2 * Copyright (c) 2005 John Bicket
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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.
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.
36 * $FreeBSD: head/sys/dev/ath/ath_rate/sample/sample.c 194135 2009-06-13 23:36:54Z sam $
40 * John Bicket's SampleRate control algorithm.
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/sysctl.h>
48 #include <sys/kernel.h>
50 #include <sys/mutex.h>
51 #include <sys/errno.h>
55 #include <sys/socket.h>
58 #include <net/if_media.h>
59 #include <net/if_arp.h>
61 #include <netproto/802_11/ieee80211_var.h>
66 #include <netinet/in.h>
67 #include <netinet/if_ether.h>
70 #include <dev/netif/ath/ath/if_athvar.h>
71 #include <dev/netif/ath/rate_sample/sample.h>
72 #include <dev/netif/ath/hal/ath_hal/ah_desc.h>
75 * This file is an implementation of the SampleRate algorithm
76 * in "Bit-rate Selection in Wireless Networks"
77 * (http://www.pdos.lcs.mit.edu/papers/jbicket-ms.ps)
79 * SampleRate chooses the bit-rate it predicts will provide the most
80 * throughput based on estimates of the expected per-packet
81 * transmission time for each bit-rate. SampleRate periodically sends
82 * packets at bit-rates other than the current one to estimate when
83 * another bit-rate will provide better performance. SampleRate
84 * switches to another bit-rate when its estimated per-packet
85 * transmission time becomes smaller than the current bit-rate's.
86 * SampleRate reduces the number of bit-rates it must sample by
87 * eliminating those that could not perform better than the one
88 * currently being used. SampleRate also stops probing at a bit-rate
89 * if it experiences several successive losses.
91 * The difference between the algorithm in the thesis and the one in this
92 * file is that the one in this file uses a ewma instead of a window.
94 * Also, this implementation tracks the average transmission time for
95 * a few different packet sizes independently for each link.
98 static void ath_rate_ctl_reset(struct ath_softc *, struct ieee80211_node *);
100 static const int packet_size_bins[NUM_PACKET_SIZE_BINS] = { 250, 1600 };
103 size_to_bin(int size)
105 #if NUM_PACKET_SIZE_BINS > 1
106 if (size <= packet_size_bins[0])
109 #if NUM_PACKET_SIZE_BINS > 2
110 if (size <= packet_size_bins[1])
113 #if NUM_PACKET_SIZE_BINS > 3
114 if (size <= packet_size_bins[2])
117 #if NUM_PACKET_SIZE_BINS > 4
118 #error "add support for more packet sizes"
120 return NUM_PACKET_SIZE_BINS-1;
124 bin_to_size(int index)
126 return packet_size_bins[index];
130 ath_rate_node_init(struct ath_softc *sc, struct ath_node *an)
132 /* NB: assumed to be zero'd by caller */
136 ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an)
141 * Return the rix with the lowest average_tx_time,
142 * or -1 if all the average_tx_times are 0.
145 pick_best_rate(struct sample_node *sn, const HAL_RATE_TABLE *rt,
146 int size_bin, int require_acked_before)
148 int best_rate_rix, best_rate_tt;
154 for (mask = sn->ratemask, rix = 0; mask != 0; mask >>= 1, rix++) {
155 if ((mask & 1) == 0) /* not a supported rate */
158 tt = sn->stats[size_bin][rix].average_tx_time;
160 (require_acked_before &&
161 !sn->stats[size_bin][rix].packets_acked))
164 /* don't use a bit-rate that has been failing */
165 if (sn->stats[size_bin][rix].successive_failures > 3)
168 if (best_rate_tt == 0 || tt < best_rate_tt) {
173 return (best_rate_tt ? best_rate_rix : -1);
177 * Pick a good "random" bit-rate to sample other than the current one.
