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afe4fd06 ED |
1 | /* |
2 | * net/sched/sch_fq.c Fair Queue Packet Scheduler (per flow pacing) | |
3 | * | |
86b3bfe9 | 4 | * Copyright (C) 2013-2015 Eric Dumazet <edumazet@google.com> |
afe4fd06 ED |
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 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the License, or (at your option) any later version. | |
10 | * | |
05e8bb86 | 11 | * Meant to be mostly used for locally generated traffic : |
afe4fd06 ED |
12 | * Fast classification depends on skb->sk being set before reaching us. |
13 | * If not, (router workload), we use rxhash as fallback, with 32 bits wide hash. | |
14 | * All packets belonging to a socket are considered as a 'flow'. | |
15 | * | |
16 | * Flows are dynamically allocated and stored in a hash table of RB trees | |
17 | * They are also part of one Round Robin 'queues' (new or old flows) | |
18 | * | |
19 | * Burst avoidance (aka pacing) capability : | |
20 | * | |
21 | * Transport (eg TCP) can set in sk->sk_pacing_rate a rate, enqueue a | |
22 | * bunch of packets, and this packet scheduler adds delay between | |
23 | * packets to respect rate limitation. | |
24 | * | |
25 | * enqueue() : | |
26 | * - lookup one RB tree (out of 1024 or more) to find the flow. | |
27 | * If non existent flow, create it, add it to the tree. | |
28 | * Add skb to the per flow list of skb (fifo). | |
29 | * - Use a special fifo for high prio packets | |
30 | * | |
31 | * dequeue() : serves flows in Round Robin | |
32 | * Note : When a flow becomes empty, we do not immediately remove it from | |
33 | * rb trees, for performance reasons (its expected to send additional packets, | |
34 | * or SLAB cache will reuse socket for another flow) | |
35 | */ | |
36 | ||
37 | #include <linux/module.h> | |
38 | #include <linux/types.h> | |
39 | #include <linux/kernel.h> | |
40 | #include <linux/jiffies.h> | |
41 | #include <linux/string.h> | |
42 | #include <linux/in.h> | |
43 | #include <linux/errno.h> | |
44 | #include <linux/init.h> | |
45 | #include <linux/skbuff.h> | |
46 | #include <linux/slab.h> | |
47 | #include <linux/rbtree.h> | |
48 | #include <linux/hash.h> | |
08f89b98 | 49 | #include <linux/prefetch.h> |
c3bd8549 | 50 | #include <linux/vmalloc.h> |
afe4fd06 ED |
51 | #include <net/netlink.h> |
52 | #include <net/pkt_sched.h> | |
53 | #include <net/sock.h> | |
54 | #include <net/tcp_states.h> | |
98781965 | 55 | #include <net/tcp.h> |
afe4fd06 ED |
56 | |
57 | /* | |
58 | * Per flow structure, dynamically allocated | |
59 | */ | |
60 | struct fq_flow { | |
61 | struct sk_buff *head; /* list of skbs for this flow : first skb */ | |
62 | union { | |
63 | struct sk_buff *tail; /* last skb in the list */ | |
64 | unsigned long age; /* jiffies when flow was emptied, for gc */ | |
65 | }; | |
05e8bb86 | 66 | struct rb_node fq_node; /* anchor in fq_root[] trees */ |
afe4fd06 ED |
67 | struct sock *sk; |
68 | int qlen; /* number of packets in flow queue */ | |
69 | int credit; | |
70 | u32 socket_hash; /* sk_hash */ | |
71 | struct fq_flow *next; /* next pointer in RR lists, or &detached */ | |
72 | ||
73 | struct rb_node rate_node; /* anchor in q->delayed tree */ | |
74 | u64 time_next_packet; | |
75 | }; | |
76 | ||
77 | struct fq_flow_head { | |
78 | struct fq_flow *first; | |
79 | struct fq_flow *last; | |
80 | }; | |
81 | ||
82 | struct fq_sched_data { | |
83 | struct fq_flow_head new_flows; | |
84 | ||
85 | struct fq_flow_head old_flows; | |
86 | ||
87 | struct rb_root delayed; /* for rate limited flows */ | |
88 | u64 time_next_delayed_flow; | |
fefa569a | 89 | unsigned long unthrottle_latency_ns; |
afe4fd06 ED |
90 | |
91 | struct fq_flow internal; /* for non classified or high prio packets */ | |
92 | u32 quantum; | |
93 | u32 initial_quantum; | |
f52ed899 | 94 | u32 flow_refill_delay; |
afe4fd06 ED |
95 | u32 flow_max_rate; /* optional max rate per flow */ |
96 | u32 flow_plimit; /* max packets per flow */ | |
06eb395f | 97 | u32 orphan_mask; /* mask for orphaned skb */ |
77879147 | 98 | u32 low_rate_threshold; |
