1 /* $NetBSD: athrate-sample.c,v 1.21 2021/08/09 21:20:50 andvar Exp $ */
2
3 /*-
4 * Copyright (c) 2005 John Bicket
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer,
12 * without modification.
13 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
14 * similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
15 * redistribution must be conditioned upon including a substantially
16 * similar Disclaimer requirement for further binary redistribution.
17 * 3. Neither the names of the above-listed copyright holders nor the names
18 * of any contributors may be used to endorse or promote products derived
19 * from this software without specific prior written permission.
20 *
21 * Alternatively, this software may be distributed under the terms of the
22 * GNU General Public License ("GPL") version 2 as published by the Free
23 * Software Foundation.
24 *
25 * NO WARRANTY
26 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
28 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
29 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
30 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
31 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
34 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
36 * THE POSSIBILITY OF SUCH DAMAGES.
37 */
38
39 #include <sys/cdefs.h>
40 #ifdef __FreeBSD__
41 __FBSDID("$FreeBSD: src/sys/dev/ath/ath_rate/sample/sample.c,v 1.9 2005/07/22 16:50:17 sam Exp $");
42 #endif
43 #ifdef __NetBSD__
44 __KERNEL_RCSID(0, "$NetBSD: athrate-sample.c,v 1.21 2021/08/09 21:20:50 andvar Exp $");
45 #endif
46
47
48 /*
49 * John Bicket's SampleRate control algorithm.
50 */
51 #ifdef _KERNEL_OPT
52 #include "opt_inet.h"
53 #endif
54
55 #include <sys/param.h>
56 #include <sys/systm.h>
57 #include <sys/sysctl.h>
58 #include <sys/kernel.h>
59 #include <sys/errno.h>
60 #include <sys/device.h>
61
62 #include <sys/bus.h>
63
64 #include <sys/socket.h>
65
66 #include <net/if.h>
67 #include <net/if_media.h>
68 #include <net/if_arp.h>
69 #include <net/if_ether.h> /* XXX for ether_sprintf */
70
71 #include <net80211/ieee80211_var.h>
72
73 #include <net/bpf.h>
74
75 #ifdef INET
76 #include <netinet/in.h>
77 #endif
78
79 #include "ah_desc.h"
80 #include <dev/ic/athvar.h>
81 #include <dev/ic/athrate-sample.h>
82
83 #define SAMPLE_DEBUG
84 #ifdef SAMPLE_DEBUG
85 enum {
86 ATH_DEBUG_RATE = 0x00000010 /* rate control */
87 };
88 #define DPRINTF(sc, _fmt, ...) do { \
89 if (sc->sc_debug & ATH_DEBUG_RATE) \
90 printf(_fmt, __VA_ARGS__); \
91 } while (0)
92 #else
93 #define DPRINTF(sc, _fmt, ...)
94 #endif
95
96 /*
97 * This file is an implementation of the SampleRate algorithm
98 * in "Bit-rate Selection in Wireless Networks"
99 * (http://www.pdos.lcs.mit.edu/papers/jbicket-ms.ps)
100 *
101 * SampleRate chooses the bit-rate it predicts will provide the most
102 * throughput based on estimates of the expected per-packet
103 * transmission time for each bit-rate. SampleRate periodically sends
104 * packets at bit-rates other than the current one to estimate when
105 * another bit-rate will provide better performance. SampleRate
106 * switches to another bit-rate when its estimated per-packet
107 * transmission time becomes smaller than the current bit-rate's.
108 * SampleRate reduces the number of bit-rates it must sample by
109 * eliminating those that could not perform better than the one
110 * currently being used. SampleRate also stops probing at a bit-rate
111 * if it experiences several successive losses.
112 *
113 * The difference between the algorithm in the thesis and the one in this
114 * file is that the one in this file uses a ewma instead of a window.
115 *
116 * Also, this implementation tracks the average transmission time for
117 * a few different packet sizes independently for each link.