180 pick_sample_rate(struct sample_softc *ssc , struct sample_node *sn,
181 const HAL_RATE_TABLE *rt, int size_bin)
183 #define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
184 int current_rix, rix;
188 current_rix = sn->current_rix[size_bin];
189 if (current_rix < 0) {
190 /* no successes yet, send at the lowest bit-rate */
194 current_tt = sn->stats[size_bin][current_rix].average_tx_time;
196 rix = sn->last_sample_rix[size_bin]+1; /* next sample rate */
197 mask = sn->ratemask &~ (1<<current_rix);/* don't sample current rate */
199 if ((mask & (1<<rix)) == 0) { /* not a supported rate */
201 if (++rix >= rt->rateCount)
206 /* this bit-rate is always worse than the current one */
207 if (sn->stats[size_bin][rix].perfect_tx_time > current_tt) {
212 /* rarely sample bit-rates that fail a lot */
213 if (sn->stats[size_bin][rix].successive_failures > ssc->max_successive_failures &&
214 ticks - sn->stats[size_bin][rix].last_tx < ssc->stale_failure_timeout) {
219 /* don't sample more than 2 rates higher for rates > 11M */
220 if (DOT11RATE(rix) > 2*11 && rix > current_rix + 2) {
225 sn->last_sample_rix[size_bin] = rix;
233 ath_rate_findrate(struct ath_softc *sc, struct ath_node *an,
234 int shortPreamble, size_t frameLen,
235 u_int8_t *rix0, int *try0, u_int8_t *txrate)
237 #define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
238 #define RATE(ix) (DOT11RATE(ix) / 2)
239 struct sample_node *sn = ATH_NODE_SAMPLE(an);
240 struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc);
241 struct ifnet *ifp = sc->sc_ifp;
242 struct ieee80211com *ic = ifp->if_l2com;
243 const HAL_RATE_TABLE *rt = sc->sc_currates;
244 const int size_bin = size_to_bin(frameLen);
245 int rix, mrr, best_rix, change_rates;
246 unsigned average_tx_time;
248 if (sn->static_rix != -1) {
249 rix = sn->static_rix;
250 *try0 = ATH_TXMAXTRY;
254 mrr = sc->sc_mrretry && !(ic->ic_flags & IEEE80211_F_USEPROT);
256 best_rix = pick_best_rate(sn, rt, size_bin, !mrr);
258 average_tx_time = sn->stats[size_bin][best_rix].average_tx_time;
263 * Limit the time measuring the performance of other tx
264 * rates to sample_rate% of the total transmission time.
266 if (sn->sample_tt[size_bin] < average_tx_time * (sn->packets_since_sample[size_bin]*ssc->sample_rate/100)) {
267 rix = pick_sample_rate(ssc, sn, rt, size_bin);
268 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
269 &an->an_node, "size %u sample rate %d current rate %d",
270 bin_to_size(size_bin), RATE(rix),
271 RATE(sn->current_rix[size_bin]));
272 if (rix != sn->current_rix[size_bin]) {
273 sn->current_sample_rix[size_bin] = rix;
275 sn->current_sample_rix[size_bin] = -1;
277 sn->packets_since_sample[size_bin] = 0;
280 if (!sn->packets_sent[size_bin] || best_rix == -1) {
281 /* no packet has been sent successfully yet */
282 for (rix = rt->rateCount-1; rix > 0; rix--) {
283 if ((sn->ratemask & (1<<rix)) == 0)
286 * Pick the highest rate <= 36 Mbps
287 * that hasn't failed.
289 if (DOT11RATE(rix) <= 72 &&
290 sn->stats[size_bin][rix].successive_failures == 0) {
296 } else if (sn->packets_sent[size_bin] < 20) {
297 /* let the bit-rate switch quickly during the first few packets */
299 } else if (ticks - ssc->min_switch > sn->ticks_since_switch[size_bin]) {
300 /* min_switch seconds have gone by */
302 } else if (2*average_tx_time < sn->stats[size_bin][sn->current_rix[size_bin]].average_tx_time) {
303 /* the current bit-rate is twice as slow as the best one */
307 sn->packets_since_sample[size_bin]++;
310 if (best_rix != sn->current_rix[size_bin]) {
311 IEEE80211_NOTE(an->an_node.ni_vap,
312 IEEE80211_MSG_RATECTL,
314 "%s: size %d switch rate %d (%d/%d) -> %d (%d/%d) after %d packets mrr %d",
316 bin_to_size(size_bin),
317 RATE(sn->current_rix[size_bin]),
318 sn->stats[size_bin][sn->current_rix[size_bin]].average_tx_time,
319 sn->stats[size_bin][sn->current_rix[size_bin]].perfect_tx_time,
321 sn->stats[size_bin][best_rix].average_tx_time,
322 sn->stats[size_bin][best_rix].perfect_tx_time,
323 sn->packets_since_switch[size_bin],
326 sn->packets_since_switch[size_bin] = 0;
327 sn->current_rix[size_bin] = best_rix;
328 sn->ticks_since_switch[size_bin] = ticks;
330 * Set the visible txrate for this node.
