1 /*-
2 * Copyright (c) 2005 John Bicket
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer,
10 * without modification.
11 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
12 * similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
13 * redistribution must be conditioned upon including a substantially
14 * similar Disclaimer requirement for further binary redistribution.
15 * 3. Neither the names of the above-listed copyright holders nor the names
16 * of any contributors may be used to endorse or promote products derived
17 * from this software without specific prior written permission.
18 *
19 * Alternatively, this software may be distributed under the terms of the
20 * GNU General Public License ("GPL") version 2 as published by the Free
21 * Software Foundation.
22 *
23 * NO WARRANTY
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
25 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
26 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
27 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
28 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
29 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
32 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
34 * THE POSSIBILITY OF SUCH DAMAGES.
35 *
36 */
37
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40
41 /*
42 * John Bicket's SampleRate control algorithm.
43 */
44 #include "opt_ath.h"
45 #include "opt_inet.h"
46 #include "opt_wlan.h"
47 #include "opt_ah.h"
48
49 #include <sys/param.h>
50 #include <sys/systm.h>
51 #include <sys/sysctl.h>
52 #include <sys/kernel.h>
53 #include <sys/lock.h>
54 #include <sys/malloc.h>
55 #include <sys/mutex.h>
56 #include <sys/errno.h>
57
58 #include <machine/bus.h>
59 #include <machine/resource.h>
60 #include <sys/bus.h>
61
62 #include <sys/socket.h>
63
64 #include <net/if.h>
65 #include <net/if_var.h>
66 #include <net/if_media.h>
67 #include <net/if_arp.h>
68 #include <net/ethernet.h> /* XXX for ether_sprintf */
69
70 #include <net80211/ieee80211_var.h>
71
72 #include <net/bpf.h>
73
74 #ifdef INET
75 #include <netinet/in.h>
76 #include <netinet/if_ether.h>
77 #endif
78
79 #include <dev/ath/if_athvar.h>
80 #include <dev/ath/ath_rate/sample/sample.h>
81 #include <dev/ath/ath_hal/ah_desc.h>
82 #include <dev/ath/ath_rate/sample/tx_schedules.h>
83
84 /*
85 * This file is an implementation of the SampleRate algorithm
86 * in "Bit-rate Selection in Wireless Networks"
87 * (http://www.pdos.lcs.mit.edu/papers/jbicket-ms.ps)
88 *
89 * SampleRate chooses the bit-rate it predicts will provide the most
90 * throughput based on estimates of the expected per-packet
91 * transmission time for each bit-rate. SampleRate periodically sends
92 * packets at bit-rates other than the current one to estimate when
93 * another bit-rate will provide better performance. SampleRate
94 * switches to another bit-rate when its estimated per-packet
95 * transmission time becomes smaller than the current bit-rate's.
96 * SampleRate reduces the number of bit-rates it must sample by
97 * eliminating those that could not perform better than the one
98 * currently being used. SampleRate also stops probing at a bit-rate
99 * if it experiences several successive losses.
100 *
101 * The difference between the algorithm in the thesis and the one in this
102 * file is that the one in this file uses a ewma instead of a window.
103 *
104 * Also, this implementation tracks the average transmission time for
105 * a few different packet sizes independently for each link.
106 */
107
108 static void ath_rate_ctl_reset(struct ath_softc *, struct ieee80211_node *);
109
110 static __inline int
size_to_bin(int size)111 size_to_bin(int size)
112 {
113 #if NUM_PACKET_SIZE_BINS > 1
114 if (size <= packet_size_bins[0])
115 return 0;
116 #endif
117 #if NUM_PACKET_SIZE_BINS > 2
118 if (size <= packet_size_bins[1])
119 return 1;
120 #endif
121 #if NUM_PACKET_SIZE_BINS > 3
122 if (size <= packet_size_bins[2])
123 return 2;
124 #endif
125 #if NUM_PACKET_SIZE_BINS > 4
126 #error "add support for more packet sizes"
127 #endif
128 return NUM_PACKET_SIZE_BINS-1;
129 }
130
131 void
ath_rate_node_init(struct ath_softc * sc,struct ath_node * an)132 ath_rate_node_init(struct ath_softc *sc, struct ath_node *an)
133 {
134 /* NB: assumed to be zero'd by caller */
135 }
136
137 void
ath_rate_node_cleanup(struct ath_softc * sc,struct ath_node * an)138 ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an)
139 {
140 }
141
142 static int
dot11rate(const HAL_RATE_TABLE * rt,int rix)143 dot11rate(const HAL_RATE_TABLE *rt, int rix)
144 {
145 if (rix < 0)
146 return -1;
147 return rt->info[rix].phy == IEEE80211_T_HT ?
148 rt->info[rix].dot11Rate : (rt->info[rix].dot11Rate & IEEE80211_RATE_VAL) / 2;
149 }
150
151 static const char *
dot11rate_label(const HAL_RATE_TABLE * rt,int rix)152 dot11rate_label(const HAL_RATE_TABLE *rt, int rix)
153 {
154 if (rix < 0)
155 return "";
156 return rt->info[rix].phy == IEEE80211_T_HT ? "MCS" : "Mb ";
157 }
158
159 /*
160 * Return the rix with the lowest average_tx_time,
161 * or -1 if all the average_tx_times are 0.
162 */
163 static __inline int
pick_best_rate(struct ath_node * an,const HAL_RATE_TABLE * rt,int size_bin,int require_acked_before)164 pick_best_rate(struct ath_node *an, const HAL_RATE_TABLE *rt,
165 int size_bin, int require_acked_before)
166 {
167 struct sample_node *sn = ATH_NODE_SAMPLE(an);
168 int best_rate_rix, best_rate_tt, best_rate_pct;
169 uint64_t mask;
170 int rix, tt, pct;
171
172 best_rate_rix = 0;
173 best_rate_tt = 0;
174 best_rate_pct = 0;
175 for (mask = sn->ratemask, rix = 0; mask != 0; mask >>= 1, rix++) {
176 if ((mask & 1) == 0) /* not a supported rate */
177 continue;
178
179 /* Don't pick a non-HT rate for a HT node */
180 if ((an->an_node.ni_flags & IEEE80211_NODE_HT) &&
181 (rt->info[rix].phy != IEEE80211_T_HT)) {
182 continue;
183 }
184
185 tt = sn->stats[size_bin][rix].average_tx_time;
186 if (tt <= 0 ||
187 (require_acked_before &&
188 !sn->stats[size_bin][rix].packets_acked))
189 continue;
190
191 /* Calculate percentage if possible */
192 if (sn->stats[size_bin][rix].total_packets > 0) {
193 pct = sn->stats[size_bin][rix].ewma_pct;
194 } else {
195 /* XXX for now, assume 95% ok */
196 pct = 95;
197 }
198
199 /* don't use a bit-rate that has been failing */
200 if (sn->stats[size_bin][rix].successive_failures > 3)
201 continue;
202
203 /*
204 * For HT, Don't use a bit rate that is much more
205 * lossy than the best.
206 *
207 * XXX this isn't optimal; it's just designed to
208 * eliminate rates that are going to be obviously
209 * worse.
210 */
211 if (an->an_node.ni_flags & IEEE80211_NODE_HT) {
212 if (best_rate_pct > (pct + 50))
213 continue;
214 }
215
216 /*
217 * For non-MCS rates, use the current average txtime for
218 * comparison.