118 */
119
120 #define STALE_FAILURE_TIMEOUT_MS 10000
121 #define MIN_SWITCH_MS 1000
122
123 static void ath_rate_ctl_reset(struct ath_softc *, struct ieee80211_node *);
124
125 static inline int
size_to_bin(int size)126 size_to_bin(int size)
127 {
128 int x = 0;
129 for (x = 0; x < NUM_PACKET_SIZE_BINS; x++) {
130 if (size <= packet_size_bins[x]) {
131 return x;
132 }
133 }
134 return NUM_PACKET_SIZE_BINS-1;
135 }
bin_to_size(int index)136 static inline int bin_to_size(int index) {
137 return packet_size_bins[index];
138 }
139
140 static inline int
rate_to_ndx(struct sample_node * sn,int rate)141 rate_to_ndx(struct sample_node *sn, int rate) {
142 int x = 0;
143 for (x = 0; x < sn->num_rates; x++) {
144 if (sn->rates[x].rate == rate) {
145 return x;
146 }
147 }
148 return -1;
149 }
150
151 void
ath_rate_node_init(struct ath_softc * sc,struct ath_node * an)152 ath_rate_node_init(struct ath_softc *sc, struct ath_node *an)
153 {
154 DPRINTF(sc, "%s:\n", __func__);
155 /* NB: assumed to be zero'd by caller */
156 }
157
158 void
ath_rate_node_cleanup(struct ath_softc * sc,struct ath_node * an)159 ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an)
160 {
161 DPRINTF(sc, "%s:\n", __func__);
162 }
163
164
165 /*
166 * returns the ndx with the lowest average_tx_time,
167 * or -1 if all the average_tx_times are 0.
168 */
best_rate_ndx(struct sample_node * sn,int size_bin,int require_acked_before)169 static inline int best_rate_ndx(struct sample_node *sn, int size_bin,
170 int require_acked_before)
171 {
172 int x = 0;
173 int best_ndx = 0;
174 int best_rate_tt = 0;
175 for (x = 0; x < sn->num_rates; x++) {
176 int tt = sn->stats[size_bin][x].average_tx_time;
177 if (tt <= 0 || (require_acked_before &&
178 !sn->stats[size_bin][x].packets_acked)) {
179 continue;
180 }
181
182 /* 9 megabits never works better than 12 */
183 if (sn->rates[x].rate == 18)
184 continue;
185
186 /* don't use a bit-rate that has been failing */
187 if (sn->stats[size_bin][x].successive_failures > 3)
188 continue;
189
190 if (!best_rate_tt || best_rate_tt > tt) {
191 best_rate_tt = tt;
192 best_ndx = x;
193 }
194 }
195 return (best_rate_tt) ? best_ndx : -1;
196 }
197
198 /*
199 * pick a good "random" bit-rate to sample other than the current one
200 */
201 static inline int
pick_sample_ndx(struct sample_node * sn,int size_bin)202 pick_sample_ndx(struct sample_node *sn, int size_bin)
203 {
204 int x = 0;
205 int current_ndx = 0;
206 unsigned current_tt = 0;
207
208 current_ndx = sn->current_rate[size_bin];
209 if (current_ndx < 0) {
210 /* no successes yet, send at the lowest bit-rate */
211 return 0;
212 }
213
214 current_tt = sn->stats[size_bin][current_ndx].average_tx_time;
215
216 for (x = 0; x < sn->num_rates; x++) {
217 int ndx = (sn->last_sample_ndx[size_bin]+1+x) % sn->num_rates;
218
219 /* don't sample the current bit-rate */
220 if (ndx == current_ndx)
221 continue;
222
223 /* this bit-rate is always worse than the current one */
224 if (sn->stats[size_bin][ndx].perfect_tx_time > current_tt)
225 continue;
226
227 /* rarely sample bit-rates that fail a lot */
228 if (ticks - sn->stats[size_bin][ndx].last_tx < ((hz * STALE_FAILURE_TIMEOUT_MS)/1000) &&
229 sn->stats[size_bin][ndx].successive_failures > 3)
230 continue;
231
232 /* don't sample more than 2 indexes higher
233 * for rates higher than 11 megabits
234 */
235 if (sn->rates[ndx].rate > 22 && ndx > current_ndx + 2)
236 continue;
237
238 /* 9 megabits never works better than 12 */
239 if (sn->rates[ndx].rate == 18)
240 continue;
241
242 /* if we're using 11 megabits, only sample up to 12 megabits
243 */
244 if (sn->rates[current_ndx].rate == 22 && ndx > current_ndx + 1)