332 an->an_node.ni_txrate = DOT11RATE(best_rix);
334 rix = sn->current_rix[size_bin];
335 sn->packets_since_switch[size_bin]++;
337 *try0 = mrr ? sn->sched[rix].t0 : ATH_TXMAXTRY;
339 KASSERT(rix >= 0 && rix < rt->rateCount, ("rix is %d", rix));
342 *txrate = rt->info[rix].rateCode
343 | (shortPreamble ? rt->info[rix].shortPreamble : 0);
344 sn->packets_sent[size_bin]++;
350 (((_r) == 6) ? 0 : (((_r) == 9) ? 1 : (((_r) == 12) ? 2 : \
351 (((_r) == 18) ? 3 : (((_r) == 24) ? 4 : (((_r) == 36) ? 5 : \
352 (((_r) == 48) ? 6 : (((_r) == 54) ? 7 : 0))))))))
353 static const struct txschedule series_11a[] = {
354 { 3,A( 6), 3,A( 6), 0,A( 6), 0,A( 6) }, /* 6Mb/s */
355 { 4,A( 9), 3,A( 6), 4,A( 6), 0,A( 6) }, /* 9Mb/s */
356 { 4,A(12), 3,A( 6), 4,A( 6), 0,A( 6) }, /* 12Mb/s */
357 { 4,A(18), 3,A( 12), 4,A( 6), 2,A( 6) }, /* 18Mb/s */
358 { 4,A(24), 3,A( 18), 4,A( 12), 2,A( 6) }, /* 24Mb/s */
359 { 4,A(36), 3,A( 24), 4,A( 18), 2,A( 6) }, /* 36Mb/s */
360 { 4,A(48), 3,A( 36), 4,A( 24), 2,A(12) }, /* 48Mb/s */
361 { 4,A(54), 3,A( 48), 4,A( 36), 2,A(24) } /* 54Mb/s */
366 (((_r) == 1) ? 0 : (((_r) == 2) ? 1 : (((_r) == 5.5) ? 2 : \
367 (((_r) == 11) ? 3 : (((_r) == 6) ? 4 : (((_r) == 9) ? 5 : \
368 (((_r) == 12) ? 6 : (((_r) == 18) ? 7 : (((_r) == 24) ? 8 : \
369 (((_r) == 36) ? 9 : (((_r) == 48) ? 10 : (((_r) == 54) ? 11 : 0))))))))))))
370 static const struct txschedule series_11g[] = {
371 { 3,G( 1), 3,G( 1), 0,G( 1), 0,G( 1) }, /* 1Mb/s */
372 { 4,G( 2), 3,G( 1), 4,G( 1), 0,G( 1) }, /* 2Mb/s */
373 { 4,G(5.5),3,G( 2), 4,G( 1), 2,G( 1) }, /* 5.5Mb/s */
374 { 4,G(11), 3,G(5.5), 4,G( 2), 2,G( 1) }, /* 11Mb/s */
375 { 4,G( 6), 3,G(5.5), 4,G( 2), 2,G( 1) }, /* 6Mb/s */
376 { 4,G( 9), 3,G( 6), 4,G(5.5), 2,G( 1) }, /* 9Mb/s */
377 { 4,G(12), 3,G( 11), 4,G(5.5), 2,G( 1) }, /* 12Mb/s */
378 { 4,G(18), 3,G( 12), 4,G( 11), 2,G( 1) }, /* 18Mb/s */
379 { 4,G(24), 3,G( 18), 4,G( 12), 2,G( 1) }, /* 24Mb/s */
380 { 4,G(36), 3,G( 24), 4,G( 18), 2,G( 1) }, /* 36Mb/s */
381 { 4,G(48), 3,G( 36), 4,G( 24), 2,G( 1) }, /* 48Mb/s */
382 { 4,G(54), 3,G( 48), 4,G( 36), 2,G( 1) } /* 54Mb/s */
387 (((_r) == 3) ? 0 : (((_r) == 4.5) ? 1 : (((_r) == 6) ? 2 : \
388 (((_r) == 9) ? 3 : (((_r) == 12) ? 4 : (((_r) == 18) ? 5 : \
389 (((_r) == 24) ? 6 : (((_r) == 27) ? 7 : 0))))))))
390 static const struct txschedule series_half[] = {
391 { 3,H( 3), 3,H( 3), 0,H( 3), 0,H( 3) }, /* 3Mb/s */
392 { 4,H(4.5),3,H( 3), 4,H( 3), 0,H( 3) }, /* 4.5Mb/s */
393 { 4,H( 6), 3,H( 3), 4,H( 3), 0,H( 3) }, /* 6Mb/s */
394 { 4,H( 9), 3,H( 6), 4,H( 3), 2,H( 3) }, /* 9Mb/s */
395 { 4,H(12), 3,H( 9), 4,H( 6), 2,H( 3) }, /* 12Mb/s */
396 { 4,H(18), 3,H( 12), 4,H( 9), 2,H( 3) }, /* 18Mb/s */
397 { 4,H(24), 3,H( 18), 4,H( 12), 2,H( 6) }, /* 24Mb/s */
398 { 4,H(27), 3,H( 24), 4,H( 18), 2,H(12) } /* 27Mb/s */
403 #undef Q /* sun4v bogosity */
406 (((_r) == 1.5) ? 0 : (((_r) ==2.25) ? 1 : (((_r) == 3) ? 2 : \
407 (((_r) == 4.5) ? 3 : (((_r) == 6) ? 4 : (((_r) == 9) ? 5 : \
408 (((_r) == 12) ? 6 : (((_r) == 13.5)? 7 : 0))))))))
409 static const struct txschedule series_quarter[] = {
410 { 3,Q( 1.5),3,Q(1.5), 0,Q(1.5), 0,Q(1.5) }, /* 1.5Mb/s */
411 { 4,Q(2.25),3,Q(1.5), 4,Q(1.5), 0,Q(1.5) }, /*2.25Mb/s */