219 */
220 if (! (an->an_node.ni_flags & IEEE80211_NODE_HT)) {
221 if (best_rate_tt == 0 || tt <= best_rate_tt) {
222 best_rate_tt = tt;
223 best_rate_rix = rix;
224 best_rate_pct = pct;
225 }
226 }
227
228 /*
229 * Since 2 stream rates have slightly higher TX times,
230 * allow a little bit of leeway. This should later
231 * be abstracted out and properly handled.
232 */
233 if (an->an_node.ni_flags & IEEE80211_NODE_HT) {
234 if (best_rate_tt == 0 || (tt * 8 <= best_rate_tt * 10)) {
235 best_rate_tt = tt;
236 best_rate_rix = rix;
237 best_rate_pct = pct;
238 }
239 }
240 }
241 return (best_rate_tt ? best_rate_rix : -1);
242 }
243
244 /*
245 * Pick a good "random" bit-rate to sample other than the current one.
246 */
247 static __inline int
pick_sample_rate(struct sample_softc * ssc,struct ath_node * an,const HAL_RATE_TABLE * rt,int size_bin)248 pick_sample_rate(struct sample_softc *ssc , struct ath_node *an,
249 const HAL_RATE_TABLE *rt, int size_bin)
250 {
251 #define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
252 #define MCS(ix) (rt->info[ix].dot11Rate | IEEE80211_RATE_MCS)
253 struct sample_node *sn = ATH_NODE_SAMPLE(an);
254 int current_rix, rix;
255 unsigned current_tt;
256 uint64_t mask;
257
258 current_rix = sn->current_rix[size_bin];
259 if (current_rix < 0) {
260 /* no successes yet, send at the lowest bit-rate */
261 /* XXX should return MCS0 if HT */
262 return 0;
263 }
264
265 current_tt = sn->stats[size_bin][current_rix].average_tx_time;
266
267 rix = sn->last_sample_rix[size_bin]+1; /* next sample rate */
268 mask = sn->ratemask &~ ((uint64_t) 1<<current_rix);/* don't sample current rate */
269 while (mask != 0) {
270 if ((mask & ((uint64_t) 1<<rix)) == 0) { /* not a supported rate */
271 nextrate:
272 if (++rix >= rt->rateCount)
273 rix = 0;
274 continue;
275 }
276
277 /*
278 * The following code stops trying to sample
279 * non-MCS rates when speaking to an MCS node.
280 * However, at least for CCK rates in 2.4GHz mode,
281 * the non-MCS rates MAY actually provide better
282 * PER at the very far edge of reception.
283 *
284 * However! Until ath_rate_form_aggr() grows
285 * some logic to not form aggregates if the
286 * selected rate is non-MCS, this won't work.
287 *
288 * So don't disable this code until you've taught
289 * ath_rate_form_aggr() to drop out if any of
290 * the selected rates are non-MCS.
291 */
292 #if 1
293 /* if the node is HT and the rate isn't HT, don't bother sample */
294 if ((an->an_node.ni_flags & IEEE80211_NODE_HT) &&
295 (rt->info[rix].phy != IEEE80211_T_HT)) {
296 mask &= ~((uint64_t) 1<<rix);
297 goto nextrate;
298 }
299 #endif
300
301 /* this bit-rate is always worse than the current one */
302 if (sn->stats[size_bin][rix].perfect_tx_time > current_tt) {
303 mask &= ~((uint64_t) 1<<rix);
304 goto nextrate;
305 }
306
307 /* rarely sample bit-rates that fail a lot */
308 if (sn->stats[size_bin][rix].successive_failures > ssc->max_successive_failures &&
309 ticks - sn->stats[size_bin][rix].last_tx < ssc->stale_failure_timeout) {
310 mask &= ~((uint64_t) 1<<rix);
311 goto nextrate;
312 }
313
314 /*
315 * For HT, only sample a few rates on either side of the
316 * current rix; there's quite likely a lot of them.
317 */
318 if (an->an_node.ni_flags & IEEE80211_NODE_HT) {
319 if (rix < (current_rix - 3) ||
320 rix > (current_rix + 3)) {
321 mask &= ~((uint64_t) 1<<rix);
322 goto nextrate;
323 }
324 }
325
326 /* Don't sample more than 2 rates higher for rates > 11M for non-HT rates */
327 if (! (an->an_node.ni_flags & IEEE80211_NODE_HT)) {
328 if (DOT11RATE(rix) > 2*11 && rix > current_rix + 2) {
329 mask &= ~((uint64_t) 1<<rix);
330 goto nextrate;
331 }
332 }
333
334 sn->last_sample_rix[size_bin] = rix;
335 return rix;
336 }
337 return current_rix;
338 #undef DOT11RATE
339 #undef MCS
340 }
341
342 static int
ath_rate_get_static_rix(struct ath_softc * sc,const struct ieee80211_node * ni)343 ath_rate_get_static_rix(struct ath_softc *sc, const struct ieee80211_node *ni)
344 {
345 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
346 #define DOT11RATE(_ix) (rt->info[(_ix)].dot11Rate & IEEE80211_RATE_VAL)
347 #define MCS(_ix) (ni->ni_htrates.rs_rates[_ix] | IEEE80211_RATE_MCS)
348 const struct ieee80211_txparam *tp = ni->ni_txparms;
349 int srate;
350
351 /* Check MCS rates */
352 for (srate = ni->ni_htrates.rs_nrates - 1; srate >= 0; srate--) {
353 if (MCS(srate) == tp->ucastrate)
354 return sc->sc_rixmap[tp->ucastrate];
355 }
356
357 /* Check legacy rates */
358 for (srate = ni->ni_rates.rs_nrates - 1; srate >= 0; srate--) {
359 if (RATE(srate) == tp->ucastrate)
360 return sc->sc_rixmap[tp->ucastrate];
361 }
362 return -1;
363 #undef RATE
364 #undef DOT11RATE
365 #undef MCS
366 }
367
368 static void
ath_rate_update_static_rix(struct ath_softc * sc,struct ieee80211_node * ni)369 ath_rate_update_static_rix(struct ath_softc *sc, struct ieee80211_node *ni)
370 {
371 struct ath_node *an = ATH_NODE(ni);
372 const struct ieee80211_txparam *tp = ni->ni_txparms;
373 struct sample_node *sn = ATH_NODE_SAMPLE(an);
374
375 if (tp != NULL && tp->ucastrate != IEEE80211_FIXED_RATE_NONE) {
376 /*
377 * A fixed rate is to be used; ucastrate is the IEEE code
378 * for this rate (sans basic bit). Check this against the
379 * negotiated rate set for the node. Note the fixed rate
380 * may not be available for various reasons so we only
381 * setup the static rate index if the lookup is successful.
382 */
383 sn->static_rix = ath_rate_get_static_rix(sc, ni);
384 } else {
385 sn->static_rix = -1;
386 }
387 }
388
389 /*
390 * Pick a non-HT rate to begin using.