245 continue;
246
247 sn->last_sample_ndx[size_bin] = ndx;
248 return ndx;
249 }
250 return current_ndx;
251 }
252
253 void
ath_rate_findrate(struct ath_softc * sc,struct ath_node * an,int shortPreamble,size_t frameLen,u_int8_t * rix,int * try0,u_int8_t * txrate)254 ath_rate_findrate(struct ath_softc *sc, struct ath_node *an,
255 int shortPreamble, size_t frameLen,
256 u_int8_t *rix, int *try0, u_int8_t *txrate)
257 {
258 struct sample_node *sn = ATH_NODE_SAMPLE(an);
259 struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc);
260 struct ieee80211com *ic = &sc->sc_ic;
261 int ndx, size_bin, mrr, best_ndx, change_rates;
262 unsigned average_tx_time;
263
264 mrr = sc->sc_mrretry && !(ic->ic_flags & IEEE80211_F_USEPROT);
265 size_bin = size_to_bin(frameLen);
266 best_ndx = best_rate_ndx(sn, size_bin, !mrr);
267
268 if (best_ndx >= 0) {
269 average_tx_time = sn->stats[size_bin][best_ndx].average_tx_time;
270 } else {
271 average_tx_time = 0;
272 }
273
274 if (sn->static_rate_ndx != -1) {
275 ndx = sn->static_rate_ndx;
276 *try0 = ATH_TXMAXTRY;
277 } else {
278 *try0 = mrr ? 2 : ATH_TXMAXTRY;
279
280 if (sn->sample_tt[size_bin] < average_tx_time * (sn->packets_since_sample[size_bin]*ssc->ath_sample_rate/100)) {
281 /*
282 * we want to limit the time measuring the performance
283 * of other bit-rates to ath_sample_rate% of the
284 * total transmission time.
285 */
286 ndx = pick_sample_ndx(sn, size_bin);
287 if (ndx != sn->current_rate[size_bin]) {
288 sn->current_sample_ndx[size_bin] = ndx;
289 } else {
290 sn->current_sample_ndx[size_bin] = -1;
291 }
292 sn->packets_since_sample[size_bin] = 0;
293
294 } else {
295 change_rates = 0;
296 if (!sn->packets_sent[size_bin] || best_ndx == -1) {
297 /* no packet has been sent successfully yet */
298 for (ndx = sn->num_rates-1; ndx > 0; ndx--) {
299 /*
300 * pick the highest rate <= 36 Mbps
301 * that hasn't failed.
302 */
303 if (sn->rates[ndx].rate <= 72 &&
304 sn->stats[size_bin][ndx].successive_failures == 0) {
305 break;
306 }
307 }
308 change_rates = 1;
309 best_ndx = ndx;
310 } else if (sn->packets_sent[size_bin] < 20) {
311 /* let the bit-rate switch quickly during the first few packets */
312 change_rates = 1;
313 } else if (ticks - ((hz*MIN_SWITCH_MS)/1000) > sn->ticks_since_switch[size_bin]) {
314 /* 2 seconds have gone by */
315 change_rates = 1;
316 } else if (average_tx_time * 2 < sn->stats[size_bin][sn->current_rate[size_bin]].average_tx_time) {
317 /* the current bit-rate is twice as slow as the best one */
318 change_rates = 1;
319 }
320
321 sn->packets_since_sample[size_bin]++;
322
323 if (change_rates) {
324 if (best_ndx != sn->current_rate[size_bin]) {
325 DPRINTF(sc, "%s: %s size %d switch rate %d (%d/%d) -> %d (%d/%d) after %d packets mrr %d\n",
326 __func__,
327 ether_sprintf(an->an_node.ni_macaddr),
328 packet_size_bins[size_bin],
329 sn->rates[sn->current_rate[size_bin]].rate,
330 sn->stats[size_bin][sn->current_rate[size_bin]].average_tx_time,
331 sn->stats[size_bin][sn->current_rate[size_bin]].perfect_tx_time,
332 sn->rates[best_ndx].rate,
333 sn->stats[size_bin][best_ndx].average_tx_time,
334 sn->stats[size_bin][best_ndx].perfect_tx_time,
335 sn->packets_since_switch[size_bin],
336 mrr);
337 }
338 sn->packets_since_switch[size_bin] = 0;
339 sn->current_rate[size_bin] = best_ndx;
340 sn->ticks_since_switch[size_bin] = ticks;
341 }
342 ndx = sn->current_rate[size_bin];
343 sn->packets_since_switch[size_bin]++;
344 if (size_bin == 0) {
345 /*
346 * set the visible txrate for this node
347 * to the rate of small packets
348 */
349 an->an_node.ni_txrate = ndx;
350 }
351 }
352 }
353
354 KASSERTMSG(ndx >= 0 && ndx < sn->num_rates, "ndx is %d", ndx);