412 { 4,Q( 3),3,Q(1.5), 4,Q(1.5), 0,Q(1.5) }, /* 3Mb/s */
413 { 4,Q( 4.5),3,Q( 3), 4,Q(1.5), 2,Q(1.5) }, /* 4.5Mb/s */
414 { 4,Q( 6),3,Q(4.5), 4,Q( 3), 2,Q(1.5) }, /* 6Mb/s */
415 { 4,Q( 9),3,Q( 6), 4,Q(4.5), 2,Q(1.5) }, /* 9Mb/s */
416 { 4,Q( 12),3,Q( 9), 4,Q( 6), 2,Q( 3) }, /* 12Mb/s */
417 { 4,Q(13.5),3,Q( 12), 4,Q( 9), 2,Q( 6) } /*13.5Mb/s */
422 ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an,
423 struct ath_desc *ds, int shortPreamble, u_int8_t rix)
425 struct sample_node *sn = ATH_NODE_SAMPLE(an);
426 const struct txschedule *sched = &sn->sched[rix];
427 const HAL_RATE_TABLE *rt = sc->sc_currates;
428 uint8_t rix1, s1code, rix2, s2code, rix3, s3code;
430 /* XXX precalculate short preamble tables */
432 s1code = rt->info[rix1].rateCode
433 | (shortPreamble ? rt->info[rix1].shortPreamble : 0);
435 s2code = rt->info[rix2].rateCode
436 | (shortPreamble ? rt->info[rix2].shortPreamble : 0);
438 s3code = rt->info[rix3].rateCode
439 | (shortPreamble ? rt->info[rix3].shortPreamble : 0);
440 ath_hal_setupxtxdesc(sc->sc_ah, ds,
441 s1code, sched->t1, /* series 1 */
442 s2code, sched->t2, /* series 2 */
443 s3code, sched->t3); /* series 3 */
447 update_stats(struct ath_softc *sc, struct ath_node *an,
449 int rix0, int tries0,
450 int rix1, int tries1,
451 int rix2, int tries2,
452 int rix3, int tries3,
453 int short_tries, int tries, int status)
455 struct sample_node *sn = ATH_NODE_SAMPLE(an);
456 struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc);
457 const int size_bin = size_to_bin(frame_size);
458 const int size = bin_to_size(size_bin);
459 int tt, tries_so_far;
461 if (!IS_RATE_DEFINED(sn, rix0))
463 tt = calc_usecs_unicast_packet(sc, size, rix0, short_tries,
464 MIN(tries0, tries) - 1);
465 tries_so_far = tries0;
467 if (tries1 && tries_so_far < tries) {
468 if (!IS_RATE_DEFINED(sn, rix1))
470 tt += calc_usecs_unicast_packet(sc, size, rix1, short_tries,
471 MIN(tries1 + tries_so_far, tries) - tries_so_far - 1);
472 tries_so_far += tries1;
475 if (tries2 && tries_so_far < tries) {
476 if (!IS_RATE_DEFINED(sn, rix2))
478 tt += calc_usecs_unicast_packet(sc, size, rix2, short_tries,
479 MIN(tries2 + tries_so_far, tries) - tries_so_far - 1);
480 tries_so_far += tries2;
483 if (tries3 && tries_so_far < tries) {
484 if (!IS_RATE_DEFINED(sn, rix3))
486 tt += calc_usecs_unicast_packet(sc, size, rix3, short_tries,
487 MIN(tries3 + tries_so_far, tries) - tries_so_far - 1);
490 if (sn->stats[size_bin][rix0].total_packets < ssc->smoothing_minpackets) {
491 /* just average the first few packets */
492 int avg_tx = sn->stats[size_bin][rix0].average_tx_time;
493 int packets = sn->stats[size_bin][rix0].total_packets;
494 sn->stats[size_bin][rix0].average_tx_time = (tt+(avg_tx*packets))/(packets+1);
497 sn->stats[size_bin][rix0].average_tx_time =
498 ((sn->stats[size_bin][rix0].average_tx_time * ssc->smoothing_rate) +
499 (tt * (100 - ssc->smoothing_rate))) / 100;
504 sn->stats[size_bin][rix0].successive_failures++;
505 for (y = size_bin+1; y < NUM_PACKET_SIZE_BINS; y++) {
507 * Also say larger packets failed since we
508 * assume if a small packet fails at a
509 * bit-rate then a larger one will also.
