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1 | /* | |
2 | * Fair Queue CoDel discipline | |
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 | * Copyright (C) 2012,2015 Eric Dumazet <edumazet@google.com> | |
10 | */ | |
11 | ||
12 | #include <linux/module.h> | |
13 | #include <linux/types.h> | |
14 | #include <linux/kernel.h> | |
15 | #include <linux/jiffies.h> | |
16 | #include <linux/string.h> | |
17 | #include <linux/in.h> | |
18 | #include <linux/errno.h> | |
19 | #include <linux/init.h> | |
20 | #include <linux/skbuff.h> | |
21 | #include <linux/jhash.h> | |
22 | #include <linux/slab.h> | |
23 | #include <linux/vmalloc.h> | |
24 | #include <net/netlink.h> | |
25 | #include <net/pkt_sched.h> | |
26 | #include <net/pkt_cls.h> | |
27 | #include <net/codel.h> | |
28 | #include <net/codel_impl.h> | |
29 | #include <net/codel_qdisc.h> | |
30 | ||
31 | /* Fair Queue CoDel. | |
32 | * | |
33 | * Principles : | |
34 | * Packets are classified (internal classifier or external) on flows. | |
35 | * This is a Stochastic model (as we use a hash, several flows | |
36 | * might be hashed on same slot) | |
37 | * Each flow has a CoDel managed queue. | |
38 | * Flows are linked onto two (Round Robin) lists, | |
39 | * so that new flows have priority on old ones. | |
40 | * | |
41 | * For a given flow, packets are not reordered (CoDel uses a FIFO) | |
42 | * head drops only. | |
43 | * ECN capability is on by default. | |
44 | * Low memory footprint (64 bytes per flow) | |
45 | */ | |
46 | ||
47 | struct fq_codel_flow { | |
48 | struct sk_buff *head; | |
49 | struct sk_buff *tail; | |
50 | struct list_head flowchain; | |
51 | int deficit; | |
52 | u32 dropped; /* number of drops (or ECN marks) on this flow */ | |
53 | struct codel_vars cvars; | |
54 | }; /* please try to keep this structure <= 64 bytes */ | |
55 | ||
56 | struct fq_codel_sched_data { | |
57 | struct tcf_proto __rcu *filter_list; /* optional external classifier */ | |
58 | struct fq_codel_flow *flows; /* Flows table [flows_cnt] */ | |
59 | u32 *backlogs; /* backlog table [flows_cnt] */ | |
60 | u32 flows_cnt; /* number of flows */ | |
61 | u32 quantum; /* psched_mtu(qdisc_dev(sch)); */ | |
62 | u32 drop_batch_size; | |
63 | u32 memory_limit; | |
64 | struct codel_params cparams; | |
65 | struct codel_stats cstats; | |
66 | u32 memory_usage; | |
67 | u32 drop_overmemory; | |
68 | u32 drop_overlimit; | |
69 | u32 new_flow_count; | |
70 | ||
71 | struct list_head new_flows; /* list of new flows */ | |
72 | struct list_head old_flows; /* list of old flows */ | |
73 | }; | |
74 | ||
75 | static unsigned int fq_codel_hash(const struct fq_codel_sched_data *q, | |
76 | struct sk_buff *skb) | |
77 | { | |
78 | return reciprocal_scale(skb_get_hash(skb), q->flows_cnt); | |
79 | } | |
80 | ||
81 | static unsigned int fq_codel_classify(struct sk_buff *skb, struct Qdisc *sch, | |
82 | int *qerr) | |
83 | { | |
84 | struct fq_codel_sched_data *q = qdisc_priv(sch); | |
85 | struct tcf_proto *filter; | |
86 | struct tcf_result res; | |
87 | int result; | |
88 | ||
89 | if (TC_H_MAJ(skb->priority) == sch->handle && | |
90 | TC_H_MIN(skb->priority) > 0 && | |