391 */
392 static int
ath_rate_pick_seed_rate_legacy(struct ath_softc * sc,struct ath_node * an,int frameLen)393 ath_rate_pick_seed_rate_legacy(struct ath_softc *sc, struct ath_node *an,
394 int frameLen)
395 {
396 #define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
397 #define MCS(ix) (rt->info[ix].dot11Rate | IEEE80211_RATE_MCS)
398 #define RATE(ix) (DOT11RATE(ix) / 2)
399 int rix = -1;
400 const HAL_RATE_TABLE *rt = sc->sc_currates;
401 struct sample_node *sn = ATH_NODE_SAMPLE(an);
402 const int size_bin = size_to_bin(frameLen);
403
404 /* no packet has been sent successfully yet */
405 for (rix = rt->rateCount-1; rix > 0; rix--) {
406 if ((sn->ratemask & ((uint64_t) 1<<rix)) == 0)
407 continue;
408
409 /* Skip HT rates */
410 if (rt->info[rix].phy == IEEE80211_T_HT)
411 continue;
412
413 /*
414 * Pick the highest rate <= 36 Mbps
415 * that hasn't failed.
416 */
417 if (DOT11RATE(rix) <= 72 &&
418 sn->stats[size_bin][rix].successive_failures == 0) {
419 break;
420 }
421 }
422 return rix;
423 #undef RATE
424 #undef MCS
425 #undef DOT11RATE
426 }
427
428 /*
429 * Pick a HT rate to begin using.
430 *
431 * Don't use any non-HT rates; only consider HT rates.
432 */
433 static int
ath_rate_pick_seed_rate_ht(struct ath_softc * sc,struct ath_node * an,int frameLen)434 ath_rate_pick_seed_rate_ht(struct ath_softc *sc, struct ath_node *an,
435 int frameLen)
436 {
437 #define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
438 #define MCS(ix) (rt->info[ix].dot11Rate | IEEE80211_RATE_MCS)
439 #define RATE(ix) (DOT11RATE(ix) / 2)
440 int rix = -1, ht_rix = -1;
441 const HAL_RATE_TABLE *rt = sc->sc_currates;
442 struct sample_node *sn = ATH_NODE_SAMPLE(an);
443 const int size_bin = size_to_bin(frameLen);
444
445 /* no packet has been sent successfully yet */
446 for (rix = rt->rateCount-1; rix > 0; rix--) {
447 /* Skip rates we can't use */
448 if ((sn->ratemask & ((uint64_t) 1<<rix)) == 0)
449 continue;
450
451 /* Keep a copy of the last seen HT rate index */
452 if (rt->info[rix].phy == IEEE80211_T_HT)
453 ht_rix = rix;
454
455 /* Skip non-HT rates */
456 if (rt->info[rix].phy != IEEE80211_T_HT)
457 continue;
458
459 /*
460 * Pick a medium-speed rate regardless of stream count
461 * which has not seen any failures. Higher rates may fail;
462 * we'll try them later.
463 */
464 if (((MCS(rix) & 0x7) <= 4) &&
465 sn->stats[size_bin][rix].successive_failures == 0) {
466 break;
467 }
468 }
469
470 /*
471 * If all the MCS rates have successive failures, rix should be
472 * > 0; otherwise use the lowest MCS rix (hopefully MCS 0.)
473 */
474 return MAX(rix, ht_rix);
475 #undef RATE
476 #undef MCS
477 #undef DOT11RATE
478 }
479
480
481 void
ath_rate_findrate(struct ath_softc * sc,struct ath_node * an,int shortPreamble,size_t frameLen,u_int8_t * rix0,int * try0,u_int8_t * txrate)482 ath_rate_findrate(struct ath_softc *sc, struct ath_node *an,
483 int shortPreamble, size_t frameLen,
484 u_int8_t *rix0, int *try0, u_int8_t *txrate)
485 {
486 #define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
487 #define MCS(ix) (rt->info[ix].dot11Rate | IEEE80211_RATE_MCS)
488 #define RATE(ix) (DOT11RATE(ix) / 2)
489 struct sample_node *sn = ATH_NODE_SAMPLE(an);
490 struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc);
491 struct ieee80211com *ic = &sc->sc_ic;
492 const HAL_RATE_TABLE *rt = sc->sc_currates;
493 const int size_bin = size_to_bin(frameLen);
494 int rix, mrr, best_rix, change_rates;
495 unsigned average_tx_time;
496
497 ath_rate_update_static_rix(sc, &an->an_node);
498
499 if (sn->currates != sc->sc_currates) {
500 device_printf(sc->sc_dev, "%s: currates != sc_currates!\n",
501 __func__);
502 rix = 0;
503 *try0 = ATH_TXMAXTRY;
504 goto done;
505 }
506
507 if (sn->static_rix != -1) {
508 rix = sn->static_rix;
509 *try0 = ATH_TXMAXTRY;
510 goto done;
511 }
512
513 mrr = sc->sc_mrretry;
514 /* XXX check HT protmode too */
515 if (mrr && (ic->ic_flags & IEEE80211_F_USEPROT && !sc->sc_mrrprot))
516 mrr = 0;
517
518 best_rix = pick_best_rate(an, rt, size_bin, !mrr);
519 if (best_rix >= 0) {
520 average_tx_time = sn->stats[size_bin][best_rix].average_tx_time;
521 } else {
522 average_tx_time = 0;
523 }
524 /*
525 * Limit the time measuring the performance of other tx
526 * rates to sample_rate% of the total transmission time.
527 */
528 if (sn->sample_tt[size_bin] < average_tx_time * (sn->packets_since_sample[size_bin]*ssc->sample_rate/100)) {
529 rix = pick_sample_rate(ssc, an, rt, size_bin);
530 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
531 &an->an_node, "att %d sample_tt %d size %u sample rate %d %s current rate %d %s",
532 average_tx_time,
533 sn->sample_tt[size_bin],
534 bin_to_size(size_bin),
535 dot11rate(rt, rix),
536 dot11rate_label(rt, rix),
537 dot11rate(rt, sn->current_rix[size_bin]),
538 dot11rate_label(rt, sn->current_rix[size_bin]));
539 if (rix != sn->current_rix[size_bin]) {
540 sn->current_sample_rix[size_bin] = rix;
541 } else {
542 sn->current_sample_rix[size_bin] = -1;
543 }
544 sn->packets_since_sample[size_bin] = 0;
545 } else {
546 change_rates = 0;
547 if (!sn->packets_sent[size_bin] || best_rix == -1) {
548 /* no packet has been sent successfully yet */
549 change_rates = 1;
550 if (an->an_node.ni_flags & IEEE80211_NODE_HT)
551 best_rix =
552 ath_rate_pick_seed_rate_ht(sc, an, frameLen);
553 else
554 best_rix =
555 ath_rate_pick_seed_rate_legacy(sc, an, frameLen);
556 } else if (sn->packets_sent[size_bin] < 20) {
557 /* let the bit-rate switch quickly during the first few packets */
558 IEEE80211_NOTE(an->an_node.ni_vap,
559 IEEE80211_MSG_RATECTL, &an->an_node,
560 "%s: switching quickly..", __func__);
561 change_rates = 1;
562 } else if (ticks - ssc->min_switch > sn->ticks_since_switch[size_bin]) {
563 /* min_switch seconds have gone by */
564 IEEE80211_NOTE(an->an_node.ni_vap,
565 IEEE80211_MSG_RATECTL, &an->an_node,
566 "%s: min_switch %d > ticks_since_switch %d..",
567 __func__, ticks - ssc->min_switch, sn->ticks_since_switch[size_bin]);
568 change_rates = 1;
569 } else if ((! (an->an_node.ni_flags & IEEE80211_NODE_HT)) &&
570 (2*average_tx_time < sn->stats[size_bin][sn->current_rix[size_bin]].average_tx_time)) {
571 /* the current bit-rate is twice as slow as the best one */
572 IEEE80211_NOTE(an->an_node.ni_vap,
573 IEEE80211_MSG_RATECTL, &an->an_node,
574 "%s: 2x att (= %d) < cur_rix att %d",
575 __func__,
576 2 * average_tx_time, sn->stats[size_bin][sn->current_rix[size_bin]].average_tx_time);
577 change_rates = 1;
578 } else if ((an->an_node.ni_flags & IEEE80211_NODE_HT)) {
579 int cur_rix = sn->current_rix[size_bin];
580 int cur_att = sn->stats[size_bin][cur_rix].average_tx_time;
581 /*
582 * If the node is HT, upgrade it if the MCS rate is
583 * higher and the average tx time is within 20% of
584 * the current rate. It can fail a little.