511 sn->stats[y][rix0].successive_failures++;
512 sn->stats[y][rix0].last_tx = ticks;
513 sn->stats[y][rix0].tries += tries;
514 sn->stats[y][rix0].total_packets++;
517 sn->stats[size_bin][rix0].packets_acked++;
518 sn->stats[size_bin][rix0].successive_failures = 0;
520 sn->stats[size_bin][rix0].tries += tries;
521 sn->stats[size_bin][rix0].last_tx = ticks;
522 sn->stats[size_bin][rix0].total_packets++;
524 if (rix0 == sn->current_sample_rix[size_bin]) {
525 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
527 "%s: size %d %s sample rate %d tries (%d/%d) tt %d avg_tt (%d/%d)",
530 status ? "FAIL" : "OK",
531 rix0, short_tries, tries, tt,
532 sn->stats[size_bin][rix0].average_tx_time,
533 sn->stats[size_bin][rix0].perfect_tx_time);
534 sn->sample_tt[size_bin] = tt;
535 sn->current_sample_rix[size_bin] = -1;
540 badrate(struct ifnet *ifp, int series, int hwrate, int tries, int status)
542 if_printf(ifp, "bad series%d hwrate 0x%x, tries %u ts_status 0x%x\n",
543 series, hwrate, tries, status);
547 ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an,
548 const struct ath_buf *bf)
550 struct ifnet *ifp = sc->sc_ifp;
551 struct ieee80211com *ic = ifp->if_l2com;
552 struct sample_node *sn = ATH_NODE_SAMPLE(an);
553 const struct ath_tx_status *ts = &bf->bf_status.ds_txstat;
554 const struct ath_desc *ds0 = &bf->bf_desc[0];
555 int final_rix, short_tries, long_tries, frame_size;
556 const HAL_RATE_TABLE *rt = sc->sc_currates;
559 final_rix = rt->rateCodeToIndex[ts->ts_rate];
560 short_tries = ts->ts_shortretry;
561 long_tries = ts->ts_longretry + 1;
562 frame_size = ds0->ds_ctl0 & 0x0fff; /* low-order 12 bits of ds_ctl0 */
563 if (frame_size == 0) /* NB: should not happen */
566 if (sn->ratemask == 0) {
567 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
569 "%s: size %d %s rate/try %d/%d no rates yet",
571 bin_to_size(size_to_bin(frame_size)),
572 ts->ts_status ? "FAIL" : "OK",
573 short_tries, long_tries);
576 mrr = sc->sc_mrretry && !(ic->ic_flags & IEEE80211_F_USEPROT);
577 if (!mrr || ts->ts_finaltsi == 0) {
578 if (!IS_RATE_DEFINED(sn, final_rix)) {
579 badrate(ifp, 0, ts->ts_rate, long_tries, ts->ts_status);
583 * Only one rate was used; optimize work.
585 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
586 &an->an_node, "%s: size %d %s rate/try %d/%d/%d",
588 bin_to_size(size_to_bin(frame_size)),
589 ts->ts_status ? "FAIL" : "OK",
590 final_rix, short_tries, long_tries);
591 update_stats(sc, an, frame_size,
592 final_rix, long_tries,
596 short_tries, long_tries, ts->ts_status);
598 int hwrate0, rix0, tries0;
599 int hwrate1, rix1, tries1;
600 int hwrate2, rix2, tries2;
601 int hwrate3, rix3, tries3;
602 int finalTSIdx = ts->ts_finaltsi;
605 * Process intermediate rates that failed.