91 | TC_H_MIN(skb->priority) <= q->flows_cnt) | |
92 | return TC_H_MIN(skb->priority); | |
93 | ||
94 | filter = rcu_dereference_bh(q->filter_list); | |
95 | if (!filter) | |
96 | return fq_codel_hash(q, skb) + 1; | |
97 | ||
98 | *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; | |
99 | result = tc_classify(skb, filter, &res, false); | |
100 | if (result >= 0) { | |
101 | #ifdef CONFIG_NET_CLS_ACT | |
102 | switch (result) { | |
103 | case TC_ACT_STOLEN: | |
104 | case TC_ACT_QUEUED: | |
105 | *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN; | |
106 | case TC_ACT_SHOT: | |
107 | return 0; | |
108 | } | |
109 | #endif | |
110 | if (TC_H_MIN(res.classid) <= q->flows_cnt) | |
111 | return TC_H_MIN(res.classid); | |
112 | } | |
113 | return 0; | |
114 | } | |
115 | ||
116 | /* helper functions : might be changed when/if skb use a standard list_head */ | |
117 | ||
118 | /* remove one skb from head of slot queue */ | |
119 | static inline struct sk_buff *dequeue_head(struct fq_codel_flow *flow) | |
120 | { | |
121 | struct sk_buff *skb = flow->head; | |
122 | ||
123 | flow->head = skb->next; | |
124 | skb->next = NULL; | |
125 | return skb; | |
126 | } | |
127 | ||
128 | /* add skb to flow queue (tail add) */ | |
129 | static inline void flow_queue_add(struct fq_codel_flow *flow, | |
130 | struct sk_buff *skb) | |
131 | { | |
132 | if (flow->head == NULL) | |
133 | flow->head = skb; | |
134 | else | |
135 | flow->tail->next = skb; | |
136 | flow->tail = skb; | |
137 | skb->next = NULL; | |
138 | } | |
139 | ||
140 | static unsigned int fq_codel_drop(struct Qdisc *sch, unsigned int max_packets, | |
141 | struct sk_buff **to_free) | |
142 | { | |
143 | struct fq_codel_sched_data *q = qdisc_priv(sch); | |
144 | struct sk_buff *skb; | |
145 | unsigned int maxbacklog = 0, idx = 0, i, len; | |
146 | struct fq_codel_flow *flow; | |
147 | unsigned int threshold; | |
148 | unsigned int mem = 0; | |
149 | ||
150 | /* Queue is full! Find the fat flow and drop packet(s) from it. | |
151 | * This might sound expensive, but with 1024 flows, we scan | |
152 | * 4KB of memory, and we dont need to handle a complex tree | |
153 | * in fast path (packet queue/enqueue) with many cache misses. | |
154 | * In stress mode, we'll try to drop 64 packets from the flow, | |
155 | * amortizing this linear lookup to one cache line per drop. | |
156 | */ | |
157 | for (i = 0; i < q->flows_cnt; i++) { | |
158 | if (q->backlogs[i] > maxbacklog) { | |
159 | maxbacklog = q->backlogs[i]; | |
160 | idx = i; | |
161 | } | |
162 | } | |
163 | ||
164 | /* Our goal is to drop half of this fat flow backlog */ | |
165 | threshold = maxbacklog >> 1; | |
166 | ||
167 | flow = &q->flows[idx]; | |
168 | len = 0; | |
169 | i = 0; | |
170 | do { | |
171 | skb = dequeue_head(flow); | |
172 | len += qdisc_pkt_len(skb); | |
173 | mem += get_codel_cb(skb)->mem_usage; | |
174 | __qdisc_drop(skb, to_free); | |
175 | } while (++i < max_packets && len < threshold); | |
176 | ||
177 | flow->dropped += i; | |
178 | q->backlogs[idx] -= len; | |
179 | q->memory_usage -= mem; | |
180 | sch->qstats.drops += i; | |
181 | sch->qstats.backlog -= len; | |
182 | sch->q.qlen -= i; | |
183 | return idx; | |
