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