607 if (sc->sc_ah->ah_magic != 0x20065416) {
608 hwrate0 = MS(ds0->ds_ctl3, AR_XmitRate0);
609 hwrate1 = MS(ds0->ds_ctl3, AR_XmitRate1);
610 hwrate2 = MS(ds0->ds_ctl3, AR_XmitRate2);
611 hwrate3 = MS(ds0->ds_ctl3, AR_XmitRate3);
613 hwrate0 = MS(ds0->ds_ctl3, AR5416_XmitRate0);
614 hwrate1 = MS(ds0->ds_ctl3, AR5416_XmitRate1);
615 hwrate2 = MS(ds0->ds_ctl3, AR5416_XmitRate2);
616 hwrate3 = MS(ds0->ds_ctl3, AR5416_XmitRate3);
619 rix0 = rt->rateCodeToIndex[hwrate0];
620 tries0 = MS(ds0->ds_ctl2, AR_XmitDataTries0);
622 rix1 = rt->rateCodeToIndex[hwrate1];
623 tries1 = MS(ds0->ds_ctl2, AR_XmitDataTries1);
625 rix2 = rt->rateCodeToIndex[hwrate2];
626 tries2 = MS(ds0->ds_ctl2, AR_XmitDataTries2);
628 rix3 = rt->rateCodeToIndex[hwrate3];
629 tries3 = MS(ds0->ds_ctl2, AR_XmitDataTries3);
631 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
633 "%s: size %d finaltsidx %d tries %d %s rate/try [%d/%d %d/%d %d/%d %d/%d]",
635 bin_to_size(size_to_bin(frame_size)),
638 ts->ts_status ? "FAIL" : "OK",
644 if (tries0 && !IS_RATE_DEFINED(sn, rix0))
645 badrate(ifp, 0, hwrate0, tries0, ts->ts_status);
646 if (tries1 && !IS_RATE_DEFINED(sn, rix1))
647 badrate(ifp, 1, hwrate1, tries1, ts->ts_status);
648 if (tries2 && !IS_RATE_DEFINED(sn, rix2))
649 badrate(ifp, 2, hwrate2, tries2, ts->ts_status);
650 if (tries3 && !IS_RATE_DEFINED(sn, rix3))
651 badrate(ifp, 3, hwrate3, tries3, ts->ts_status);
654 * NB: series > 0 are not penalized for failure
655 * based on the try counts under the assumption
656 * that losses are often bursty and since we
657 * sample higher rates 1 try at a time doing so
658 * may unfairly penalize them.
661 update_stats(sc, an, frame_size,
666 short_tries, long_tries,
667 long_tries > tries0);
668 long_tries -= tries0;
671 if (tries1 && finalTSIdx > 0) {
672 update_stats(sc, an, frame_size,
677 short_tries, long_tries,
679 long_tries -= tries1;
682 if (tries2 && finalTSIdx > 1) {
683 update_stats(sc, an, frame_size,
688 short_tries, long_tries,
690 long_tries -= tries2;
693 if (tries3 && finalTSIdx > 2) {
694 update_stats(sc, an, frame_size,
699 short_tries, long_tries,
706 ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew)
709 ath_rate_ctl_reset(sc, &an->an_node);
712 static const struct txschedule *mrr_schedules[IEEE80211_MODE_MAX+2] = {
713 NULL, /* IEEE80211_MODE_AUTO */
714 series_11a, /* IEEE80211_MODE_11A */
715 series_11g, /* IEEE80211_MODE_11B */
716 series_11g, /* IEEE80211_MODE_11G */
717 NULL, /* IEEE80211_MODE_FH */
718 series_11a, /* IEEE80211_MODE_TURBO_A */
719 series_11g, /* IEEE80211_MODE_TURBO_G */
720 series_11a, /* IEEE80211_MODE_STURBO_A */
721 series_11a, /* IEEE80211_MODE_11NA */
722 series_11g, /* IEEE80211_MODE_11NG */
723 series_half, /* IEEE80211_MODE_HALF */
724 series_quarter, /* IEEE80211_MODE_QUARTER */
728 * Initialize the tables for a node.
731 ath_rate_ctl_reset(struct ath_softc *sc, struct ieee80211_node *ni)
733 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
734 #define DOT11RATE(_ix) (rt->info[(_ix)].dot11Rate & IEEE80211_RATE_VAL)
735 struct ath_node *an = ATH_NODE(ni);
736 const struct ieee80211_txparam *tp = ni->ni_txparms;
737 struct sample_node *sn = ATH_NODE_SAMPLE(an);
738 const HAL_RATE_TABLE *rt = sc->sc_currates;
739 int x, y, srate, rix;
741 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
743 KASSERT(sc->sc_curmode < IEEE80211_MODE_MAX+2,
744 ("curmode %u", sc->sc_curmode));
745 sn->sched = mrr_schedules[sc->sc_curmode];
746 KASSERT(sn->sched != NULL,
747 ("no mrr schedule for mode %u", sc->sc_curmode));
750 if (tp != NULL && tp->ucastrate != IEEE80211_FIXED_RATE_NONE) {
752 * A fixed rate is to be used; ucastrate is the IEEE code
753 * for this rate (sans basic bit). Check this against the
754 * negotiated rate set for the node. Note the fixed rate
755 * may not be available for various reasons so we only
756 * setup the static rate index if the lookup is successful.