355
356 *rix = sn->rates[ndx].rix;
357 if (shortPreamble) {
358 *txrate = sn->rates[ndx].shortPreambleRateCode;
359 } else {
360 *txrate = sn->rates[ndx].rateCode;
361 }
362 sn->packets_sent[size_bin]++;
363 }
364
365 void
ath_rate_setupxtxdesc(struct ath_softc * sc,struct ath_node * an,struct ath_desc * ds,int shortPreamble,u_int8_t rix)366 ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an,
367 struct ath_desc *ds, int shortPreamble, u_int8_t rix)
368 {
369 struct sample_node *sn = ATH_NODE_SAMPLE(an);
370 int rateCode = -1;
371 int frame_size = 0;
372 int size_bin = 0;
373 int ndx = 0;
374
375 size_bin = size_to_bin(frame_size); // TODO: it's correct that frame_size always 0 ?
376 ndx = sn->current_rate[size_bin]; /* retry at the current bit-rate */
377
378 if (!sn->stats[size_bin][ndx].packets_acked) {
379 ndx = 0; /* use the lowest bit-rate */
380 }
381
382 if (shortPreamble) {
383 rateCode = sn->rates[ndx].shortPreambleRateCode;
384 } else {
385 rateCode = sn->rates[ndx].rateCode;
386 }
387 ath_hal_setupxtxdesc(sc->sc_ah, ds
388 , rateCode, 3 /* series 1 */
389 , sn->rates[0].rateCode, 3 /* series 2 */
390 , 0, 0 /* series 3 */
391 );
392 }
393
394 static void
update_stats(struct ath_softc * sc,struct ath_node * an,int frame_size,int ndx0,int tries0,int ndx1,int tries1,int ndx2,int tries2,int ndx3,int tries3,int short_tries,int tries,int status)395 update_stats(struct ath_softc *sc, struct ath_node *an,
396 int frame_size,
397 int ndx0, int tries0,
398 int ndx1, int tries1,
399 int ndx2, int tries2,
400 int ndx3, int tries3,
401 int short_tries, int tries, int status)
402 {
403 struct sample_node *sn = ATH_NODE_SAMPLE(an);
404 struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc);
405 int tt = 0;
406 int tries_so_far = 0;
407 int size_bin;
408 int size;
409 int rate;
410
411 if (ndx0 == -1)
412 return;
413
414 size_bin = size_to_bin(frame_size);
415 size = bin_to_size(size_bin);
416 rate = sn->rates[ndx0].rate;
417
418 tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx0].rix,
419 short_tries - 1, MIN(tries0, tries) - 1);
420 tries_so_far += tries0;
421 if (tries1 && tries0 < tries) {
422 tt += calc_usecs_unicast_packet(sc, size,
423 ndx1 == -1 ? 0 : sn->rates[ndx1].rix, short_tries - 1,
424 MIN(tries1 + tries_so_far, tries) - tries_so_far - 1);
425 }
426 tries_so_far += tries1;
427
428 if (tries2 && tries0 + tries1 < tries) {
429 tt += calc_usecs_unicast_packet(sc, size,
430 ndx2 == -1 ? 0 : sn->rates[ndx2].rix, short_tries - 1,
431 MIN(tries2 + tries_so_far, tries) - tries_so_far - 1);
432 }
433
434 tries_so_far += tries2;
435
436 if (tries3 && tries0 + tries1 + tries2 < tries) {
437 tt += calc_usecs_unicast_packet(sc, size,
438 ndx3 == -1 ? 0 : sn->rates[ndx3].rix, short_tries - 1,
439 MIN(tries3 + tries_so_far, tries) - tries_so_far - 1);
440 }
441
442 if (sn->stats[size_bin][ndx0].total_packets < (100 / (100 - ssc->ath_smoothing_rate))) {
443 /* just average the first few packets */
444 int avg_tx = sn->stats[size_bin][ndx0].average_tx_time;
445 int packets = sn->stats[size_bin][ndx0].total_packets;
446 sn->stats[size_bin][ndx0].average_tx_time = (tt+(avg_tx*packets))/(packets+1);
447 } else {
448 /* use a ewma */
449 sn->stats[size_bin][ndx0].average_tx_time =
450 ((sn->stats[size_bin][ndx0].average_tx_time * ssc->ath_smoothing_rate) +
451 (tt * (100 - ssc->ath_smoothing_rate))) / 100;
452 }
453
454 if (status) {
455 int y;
456 sn->stats[size_bin][ndx0].successive_failures++;
457 for (y = size_bin+1; y < NUM_PACKET_SIZE_BINS; y++) {
458 /* also say larger packets failed since we
459 * assume if a small packet fails at a lower
460 * bit-rate then a larger one will also.