184 | } | |
185 | ||
186 | static int fq_codel_enqueue(struct sk_buff *skb, struct Qdisc *sch, | |
187 | struct sk_buff **to_free) | |
188 | { | |
189 | struct fq_codel_sched_data *q = qdisc_priv(sch); | |
190 | unsigned int idx, prev_backlog, prev_qlen; | |
191 | struct fq_codel_flow *flow; | |
192 | int uninitialized_var(ret); | |
193 | unsigned int pkt_len; | |
194 | bool memory_limited; | |
195 | ||
196 | idx = fq_codel_classify(skb, sch, &ret); | |
197 | if (idx == 0) { | |
198 | if (ret & __NET_XMIT_BYPASS) | |
199 | qdisc_qstats_drop(sch); | |
200 | __qdisc_drop(skb, to_free); | |
201 | return ret; | |
202 | } | |
203 | idx--; | |
204 | ||
205 | codel_set_enqueue_time(skb); | |
206 | flow = &q->flows[idx]; | |
207 | flow_queue_add(flow, skb); | |
208 | q->backlogs[idx] += qdisc_pkt_len(skb); | |
209 | qdisc_qstats_backlog_inc(sch, skb); | |
210 | ||
211 | if (list_empty(&flow->flowchain)) { | |
212 | list_add_tail(&flow->flowchain, &q->new_flows); | |
213 | q->new_flow_count++; | |
214 | flow->deficit = q->quantum; | |
215 | flow->dropped = 0; | |
216 | } | |
217 | get_codel_cb(skb)->mem_usage = skb->truesize; | |
218 | q->memory_usage += get_codel_cb(skb)->mem_usage; | |
219 | memory_limited = q->memory_usage > q->memory_limit; | |
220 | if (++sch->q.qlen <= sch->limit && !memory_limited) | |
221 | return NET_XMIT_SUCCESS; | |
222 | ||
223 | prev_backlog = sch->qstats.backlog; | |
224 | prev_qlen = sch->q.qlen; | |
225 | ||
226 | /* save this packet length as it might be dropped by fq_codel_drop() */ | |
227 | pkt_len = qdisc_pkt_len(skb); | |
228 | /* fq_codel_drop() is quite expensive, as it performs a linear search | |
229 | * in q->backlogs[] to find a fat flow. | |
230 | * So instead of dropping a single packet, drop half of its backlog | |
231 | * with a 64 packets limit to not add a too big cpu spike here. | |
232 | */ | |
233 | ret = fq_codel_drop(sch, q->drop_batch_size, to_free); | |
234 | ||
235 | prev_qlen -= sch->q.qlen; | |
236 | prev_backlog -= sch->qstats.backlog; | |
237 | q->drop_overlimit += prev_qlen; | |
238 | if (memory_limited) | |
239 | q->drop_overmemory += prev_qlen; | |
240 | ||
241 | /* As we dropped packet(s), better let upper stack know this. | |
242 | * If we dropped a packet for this flow, return NET_XMIT_CN, | |
243 | * but in this case, our parents wont increase their backlogs. | |
244 | */ | |
245 | if (ret == idx) { | |
246 | qdisc_tree_reduce_backlog(sch, prev_qlen - 1, | |
247 | prev_backlog - pkt_len); | |
248 | return NET_XMIT_CN; | |
249 | } | |
250 | qdisc_tree_reduce_backlog(sch, prev_qlen, prev_backlog); | |
251 | return NET_XMIT_SUCCESS; | |
252 | } | |
253 | ||
254 | /* This is the specific function called from codel_dequeue() | |
255 | * to dequeue a packet from queue. Note: backlog is handled in | |
256 | * codel, we dont need to reduce it here. | |
257 | */ | |
258 | static struct sk_buff *dequeue_func(struct codel_vars *vars, void *ctx) | |
259 | { | |
260 | struct Qdisc *sch = ctx; | |
261 | struct fq_codel_sched_data *q = qdisc_priv(sch); | |
262 | struct fq_codel_flow *flow; | |
263 | struct sk_buff *skb = NULL; | |
264 | ||
265 | flow = container_of(vars, struct fq_codel_flow, cvars); | |