585 *
586 * This is likely not optimal!
587 */
588 #if 0
589 printf("cur rix/att %x/%d, best rix/att %x/%d\n",
590 MCS(cur_rix), cur_att, MCS(best_rix), average_tx_time);
591 #endif
592 if ((MCS(best_rix) > MCS(cur_rix)) &&
593 (average_tx_time * 8) <= (cur_att * 10)) {
594 IEEE80211_NOTE(an->an_node.ni_vap,
595 IEEE80211_MSG_RATECTL, &an->an_node,
596 "%s: HT: best_rix 0x%d > cur_rix 0x%x, average_tx_time %d, cur_att %d",
597 __func__,
598 MCS(best_rix), MCS(cur_rix), average_tx_time, cur_att);
599 change_rates = 1;
600 }
601 }
602
603 sn->packets_since_sample[size_bin]++;
604
605 if (change_rates) {
606 if (best_rix != sn->current_rix[size_bin]) {
607 IEEE80211_NOTE(an->an_node.ni_vap,
608 IEEE80211_MSG_RATECTL,
609 &an->an_node,
610 "%s: size %d switch rate %d (%d/%d) -> %d (%d/%d) after %d packets mrr %d",
611 __func__,
612 bin_to_size(size_bin),
613 RATE(sn->current_rix[size_bin]),
614 sn->stats[size_bin][sn->current_rix[size_bin]].average_tx_time,
615 sn->stats[size_bin][sn->current_rix[size_bin]].perfect_tx_time,
616 RATE(best_rix),
617 sn->stats[size_bin][best_rix].average_tx_time,
618 sn->stats[size_bin][best_rix].perfect_tx_time,
619 sn->packets_since_switch[size_bin],
620 mrr);
621 }
622 sn->packets_since_switch[size_bin] = 0;
623 sn->current_rix[size_bin] = best_rix;
624 sn->ticks_since_switch[size_bin] = ticks;
625 /*
626 * Set the visible txrate for this node.
627 */
628 an->an_node.ni_txrate = (rt->info[best_rix].phy == IEEE80211_T_HT) ? MCS(best_rix) : DOT11RATE(best_rix);
629 }
630 rix = sn->current_rix[size_bin];
631 sn->packets_since_switch[size_bin]++;
632 }
633 *try0 = mrr ? sn->sched[rix].t0 : ATH_TXMAXTRY;
634 done:
635
636 /*
637 * This bug totally sucks and should be fixed.
638 *
639 * For now though, let's not panic, so we can start to figure
640 * out how to better reproduce it.
641 */
642 if (rix < 0 || rix >= rt->rateCount) {
643 printf("%s: ERROR: rix %d out of bounds (rateCount=%d)\n",
644 __func__,
645 rix,
646 rt->rateCount);
647 rix = 0; /* XXX just default for now */
648 }
649 KASSERT(rix >= 0 && rix < rt->rateCount, ("rix is %d", rix));
650
651 *rix0 = rix;
652 *txrate = rt->info[rix].rateCode
653 | (shortPreamble ? rt->info[rix].shortPreamble : 0);
654 sn->packets_sent[size_bin]++;
655 #undef DOT11RATE
656 #undef MCS
657 #undef RATE
658 }
659
660 /*
661 * Get the TX rates. Don't fiddle with short preamble flags for them;
662 * the caller can do that.
663 */
664 void
ath_rate_getxtxrates(struct ath_softc * sc,struct ath_node * an,uint8_t rix0,struct ath_rc_series * rc)665 ath_rate_getxtxrates(struct ath_softc *sc, struct ath_node *an,
666 uint8_t rix0, struct ath_rc_series *rc)
667 {
668 struct sample_node *sn = ATH_NODE_SAMPLE(an);
669 const struct txschedule *sched = &sn->sched[rix0];
670
671 KASSERT(rix0 == sched->r0, ("rix0 (%x) != sched->r0 (%x)!\n",
672 rix0, sched->r0));
673
674 rc[0].flags = rc[1].flags = rc[2].flags = rc[3].flags = 0;
675
676 rc[0].rix = sched->r0;
677 rc[1].rix = sched->r1;
678 rc[2].rix = sched->r2;
679 rc[3].rix = sched->r3;
680
681 rc[0].tries = sched->t0;
682 rc[1].tries = sched->t1;
683 rc[2].tries = sched->t2;
684 rc[3].tries = sched->t3;
685 }
686
687 void
ath_rate_setupxtxdesc(struct ath_softc * sc,struct ath_node * an,struct ath_desc * ds,int shortPreamble,u_int8_t rix)688 ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an,
689 struct ath_desc *ds, int shortPreamble, u_int8_t rix)
690 {
691 struct sample_node *sn = ATH_NODE_SAMPLE(an);
692 const struct txschedule *sched = &sn->sched[rix];
693 const HAL_RATE_TABLE *rt = sc->sc_currates;
694 uint8_t rix1, s1code, rix2, s2code, rix3, s3code;
695
696 /* XXX precalculate short preamble tables */
697 rix1 = sched->r1;
698 s1code = rt->info[rix1].rateCode
699 | (shortPreamble ? rt->info[rix1].shortPreamble : 0);
700 rix2 = sched->r2;
701 s2code = rt->info[rix2].rateCode
702 | (shortPreamble ? rt->info[rix2].shortPreamble : 0);
703 rix3 = sched->r3;
704 s3code = rt->info[rix3].rateCode
705 | (shortPreamble ? rt->info[rix3].shortPreamble : 0);
706 ath_hal_setupxtxdesc(sc->sc_ah, ds,
707 s1code, sched->t1, /* series 1 */
708 s2code, sched->t2, /* series 2 */
709 s3code, sched->t3); /* series 3 */
710 }
711
712 static void
update_stats(struct ath_softc * sc,struct ath_node * an,int frame_size,int rix0,int tries0,int rix1,int tries1,int rix2,int tries2,int rix3,int tries3,int short_tries,int tries,int status,int nframes,int nbad)713 update_stats(struct ath_softc *sc, struct ath_node *an,
714 int frame_size,
715 int rix0, int tries0,
716 int rix1, int tries1,
717 int rix2, int tries2,
718 int rix3, int tries3,
719 int short_tries, int tries, int status,
720 int nframes, int nbad)
721 {
722 struct sample_node *sn = ATH_NODE_SAMPLE(an);
723 struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc);
724 #ifdef IEEE80211_DEBUG
725 const HAL_RATE_TABLE *rt = sc->sc_currates;
726 #endif
727 const int size_bin = size_to_bin(frame_size);
728 const int size = bin_to_size(size_bin);
729 int tt, tries_so_far;
730 int is_ht40 = (an->an_node.ni_chw == 40);
731 int pct;
732
733 if (!IS_RATE_DEFINED(sn, rix0))
734 return;
735 tt = calc_usecs_unicast_packet(sc, size, rix0, short_tries,
736 MIN(tries0, tries) - 1, is_ht40);
737 tries_so_far = tries0;
738
739 if (tries1 && tries_so_far < tries) {
740 if (!IS_RATE_DEFINED(sn, rix1))
741 return;
742 tt += calc_usecs_unicast_packet(sc, size, rix1, short_tries,