759 for (srate = ni->ni_rates.rs_nrates - 1; srate >= 0; srate--)
760 if (RATE(srate) == tp->ucastrate) {
761 sn->static_rix = sc->sc_rixmap[tp->ucastrate];
764 #ifdef IEEE80211_DEBUG
765 if (sn->static_rix == -1) {
766 IEEE80211_NOTE(ni->ni_vap,
767 IEEE80211_MSG_RATECTL, ni,
768 "%s: ucastrate %u not found, nrates %u",
769 __func__, tp->ucastrate,
770 ni->ni_rates.rs_nrates);
776 * Construct a bitmask of usable rates. This has all
777 * negotiated rates minus those marked by the hal as
778 * to be ignored for doing rate control.
781 for (x = 0; x < ni->ni_rates.rs_nrates; x++) {
782 rix = sc->sc_rixmap[RATE(x)];
785 /* skip rates marked broken by hal */
786 if (!rt->info[rix].valid)
788 KASSERT(rix < SAMPLE_MAXRATES,
789 ("rate %u has rix %d", RATE(x), rix));
790 sn->ratemask |= 1<<rix;
792 #ifdef IEEE80211_DEBUG
793 if (ieee80211_msg(ni->ni_vap, IEEE80211_MSG_RATECTL)) {
796 ieee80211_note(ni->ni_vap, "[%6D] %s: size 1600 rate/tt",
797 ni->ni_macaddr, ":", __func__);
798 for (mask = sn->ratemask, rix = 0; mask != 0; mask >>= 1, rix++) {
801 kprintf(" %d/%d", DOT11RATE(rix) / 2,
802 calc_usecs_unicast_packet(sc, 1600, rix, 0,0));
807 for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) {
808 int size = bin_to_size(y);
811 sn->packets_sent[y] = 0;
812 sn->current_sample_rix[y] = -1;
813 sn->last_sample_rix[y] = 0;
814 /* XXX start with first valid rate */
815 sn->current_rix[y] = ffs(sn->ratemask)-1;
818 * Initialize the statistics buckets; these are
819 * indexed by the rate code index.
821 for (rix = 0, mask = sn->ratemask; mask != 0; rix++, mask >>= 1) {
822 if ((mask & 1) == 0) /* not a valid rate */
824 sn->stats[y][rix].successive_failures = 0;
825 sn->stats[y][rix].tries = 0;
826 sn->stats[y][rix].total_packets = 0;
827 sn->stats[y][rix].packets_acked = 0;
828 sn->stats[y][rix].last_tx = 0;
830 sn->stats[y][rix].perfect_tx_time =
831 calc_usecs_unicast_packet(sc, size, rix, 0, 0);
832 sn->stats[y][rix].average_tx_time =
833 sn->stats[y][rix].perfect_tx_time;
837 /* XXX 0, num_rates-1 are wrong */
838 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
839 "%s: %d rates %d%sMbps (%dus)- %d%sMbps (%dus)", __func__,
841 DOT11RATE(0)/2, DOT11RATE(0) % 1 ? ".5" : "",
842 sn->stats[1][0].perfect_tx_time,
843 DOT11RATE(sn->num_rates-1)/2, DOT11RATE(sn->num_rates-1) % 1 ? ".5" : "",
844 sn->stats[1][sn->num_rates-1].perfect_tx_time
847 /* set the visible bit-rate */
848 if (sn->static_rix != -1)
849 ni->ni_txrate = DOT11RATE(sn->static_rix);
851 ni->ni_txrate = RATE(0);
857 sample_stats(void *arg, struct ieee80211_node *ni)
859 struct ath_softc *sc = arg;
860 const HAL_RATE_TABLE *rt = sc->sc_currates;
861 struct sample_node *sn = ATH_NODE_SAMPLE(ATH_NODE(ni));
865 kprintf("\n[%6D] refcnt %d static_rix %d ratemask 0x%x\n",
866 ni->ni_macaddr, ":", ieee80211_node_refcnt(ni),
867 sn->static_rix, sn->ratemask);
868 for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) {
869 kprintf("[%4u] cur rix %d since switch: packets %d ticks %u\n",
870 bin_to_size(y), sn->current_rix[y],
871 sn->packets_since_switch[y], sn->ticks_since_switch[y]);
872 kprintf("[%4u] last sample %d cur sample %d packets sent %d\n",
873 bin_to_size(y), sn->last_sample_rix[y],
874 sn->current_sample_rix[y], sn->packets_sent[y]);
875 kprintf("[%4u] packets since sample %d sample tt %u\n",
876 bin_to_size(y), sn->packets_since_sample[y],
879 for (mask = sn->ratemask, rix = 0; mask != 0; mask >>= 1, rix++) {
882 for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) {
883 if (sn->stats[y][rix].total_packets == 0)