266 | if (flow->head) { | |
267 | skb = dequeue_head(flow); | |
268 | q->backlogs[flow - q->flows] -= qdisc_pkt_len(skb); | |
269 | q->memory_usage -= get_codel_cb(skb)->mem_usage; | |
270 | sch->q.qlen--; | |
271 | sch->qstats.backlog -= qdisc_pkt_len(skb); | |
272 | } | |
273 | return skb; | |
274 | } | |
275 | ||
276 | static void drop_func(struct sk_buff *skb, void *ctx) | |
277 | { | |
278 | struct Qdisc *sch = ctx; | |
279 | ||
280 | kfree_skb(skb); | |
281 | qdisc_qstats_drop(sch); | |
282 | } | |
283 | ||
284 | static struct sk_buff *fq_codel_dequeue(struct Qdisc *sch) | |
285 | { | |
286 | struct fq_codel_sched_data *q = qdisc_priv(sch); | |
287 | struct sk_buff *skb; | |
288 | struct fq_codel_flow *flow; | |
289 | struct list_head *head; | |
290 | u32 prev_drop_count, prev_ecn_mark; | |
291 | unsigned int prev_backlog; | |
292 | ||
293 | begin: | |
294 | head = &q->new_flows; | |
295 | if (list_empty(head)) { | |
296 | head = &q->old_flows; | |
297 | if (list_empty(head)) | |
298 | return NULL; | |
299 | } | |
300 | flow = list_first_entry(head, struct fq_codel_flow, flowchain); | |
301 | ||
302 | if (flow->deficit <= 0) { | |
303 | flow->deficit += q->quantum; | |
304 | list_move_tail(&flow->flowchain, &q->old_flows); | |
305 | goto begin; | |
306 | } | |
307 | ||
308 | prev_drop_count = q->cstats.drop_count; | |
309 | prev_ecn_mark = q->cstats.ecn_mark; | |
310 | prev_backlog = sch->qstats.backlog; | |
311 | ||
312 | skb = codel_dequeue(sch, &sch->qstats.backlog, &q->cparams, | |
313 | &flow->cvars, &q->cstats, qdisc_pkt_len, | |
314 | codel_get_enqueue_time, drop_func, dequeue_func); | |
315 | ||
316 | flow->dropped += q->cstats.drop_count - prev_drop_count; | |
317 | flow->dropped += q->cstats.ecn_mark - prev_ecn_mark; | |
318 | ||
319 | if (!skb) { | |
320 | /* force a pass through old_flows to prevent starvation */ | |
321 | if ((head == &q->new_flows) && !list_empty(&q->old_flows)) | |
322 | list_move_tail(&flow->flowchain, &q->old_flows); | |
323 | else | |
324 | list_del_init(&flow->flowchain); | |
325 | goto begin; | |
326 | } | |
327 | qdisc_bstats_update(sch, skb); | |
328 | flow->deficit -= qdisc_pkt_len(skb); | |
329 | /* We cant call qdisc_tree_reduce_backlog() if our qlen is 0, | |
330 | * or HTB crashes. Defer it for next round. | |
331 | */ | |
332 | if (q->cstats.drop_count && sch->q.qlen) { | |
333 | qdisc_tree_reduce_backlog(sch, q->cstats.drop_count, | |
334 | q->cstats.drop_len); | |
335 | q->cstats.drop_count = 0; | |
336 | q->cstats.drop_len = 0; | |
337 | } | |
338 | return skb; | |
339 | } | |
340 | ||
341 | static void fq_codel_flow_purge(struct fq_codel_flow *flow) | |
342 | { | |
343 | rtnl_kfree_skbs(flow->head, flow->tail); | |
344 | flow->head = NULL; | |
345 | } | |
346 | ||
347 | static void fq_codel_reset(struct Qdisc *sch) | |
348 | { | |
349 | struct fq_codel_sched_data *q = qdisc_priv(sch); | |
350 | int i; | |
351 | ||
352 | INIT_LIST_HEAD(&q->new_flows); | |
353 | INIT_LIST_HEAD(&q->old_flows); | |
354 | for (i = 0; i < q->flows_cnt; i++) { | |
355 | struct fq_codel_flow *flow = q->flows + i; | |
356 | ||
357 | fq_codel_flow_purge(flow); | |