461 */
462 sn->stats[y][ndx0].successive_failures++;
463 sn->stats[y][ndx0].last_tx = ticks;
464 sn->stats[y][ndx0].tries += tries;
465 sn->stats[y][ndx0].total_packets++;
466 }
467 } else {
468 sn->stats[size_bin][ndx0].packets_acked++;
469 sn->stats[size_bin][ndx0].successive_failures = 0;
470 }
471 sn->stats[size_bin][ndx0].tries += tries;
472 sn->stats[size_bin][ndx0].last_tx = ticks;
473 sn->stats[size_bin][ndx0].total_packets++;
474
475
476 if (ndx0 == sn->current_sample_ndx[size_bin]) {
477 DPRINTF(sc, "%s: %s size %d sample rate %d tries (%d/%d) tt %d avg_tt (%d/%d) status %d\n",
478 __func__, ether_sprintf(an->an_node.ni_macaddr),
479 size, rate, short_tries, tries, tt,
480 sn->stats[size_bin][ndx0].average_tx_time,
481 sn->stats[size_bin][ndx0].perfect_tx_time,
482 status);
483 sn->sample_tt[size_bin] = tt;
484 sn->current_sample_ndx[size_bin] = -1;
485 }
486 }
487
488 void
ath_rate_tx_complete(struct ath_softc * sc,struct ath_node * an,const struct ath_desc * ds,const struct ath_desc * ds0)489 ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an,
490 const struct ath_desc *ds, const struct ath_desc *ds0)
491 {
492 struct ieee80211com *ic = &sc->sc_ic;
493 struct sample_node *sn = ATH_NODE_SAMPLE(an);
494 const struct ar5212_desc *ads = (const struct ar5212_desc *)&ds->ds_ctl0;
495 int final_rate, short_tries, long_tries, frame_size;
496 int ndx = -1;
497 int mrr;
498
499 final_rate = sc->sc_hwmap[ds->ds_txstat.ts_rate &~ HAL_TXSTAT_ALTRATE].ieeerate;
500 short_tries = ds->ds_txstat.ts_shortretry + 1;
501 long_tries = ds->ds_txstat.ts_longretry + 1;
502 frame_size = ds0->ds_ctl0 & 0x0fff; /* low-order 12 bits of ds_ctl0 */
503 if (frame_size == 0) /* NB: should not happen */
504 frame_size = 1500;
505
506 if (sn->num_rates <= 0) {
507 DPRINTF(sc, "%s: %s size %d status %d rate/try %d/%d "
508 "no rates yet\n",
509 __func__, ether_sprintf(an->an_node.ni_macaddr),
510 bin_to_size(size_to_bin(frame_size)),
511 ds->ds_txstat.ts_status,
512 short_tries, long_tries);
513 return;
514 }
515
516 mrr = sc->sc_mrretry && !(ic->ic_flags & IEEE80211_F_USEPROT);
517
518 if (sc->sc_mrretry && ds->ds_txstat.ts_status) {
519 /* this packet failed */
520 DPRINTF(sc, "%s: %s size %d rate/try %d/%d %d/%d %d/%d %d/%d status %s retries (%d/%d)\n",
521 __func__,
522 ether_sprintf(an->an_node.ni_macaddr),
523 bin_to_size(size_to_bin(frame_size)),
524 sc->sc_hwmap[ads->xmit_rate0].ieeerate,
525 ads->xmit_tries0,
526 sc->sc_hwmap[ads->xmit_rate1].ieeerate,
527 ads->xmit_tries1,
528 sc->sc_hwmap[ads->xmit_rate2].ieeerate,
529 ads->xmit_tries2,
530 sc->sc_hwmap[ads->xmit_rate3].ieeerate,
531 ads->xmit_tries3,
532 ds->ds_txstat.ts_status ? "FAIL" : "OK",
533 short_tries,
534 long_tries);
535 }
536
537 if (!mrr || !(ds->ds_txstat.ts_rate & HAL_TXSTAT_ALTRATE)) {
538 /* only one rate was used */