743 MIN(tries1 + tries_so_far, tries) - tries_so_far - 1, is_ht40);
744 tries_so_far += tries1;
745 }
746
747 if (tries2 && tries_so_far < tries) {
748 if (!IS_RATE_DEFINED(sn, rix2))
749 return;
750 tt += calc_usecs_unicast_packet(sc, size, rix2, short_tries,
751 MIN(tries2 + tries_so_far, tries) - tries_so_far - 1, is_ht40);
752 tries_so_far += tries2;
753 }
754
755 if (tries3 && tries_so_far < tries) {
756 if (!IS_RATE_DEFINED(sn, rix3))
757 return;
758 tt += calc_usecs_unicast_packet(sc, size, rix3, short_tries,
759 MIN(tries3 + tries_so_far, tries) - tries_so_far - 1, is_ht40);
760 }
761
762 if (sn->stats[size_bin][rix0].total_packets < ssc->smoothing_minpackets) {
763 /* just average the first few packets */
764 int avg_tx = sn->stats[size_bin][rix0].average_tx_time;
765 int packets = sn->stats[size_bin][rix0].total_packets;
766 sn->stats[size_bin][rix0].average_tx_time = (tt+(avg_tx*packets))/(packets+nframes);
767 } else {
768 /* use a ewma */
769 sn->stats[size_bin][rix0].average_tx_time =
770 ((sn->stats[size_bin][rix0].average_tx_time * ssc->smoothing_rate) +
771 (tt * (100 - ssc->smoothing_rate))) / 100;
772 }
773
774 /*
775 * XXX Don't mark the higher bit rates as also having failed; as this
776 * unfortunately stops those rates from being tasted when trying to
777 * TX. This happens with 11n aggregation.
778 */
779 if (nframes == nbad) {
780 #if 0
781 int y;
782 #endif
783 sn->stats[size_bin][rix0].successive_failures += nbad;
784 #if 0
785 for (y = size_bin+1; y < NUM_PACKET_SIZE_BINS; y++) {
786 /*
787 * Also say larger packets failed since we
788 * assume if a small packet fails at a
789 * bit-rate then a larger one will also.
790 */
791 sn->stats[y][rix0].successive_failures += nbad;
792 sn->stats[y][rix0].last_tx = ticks;
793 sn->stats[y][rix0].tries += tries;
794 sn->stats[y][rix0].total_packets += nframes;
795 }
796 #endif
797 } else {
798 sn->stats[size_bin][rix0].packets_acked += (nframes - nbad);
799 sn->stats[size_bin][rix0].successive_failures = 0;
800 }
801 sn->stats[size_bin][rix0].tries += tries;
802 sn->stats[size_bin][rix0].last_tx = ticks;
803 sn->stats[size_bin][rix0].total_packets += nframes;
804
805 /* update EWMA for this rix */
806
807 /* Calculate percentage based on current rate */
808 if (nframes == 0)
809 nframes = nbad = 1;
810 pct = ((nframes - nbad) * 1000) / nframes;
811
812 if (sn->stats[size_bin][rix0].total_packets <
813 ssc->smoothing_minpackets) {
814 /* just average the first few packets */
815 int a_pct = (sn->stats[size_bin][rix0].packets_acked * 1000) /
816 (sn->stats[size_bin][rix0].total_packets);
817 sn->stats[size_bin][rix0].ewma_pct = a_pct;
818 } else {
819 /* use a ewma */
820 sn->stats[size_bin][rix0].ewma_pct =
821 ((sn->stats[size_bin][rix0].ewma_pct * ssc->smoothing_rate) +
822 (pct * (100 - ssc->smoothing_rate))) / 100;
823 }
824
825
826 if (rix0 == sn->current_sample_rix[size_bin]) {
827 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
828 &an->an_node,
829 "%s: size %d %s sample rate %d %s tries (%d/%d) tt %d avg_tt (%d/%d) nfrm %d nbad %d",
830 __func__,
831 size,
832 status ? "FAIL" : "OK",
833 dot11rate(rt, rix0),
834 dot11rate_label(rt, rix0),
835 short_tries, tries, tt,
836 sn->stats[size_bin][rix0].average_tx_time,
837 sn->stats[size_bin][rix0].perfect_tx_time,
838 nframes, nbad);
839 sn->sample_tt[size_bin] = tt;
840 sn->current_sample_rix[size_bin] = -1;
841 }
842 }
843
844 static void
badrate(struct ath_softc * sc,int series,int hwrate,int tries,int status)845 badrate(struct ath_softc *sc, int series, int hwrate, int tries, int status)
846 {
847
848 device_printf(sc->sc_dev,
849 "bad series%d hwrate 0x%x, tries %u ts_status 0x%x\n",
850 series, hwrate, tries, status);
851 }
852
853 void
ath_rate_tx_complete(struct ath_softc * sc,struct ath_node * an,const struct ath_rc_series * rc,const struct ath_tx_status * ts,int frame_size,int nframes,int nbad)854 ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an,
855 const struct ath_rc_series *rc, const struct ath_tx_status *ts,
856 int frame_size, int nframes, int nbad)
857 {
858 struct ieee80211com *ic = &sc->sc_ic;
859 struct sample_node *sn = ATH_NODE_SAMPLE(an);
860 int final_rix, short_tries, long_tries;
861 const HAL_RATE_TABLE *rt = sc->sc_currates;
862 int status = ts->ts_status;
863 int mrr;
864
865 final_rix = rt->rateCodeToIndex[ts->ts_rate];
866 short_tries = ts->ts_shortretry;
867 long_tries = ts->ts_longretry + 1;
868
869 if (nframes == 0) {
870 device_printf(sc->sc_dev, "%s: nframes=0?\n", __func__);
871 return;
872 }
873
874 if (frame_size == 0) /* NB: should not happen */
875 frame_size = 1500;
876
877 if (sn->ratemask == 0) {
878 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
879 &an->an_node,
880 "%s: size %d %s rate/try %d/%d no rates yet",
881 __func__,
882 bin_to_size(size_to_bin(frame_size)),
883 status ? "FAIL" : "OK",
884 short_tries, long_tries);
885 return;
886 }
887 mrr = sc->sc_mrretry;
888 /* XXX check HT protmode too */
889 if (mrr && (ic->ic_flags & IEEE80211_F_USEPROT && !sc->sc_mrrprot))
890 mrr = 0;
891
892 if (!mrr || ts->ts_finaltsi == 0) {
893 if (!IS_RATE_DEFINED(sn, final_rix)) {
894 device_printf(sc->sc_dev,
895 "%s: ts_rate=%d ts_finaltsi=%d, final_rix=%d\n",
896 __func__, ts->ts_rate, ts->ts_finaltsi, final_rix);
897 badrate(sc, 0, ts->ts_rate, long_tries, status);
898 return;
899 }
900 /*
901 * Only one rate was used; optimize work.