afe4fd06 ED |
99 | struct rb_root *fq_root; |
100 | u8 rate_enable; | |
101 | u8 fq_trees_log; | |
102 | ||
103 | u32 flows; | |
104 | u32 inactive_flows; | |
105 | u32 throttled_flows; | |
106 | ||
107 | u64 stat_gc_flows; | |
108 | u64 stat_internal_packets; | |
109 | u64 stat_tcp_retrans; | |
110 | u64 stat_throttled; | |
111 | u64 stat_flows_plimit; | |
112 | u64 stat_pkts_too_long; | |
113 | u64 stat_allocation_errors; | |
114 | struct qdisc_watchdog watchdog; | |
115 | }; | |
116 | ||
117 | /* special value to mark a detached flow (not on old/new list) */ | |
118 | static struct fq_flow detached, throttled; | |
119 | ||
120 | static void fq_flow_set_detached(struct fq_flow *f) | |
121 | { | |
122 | f->next = &detached; | |
f52ed899 | 123 | f->age = jiffies; |
afe4fd06 ED |
124 | } |
125 | ||
126 | static bool fq_flow_is_detached(const struct fq_flow *f) | |
127 | { | |
128 | return f->next == &detached; | |
129 | } | |
130 | ||
dc099048 ED |
131 | static bool fq_flow_is_throttled(const struct fq_flow *f) |
132 | { | |
133 | return f->next == &throttled; | |
134 | } | |
135 | ||
136 | static void fq_flow_add_tail(struct fq_flow_head *head, struct fq_flow *flow) | |
137 | { | |
138 | if (head->first) | |
139 | head->last->next = flow; | |
140 | else | |
141 | head->first = flow; | |
142 | head->last = flow; | |
143 | flow->next = NULL; | |
144 | } | |
145 | ||
146 | static void fq_flow_unset_throttled(struct fq_sched_data *q, struct fq_flow *f) | |
147 | { | |
148 | rb_erase(&f->rate_node, &q->delayed); | |
149 | q->throttled_flows--; | |
150 | fq_flow_add_tail(&q->old_flows, f); | |
151 | } | |
152 | ||
afe4fd06 ED |
153 | static void fq_flow_set_throttled(struct fq_sched_data *q, struct fq_flow *f) |
154 | { | |
155 | struct rb_node **p = &q->delayed.rb_node, *parent = NULL; | |
156 | ||
157 | while (*p) { | |
158 | struct fq_flow *aux; | |
159 | ||
160 | parent = *p; | |
e124557d | 161 | aux = rb_entry(parent, struct fq_flow, rate_node); |
afe4fd06 ED |
162 | if (f->time_next_packet >= aux->time_next_packet) |
163 | p = &parent->rb_right; | |
164 | else | |
165 | p = &parent->rb_left; | |
166 | } | |
167 | rb_link_node(&f->rate_node, parent, p); | |
168 | rb_insert_color(&f->rate_node, &q->delayed); | |
169 | q->throttled_flows++; | |
170 | q->stat_throttled++; | |
171 | ||
172 | f->next = &throttled; | |
173 | if (q->time_next_delayed_flow > f->time_next_packet) | |
174 | q->time_next_delayed_flow = f->time_next_packet; | |
175 | } | |
176 | ||
177 | ||
178 | static struct kmem_cache *fq_flow_cachep __read_mostly; | |
179 | ||
afe4fd06 ED |
180 | |
181 | /* limit number of collected flows per round */ | |
182 | #define FQ_GC_MAX 8 | |
183 | #define FQ_GC_AGE (3*HZ) | |
184 | ||
185 | static bool fq_gc_candidate(const struct fq_flow *f) | |
186 | { | |
187 | return fq_flow_is_detached(f) && | |
188 | time_after(jiffies, f->age + FQ_GC_AGE); | |
189 | } | |
190 | ||
191 | static void fq_gc(struct fq_sched_data *q, | |
192 | struct rb_root *root, | |
193 | struct sock *sk) | |
194 | { | |
195 | struct fq_flow *f, *tofree[FQ_GC_MAX]; | |
196 | struct rb_node **p, *parent; | |
197 | int fcnt = 0; | |
198 | ||
199 | p = &root->rb_node; | |
200 | parent = NULL; | |
201 | while (*p) { | |
202 | parent = *p; | |
203 | ||
e124557d | 204 | f = rb_entry(parent, struct fq_flow, fq_node); |
afe4fd06 ED |
205 | if (f->sk == sk) |
206 | break; | |
207 | ||
208 | if (fq_gc_candidate(f)) { | |
209 | tofree[fcnt++] = f; | |
210 | if (fcnt == FQ_GC_MAX) | |
211 | break; | |
212 | } | |
213 | ||
214 | if (f->sk > sk) | |
215 | p = &parent->rb_right; | |
216 | else | |
217 | p = &parent->rb_left; | |
218 | } | |
219 | ||
220 | q->flows -= fcnt; | |
221 | q->inactive_flows -= fcnt; | |
222 | q->stat_gc_flows += fcnt; | |
223 | while (fcnt) { | |
224 | struct fq_flow *f = tofree[--fcnt]; | |
225 | ||
226 | rb_erase(&f->fq_node, root); | |
227 | kmem_cache_free(fq_flow_cachep, f); | |
228 | } | |
229 | } | |
230 | ||
afe4fd06 ED |
231 | static struct fq_flow *fq_classify(struct sk_buff *skb, struct fq_sched_data *q) |