539 ndx = rate_to_ndx(sn, final_rate);
540 DPRINTF(sc, "%s: %s size %d status %d rate/try %d/%d/%d\n",
541 __func__, ether_sprintf(an->an_node.ni_macaddr),
542 bin_to_size(size_to_bin(frame_size)),
543 ds->ds_txstat.ts_status,
544 ndx, short_tries, long_tries);
545 if (ndx >= 0 && ndx < sn->num_rates) {
546 update_stats(sc, an, frame_size,
547 ndx, long_tries,
548 0, 0,
549 0, 0,
550 0, 0,
551 short_tries, long_tries, ds->ds_txstat.ts_status);
552 }
553 } else {
554 int rate0, tries0, ndx0;
555 int rate1, tries1, ndx1;
556 int rate2, tries2, ndx2;
557 int rate3, tries3, ndx3;
558 int finalTSIdx = ads->final_ts_index;
559
560 /*
561 * Process intermediate rates that failed.
562 */
563
564 rate0 = sc->sc_hwmap[ads->xmit_rate0].ieeerate;
565 tries0 = ads->xmit_tries0;
566 ndx0 = rate_to_ndx(sn, rate0);
567
568 rate1 = sc->sc_hwmap[ads->xmit_rate1].ieeerate;
569 tries1 = ads->xmit_tries1;
570 ndx1 = rate_to_ndx(sn, rate1);
571
572 rate2 = sc->sc_hwmap[ads->xmit_rate2].ieeerate;
573 tries2 = ads->xmit_tries2;
574 ndx2 = rate_to_ndx(sn, rate2);
575
576 rate3 = sc->sc_hwmap[ads->xmit_rate3].ieeerate;
577 tries3 = ads->xmit_tries3;
578 ndx3 = rate_to_ndx(sn, rate3);
579
580 #if 1
581 DPRINTF(sc, "%s: %s size %d finaltsidx %d tries %d status %d rate/try %d/%d %d/%d %d/%d %d/%d\n",
582 __func__, ether_sprintf(an->an_node.ni_macaddr),
583 bin_to_size(size_to_bin(frame_size)),
584 finalTSIdx,
585 long_tries,
586 ds->ds_txstat.ts_status,
587 rate0, tries0,
588 rate1, tries1,
589 rate2, tries2,
590 rate3, tries3);
591 #endif
592
593 if (tries0) {
594 update_stats(sc, an, frame_size,
595 ndx0, tries0,
596 ndx1, tries1,
597 ndx2, tries2,
598 ndx3, tries3,
599 short_tries, ds->ds_txstat.ts_longretry + 1,
600 long_tries > tries0);
601 }
602
603 if (tries1 && finalTSIdx > 0) {
604 update_stats(sc, an, frame_size,
605 ndx1, tries1,
606 ndx2, tries2,
607 ndx3, tries3,
608 0, 0,
609 short_tries, ds->ds_txstat.ts_longretry + 1 - tries0,
610 ds->ds_txstat.ts_status);
611 }
612
613 if (tries2 && finalTSIdx > 1) {
614 update_stats(sc, an, frame_size,
615 ndx2, tries2,
616 ndx3, tries3,
617 0, 0,
618 0, 0,
619 short_tries, ds->ds_txstat.ts_longretry + 1 - tries0 - tries1,
620 ds->ds_txstat.ts_status);
621 }
622
623 if (tries3 && finalTSIdx > 2) {
624 update_stats(sc, an, frame_size,
625 ndx3, tries3,
626 0, 0,
627 0, 0,
628 0, 0,
629 short_tries, ds->ds_txstat.ts_longretry + 1 - tries0 - tries1 - tries2,
630 ds->ds_txstat.ts_status);
631 }
632 }
633 }
634
635 void
ath_rate_newassoc(struct ath_softc * sc,struct ath_node * an,int isnew)636 ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew)
637 {
638 DPRINTF(sc, "%s: %s isnew %d\n", __func__,
639 ether_sprintf(an->an_node.ni_macaddr), isnew);
640 if (isnew)
641 ath_rate_ctl_reset(sc, &an->an_node);
642 }
643
644 /*
645 * Initialize the tables for a node.