902 */
903 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
904 &an->an_node, "%s: size %d (%d bytes) %s rate/short/long %d %s/%d/%d nframes/nbad [%d/%d]",
905 __func__,
906 bin_to_size(size_to_bin(frame_size)),
907 frame_size,
908 status ? "FAIL" : "OK",
909 dot11rate(rt, final_rix), dot11rate_label(rt, final_rix),
910 short_tries, long_tries, nframes, nbad);
911 update_stats(sc, an, frame_size,
912 final_rix, long_tries,
913 0, 0,
914 0, 0,
915 0, 0,
916 short_tries, long_tries, status,
917 nframes, nbad);
918
919 } else {
920 int finalTSIdx = ts->ts_finaltsi;
921 int i;
922
923 /*
924 * Process intermediate rates that failed.
925 */
926
927 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
928 &an->an_node,
929 "%s: size %d (%d bytes) finaltsidx %d short %d long %d %s rate/try [%d %s/%d %d %s/%d %d %s/%d %d %s/%d] nframes/nbad [%d/%d]",
930 __func__,
931 bin_to_size(size_to_bin(frame_size)),
932 frame_size,
933 finalTSIdx,
934 short_tries,
935 long_tries,
936 status ? "FAIL" : "OK",
937 dot11rate(rt, rc[0].rix),
938 dot11rate_label(rt, rc[0].rix), rc[0].tries,
939 dot11rate(rt, rc[1].rix),
940 dot11rate_label(rt, rc[1].rix), rc[1].tries,
941 dot11rate(rt, rc[2].rix),
942 dot11rate_label(rt, rc[2].rix), rc[2].tries,
943 dot11rate(rt, rc[3].rix),
944 dot11rate_label(rt, rc[3].rix), rc[3].tries,
945 nframes, nbad);
946
947 for (i = 0; i < 4; i++) {
948 if (rc[i].tries && !IS_RATE_DEFINED(sn, rc[i].rix))
949 badrate(sc, 0, rc[i].ratecode, rc[i].tries,
950 status);
951 }
952
953 /*
954 * NB: series > 0 are not penalized for failure
955 * based on the try counts under the assumption
956 * that losses are often bursty and since we
957 * sample higher rates 1 try at a time doing so
958 * may unfairly penalize them.
959 */
960 if (rc[0].tries) {
961 update_stats(sc, an, frame_size,
962 rc[0].rix, rc[0].tries,
963 rc[1].rix, rc[1].tries,
964 rc[2].rix, rc[2].tries,
965 rc[3].rix, rc[3].tries,
966 short_tries, long_tries,
967 long_tries > rc[0].tries,
968 nframes, nbad);
969 long_tries -= rc[0].tries;
970 }
971
972 if (rc[1].tries && finalTSIdx > 0) {
973 update_stats(sc, an, frame_size,
974 rc[1].rix, rc[1].tries,
975 rc[2].rix, rc[2].tries,
976 rc[3].rix, rc[3].tries,
977 0, 0,
978 short_tries, long_tries,
979 status,
980 nframes, nbad);
981 long_tries -= rc[1].tries;
982 }
983
984 if (rc[2].tries && finalTSIdx > 1) {
985 update_stats(sc, an, frame_size,
986 rc[2].rix, rc[2].tries,
987 rc[3].rix, rc[3].tries,
988 0, 0,
989 0, 0,
990 short_tries, long_tries,
991 status,
992 nframes, nbad);
993 long_tries -= rc[2].tries;
994 }
995
996 if (rc[3].tries && finalTSIdx > 2) {
997 update_stats(sc, an, frame_size,
998 rc[3].rix, rc[3].tries,
999 0, 0,
1000 0, 0,
1001 0, 0,
1002 short_tries, long_tries,
1003 status,
1004 nframes, nbad);
1005 }
1006 }
1007 }
1008
1009 void
ath_rate_newassoc(struct ath_softc * sc,struct ath_node * an,int isnew)1010 ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew)
1011 {
1012 if (isnew)
1013 ath_rate_ctl_reset(sc, &an->an_node);
1014 }
1015
1016 static const struct txschedule *mrr_schedules[IEEE80211_MODE_MAX+2] = {
1017 NULL, /* IEEE80211_MODE_AUTO */
1018 series_11a, /* IEEE80211_MODE_11A */
1019 series_11g, /* IEEE80211_MODE_11B */
1020 series_11g, /* IEEE80211_MODE_11G */
1021 NULL, /* IEEE80211_MODE_FH */
1022 series_11a, /* IEEE80211_MODE_TURBO_A */
1023 series_11g, /* IEEE80211_MODE_TURBO_G */
1024 series_11a, /* IEEE80211_MODE_STURBO_A */
1025 series_11na, /* IEEE80211_MODE_11NA */
1026 series_11ng, /* IEEE80211_MODE_11NG */
1027 series_half, /* IEEE80211_MODE_HALF */
1028 series_quarter, /* IEEE80211_MODE_QUARTER */
1029 };
1030
1031 /*
1032 * Initialize the tables for a node.
1033 */
1034 static void
ath_rate_ctl_reset(struct ath_softc * sc,struct ieee80211_node * ni)1035 ath_rate_ctl_reset(struct ath_softc *sc, struct ieee80211_node *ni)
1036 {
1037 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
1038 #define DOT11RATE(_ix) (rt->info[(_ix)].dot11Rate & IEEE80211_RATE_VAL)
1039 #define MCS(_ix) (ni->ni_htrates.rs_rates[_ix] | IEEE80211_RATE_MCS)
1040 struct ath_node *an = ATH_NODE(ni);
1041 struct sample_node *sn = ATH_NODE_SAMPLE(an);
1042 const HAL_RATE_TABLE *rt = sc->sc_currates;
1043 int x, y, rix;
1044
1045 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
1046
1047 KASSERT(sc->sc_curmode < IEEE80211_MODE_MAX+2,
1048 ("curmode %u", sc->sc_curmode));
1049
1050 sn->sched = mrr_schedules[sc->sc_curmode];
1051 KASSERT(sn->sched != NULL,
1052 ("no mrr schedule for mode %u", sc->sc_curmode));
1053
1054 sn->static_rix = -1;
1055 ath_rate_update_static_rix(sc, ni);
1056
1057 sn->currates = sc->sc_currates;
1058
1059 /*
1060 * Construct a bitmask of usable rates. This has all
1061 * negotiated rates minus those marked by the hal as
1062 * to be ignored for doing rate control.