232 | { | |
233 | struct rb_node **p, *parent; | |
234 | struct sock *sk = skb->sk; | |
235 | struct rb_root *root; | |
236 | struct fq_flow *f; | |
afe4fd06 ED |
237 | |
238 | /* warning: no starvation prevention... */ | |
2abc2f07 | 239 | if (unlikely((skb->priority & TC_PRIO_MAX) == TC_PRIO_CONTROL)) |
afe4fd06 ED |
240 | return &q->internal; |
241 | ||
ca6fb065 | 242 | /* SYNACK messages are attached to a TCP_NEW_SYN_RECV request socket |
e446f9df | 243 | * or a listener (SYNCOOKIE mode) |
ca6fb065 ED |
244 | * 1) request sockets are not full blown, |
245 | * they do not contain sk_pacing_rate | |
246 | * 2) They are not part of a 'flow' yet | |
247 | * 3) We do not want to rate limit them (eg SYNFLOOD attack), | |
06eb395f | 248 | * especially if the listener set SO_MAX_PACING_RATE |
ca6fb065 | 249 | * 4) We pretend they are orphaned |
06eb395f | 250 | */ |
e446f9df | 251 | if (!sk || sk_listener(sk)) { |
06eb395f ED |
252 | unsigned long hash = skb_get_hash(skb) & q->orphan_mask; |
253 | ||
afe4fd06 ED |
254 | /* By forcing low order bit to 1, we make sure to not |
255 | * collide with a local flow (socket pointers are word aligned) | |
256 | */ | |
06eb395f ED |
257 | sk = (struct sock *)((hash << 1) | 1UL); |
258 | skb_orphan(skb); | |
afe4fd06 ED |
259 | } |
260 | ||
29c58472 | 261 | root = &q->fq_root[hash_ptr(sk, q->fq_trees_log)]; |
afe4fd06 ED |
262 | |
263 | if (q->flows >= (2U << q->fq_trees_log) && | |
264 | q->inactive_flows > q->flows/2) | |
265 | fq_gc(q, root, sk); | |
266 | ||
267 | p = &root->rb_node; | |
268 | parent = NULL; | |
269 | while (*p) { | |
270 | parent = *p; | |
271 | ||
e124557d | 272 | f = rb_entry(parent, struct fq_flow, fq_node); |
afe4fd06 ED |
273 | if (f->sk == sk) { |
274 | /* socket might have been reallocated, so check | |
275 | * if its sk_hash is the same. | |
276 | * It not, we need to refill credit with | |
277 | * initial quantum | |
278 | */ | |
279 | if (unlikely(skb->sk && | |
280 | f->socket_hash != sk->sk_hash)) { | |
281 | f->credit = q->initial_quantum; | |
282 | f->socket_hash = sk->sk_hash; | |
dc099048 ED |
283 | if (fq_flow_is_throttled(f)) |
284 | fq_flow_unset_throttled(q, f); | |
fc59d5bd | 285 | f->time_next_packet = 0ULL; |
afe4fd06 ED |
286 | } |
287 | return f; | |
288 | } | |
289 | if (f->sk > sk) | |
290 | p = &parent->rb_right; | |
291 | else | |
292 | p = &parent->rb_left; | |
293 | } | |
294 | ||
295 | f = kmem_cache_zalloc(fq_flow_cachep, GFP_ATOMIC | __GFP_NOWARN); | |
296 | if (unlikely(!f)) { | |
297 | q->stat_allocation_errors++; | |
298 | return &q->internal; | |
299 | } | |
300 | fq_flow_set_detached(f); | |
301 | f->sk = sk; | |
302 | if (skb->sk) | |
303 | f->socket_hash = sk->sk_hash; | |
304 | f->credit = q->initial_quantum; | |
305 | ||
306 | rb_link_node(&f->fq_node, parent, p); | |
307 | rb_insert_color(&f->fq_node, root); | |
308 | ||
309 | q->flows++; | |
310 | q->inactive_flows++; | |
311 | return f; | |
312 | } | |
313 | ||
314 | ||
315 | /* remove one skb from head of flow queue */ | |
8d34ce10 | 316 | static struct sk_buff *fq_dequeue_head(struct Qdisc *sch, struct fq_flow *flow) |
afe4fd06 ED |
317 | { |
318 | struct sk_buff *skb = flow->head; | |
319 | ||
320 | if (skb) { | |
321 | flow->head = skb->next; | |
322 | skb->next = NULL; | |
323 | flow->qlen--; | |
25331d6c | 324 | qdisc_qstats_backlog_dec(sch, skb); |
8d34ce10 | 325 | sch->q.qlen--; |
afe4fd06 ED |
326 | } |
327 | return skb; | |
328 | } | |
329 | ||
330 | /* We might add in the future detection of retransmits | |
331 | * For the time being, just return false | |
332 | */ | |
333 | static bool skb_is_retransmit(struct sk_buff *skb) | |
334 | { | |
335 | return false; | |
336 | } | |
337 | ||
338 | /* add skb to flow queue | |
339 | * flow queue is a linked list, kind of FIFO, except for TCP retransmits | |
340 | * We special case tcp retransmits to be transmitted before other packets. | |
341 | * We rely on fact that TCP retransmits are unlikely, so we do not waste | |
342 | * a separate queue or a pointer. | |