358 | INIT_LIST_HEAD(&flow->flowchain); | |
359 | codel_vars_init(&flow->cvars); | |
360 | } | |
361 | memset(q->backlogs, 0, q->flows_cnt * sizeof(u32)); | |
362 | sch->q.qlen = 0; | |
363 | sch->qstats.backlog = 0; | |
364 | q->memory_usage = 0; | |
365 | } | |
366 | ||
367 | static const struct nla_policy fq_codel_policy[TCA_FQ_CODEL_MAX + 1] = { | |
368 | [TCA_FQ_CODEL_TARGET] = { .type = NLA_U32 }, | |
369 | [TCA_FQ_CODEL_LIMIT] = { .type = NLA_U32 }, | |
370 | [TCA_FQ_CODEL_INTERVAL] = { .type = NLA_U32 }, | |
371 | [TCA_FQ_CODEL_ECN] = { .type = NLA_U32 }, | |
372 | [TCA_FQ_CODEL_FLOWS] = { .type = NLA_U32 }, | |
373 | [TCA_FQ_CODEL_QUANTUM] = { .type = NLA_U32 }, | |
374 | [TCA_FQ_CODEL_CE_THRESHOLD] = { .type = NLA_U32 }, | |
375 | [TCA_FQ_CODEL_DROP_BATCH_SIZE] = { .type = NLA_U32 }, | |
376 | [TCA_FQ_CODEL_MEMORY_LIMIT] = { .type = NLA_U32 }, | |
377 | }; | |
378 | ||
379 | static int fq_codel_change(struct Qdisc *sch, struct nlattr *opt) | |
380 | { | |
381 | struct fq_codel_sched_data *q = qdisc_priv(sch); | |
382 | struct nlattr *tb[TCA_FQ_CODEL_MAX + 1]; | |
383 | int err; | |
384 | ||
385 | if (!opt) | |
386 | return -EINVAL; | |
387 | ||
388 | err = nla_parse_nested(tb, TCA_FQ_CODEL_MAX, opt, fq_codel_policy); | |
389 | if (err < 0) | |
390 | return err; | |
391 | if (tb[TCA_FQ_CODEL_FLOWS]) { | |
392 | if (q->flows) | |
393 | return -EINVAL; | |
394 | q->flows_cnt = nla_get_u32(tb[TCA_FQ_CODEL_FLOWS]); | |
395 | if (!q->flows_cnt || | |
396 | q->flows_cnt > 65536) | |
397 | return -EINVAL; | |
398 | } | |
399 | sch_tree_lock(sch); | |
400 | ||
401 | if (tb[TCA_FQ_CODEL_TARGET]) { | |
402 | u64 target = nla_get_u32(tb[TCA_FQ_CODEL_TARGET]); | |
403 | ||
404 | q->cparams.target = (target * NSEC_PER_USEC) >> CODEL_SHIFT; | |
405 | } | |
406 | ||
407 | if (tb[TCA_FQ_CODEL_CE_THRESHOLD]) { | |
408 | u64 val = nla_get_u32(tb[TCA_FQ_CODEL_CE_THRESHOLD]); | |
409 | ||
410 | q->cparams.ce_threshold = (val * NSEC_PER_USEC) >> CODEL_SHIFT; | |
411 | } | |
412 | ||
413 | if (tb[TCA_FQ_CODEL_INTERVAL]) { | |
414 | u64 interval = nla_get_u32(tb[TCA_FQ_CODEL_INTERVAL]); | |
415 | ||
416 | q->cparams.interval = (interval * NSEC_PER_USEC) >> CODEL_SHIFT; | |
417 | } | |
418 | ||
419 | if (tb[TCA_FQ_CODEL_LIMIT]) | |
420 | sch->limit = nla_get_u32(tb[TCA_FQ_CODEL_LIMIT]); | |
421 | ||
422 | if (tb[TCA_FQ_CODEL_ECN]) | |
423 | q->cparams.ecn = !!nla_get_u32(tb[TCA_FQ_CODEL_ECN]); | |
424 | ||
425 | if (tb[TCA_FQ_CODEL_QUANTUM]) | |
426 | q->quantum = max(256U, nla_get_u32(tb[TCA_FQ_CODEL_QUANTUM])); | |
427 | ||
428 | if (tb[TCA_FQ_CODEL_DROP_BATCH_SIZE]) | |
429 | q->drop_batch_size = min(1U, nla_get_u32(tb[TCA_FQ_CODEL_DROP_BATCH_SIZE])); | |
430 | ||
431 | if (tb[TCA_FQ_CODEL_MEMORY_LIMIT]) | |
432 | q->memory_limit = min(1U << 31, nla_get_u32(tb[TCA_FQ_CODEL_MEMORY_LIMIT])); | |
433 | ||
434 | while (sch->q.qlen > sch->limit || | |
435 | q->memory_usage > q->memory_limit) { | |
436 | struct sk_buff *skb = fq_codel_dequeue(sch); | |
437 | ||
438 | q->cstats.drop_len += qdisc_pkt_len(skb); | |
439 | rtnl_kfree_skbs(skb, skb); | |
440 | q->cstats.drop_count++; | |
441 | } | |
442 | qdisc_tree_reduce_backlog(sch, q->cstats.drop_count, q->cstats.drop_len); | |