1063 */
1064 sn->ratemask = 0;
1065 /* MCS rates */
1066 if (ni->ni_flags & IEEE80211_NODE_HT) {
1067 for (x = 0; x < ni->ni_htrates.rs_nrates; x++) {
1068 rix = sc->sc_rixmap[MCS(x)];
1069 if (rix == 0xff)
1070 continue;
1071 /* skip rates marked broken by hal */
1072 if (!rt->info[rix].valid)
1073 continue;
1074 KASSERT(rix < SAMPLE_MAXRATES,
1075 ("mcs %u has rix %d", MCS(x), rix));
1076 sn->ratemask |= (uint64_t) 1<<rix;
1077 }
1078 }
1079
1080 /* Legacy rates */
1081 for (x = 0; x < ni->ni_rates.rs_nrates; x++) {
1082 rix = sc->sc_rixmap[RATE(x)];
1083 if (rix == 0xff)
1084 continue;
1085 /* skip rates marked broken by hal */
1086 if (!rt->info[rix].valid)
1087 continue;
1088 KASSERT(rix < SAMPLE_MAXRATES,
1089 ("rate %u has rix %d", RATE(x), rix));
1090 sn->ratemask |= (uint64_t) 1<<rix;
1091 }
1092 #ifdef IEEE80211_DEBUG
1093 if (ieee80211_msg(ni->ni_vap, IEEE80211_MSG_RATECTL)) {
1094 uint64_t mask;
1095
1096 ieee80211_note(ni->ni_vap, "[%6D] %s: size 1600 rate/tt",
1097 ni->ni_macaddr, ":", __func__);
1098 for (mask = sn->ratemask, rix = 0; mask != 0; mask >>= 1, rix++) {
1099 if ((mask & 1) == 0)
1100 continue;
1101 printf(" %d %s/%d", dot11rate(rt, rix), dot11rate_label(rt, rix),
1102 calc_usecs_unicast_packet(sc, 1600, rix, 0,0,
1103 (ni->ni_chw == 40)));
1104 }
1105 printf("\n");
1106 }
1107 #endif
1108 for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) {
1109 int size = bin_to_size(y);
1110 uint64_t mask;
1111
1112 sn->packets_sent[y] = 0;
1113 sn->current_sample_rix[y] = -1;
1114 sn->last_sample_rix[y] = 0;
1115 /* XXX start with first valid rate */
1116 sn->current_rix[y] = ffs(sn->ratemask)-1;
1117
1118 /*
1119 * Initialize the statistics buckets; these are
1120 * indexed by the rate code index.
1121 */
1122 for (rix = 0, mask = sn->ratemask; mask != 0; rix++, mask >>= 1) {
1123 if ((mask & 1) == 0) /* not a valid rate */
1124 continue;
1125 sn->stats[y][rix].successive_failures = 0;
1126 sn->stats[y][rix].tries = 0;
1127 sn->stats[y][rix].total_packets = 0;
1128 sn->stats[y][rix].packets_acked = 0;
1129 sn->stats[y][rix].last_tx = 0;
1130 sn->stats[y][rix].ewma_pct = 0;
1131
1132 sn->stats[y][rix].perfect_tx_time =
1133 calc_usecs_unicast_packet(sc, size, rix, 0, 0,
1134 (ni->ni_chw == 40));
1135 sn->stats[y][rix].average_tx_time =
1136 sn->stats[y][rix].perfect_tx_time;
1137 }
1138 }
1139 #if 0
1140 /* XXX 0, num_rates-1 are wrong */
1141 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
1142 "%s: %d rates %d%sMbps (%dus)- %d%sMbps (%dus)", __func__,
1143 sn->num_rates,
1144 DOT11RATE(0)/2, DOT11RATE(0) % 1 ? ".5" : "",
1145 sn->stats[1][0].perfect_tx_time,
1146 DOT11RATE(sn->num_rates-1)/2, DOT11RATE(sn->num_rates-1) % 1 ? ".5" : "",
1147 sn->stats[1][sn->num_rates-1].perfect_tx_time
1148 );
1149 #endif
1150 /* set the visible bit-rate */
1151 if (sn->static_rix != -1)
1152 ni->ni_txrate = DOT11RATE(sn->static_rix);
1153 else
1154 ni->ni_txrate = RATE(0);
1155 #undef RATE
1156 #undef DOT11RATE
1157 }
1158
1159 /*
1160 * Fetch the statistics for the given node.
1161 *
1162 * The ieee80211 node must be referenced and unlocked, however the ath_node
1163 * must be locked.
1164 *
1165 * The main difference here is that we convert the rate indexes
1166 * to 802.11 rates, or the userland output won't make much sense
1167 * as it has no access to the rix table.
1168 */
1169 int
ath_rate_fetch_node_stats(struct ath_softc * sc,struct ath_node * an,struct ath_rateioctl * rs)1170 ath_rate_fetch_node_stats(struct ath_softc *sc, struct ath_node *an,
1171 struct ath_rateioctl *rs)
1172 {
1173 struct sample_node *sn = ATH_NODE_SAMPLE(an);
1174 const HAL_RATE_TABLE *rt = sc->sc_currates;
1175 struct ath_rateioctl_tlv av;
1176 struct ath_rateioctl_rt *tv;
1177 int y;
1178 int o = 0;
1179
1180 ATH_NODE_LOCK_ASSERT(an);
1181
1182 /*
1183 * Ensure there's enough space for the statistics.
1184 */
1185 if (rs->len <
1186 sizeof(struct ath_rateioctl_tlv) +
1187 sizeof(struct ath_rateioctl_rt) +
1188 sizeof(struct ath_rateioctl_tlv) +
1189 sizeof(struct sample_node)) {
1190 device_printf(sc->sc_dev, "%s: len=%d, too short\n",
1191 __func__,
1192 rs->len);
1193 return (EINVAL);
1194 }
1195
1196 /*
1197 * Take a temporary copy of the sample node state so we can
1198 * modify it before we copy it.
1199 */
1200 tv = malloc(sizeof(struct ath_rateioctl_rt), M_TEMP,
1201 M_NOWAIT | M_ZERO);
1202 if (tv == NULL) {
1203 return (ENOMEM);
1204 }
1205
1206 /*
1207 * Populate the rate table mapping TLV.
1208 */
1209 tv->nentries = rt->rateCount;
1210 for (y = 0; y < rt->rateCount; y++) {
1211 tv->ratecode[y] = rt->info[y].dot11Rate & IEEE80211_RATE_VAL;
1212 if (rt->info[y].phy == IEEE80211_T_HT)
1213 tv->ratecode[y] |= IEEE80211_RATE_MCS;
1214 }
1215
1216 o = 0;
1217 /*
1218 * First TLV - rate code mapping
1219 */
1220 av.tlv_id = ATH_RATE_TLV_RATETABLE;
1221 av.tlv_len = sizeof(struct ath_rateioctl_rt);
1222 copyout(&av, rs->buf + o, sizeof(struct ath_rateioctl_tlv));
1223 o += sizeof(struct ath_rateioctl_tlv);
1224 copyout(tv, rs->buf + o, sizeof(struct ath_rateioctl_rt));
1225 o += sizeof(struct ath_rateioctl_rt);
1226
1227 /*
1228 * Second TLV - sample node statistics
1229 */
1230 av.tlv_id = ATH_RATE_TLV_SAMPLENODE;
1231 av.tlv_len = sizeof(struct sample_node);
1232 copyout(&av, rs->buf + o, sizeof(struct ath_rateioctl_tlv));
1233 o += sizeof(struct ath_rateioctl_tlv);
1234
1235 /*
1236 * Copy the statistics over to the provided buffer.