343 | * head-> [retrans pkt 1] | |
344 | * [retrans pkt 2] | |
345 | * [ normal pkt 1] | |
346 | * [ normal pkt 2] | |
347 | * [ normal pkt 3] | |
348 | * tail-> [ normal pkt 4] | |
349 | */ | |
350 | static void flow_queue_add(struct fq_flow *flow, struct sk_buff *skb) | |
351 | { | |
352 | struct sk_buff *prev, *head = flow->head; | |
353 | ||
354 | skb->next = NULL; | |
355 | if (!head) { | |
356 | flow->head = skb; | |
357 | flow->tail = skb; | |
358 | return; | |
359 | } | |
360 | if (likely(!skb_is_retransmit(skb))) { | |
361 | flow->tail->next = skb; | |
362 | flow->tail = skb; | |
363 | return; | |
364 | } | |
365 | ||
366 | /* This skb is a tcp retransmit, | |
367 | * find the last retrans packet in the queue | |
368 | */ | |
369 | prev = NULL; | |
370 | while (skb_is_retransmit(head)) { | |
371 | prev = head; | |
372 | head = head->next; | |
373 | if (!head) | |
374 | break; | |
375 | } | |
376 | if (!prev) { /* no rtx packet in queue, become the new head */ | |
377 | skb->next = flow->head; | |
378 | flow->head = skb; | |
379 | } else { | |
380 | if (prev == flow->tail) | |
381 | flow->tail = skb; | |
382 | else | |
383 | skb->next = prev->next; | |
384 | prev->next = skb; | |
385 | } | |
386 | } | |
387 | ||
520ac30f ED |
388 | static int fq_enqueue(struct sk_buff *skb, struct Qdisc *sch, |
389 | struct sk_buff **to_free) | |
afe4fd06 ED |
390 | { |
391 | struct fq_sched_data *q = qdisc_priv(sch); | |
392 | struct fq_flow *f; | |
393 | ||
394 | if (unlikely(sch->q.qlen >= sch->limit)) | |
520ac30f | 395 | return qdisc_drop(skb, sch, to_free); |
afe4fd06 ED |
396 | |
397 | f = fq_classify(skb, q); | |
398 | if (unlikely(f->qlen >= q->flow_plimit && f != &q->internal)) { | |
399 | q->stat_flows_plimit++; | |
520ac30f | 400 | return qdisc_drop(skb, sch, to_free); |
afe4fd06 ED |
401 | } |
402 | ||
403 | f->qlen++; | |
afe4fd06 ED |
404 | if (skb_is_retransmit(skb)) |
405 | q->stat_tcp_retrans++; | |
25331d6c | 406 | qdisc_qstats_backlog_inc(sch, skb); |
afe4fd06 | 407 | if (fq_flow_is_detached(f)) { |
218af599 ED |
408 | struct sock *sk = skb->sk; |
409 | ||
afe4fd06 | 410 | fq_flow_add_tail(&q->new_flows, f); |
f52ed899 ED |
411 | if (time_after(jiffies, f->age + q->flow_refill_delay)) |
412 | f->credit = max_t(u32, f->credit, q->quantum); | |
218af599 ED |
413 | if (sk && q->rate_enable) { |
414 | if (unlikely(smp_load_acquire(&sk->sk_pacing_status) != | |
415 | SK_PACING_FQ)) | |
416 | smp_store_release(&sk->sk_pacing_status, | |
417 | SK_PACING_FQ); | |
418 | } | |
afe4fd06 | 419 | q->inactive_flows--; |
afe4fd06 | 420 | } |
f52ed899 ED |
421 | |
422 | /* Note: this overwrites f->age */ | |
423 | flow_queue_add(f, skb); | |
424 | ||
afe4fd06 ED |
425 | if (unlikely(f == &q->internal)) { |
426 | q->stat_internal_packets++; | |
afe4fd06 ED |
427 | } |
428 | sch->q.qlen++; | |
429 | ||
430 | return NET_XMIT_SUCCESS; | |
431 | } | |
432 | ||
433 | static void fq_check_throttled(struct fq_sched_data *q, u64 now) | |
434 | { | |
fefa569a | 435 | unsigned long sample; |
afe4fd06 ED |
436 | struct rb_node *p; |
437 | ||
438 | if (q->time_next_delayed_flow > now) | |
439 | return; | |
440 | ||
fefa569a ED |
441 | /* Update unthrottle latency EWMA. |
442 | * This is cheap and can help diagnosing timer/latency problems. | |
443 | */ | |
444 | sample = (unsigned long)(now - q->time_next_delayed_flow); | |
445 | q->unthrottle_latency_ns -= q->unthrottle_latency_ns >> 3; | |
446 | q->unthrottle_latency_ns += sample >> 3; | |
447 | ||
afe4fd06 ED |
448 | q->time_next_delayed_flow = ~0ULL; |
449 | while ((p = rb_first(&q->delayed)) != NULL) { | |
e124557d | 450 | struct fq_flow *f = rb_entry(p, struct fq_flow, rate_node); |
afe4fd06 ED |
451 | |
452 | if (f->time_next_packet > now) { | |
453 | q->time_next_delayed_flow = f->time_next_packet; | |
454 | break; | |
455 | } | |
dc099048 | 456 | fq_flow_unset_throttled(q, f); |
afe4fd06 ED |
457 | } |
458 | } | |
459 | ||
460 | static struct sk_buff *fq_dequeue(struct Qdisc *sch) | |
461 | { | |
462 | struct fq_sched_data *q = qdisc_priv(sch); | |