646 */
647 static void
ath_rate_ctl_reset(struct ath_softc * sc,struct ieee80211_node * ni)648 ath_rate_ctl_reset(struct ath_softc *sc, struct ieee80211_node *ni)
649 {
650 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
651 struct ieee80211com *ic = &sc->sc_ic;
652 struct ath_node *an = ATH_NODE(ni);
653 struct sample_node *sn = ATH_NODE_SAMPLE(an);
654 const HAL_RATE_TABLE *rt = sc->sc_currates;
655 int x, y, srate;
656
657 KASSERTMSG(rt != NULL, "no rate table, mode %u", sc->sc_curmode);
658 sn->static_rate_ndx = -1;
659 if (ic->ic_fixed_rate != IEEE80211_FIXED_RATE_NONE) {
660 /*
661 * A fixed rate is to be used; ic_fixed_rate is an
662 * index into the supported rate set. Convert this
663 * to the index into the negotiated rate set for
664 * the node. We know the rate is there because the
665 * rate set is checked when the station associates.
666 */
667 const struct ieee80211_rateset *rs =
668 &ic->ic_sup_rates[ic->ic_curmode];
669 int r = rs->rs_rates[ic->ic_fixed_rate] & IEEE80211_RATE_VAL;
670 /* NB: the rate set is assumed sorted */
671 srate = ni->ni_rates.rs_nrates - 1;
672 for (; srate >= 0 && RATE(srate) != r; srate--)
673 ;
674 KASSERTMSG(srate >= 0,
675 "fixed rate %d not in rate set", ic->ic_fixed_rate);
676 sn->static_rate_ndx = srate;
677 }
678
679 DPRINTF(sc, "%s: %s size 1600 rate/tt", __func__, ether_sprintf(ni->ni_macaddr));
680
681 sn->num_rates = ni->ni_rates.rs_nrates;
682 for (x = 0; x < ni->ni_rates.rs_nrates; x++) {
683 sn->rates[x].rate = ni->ni_rates.rs_rates[x] & IEEE80211_RATE_VAL;
684 sn->rates[x].rix = sc->sc_rixmap[sn->rates[x].rate];
685 sn->rates[x].rateCode = rt->info[sn->rates[x].rix].rateCode;
686 sn->rates[x].shortPreambleRateCode =
687 rt->info[sn->rates[x].rix].rateCode |
688 rt->info[sn->rates[x].rix].shortPreamble;
689
690 DPRINTF(sc, " %d/%d", sn->rates[x].rate,
691 calc_usecs_unicast_packet(sc, 1600, sn->rates[x].rix,
692 0,0));
693 }
694 DPRINTF(sc, "%s\n", "");
695
696 /* set the visible bit-rate to the lowest one available */
697 ni->ni_txrate = 0;
698 sn->num_rates = ni->ni_rates.rs_nrates;
699
700 for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) {
701 int size = bin_to_size(y);
702 int ndx = 0;
703 sn->packets_sent[y] = 0;
704 sn->current_sample_ndx[y] = -1;
705 sn->last_sample_ndx[y] = 0;
706
707 for (x = 0; x < ni->ni_rates.rs_nrates; x++) {
708 sn->stats[y][x].successive_failures = 0;
709 sn->stats[y][x].tries = 0;
710 sn->stats[y][x].total_packets = 0;
711 sn->stats[y][x].packets_acked = 0;
712 sn->stats[y][x].last_tx = 0;
713
714 sn->stats[y][x].perfect_tx_time =
715 calc_usecs_unicast_packet(sc, size,
716 sn->rates[x].rix,
717 0, 0);
718 sn->stats[y][x].average_tx_time = sn->stats[y][x].perfect_tx_time;
719 }
720
721 /* set the initial rate */
722 for (ndx = sn->num_rates-1; ndx > 0; ndx--) {
723 if (sn->rates[ndx].rate <= 72) {
724 break;