1237 */
1238 copyout(sn, rs->buf + o, sizeof(struct sample_node));
1239 o += sizeof(struct sample_node);
1240
1241 free(tv, M_TEMP);
1242
1243 return (0);
1244 }
1245
1246 static void
sample_stats(void * arg,struct ieee80211_node * ni)1247 sample_stats(void *arg, struct ieee80211_node *ni)
1248 {
1249 struct ath_softc *sc = arg;
1250 const HAL_RATE_TABLE *rt = sc->sc_currates;
1251 struct sample_node *sn = ATH_NODE_SAMPLE(ATH_NODE(ni));
1252 uint64_t mask;
1253 int rix, y;
1254
1255 printf("\n[%s] refcnt %d static_rix (%d %s) ratemask 0x%jx\n",
1256 ether_sprintf(ni->ni_macaddr), ieee80211_node_refcnt(ni),
1257 dot11rate(rt, sn->static_rix),
1258 dot11rate_label(rt, sn->static_rix),
1259 (uintmax_t)sn->ratemask);
1260 for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) {
1261 printf("[%4u] cur rix %d (%d %s) since switch: packets %d ticks %u\n",
1262 bin_to_size(y), sn->current_rix[y],
1263 dot11rate(rt, sn->current_rix[y]),
1264 dot11rate_label(rt, sn->current_rix[y]),
1265 sn->packets_since_switch[y], sn->ticks_since_switch[y]);
1266 printf("[%4u] last sample (%d %s) cur sample (%d %s) packets sent %d\n",
1267 bin_to_size(y),
1268 dot11rate(rt, sn->last_sample_rix[y]),
1269 dot11rate_label(rt, sn->last_sample_rix[y]),
1270 dot11rate(rt, sn->current_sample_rix[y]),
1271 dot11rate_label(rt, sn->current_sample_rix[y]),
1272 sn->packets_sent[y]);
1273 printf("[%4u] packets since sample %d sample tt %u\n",
1274 bin_to_size(y), sn->packets_since_sample[y],
1275 sn->sample_tt[y]);
1276 }
1277 for (mask = sn->ratemask, rix = 0; mask != 0; mask >>= 1, rix++) {
1278 if ((mask & 1) == 0)
1279 continue;
1280 for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) {
1281 if (sn->stats[y][rix].total_packets == 0)
1282 continue;
1283 printf("[%2u %s:%4u] %8ju:%-8ju (%3d%%) (EWMA %3d.%1d%%) T %8ju F %4d avg %5u last %u\n",
1284 dot11rate(rt, rix), dot11rate_label(rt, rix),
1285 bin_to_size(y),
1286 (uintmax_t) sn->stats[y][rix].total_packets,
1287 (uintmax_t) sn->stats[y][rix].packets_acked,
1288 (int) ((sn->stats[y][rix].packets_acked * 100ULL) /
1289 sn->stats[y][rix].total_packets),
1290 sn->stats[y][rix].ewma_pct / 10,
1291 sn->stats[y][rix].ewma_pct % 10,
1292 (uintmax_t) sn->stats[y][rix].tries,
1293 sn->stats[y][rix].successive_failures,
1294 sn->stats[y][rix].average_tx_time,
1295 ticks - sn->stats[y][rix].last_tx);
1296 }
1297 }
1298 }
1299
1300 static int
ath_rate_sysctl_stats(SYSCTL_HANDLER_ARGS)1301 ath_rate_sysctl_stats(SYSCTL_HANDLER_ARGS)
1302 {
1303 struct ath_softc *sc = arg1;
1304 struct ieee80211com *ic = &sc->sc_ic;
1305 int error, v;
1306
1307 v = 0;
1308 error = sysctl_handle_int(oidp, &v, 0, req);
1309 if (error || !req->newptr)
1310 return error;
1311 ieee80211_iterate_nodes(&ic->ic_sta, sample_stats, sc);
1312 return 0;
1313 }
1314
1315 static int
ath_rate_sysctl_smoothing_rate(SYSCTL_HANDLER_ARGS)1316 ath_rate_sysctl_smoothing_rate(SYSCTL_HANDLER_ARGS)
1317 {
1318 struct sample_softc *ssc = arg1;
1319 int rate, error;
1320
1321 rate = ssc->smoothing_rate;
1322 error = sysctl_handle_int(oidp, &rate, 0, req);
1323 if (error || !req->newptr)
1324 return error;
1325 if (!(0 <= rate && rate < 100))
1326 return EINVAL;
1327 ssc->smoothing_rate = rate;
1328 ssc->smoothing_minpackets = 100 / (100 - rate);
1329 return 0;
1330 }
1331
1332 static int
ath_rate_sysctl_sample_rate(SYSCTL_HANDLER_ARGS)1333 ath_rate_sysctl_sample_rate(SYSCTL_HANDLER_ARGS)
1334 {
1335 struct sample_softc *ssc = arg1;
1336 int rate, error;
1337
1338 rate = ssc->sample_rate;
1339 error = sysctl_handle_int(oidp, &rate, 0, req);
1340 if (error || !req->newptr)
1341 return error;
1342 if (!(2 <= rate && rate <= 100))
1343 return EINVAL;
1344 ssc->sample_rate = rate;
1345 return 0;
1346 }
1347
1348 static void
ath_rate_sysctlattach(struct ath_softc * sc,struct sample_softc * ssc)1349 ath_rate_sysctlattach(struct ath_softc *sc, struct sample_softc *ssc)
1350 {
1351 struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev);
1352 struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev);
1353
1354 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
1355 "smoothing_rate", CTLTYPE_INT | CTLFLAG_RW, ssc, 0,
1356 ath_rate_sysctl_smoothing_rate, "I",
1357 "sample: smoothing rate for avg tx time (%%)");
1358 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
1359 "sample_rate", CTLTYPE_INT | CTLFLAG_RW, ssc, 0,
1360 ath_rate_sysctl_sample_rate, "I",
1361 "sample: percent air time devoted to sampling new rates (%%)");
1362 /* XXX max_successive_failures, stale_failure_timeout, min_switch */
1363 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
1364 "sample_stats", CTLTYPE_INT | CTLFLAG_RW, sc, 0,
1365 ath_rate_sysctl_stats, "I", "sample: print statistics");
1366 }
1367
1368 struct ath_ratectrl *
ath_rate_attach(struct ath_softc * sc)1369 ath_rate_attach(struct ath_softc *sc)
1370 {
1371 struct sample_softc *ssc;
1372
1373 ssc = malloc(sizeof(struct sample_softc), M_DEVBUF, M_NOWAIT|M_ZERO);
1374 if (ssc == NULL)
1375 return NULL;
1376 ssc->arc.arc_space = sizeof(struct sample_node);
1377 ssc->smoothing_rate = 75; /* ewma percentage ([0..99]) */
1378 ssc->smoothing_minpackets = 100 / (100 - ssc->smoothing_rate);
1379 ssc->sample_rate = 10; /* %time to try diff tx rates */
1380 ssc->max_successive_failures = 3; /* threshold for rate sampling*/
1381 ssc->stale_failure_timeout = 10 * hz; /* 10 seconds */
1382 ssc->min_switch = hz; /* 1 second */
1383 ath_rate_sysctlattach(sc, ssc);
1384 return &ssc->arc;
1385 }
1386
1387 void
ath_rate_detach(struct ath_ratectrl * arc)1388 ath_rate_detach(struct ath_ratectrl *arc)
1389 {
1390 struct sample_softc *ssc = (struct sample_softc *) arc;
1391
1392 free(ssc, M_DEVBUF);
1393 }
1394