443 | q->cstats.drop_count = 0; | |
444 | q->cstats.drop_len = 0; | |
445 | ||
446 | sch_tree_unlock(sch); | |
447 | return 0; | |
448 | } | |
449 | ||
450 | static void *fq_codel_zalloc(size_t sz) | |
451 | { | |
452 | void *ptr = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN); | |
453 | ||
454 | if (!ptr) | |
455 | ptr = vzalloc(sz); | |
456 | return ptr; | |
457 | } | |
458 | ||
459 | static void fq_codel_free(void *addr) | |
460 | { | |
461 | kvfree(addr); | |
462 | } | |
463 | ||
464 | static void fq_codel_destroy(struct Qdisc *sch) | |
465 | { | |
466 | struct fq_codel_sched_data *q = qdisc_priv(sch); | |
467 | ||
468 | tcf_destroy_chain(&q->filter_list); | |
469 | fq_codel_free(q->backlogs); | |
470 | fq_codel_free(q->flows); | |
471 | } | |
472 | ||
473 | static int fq_codel_init(struct Qdisc *sch, struct nlattr *opt) | |
474 | { | |
475 | struct fq_codel_sched_data *q = qdisc_priv(sch); | |
476 | int i; | |
477 | ||
478 | sch->limit = 10*1024; | |
479 | q->flows_cnt = 1024; | |
480 | q->memory_limit = 32 << 20; /* 32 MBytes */ | |
481 | q->drop_batch_size = 64; | |
482 | q->quantum = psched_mtu(qdisc_dev(sch)); | |
483 | INIT_LIST_HEAD(&q->new_flows); | |
484 | INIT_LIST_HEAD(&q->old_flows); | |
485 | codel_params_init(&q->cparams); | |
486 | codel_stats_init(&q->cstats); | |
487 | q->cparams.ecn = true; | |
488 | q->cparams.mtu = psched_mtu(qdisc_dev(sch)); | |
489 | ||
490 | if (opt) { | |
491 | int err = fq_codel_change(sch, opt); | |
492 | if (err) | |
493 | return err; | |
494 | } | |
495 | ||
496 | if (!q->flows) { | |
497 | q->flows = fq_codel_zalloc(q->flows_cnt * | |
498 | sizeof(struct fq_codel_flow)); | |
499 | if (!q->flows) | |
500 | return -ENOMEM; | |
501 | q->backlogs = fq_codel_zalloc(q->flows_cnt * sizeof(u32)); | |
502 | if (!q->backlogs) { | |
503 | fq_codel_free(q->flows); | |
504 | return -ENOMEM; | |
505 | } | |
506 | for (i = 0; i < q->flows_cnt; i++) { | |
507 | struct fq_codel_flow *flow = q->flows + i; | |
508 | ||
509 | INIT_LIST_HEAD(&flow->flowchain); | |
510 | codel_vars_init(&flow->cvars); | |
511 | } | |
512 | } | |
513 | if (sch->limit >= 1) | |
514 | sch->flags |= TCQ_F_CAN_BYPASS; | |
515 | else | |
516 | sch->flags &= ~TCQ_F_CAN_BYPASS; | |
517 | return 0; | |
518 | } | |
519 | ||
520 | static int fq_codel_dump(struct Qdisc *sch, struct sk_buff *skb) | |
521 | { | |
522 | struct fq_codel_sched_data *q = qdisc_priv(sch); | |
523 | struct nlattr *opts; | |
524 | ||
525 | opts = nla_nest_start(skb, TCA_OPTIONS); | |
526 | if (opts == NULL) | |
527 | goto nla_put_failure; | |
528 | ||
529 | if (nla_put_u32(skb, TCA_FQ_CODEL_TARGET, | |
530 | codel_time_to_us(q->cparams.target)) || | |
531 | nla_put_u32(skb, TCA_FQ_CODEL_LIMIT, | |
532 | sch->limit) || | |
533 | nla_put_u32(skb, TCA_FQ_CODEL_INTERVAL, | |
534 | codel_time_to_us(q->cparams.interval)) || | |
535 | nla_put_u32(skb, TCA_FQ_CODEL_ECN, | |
536 | q->cparams.ecn) || | |
537 | nla_put_u32(skb, TCA_FQ_CODEL_QUANTUM, | |
538 | q->quantum) || | |
539 | nla_put_u32(skb, TCA_FQ_CODEL_DROP_BATCH_SIZE, | |
540 | q->drop_batch_size) || | |
541 | nla_put_u32(skb, TCA_FQ_CODEL_MEMORY_LIMIT, | |
542 | q->memory_limit) || | |