725 }
726 }
727 sn->current_rate[y] = ndx;
728 }
729
730 DPRINTF(sc, "%s: %s %d rates %d%sMbps (%dus)- %d%sMbps (%dus)\n",
731 __func__, ether_sprintf(ni->ni_macaddr),
732 sn->num_rates,
733 sn->rates[0].rate/2, sn->rates[0].rate % 0x1 ? ".5" : "",
734 sn->stats[1][0].perfect_tx_time,
735 sn->rates[sn->num_rates-1].rate/2,
736 sn->rates[sn->num_rates-1].rate % 0x1 ? ".5" : "",
737 sn->stats[1][sn->num_rates-1].perfect_tx_time
738 );
739
740 ni->ni_txrate = sn->current_rate[0];
741 #undef RATE
742 }
743
744 static void
rate_cb(void * arg,struct ieee80211_node * ni)745 rate_cb(void *arg, struct ieee80211_node *ni)
746 {
747 struct ath_softc *sc = arg;
748
749 ath_rate_newassoc(sc, ATH_NODE(ni), 1);
750 }
751
752 /*
753 * Reset the rate control state for each 802.11 state transition.
754 */
755 void
ath_rate_newstate(struct ath_softc * sc,enum ieee80211_state state)756 ath_rate_newstate(struct ath_softc *sc, enum ieee80211_state state)
757 {
758 struct ieee80211com *ic = &sc->sc_ic;
759
760 if (state == IEEE80211_S_RUN) {
761 if (ic->ic_opmode != IEEE80211_M_STA) {
762 /*
763 * Sync rates for associated stations and neighbors.
764 */
765 ieee80211_iterate_nodes(&ic->ic_sta, rate_cb, sc);
766 }
767 ath_rate_newassoc(sc, ATH_NODE(ic->ic_bss), 1);
768 }
769 }
770
771 static void
ath_rate_sysctlattach(struct ath_softc * sc,struct sample_softc * osc)772 ath_rate_sysctlattach(struct ath_softc *sc, struct sample_softc *osc)
773 {
774 int rc;
775 struct sysctllog **log = &sc->sc_sysctllog;
776 const struct sysctlnode *cnode, *rnode;
777
778 if ((rnode = ath_sysctl_instance(device_xname(sc->sc_dev), log)) == NULL)
779 return;
780
781 /* XXX bounds check [0..100] */
782 if ((rc = SYSCTL_PFX_INT(osc->ath_, CTLFLAG_READWRITE, smoothing_rate,
783 "rate control: retry threshold to credit rate raise (%%)")) != 0)
784 goto err;
785
786 /* XXX bounds check [2..100] */
787 if ((rc = SYSCTL_PFX_INT(osc->ath_, CTLFLAG_READWRITE, sample_rate,
788 "rate control: # good periods before raising rate")) != 0)
789 goto err;
790
791 return;
792 err:
793 printf("%s: sysctl_createv failed, rc = %d\n", __func__, rc);
794 }
795
796 struct ath_ratectrl *
ath_rate_attach(struct ath_softc * sc)797 ath_rate_attach(struct ath_softc *sc)
798 {
799 struct sample_softc *osc;
800
801 DPRINTF(sc, "%s:\n", __func__);
802 osc = malloc(sizeof(struct sample_softc), M_DEVBUF, M_WAITOK|M_ZERO);
803 osc->arc.arc_space = sizeof(struct sample_node);
804 osc->ath_smoothing_rate = 95; /* ewma percentage (out of 100) */
805 osc->ath_sample_rate = 10; /* send a different bit-rate 1/X packets */
806 ath_rate_sysctlattach(sc, osc);
807 return &osc->arc;
808 }
809
810 void
ath_rate_detach(struct ath_ratectrl * arc)811 ath_rate_detach(struct ath_ratectrl *arc)
812 {
813 struct sample_softc *osc = (struct sample_softc *) arc;
814
815 free(osc, M_DEVBUF);
816 }
817