destroy_chain(&q->filter_list);
455 for (i = 0; i < q->clhash.hashsize; i++) {
456 hlist_for_each_entry_safe(cl, n, next, &q->clhash.hash[i],
458 drr_destroy_class(sch, cl);
460 qdisc_class_hash_destroy(&q->clhash);
463 static const struct Qdisc_class_ops drr_class_ops = {
464 .change = drr_change_class,
465 .delete = drr_delete_class,
466 .get = drr_get_class,
467 .put = drr_put_class,
468 .tcf_chain = drr_tcf_chain,
469 .bind_tcf = drr_bind_tcf,
470 .unbind_tcf = drr_unbind_tcf,
471 .graft = drr_graft_class,
472 .leaf = drr_class_leaf,
473 .qlen_notify = drr_qlen_notify,
474 .dump = drr_dump_class,
475 .dump_stats = drr_dump_class_stats,
479 static struct Qdisc_ops drr_qdisc_ops __read_mostly = {
480 .cl_ops = &drr_class_ops,
482 .priv_size = sizeof(struct drr_sched),
483 .enqueue = drr_enqueue,
484 .dequeue = drr_dequeue,
485 .peek = qdisc_peek_dequeued,
487 .init = drr_init_qdisc,
488 .reset = drr_reset_qdisc,
489 .destroy = drr_destroy_qdisc,
490 .owner = THIS_MODULE,
493 static int __init drr_init(void)
495 return register_qdisc(&drr_qdisc_ops);
498 static void __exit drr_exit(void)
500 unregister_qdisc(&drr_qdisc_ops);
503 module_init(drr_init);
504 module_exit(drr_exit);
505 MODULE_LICENSE("GPL");