Root/
1 | /* |
2 | * net/sched/sch_red.c Random Early Detection queue. |
3 | * |
4 | * This program is free software; you can redistribute it and/or |
5 | * modify it under the terms of the GNU General Public License |
6 | * as published by the Free Software Foundation; either version |
7 | * 2 of the License, or (at your option) any later version. |
8 | * |
9 | * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> |
10 | * |
11 | * Changes: |
12 | * J Hadi Salim 980914: computation fixes |
13 | * Alexey Makarenko <makar@phoenix.kharkov.ua> 990814: qave on idle link was calculated incorrectly. |
14 | * J Hadi Salim 980816: ECN support |
15 | */ |
16 | |
17 | #include <linux/module.h> |
18 | #include <linux/types.h> |
19 | #include <linux/kernel.h> |
20 | #include <linux/skbuff.h> |
21 | #include <net/pkt_sched.h> |
22 | #include <net/inet_ecn.h> |
23 | #include <net/red.h> |
24 | |
25 | |
26 | /* Parameters, settable by user: |
27 | ----------------------------- |
28 | |
29 | limit - bytes (must be > qth_max + burst) |
30 | |
31 | Hard limit on queue length, should be chosen >qth_max |
32 | to allow packet bursts. This parameter does not |
33 | affect the algorithms behaviour and can be chosen |
34 | arbitrarily high (well, less than ram size) |
35 | Really, this limit will never be reached |
36 | if RED works correctly. |
37 | */ |
38 | |
39 | struct red_sched_data |
40 | { |
41 | u32 limit; /* HARD maximal queue length */ |
42 | unsigned char flags; |
43 | struct red_parms parms; |
44 | struct red_stats stats; |
45 | struct Qdisc *qdisc; |
46 | }; |
47 | |
48 | static inline int red_use_ecn(struct red_sched_data *q) |
49 | { |
50 | return q->flags & TC_RED_ECN; |
51 | } |
52 | |
53 | static inline int red_use_harddrop(struct red_sched_data *q) |
54 | { |
55 | return q->flags & TC_RED_HARDDROP; |
56 | } |
57 | |
58 | static int red_enqueue(struct sk_buff *skb, struct Qdisc* sch) |
59 | { |
60 | struct red_sched_data *q = qdisc_priv(sch); |
61 | struct Qdisc *child = q->qdisc; |
62 | int ret; |
63 | |
64 | q->parms.qavg = red_calc_qavg(&q->parms, child->qstats.backlog); |
65 | |
66 | if (red_is_idling(&q->parms)) |
67 | red_end_of_idle_period(&q->parms); |
68 | |
69 | switch (red_action(&q->parms, q->parms.qavg)) { |
70 | case RED_DONT_MARK: |
71 | break; |
72 | |
73 | case RED_PROB_MARK: |
74 | sch->qstats.overlimits++; |
75 | if (!red_use_ecn(q) || !INET_ECN_set_ce(skb)) { |
76 | q->stats.prob_drop++; |
77 | goto congestion_drop; |
78 | } |
79 | |
80 | q->stats.prob_mark++; |
81 | break; |
82 | |
83 | case RED_HARD_MARK: |
84 | sch->qstats.overlimits++; |
85 | if (red_use_harddrop(q) || !red_use_ecn(q) || |
86 | !INET_ECN_set_ce(skb)) { |
87 | q->stats.forced_drop++; |
88 | goto congestion_drop; |
89 | } |
90 | |
91 | q->stats.forced_mark++; |
92 | break; |
93 | } |
94 | |
95 | ret = qdisc_enqueue(skb, child); |
96 | if (likely(ret == NET_XMIT_SUCCESS)) { |
97 | sch->bstats.bytes += qdisc_pkt_len(skb); |
98 | sch->bstats.packets++; |
99 | sch->q.qlen++; |
100 | } else if (net_xmit_drop_count(ret)) { |
101 | q->stats.pdrop++; |
102 | sch->qstats.drops++; |
103 | } |
104 | return ret; |
105 | |
106 | congestion_drop: |
107 | qdisc_drop(skb, sch); |
108 | return NET_XMIT_CN; |
109 | } |
110 | |
111 | static struct sk_buff * red_dequeue(struct Qdisc* sch) |
112 | { |
113 | struct sk_buff *skb; |
114 | struct red_sched_data *q = qdisc_priv(sch); |
115 | struct Qdisc *child = q->qdisc; |
116 | |
117 | skb = child->dequeue(child); |