d2de875c | 463 | u64 now = ktime_get_ns(); |
afe4fd06 ED |
464 | struct fq_flow_head *head; |
465 | struct sk_buff *skb; | |
466 | struct fq_flow *f; | |
77879147 | 467 | u32 rate, plen; |
afe4fd06 | 468 | |
8d34ce10 | 469 | skb = fq_dequeue_head(sch, &q->internal); |
afe4fd06 ED |
470 | if (skb) |
471 | goto out; | |
472 | fq_check_throttled(q, now); | |
473 | begin: | |
474 | head = &q->new_flows; | |
475 | if (!head->first) { | |
476 | head = &q->old_flows; | |
477 | if (!head->first) { | |
478 | if (q->time_next_delayed_flow != ~0ULL) | |
479 | qdisc_watchdog_schedule_ns(&q->watchdog, | |
45f50bed | 480 | q->time_next_delayed_flow); |
afe4fd06 ED |
481 | return NULL; |
482 | } | |
483 | } | |
484 | f = head->first; | |
485 | ||
486 | if (f->credit <= 0) { | |
487 | f->credit += q->quantum; | |
488 | head->first = f->next; | |
489 | fq_flow_add_tail(&q->old_flows, f); | |
490 | goto begin; | |
491 | } | |
492 | ||
98781965 ED |
493 | skb = f->head; |
494 | if (unlikely(skb && now < f->time_next_packet && | |
495 | !skb_is_tcp_pure_ack(skb))) { | |
afe4fd06 ED |
496 | head->first = f->next; |
497 | fq_flow_set_throttled(q, f); | |
498 | goto begin; | |
499 | } | |
500 | ||
8d34ce10 | 501 | skb = fq_dequeue_head(sch, f); |
afe4fd06 ED |
502 | if (!skb) { |
503 | head->first = f->next; | |
504 | /* force a pass through old_flows to prevent starvation */ | |
505 | if ((head == &q->new_flows) && q->old_flows.first) { | |
506 | fq_flow_add_tail(&q->old_flows, f); | |
507 | } else { | |
508 | fq_flow_set_detached(f); | |
afe4fd06 ED |
509 | q->inactive_flows++; |
510 | } | |
511 | goto begin; | |
512 | } | |
08f89b98 | 513 | prefetch(&skb->end); |
afe4fd06 ED |
514 | f->credit -= qdisc_pkt_len(skb); |
515 | ||
77879147 | 516 | if (!q->rate_enable) |
0eab5eb7 | 517 | goto out; |
afe4fd06 | 518 | |
98781965 ED |
519 | /* Do not pace locally generated ack packets */ |
520 | if (skb_is_tcp_pure_ack(skb)) | |
521 | goto out; | |
522 | ||
7eec4174 | 523 | rate = q->flow_max_rate; |
86b3bfe9 | 524 | if (skb->sk) |
7eec4174 | 525 | rate = min(skb->sk->sk_pacing_rate, rate); |
afe4fd06 | 526 | |
77879147 ED |
527 | if (rate <= q->low_rate_threshold) { |
528 | f->credit = 0; | |
529 | plen = qdisc_pkt_len(skb); | |
530 | } else { | |
531 | plen = max(qdisc_pkt_len(skb), q->quantum); | |
532 | if (f->credit > 0) | |
533 | goto out; | |
534 | } | |
7eec4174 | 535 | if (rate != ~0U) { |
0eab5eb7 ED |
536 | u64 len = (u64)plen * NSEC_PER_SEC; |
537 | ||
7eec4174 ED |
538 | if (likely(rate)) |
539 | do_div(len, rate); | |
0eab5eb7 | 540 | /* Since socket rate can change later, |
ced7a04e ED |
541 | * clamp the delay to 1 second. |
542 | * Really, providers of too big packets should be fixed ! | |
0eab5eb7 | 543 | */ |
ced7a04e ED |
544 | if (unlikely(len > NSEC_PER_SEC)) { |
545 | len = NSEC_PER_SEC; | |
0eab5eb7 | 546 | q->stat_pkts_too_long++; |
afe4fd06 | 547 | } |
fefa569a ED |
548 | /* Account for schedule/timers drifts. |
549 | * f->time_next_packet was set when prior packet was sent, | |
550 | * and current time (@now) can be too late by tens of us. | |
551 | */ | |
552 | if (f->time_next_packet) | |
553 | len -= min(len/2, now - f->time_next_packet); | |
0eab5eb7 | 554 | f->time_next_packet = now + len; |
afe4fd06 ED |
555 | } |
556 | out: | |
afe4fd06 | 557 | qdisc_bstats_update(sch, skb); |
afe4fd06 ED |
558 | return skb; |
559 | } | |
560 | ||
e14ffdfd ED |
561 | static void fq_flow_purge(struct fq_flow *flow) |
562 | { | |
563 | rtnl_kfree_skbs(flow->head, flow->tail); | |
564 | flow->head = NULL; | |
565 | flow->qlen = 0; | |
566 | } | |
567 | ||
afe4fd06 ED |
568 | static void fq_reset(struct Qdisc *sch) |
569 | { | |
8d34ce10 ED |
570 | struct fq_sched_data *q = qdisc_priv(sch); |
571 | struct rb_root *root; | |
8d34ce10 ED |
572 | struct rb_node *p; |
573 | struct fq_flow *f; | |
574 | unsigned int idx; | |
afe4fd06 | 575 | |
e14ffdfd ED |
576 | sch->q.qlen = 0; |
577 | sch->qstats.backlog = 0; | |
578 | ||
579 | fq_flow_purge(&q->internal); | |
8d34ce10 ED |
580 | |
581 | if (!q->fq_root) | |
582 | return; | |
583 | ||