885 kprintf("[%2u:%4u] %8d:%-8d (%3d%%) T %8d F %4d avg %5u last %u\n",
886 (rt->info[rix].dot11Rate & IEEE80211_RATE_VAL)/2,
888 sn->stats[y][rix].total_packets,
889 sn->stats[y][rix].packets_acked,
890 (100*sn->stats[y][rix].packets_acked)/sn->stats[y][rix].total_packets,
891 sn->stats[y][rix].tries,
892 sn->stats[y][rix].successive_failures,
893 sn->stats[y][rix].average_tx_time,
894 ticks - sn->stats[y][rix].last_tx);
900 ath_rate_sysctl_stats(SYSCTL_HANDLER_ARGS)
902 struct ath_softc *sc = arg1;
904 struct ieee80211com *ic;
907 wlan_serialize_enter();
911 error = sysctl_handle_int(oidp, &v, 0, req);
912 if (error == 0 && req->newptr)
913 ieee80211_iterate_nodes(&ic->ic_sta, sample_stats, sc);
914 wlan_serialize_exit();
919 ath_rate_sysctl_smoothing_rate(SYSCTL_HANDLER_ARGS)
921 struct sample_softc *ssc = arg1;
924 wlan_serialize_enter();
925 rate = ssc->smoothing_rate;
926 error = sysctl_handle_int(oidp, &rate, 0, req);
927 if (error == 0 && req->newptr) {
928 if (!(0 <= rate && rate < 100)) {
931 ssc->smoothing_rate = rate;
932 ssc->smoothing_minpackets = 100 / (100 - rate);
935 wlan_serialize_exit();
940 ath_rate_sysctl_sample_rate(SYSCTL_HANDLER_ARGS)
942 struct sample_softc *ssc = arg1;
945 wlan_serialize_enter();
946 rate = ssc->sample_rate;
947 error = sysctl_handle_int(oidp, &rate, 0, req);
948 if (error == 0 && req->newptr) {
949 if (!(2 <= rate && rate <= 100))
952 ssc->sample_rate = rate;
954 wlan_serialize_exit();
959 ath_rate_sysctlattach(struct ath_softc *sc, struct sample_softc *ssc)
961 struct sysctl_ctx_list *ctx;
962 struct sysctl_oid *tree;
964 ctx = &sc->sc_sysctl_ctx;
965 tree = sc->sc_sysctl_tree;
967 device_printf(sc->sc_dev, "can't add sysctl node\n");
970 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
971 "smoothing_rate", CTLTYPE_INT | CTLFLAG_RW, ssc, 0,
972 ath_rate_sysctl_smoothing_rate, "I",
973 "sample: smoothing rate for avg tx time (%%)");
974 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
975 "sample_rate", CTLTYPE_INT | CTLFLAG_RW, ssc, 0,
976 ath_rate_sysctl_sample_rate, "I",
977 "sample: percent air time devoted to sampling new rates (%%)");
978 /* XXX max_successive_failures, stale_failure_timeout, min_switch */
979 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
980 "sample_stats", CTLTYPE_INT | CTLFLAG_RW, sc, 0,
981 ath_rate_sysctl_stats, "I", "sample: print statistics");
984 struct ath_ratectrl *
985 ath_rate_attach(struct ath_softc *sc)
987 struct sample_softc *ssc;
989 ssc = kmalloc(sizeof(struct sample_softc), M_DEVBUF, M_NOWAIT|M_ZERO);
992 ssc->arc.arc_space = sizeof(struct sample_node);
993 ssc->smoothing_rate = 95; /* ewma percentage ([0..99]) */
994 ssc->smoothing_minpackets = 100 / (100 - ssc->smoothing_rate);
995 ssc->sample_rate = 10; /* %time to try diff tx rates */
996 ssc->max_successive_failures = 3; /* threshold for rate sampling*/
997 ssc->stale_failure_timeout = 10 * hz; /* 10 seconds */
998 ssc->min_switch = hz; /* 1 second */
999 ath_rate_sysctlattach(sc, ssc);
1004 ath_rate_detach(struct ath_ratectrl *arc)
1006 struct sample_softc *ssc = (struct sample_softc *) arc;
1008 kfree(ssc, M_DEVBUF);
1015 sample_modevent(module_t mod, int type, void *unused)
1019 wlan_serialize_enter();
1024 kprintf("ath_rate: <SampleRate bit-rate "
1025 "selection algorithm>\n");
1036 wlan_serialize_exit();
1041 static moduledata_t sample_mod = {
1046 DECLARE_MODULE(ath_rate, sample_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
1047 MODULE_VERSION(ath_rate, 1);
1048 MODULE_DEPEND(ath_rate, ath_hal, 1, 1, 1); /* Atheros HAL */
1049 MODULE_DEPEND(ath_rate, wlan, 1, 1, 1);