118 | if (skb) |
119 | sch->q.qlen--; |
120 | else if (!red_is_idling(&q->parms)) |
121 | red_start_of_idle_period(&q->parms); |
122 | |
123 | return skb; |
124 | } |
125 | |
126 | static struct sk_buff * red_peek(struct Qdisc* sch) |
127 | { |
128 | struct red_sched_data *q = qdisc_priv(sch); |
129 | struct Qdisc *child = q->qdisc; |
130 | |
131 | return child->ops->peek(child); |
132 | } |
133 | |
134 | static unsigned int red_drop(struct Qdisc* sch) |
135 | { |
136 | struct red_sched_data *q = qdisc_priv(sch); |
137 | struct Qdisc *child = q->qdisc; |
138 | unsigned int len; |
139 | |
140 | if (child->ops->drop && (len = child->ops->drop(child)) > 0) { |
141 | q->stats.other++; |
142 | sch->qstats.drops++; |
143 | sch->q.qlen--; |
144 | return len; |
145 | } |
146 | |
147 | if (!red_is_idling(&q->parms)) |
148 | red_start_of_idle_period(&q->parms); |
149 | |
150 | return 0; |
151 | } |
152 | |
153 | static void red_reset(struct Qdisc* sch) |
154 | { |
155 | struct red_sched_data *q = qdisc_priv(sch); |
156 | |
157 | qdisc_reset(q->qdisc); |
158 | sch->q.qlen = 0; |
159 | red_restart(&q->parms); |
160 | } |
161 | |
162 | static void red_destroy(struct Qdisc *sch) |
163 | { |
164 | struct red_sched_data *q = qdisc_priv(sch); |
165 | qdisc_destroy(q->qdisc); |
166 | } |
167 | |
168 | static const struct nla_policy red_policy[TCA_RED_MAX + 1] = { |
169 | [TCA_RED_PARMS] = { .len = sizeof(struct tc_red_qopt) }, |
170 | [TCA_RED_STAB] = { .len = RED_STAB_SIZE }, |
171 | }; |
172 | |
173 | static int red_change(struct Qdisc *sch, struct nlattr *opt) |
174 | { |
175 | struct red_sched_data *q = qdisc_priv(sch); |
176 | struct nlattr *tb[TCA_RED_MAX + 1]; |
177 | struct tc_red_qopt *ctl; |
178 | struct Qdisc *child = NULL; |
179 | int err; |
180 | |
181 | if (opt == NULL) |
182 | return -EINVAL; |
183 | |
184 | err = nla_parse_nested(tb, TCA_RED_MAX, opt, red_policy); |
185 | if (err < 0) |
186 | return err; |
187 | |
188 | if (tb[TCA_RED_PARMS] == NULL || |
189 | tb[TCA_RED_STAB] == NULL) |
190 | return -EINVAL; |
191 | |
192 | ctl = nla_data(tb[TCA_RED_PARMS]); |
193 | |
194 | if (ctl->limit > 0) { |
195 | child = fifo_create_dflt(sch, &bfifo_qdisc_ops, ctl->limit); |
196 | if (IS_ERR(child)) |
197 | return PTR_ERR(child); |
198 | } |
199 | |
200 | sch_tree_lock(sch); |
201 | q->flags = ctl->flags; |
202 | q->limit = ctl->limit; |
203 | if (child) { |
204 | qdisc_tree_decrease_qlen(q->qdisc, q->qdisc->q.qlen); |
205 | qdisc_destroy(q->qdisc); |
206 | q->qdisc = child; |
207 | } |
208 | |
209 | red_set_parms(&q->parms, ctl->qth_min, ctl->qth_max, ctl->Wlog, |
210 | ctl->Plog, ctl->Scell_log, |
211 | nla_data(tb[TCA_RED_STAB])); |
212 | |
213 | if (skb_queue_empty(&sch->q)) |
214 | red_end_of_idle_period(&q->parms); |
215 | |
216 | sch_tree_unlock(sch); |
217 | return 0; |
218 | } |
219 | |
220 | static int red_init(struct Qdisc* sch, struct nlattr *opt) |
221 | { |
222 | struct red_sched_data *q = qdisc_priv(sch); |
223 | |
224 | q->qdisc = &noop_qdisc; |
225 | return red_change(sch, opt); |
226 | } |
227 | |
228 | static int red_dump(struct Qdisc *sch, struct sk_buff *skb) |
229 | { |
230 | struct red_sched_data *q = qdisc_priv(sch); |
231 | struct nlattr *opts = NULL; |
232 | struct tc_red_qopt opt = { |
233 | .limit = q->limit, |
234 | .flags = q->flags, |
235 | .qth_min = q->parms.qth_min >> q->parms.Wlog, |
236 | .qth_max = q->parms.qth_max >> q->parms.Wlog, |
237 | .Wlog = q->parms.Wlog, |
238 | .Plog = q->parms.Plog, |