584 | for (idx = 0; idx < (1U << q->fq_trees_log); idx++) { | |
585 | root = &q->fq_root[idx]; | |
586 | while ((p = rb_first(root)) != NULL) { | |
e124557d | 587 | f = rb_entry(p, struct fq_flow, fq_node); |
8d34ce10 ED |
588 | rb_erase(p, root); |
589 | ||
e14ffdfd | 590 | fq_flow_purge(f); |
8d34ce10 ED |
591 | |
592 | kmem_cache_free(fq_flow_cachep, f); | |
593 | } | |
594 | } | |
595 | q->new_flows.first = NULL; | |
596 | q->old_flows.first = NULL; | |
597 | q->delayed = RB_ROOT; | |
598 | q->flows = 0; | |
599 | q->inactive_flows = 0; | |
600 | q->throttled_flows = 0; | |
afe4fd06 ED |
601 | } |
602 | ||
603 | static void fq_rehash(struct fq_sched_data *q, | |
604 | struct rb_root *old_array, u32 old_log, | |
605 | struct rb_root *new_array, u32 new_log) | |
606 | { | |
607 | struct rb_node *op, **np, *parent; | |
608 | struct rb_root *oroot, *nroot; | |
609 | struct fq_flow *of, *nf; | |
610 | int fcnt = 0; | |
611 | u32 idx; | |
612 | ||
613 | for (idx = 0; idx < (1U << old_log); idx++) { | |
614 | oroot = &old_array[idx]; | |
615 | while ((op = rb_first(oroot)) != NULL) { | |
616 | rb_erase(op, oroot); | |
e124557d | 617 | of = rb_entry(op, struct fq_flow, fq_node); |
afe4fd06 ED |
618 | if (fq_gc_candidate(of)) { |
619 | fcnt++; | |
620 | kmem_cache_free(fq_flow_cachep, of); | |
621 | continue; | |
622 | } | |
29c58472 | 623 | nroot = &new_array[hash_ptr(of->sk, new_log)]; |
afe4fd06 ED |
624 | |
625 | np = &nroot->rb_node; | |
626 | parent = NULL; | |
627 | while (*np) { | |
628 | parent = *np; | |
629 | ||
e124557d | 630 | nf = rb_entry(parent, struct fq_flow, fq_node); |
afe4fd06 ED |
631 | BUG_ON(nf->sk == of->sk); |
632 | ||
633 | if (nf->sk > of->sk) | |
634 | np = &parent->rb_right; | |
635 | else | |
636 | np = &parent->rb_left; | |
637 | } | |
638 | ||
639 | rb_link_node(&of->fq_node, parent, np); | |
640 | rb_insert_color(&of->fq_node, nroot); | |
641 | } | |
642 | } | |
643 | q->flows -= fcnt; | |
644 | q->inactive_flows -= fcnt; | |
645 | q->stat_gc_flows += fcnt; | |
646 | } | |
647 | ||
c3bd8549 ED |
648 | static void fq_free(void *addr) |
649 | { | |
4cb28970 | 650 | kvfree(addr); |
c3bd8549 ED |
651 | } |
652 | ||
653 | static int fq_resize(struct Qdisc *sch, u32 log) | |
654 | { | |
655 | struct fq_sched_data *q = qdisc_priv(sch); | |
afe4fd06 | 656 | struct rb_root *array; |
2d8d40af | 657 | void *old_fq_root; |
afe4fd06 ED |
658 | u32 idx; |
659 | ||
660 | if (q->fq_root && log == q->fq_trees_log) | |
661 | return 0; | |
662 | ||
c3bd8549 | 663 | /* If XPS was setup, we can allocate memory on right NUMA node */ |
dcda9b04 | 664 | array = kvmalloc_node(sizeof(struct rb_root) << log, GFP_KERNEL | __GFP_RETRY_MAYFAIL, |
c3bd8549 | 665 | netdev_queue_numa_node_read(sch->dev_queue)); |
afe4fd06 ED |
666 | if (!array) |
667 | return -ENOMEM; | |
668 | ||
669 | for (idx = 0; idx < (1U << log); idx++) | |
670 | array[idx] = RB_ROOT; | |
671 | ||
2d8d40af ED |
672 | sch_tree_lock(sch); |
673 | ||
674 | old_fq_root = q->fq_root; | |
675 | if (old_fq_root) | |
676 | fq_rehash(q, old_fq_root, q->fq_trees_log, array, log); | |
677 | ||
afe4fd06 ED |
678 | q->fq_root = array; |
679 | q->fq_trees_log = log; | |
680 | ||
2d8d40af ED |
681 | sch_tree_unlock(sch); |
682 | ||
683 | fq_free(old_fq_root); | |
684 | ||
afe4fd06 ED |
685 | return 0; |
686 | } | |
687 | ||
688 | static const struct nla_policy fq_policy[TCA_FQ_MAX + 1] = { | |
689 | [TCA_FQ_PLIMIT] = { .type = NLA_U32 }, | |
690 | [TCA_FQ_FLOW_PLIMIT] = { .type = NLA_U32 }, | |
691 | [TCA_FQ_QUANTUM] = { .type = NLA_U32 }, | |
692 | [TCA_FQ_INITIAL_QUANTUM] = { .type = NLA_U32 }, | |
693 | [TCA_FQ_RATE_ENABLE] = { .type = NLA_U32 }, | |
694 | [TCA_FQ_FLOW_DEFAULT_RATE] = { .type = NLA_U32 }, | |
695 | [TCA_FQ_FLOW_MAX_RATE] = { .type = NLA_U32 }, | |
696 | [TCA_FQ_BUCKETS_LOG] = { .type = NLA_U32 }, | |
f52ed899 | 697 | [TCA_FQ_FLOW_REFILL_DELAY] = { .type = NLA_U32 }, |
77879147 | 698 | [TCA_FQ_LOW_RATE_THRESHOLD] = { .type = NLA_U32 }, |
afe4fd06 ED |
699 | }; |
700 | ||
701 | static int fq_change(struct Qdisc *sch, struct nlattr *opt) | |