543 | nla_put_u32(skb, TCA_FQ_CODEL_FLOWS, | |
544 | q->flows_cnt)) | |
545 | goto nla_put_failure; | |
546 | ||
547 | if (q->cparams.ce_threshold != CODEL_DISABLED_THRESHOLD && | |
548 | nla_put_u32(skb, TCA_FQ_CODEL_CE_THRESHOLD, | |
549 | codel_time_to_us(q->cparams.ce_threshold))) | |
550 | goto nla_put_failure; | |
551 | ||
552 | return nla_nest_end(skb, opts); | |
553 | ||
554 | nla_put_failure: | |
555 | return -1; | |
556 | } | |
557 | ||
558 | static int fq_codel_dump_stats(struct Qdisc *sch, struct gnet_dump *d) | |
559 | { | |
560 | struct fq_codel_sched_data *q = qdisc_priv(sch); | |
561 | struct tc_fq_codel_xstats st = { | |
562 | .type = TCA_FQ_CODEL_XSTATS_QDISC, | |
563 | }; | |
564 | struct list_head *pos; | |
565 | ||
566 | st.qdisc_stats.maxpacket = q->cstats.maxpacket; | |
567 | st.qdisc_stats.drop_overlimit = q->drop_overlimit; | |
568 | st.qdisc_stats.ecn_mark = q->cstats.ecn_mark; | |
569 | st.qdisc_stats.new_flow_count = q->new_flow_count; | |
570 | st.qdisc_stats.ce_mark = q->cstats.ce_mark; | |
571 | st.qdisc_stats.memory_usage = q->memory_usage; | |
572 | st.qdisc_stats.drop_overmemory = q->drop_overmemory; | |
573 | ||
574 | sch_tree_lock(sch); | |
575 | list_for_each(pos, &q->new_flows) | |
576 | st.qdisc_stats.new_flows_len++; | |
577 | ||
578 | list_for_each(pos, &q->old_flows) | |
579 | st.qdisc_stats.old_flows_len++; | |
580 | sch_tree_unlock(sch); | |
581 | ||
582 | return gnet_stats_copy_app(d, &st, sizeof(st)); | |
583 | } | |
584 | ||
585 | static struct Qdisc *fq_codel_leaf(struct Qdisc *sch, unsigned long arg) | |
586 | { | |
587 | return NULL; | |
588 | } | |
589 | ||
590 | static unsigned long fq_codel_get(struct Qdisc *sch, u32 classid) | |
591 | { | |
592 | return 0; | |
593 | } | |
594 | ||
595 | static unsigned long fq_codel_bind(struct Qdisc *sch, unsigned long parent, | |
596 | u32 classid) | |
597 | { | |
598 | /* we cannot bypass queue discipline anymore */ | |
599 | sch->flags &= ~TCQ_F_CAN_BYPASS; | |
600 | return 0; | |
601 | } | |
602 | ||
603 | static void fq_codel_put(struct Qdisc *q, unsigned long cl) | |
604 | { | |
605 | } | |
606 | ||
607 | static struct tcf_proto __rcu **fq_codel_find_tcf(struct Qdisc *sch, | |
608 | unsigned long cl) | |
609 | { | |
610 | struct fq_codel_sched_data *q = qdisc_priv(sch); | |
611 | ||
612 | if (cl) | |
613 | return NULL; | |
614 | return &q->filter_list; | |
615 | } | |
616 | ||
617 | static int fq_codel_dump_class(struct Qdisc *sch, unsigned long cl, | |
618 | struct sk_buff *skb, struct tcmsg *tcm) | |
619 | { | |
620 | tcm->tcm_handle |= TC_H_MIN(cl); | |
621 | return 0; | |
622 | } | |
623 | ||
624 | static int fq_codel_dump_class_stats(struct Qdisc *sch, unsigned long cl, | |
625 | struct gnet_dump *d) | |
626 | { | |
627 | struct fq_codel_sched_data *q = qdisc_priv(sch); | |
628 | u32 idx = cl - 1; | |
629 | struct gnet_stats_queue qs = { 0 }; | |
630 | struct tc_fq_codel_xstats xstats; | |
631 | ||
632 | if (idx < q->flows_cnt) { | |
633 | const struct fq_codel_flow *flow = &q->flows[idx]; | |
634 | const struct sk_buff *skb; | |
635 | ||
636 | memset(&xstats, 0, sizeof(xstats)); | |
637 | xstats.type = TCA_FQ_CODEL_XSTATS_CLASS; | |