239 | .Scell_log = q->parms.Scell_log, |
240 | }; |
241 | |
242 | opts = nla_nest_start(skb, TCA_OPTIONS); |
243 | if (opts == NULL) |
244 | goto nla_put_failure; |
245 | NLA_PUT(skb, TCA_RED_PARMS, sizeof(opt), &opt); |
246 | return nla_nest_end(skb, opts); |
247 | |
248 | nla_put_failure: |
249 | nla_nest_cancel(skb, opts); |
250 | return -EMSGSIZE; |
251 | } |
252 | |
253 | static int red_dump_stats(struct Qdisc *sch, struct gnet_dump *d) |
254 | { |
255 | struct red_sched_data *q = qdisc_priv(sch); |
256 | struct tc_red_xstats st = { |
257 | .early = q->stats.prob_drop + q->stats.forced_drop, |
258 | .pdrop = q->stats.pdrop, |
259 | .other = q->stats.other, |
260 | .marked = q->stats.prob_mark + q->stats.forced_mark, |
261 | }; |
262 | |
263 | return gnet_stats_copy_app(d, &st, sizeof(st)); |
264 | } |
265 | |
266 | static int red_dump_class(struct Qdisc *sch, unsigned long cl, |
267 | struct sk_buff *skb, struct tcmsg *tcm) |
268 | { |
269 | struct red_sched_data *q = qdisc_priv(sch); |
270 | |
271 | tcm->tcm_handle |= TC_H_MIN(1); |
272 | tcm->tcm_info = q->qdisc->handle; |
273 | return 0; |
274 | } |
275 | |
276 | static int red_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, |
277 | struct Qdisc **old) |
278 | { |
279 | struct red_sched_data *q = qdisc_priv(sch); |
280 | |
281 | if (new == NULL) |
282 | new = &noop_qdisc; |
283 | |
284 | sch_tree_lock(sch); |
285 | *old = q->qdisc; |
286 | q->qdisc = new; |
287 | qdisc_tree_decrease_qlen(*old, (*old)->q.qlen); |
288 | qdisc_reset(*old); |
289 | sch_tree_unlock(sch); |
290 | return 0; |
291 | } |
292 | |
293 | static struct Qdisc *red_leaf(struct Qdisc *sch, unsigned long arg) |
294 | { |
295 | struct red_sched_data *q = qdisc_priv(sch); |
296 | return q->qdisc; |
297 | } |
298 | |
299 | static unsigned long red_get(struct Qdisc *sch, u32 classid) |
300 | { |
301 | return 1; |
302 | } |
303 | |
304 | static void red_put(struct Qdisc *sch, unsigned long arg) |
305 | { |
306 | return; |
307 | } |
308 | |
309 | static void red_walk(struct Qdisc *sch, struct qdisc_walker *walker) |
310 | { |
311 | if (!walker->stop) { |
312 | if (walker->count >= walker->skip) |
313 | if (walker->fn(sch, 1, walker) < 0) { |
314 | walker->stop = 1; |
315 | return; |
316 | } |
317 | walker->count++; |
318 | } |
319 | } |
320 | |
321 | static const struct Qdisc_class_ops red_class_ops = { |
322 | .graft = red_graft, |
323 | .leaf = red_leaf, |
324 | .get = red_get, |
325 | .put = red_put, |
326 | .walk = red_walk, |
327 | .dump = red_dump_class, |
328 | }; |
329 | |
330 | static struct Qdisc_ops red_qdisc_ops __read_mostly = { |
331 | .id = "red", |
332 | .priv_size = sizeof(struct red_sched_data), |
333 | .cl_ops = &red_class_ops, |
334 | .enqueue = red_enqueue, |
335 | .dequeue = red_dequeue, |
336 | .peek = red_peek, |
337 | .drop = red_drop, |
338 | .init = red_init, |
339 | .reset = red_reset, |
340 | .destroy = red_destroy, |
341 | .change = red_change, |
342 | .dump = red_dump, |
343 | .dump_stats = red_dump_stats, |
344 | .owner = THIS_MODULE, |
345 | }; |
346 | |
347 | static int __init red_module_init(void) |
348 | { |
349 | return register_qdisc(&red_qdisc_ops); |
350 | } |
351 | |
352 | static void __exit red_module_exit(void) |
353 | { |
354 | unregister_qdisc(&red_qdisc_ops); |
355 | } |
356 | |
357 | module_init(red_module_init) |
358 | module_exit(red_module_exit) |
359 | |
360 | MODULE_LICENSE("GPL"); |
361 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9