702 | { | |
703 | struct fq_sched_data *q = qdisc_priv(sch); | |
704 | struct nlattr *tb[TCA_FQ_MAX + 1]; | |
705 | int err, drop_count = 0; | |
2ccccf5f | 706 | unsigned drop_len = 0; |
afe4fd06 ED |
707 | u32 fq_log; |
708 | ||
709 | if (!opt) | |
710 | return -EINVAL; | |
711 | ||
fceb6435 | 712 | err = nla_parse_nested(tb, TCA_FQ_MAX, opt, fq_policy, NULL); |
afe4fd06 ED |
713 | if (err < 0) |
714 | return err; | |
715 | ||
716 | sch_tree_lock(sch); | |
717 | ||
718 | fq_log = q->fq_trees_log; | |
719 | ||
720 | if (tb[TCA_FQ_BUCKETS_LOG]) { | |
721 | u32 nval = nla_get_u32(tb[TCA_FQ_BUCKETS_LOG]); | |
722 | ||
723 | if (nval >= 1 && nval <= ilog2(256*1024)) | |
724 | fq_log = nval; | |
725 | else | |
726 | err = -EINVAL; | |
727 | } | |
728 | if (tb[TCA_FQ_PLIMIT]) | |
729 | sch->limit = nla_get_u32(tb[TCA_FQ_PLIMIT]); | |
730 | ||
731 | if (tb[TCA_FQ_FLOW_PLIMIT]) | |
732 | q->flow_plimit = nla_get_u32(tb[TCA_FQ_FLOW_PLIMIT]); | |
733 | ||
3725a269 KKJ |
734 | if (tb[TCA_FQ_QUANTUM]) { |
735 | u32 quantum = nla_get_u32(tb[TCA_FQ_QUANTUM]); | |
736 | ||
9715a83a | 737 | if (quantum > 0 && quantum <= (1 << 20)) |
3725a269 KKJ |
738 | q->quantum = quantum; |
739 | else | |
740 | err = -EINVAL; | |
741 | } | |
afe4fd06 ED |
742 | |
743 | if (tb[TCA_FQ_INITIAL_QUANTUM]) | |
ede869cd | 744 | q->initial_quantum = nla_get_u32(tb[TCA_FQ_INITIAL_QUANTUM]); |
afe4fd06 ED |
745 | |
746 | if (tb[TCA_FQ_FLOW_DEFAULT_RATE]) | |
65c5189a ED |
747 | pr_warn_ratelimited("sch_fq: defrate %u ignored.\n", |
748 | nla_get_u32(tb[TCA_FQ_FLOW_DEFAULT_RATE])); | |
afe4fd06 ED |
749 | |
750 | if (tb[TCA_FQ_FLOW_MAX_RATE]) | |
751 | q->flow_max_rate = nla_get_u32(tb[TCA_FQ_FLOW_MAX_RATE]); | |
752 | ||
77879147 ED |
753 | if (tb[TCA_FQ_LOW_RATE_THRESHOLD]) |
754 | q->low_rate_threshold = | |
755 | nla_get_u32(tb[TCA_FQ_LOW_RATE_THRESHOLD]); | |
756 | ||
afe4fd06 ED |
757 | if (tb[TCA_FQ_RATE_ENABLE]) { |
758 | u32 enable = nla_get_u32(tb[TCA_FQ_RATE_ENABLE]); | |
759 | ||
760 | if (enable <= 1) | |
761 | q->rate_enable = enable; | |
762 | else | |
763 | err = -EINVAL; | |
764 | } | |
765 | ||
f52ed899 ED |
766 | if (tb[TCA_FQ_FLOW_REFILL_DELAY]) { |
767 | u32 usecs_delay = nla_get_u32(tb[TCA_FQ_FLOW_REFILL_DELAY]) ; | |
768 | ||
769 | q->flow_refill_delay = usecs_to_jiffies(usecs_delay); | |
770 | } | |
771 | ||
06eb395f ED |
772 | if (tb[TCA_FQ_ORPHAN_MASK]) |
773 | q->orphan_mask = nla_get_u32(tb[TCA_FQ_ORPHAN_MASK]); | |
774 | ||
2d8d40af ED |
775 | if (!err) { |
776 | sch_tree_unlock(sch); | |
c3bd8549 | 777 | err = fq_resize(sch, fq_log); |
2d8d40af ED |
778 | sch_tree_lock(sch); |
779 | } | |
afe4fd06 ED |
780 | while (sch->q.qlen > sch->limit) { |
781 | struct sk_buff *skb = fq_dequeue(sch); | |
782 | ||
8d34ce10 ED |
783 | if (!skb) |
784 | break; | |
2ccccf5f | 785 | drop_len += qdisc_pkt_len(skb); |
e14ffdfd | 786 | rtnl_kfree_skbs(skb, skb); |
afe4fd06 ED |
787 | drop_count++; |
788 | } | |
2ccccf5f | 789 | qdisc_tree_reduce_backlog(sch, drop_count, drop_len); |
afe4fd06 ED |
790 | |
791 | sch_tree_unlock(sch); | |
792 | return err; | |
793 | } | |
794 | ||
795 | static void fq_destroy(struct Qdisc *sch) | |
796 | { | |
797 | struct fq_sched_data *q = qdisc_priv(sch); | |
afe4fd06 | 798 | |
8d34ce10 | 799 | fq_reset(sch); |
c3bd8549 | 800 | fq_free(q->fq_root); |
afe4fd06 ED |
801 | qdisc_watchdog_cancel(&q->watchdog); |
802 | } | |
803 | ||
804 | static int fq_init(struct Qdisc *sch, struct nlattr *opt) | |
805 | { | |
806 | struct fq_sched_data *q = qdisc_priv(sch); | |
807 | int err; | |
808 | ||
809 | sch->limit = 10000; | |
810 | q->flow_plimit = 100; | |
811 | q->quantum = 2 * psched_mtu(qdisc_dev(sch)); | |
812 | q->initial_quantum = 10 * psched_mtu(qdisc_dev(sch)); | |
f52ed899 | 813 | q->flow_refill_delay = msecs_to_jiffies(40); |
afe4fd06 | 814 | q->flow_max_rate = ~0U; |
fefa569a | 815 | q->time_next_delayed_flow = ~0ULL; |
afe4fd06 ED |
816 | q->rate_enable = 1; |
817 | q->new_flows.first = NULL; | |
818 | q->old_flows.first = NULL; | |
819 | q->delayed = RB_ROOT; | |