638 | xstats.class_stats.deficit = flow->deficit; | |
639 | xstats.class_stats.ldelay = | |
640 | codel_time_to_us(flow->cvars.ldelay); | |
641 | xstats.class_stats.count = flow->cvars.count; | |
642 | xstats.class_stats.lastcount = flow->cvars.lastcount; | |
643 | xstats.class_stats.dropping = flow->cvars.dropping; | |
644 | if (flow->cvars.dropping) { | |
645 | codel_tdiff_t delta = flow->cvars.drop_next - | |
646 | codel_get_time(); | |
647 | ||
648 | xstats.class_stats.drop_next = (delta >= 0) ? | |
649 | codel_time_to_us(delta) : | |
650 | -codel_time_to_us(-delta); | |
651 | } | |
652 | if (flow->head) { | |
653 | sch_tree_lock(sch); | |
654 | skb = flow->head; | |
655 | while (skb) { | |
656 | qs.qlen++; | |
657 | skb = skb->next; | |
658 | } | |
659 | sch_tree_unlock(sch); | |
660 | } | |
661 | qs.backlog = q->backlogs[idx]; | |
662 | qs.drops = flow->dropped; | |
663 | } | |
664 | if (gnet_stats_copy_queue(d, NULL, &qs, qs.qlen) < 0) | |
665 | return -1; | |
666 | if (idx < q->flows_cnt) | |
667 | return gnet_stats_copy_app(d, &xstats, sizeof(xstats)); | |
668 | return 0; | |
669 | } | |
670 | ||
671 | static void fq_codel_walk(struct Qdisc *sch, struct qdisc_walker *arg) | |
672 | { | |
673 | struct fq_codel_sched_data *q = qdisc_priv(sch); | |
674 | unsigned int i; | |
675 | ||
676 | if (arg->stop) | |
677 | return; | |
678 | ||
679 | for (i = 0; i < q->flows_cnt; i++) { | |
680 | if (list_empty(&q->flows[i].flowchain) || | |
681 | arg->count < arg->skip) { | |
682 | arg->count++; | |
683 | continue; | |
684 | } | |
685 | if (arg->fn(sch, i + 1, arg) < 0) { | |
686 | arg->stop = 1; | |
687 | break; | |
688 | } | |
689 | arg->count++; | |
690 | } | |
691 | } | |
692 | ||
693 | static const struct Qdisc_class_ops fq_codel_class_ops = { | |
694 | .leaf = fq_codel_leaf, | |
695 | .get = fq_codel_get, | |
696 | .put = fq_codel_put, | |
697 | .tcf_chain = fq_codel_find_tcf, | |
698 | .bind_tcf = fq_codel_bind, | |
699 | .unbind_tcf = fq_codel_put, | |
700 | .dump = fq_codel_dump_class, | |
701 | .dump_stats = fq_codel_dump_class_stats, | |
702 | .walk = fq_codel_walk, | |
703 | }; | |
704 | ||
705 | static struct Qdisc_ops fq_codel_qdisc_ops __read_mostly = { | |
706 | .cl_ops = &fq_codel_class_ops, | |
707 | .id = "fq_codel", | |
708 | .priv_size = sizeof(struct fq_codel_sched_data), | |
709 | .enqueue = fq_codel_enqueue, | |
710 | .dequeue = fq_codel_dequeue, | |
711 | .peek = qdisc_peek_dequeued, | |
712 | .init = fq_codel_init, | |
713 | .reset = fq_codel_reset, | |
714 | .destroy = fq_codel_destroy, | |
715 | .change = fq_codel_change, | |
716 | .dump = fq_codel_dump, | |
717 | .dump_stats = fq_codel_dump_stats, | |
718 | .owner = THIS_MODULE, | |
719 | }; | |
720 | ||
721 | static int __init fq_codel_module_init(void) | |
722 | { | |
723 | return register_qdisc(&fq_codel_qdisc_ops); | |
724 | } | |
725 | ||
726 | static void __exit fq_codel_module_exit(void) | |
727 | { | |
728 | unregister_qdisc(&fq_codel_qdisc_ops); | |
729 | } | |
730 | ||
731 | module_init(fq_codel_module_init) | |
732 | module_exit(fq_codel_module_exit) | |
733 | MODULE_AUTHOR("Eric Dumazet"); | |
734 | MODULE_LICENSE("GPL"); |