820 | q->fq_root = NULL; | |
821 | q->fq_trees_log = ilog2(1024); | |
06eb395f | 822 | q->orphan_mask = 1024 - 1; |
77879147 | 823 | q->low_rate_threshold = 550000 / 8; |
afe4fd06 ED |
824 | qdisc_watchdog_init(&q->watchdog, sch); |
825 | ||
826 | if (opt) | |
827 | err = fq_change(sch, opt); | |
828 | else | |
c3bd8549 | 829 | err = fq_resize(sch, q->fq_trees_log); |
afe4fd06 ED |
830 | |
831 | return err; | |
832 | } | |
833 | ||
834 | static int fq_dump(struct Qdisc *sch, struct sk_buff *skb) | |
835 | { | |
836 | struct fq_sched_data *q = qdisc_priv(sch); | |
837 | struct nlattr *opts; | |
838 | ||
839 | opts = nla_nest_start(skb, TCA_OPTIONS); | |
840 | if (opts == NULL) | |
841 | goto nla_put_failure; | |
842 | ||
65c5189a ED |
843 | /* TCA_FQ_FLOW_DEFAULT_RATE is not used anymore */ |
844 | ||
afe4fd06 ED |
845 | if (nla_put_u32(skb, TCA_FQ_PLIMIT, sch->limit) || |
846 | nla_put_u32(skb, TCA_FQ_FLOW_PLIMIT, q->flow_plimit) || | |
847 | nla_put_u32(skb, TCA_FQ_QUANTUM, q->quantum) || | |
848 | nla_put_u32(skb, TCA_FQ_INITIAL_QUANTUM, q->initial_quantum) || | |
849 | nla_put_u32(skb, TCA_FQ_RATE_ENABLE, q->rate_enable) || | |
afe4fd06 | 850 | nla_put_u32(skb, TCA_FQ_FLOW_MAX_RATE, q->flow_max_rate) || |
f52ed899 ED |
851 | nla_put_u32(skb, TCA_FQ_FLOW_REFILL_DELAY, |
852 | jiffies_to_usecs(q->flow_refill_delay)) || | |
06eb395f | 853 | nla_put_u32(skb, TCA_FQ_ORPHAN_MASK, q->orphan_mask) || |
77879147 ED |
854 | nla_put_u32(skb, TCA_FQ_LOW_RATE_THRESHOLD, |
855 | q->low_rate_threshold) || | |
afe4fd06 ED |
856 | nla_put_u32(skb, TCA_FQ_BUCKETS_LOG, q->fq_trees_log)) |
857 | goto nla_put_failure; | |
858 | ||
d59b7d80 | 859 | return nla_nest_end(skb, opts); |
afe4fd06 ED |
860 | |
861 | nla_put_failure: | |
862 | return -1; | |
863 | } | |
864 | ||
865 | static int fq_dump_stats(struct Qdisc *sch, struct gnet_dump *d) | |
866 | { | |
867 | struct fq_sched_data *q = qdisc_priv(sch); | |
695b4ec0 ED |
868 | struct tc_fq_qd_stats st; |
869 | ||
870 | sch_tree_lock(sch); | |
871 | ||
872 | st.gc_flows = q->stat_gc_flows; | |
873 | st.highprio_packets = q->stat_internal_packets; | |
874 | st.tcp_retrans = q->stat_tcp_retrans; | |
875 | st.throttled = q->stat_throttled; | |
876 | st.flows_plimit = q->stat_flows_plimit; | |
877 | st.pkts_too_long = q->stat_pkts_too_long; | |
878 | st.allocation_errors = q->stat_allocation_errors; | |
879 | st.time_next_delayed_flow = q->time_next_delayed_flow - ktime_get_ns(); | |
880 | st.flows = q->flows; | |
881 | st.inactive_flows = q->inactive_flows; | |
882 | st.throttled_flows = q->throttled_flows; | |
fefa569a ED |
883 | st.unthrottle_latency_ns = min_t(unsigned long, |
884 | q->unthrottle_latency_ns, ~0U); | |
695b4ec0 | 885 | sch_tree_unlock(sch); |
afe4fd06 ED |
886 | |
887 | return gnet_stats_copy_app(d, &st, sizeof(st)); | |
888 | } | |
889 | ||
890 | static struct Qdisc_ops fq_qdisc_ops __read_mostly = { | |
891 | .id = "fq", | |
892 | .priv_size = sizeof(struct fq_sched_data), | |
893 | ||
894 | .enqueue = fq_enqueue, | |
895 | .dequeue = fq_dequeue, | |
896 | .peek = qdisc_peek_dequeued, | |
897 | .init = fq_init, | |
898 | .reset = fq_reset, | |
899 | .destroy = fq_destroy, | |
900 | .change = fq_change, | |
901 | .dump = fq_dump, | |
902 | .dump_stats = fq_dump_stats, | |
903 | .owner = THIS_MODULE, | |
904 | }; | |
905 | ||
906 | static int __init fq_module_init(void) | |
907 | { | |
908 | int ret; | |
909 | ||
910 | fq_flow_cachep = kmem_cache_create("fq_flow_cache", | |
911 | sizeof(struct fq_flow), | |
912 | 0, 0, NULL); | |
913 | if (!fq_flow_cachep) | |
914 | return -ENOMEM; | |
915 | ||
916 | ret = register_qdisc(&fq_qdisc_ops); | |
917 | if (ret) | |
918 | kmem_cache_destroy(fq_flow_cachep); | |
919 | return ret; | |
920 | } | |
921 | ||
922 | static void __exit fq_module_exit(void) | |
923 | { | |
924 | unregister_qdisc(&fq_qdisc_ops); | |
925 | kmem_cache_destroy(fq_flow_cachep); | |
926 | } | |
927 | ||
928 | module_init(fq_module_init) | |
929 | module_exit(fq_module_exit) | |
930 | MODULE_AUTHOR("Eric Dumazet"); | |
931 | MODULE_LICENSE("GPL"); |