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
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9 * notice, this list of conditions and the following disclaimer,
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14 * similar Disclaimer requirement for further binary redistribution.
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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
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34 * THE POSSIBILITY OF SUCH DAMAGES.
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
42 * John Bicket's SampleRate control algorithm.
47 #include <sys/param.h>
48 #include <sys/systm.h>
49 #include <sys/sysctl.h>
50 #include <sys/kernel.h>
52 #include <sys/mutex.h>
53 #include <sys/errno.h>
55 #include <machine/bus.h>
56 #include <machine/resource.h>
59 #include <sys/socket.h>
62 #include <net/if_media.h>
63 #include <net/if_arp.h>
64 #include <net/ethernet.h> /* XXX for ether_sprintf */
66 #include <net80211/ieee80211_var.h>
71 #include <netinet/in.h>
72 #include <netinet/if_ether.h>
75 #include <dev/ath/if_athvar.h>
76 #include <dev/ath/ath_rate/sample/sample.h>
77 #include <dev/ath/ath_hal/ah_desc.h>
78 #include <dev/ath/ath_rate/sample/tx_schedules.h>
81 * This file is an implementation of the SampleRate algorithm
82 * in "Bit-rate Selection in Wireless Networks"
83 * (http://www.pdos.lcs.mit.edu/papers/jbicket-ms.ps)
85 * SampleRate chooses the bit-rate it predicts will provide the most
86 * throughput based on estimates of the expected per-packet
87 * transmission time for each bit-rate. SampleRate periodically sends
88 * packets at bit-rates other than the current one to estimate when
89 * another bit-rate will provide better performance. SampleRate
90 * switches to another bit-rate when its estimated per-packet
91 * transmission time becomes smaller than the current bit-rate's.
92 * SampleRate reduces the number of bit-rates it must sample by
93 * eliminating those that could not perform better than the one
94 * currently being used. SampleRate also stops probing at a bit-rate
95 * if it experiences several successive losses.
97 * The difference between the algorithm in the thesis and the one in this
98 * file is that the one in this file uses a ewma instead of a window.
100 * Also, this implementation tracks the average transmission time for
101 * a few different packet sizes independently for each link.
104 static void ath_rate_ctl_reset(struct ath_softc *, struct ieee80211_node *);
106 static const int packet_size_bins[NUM_PACKET_SIZE_BINS] = { 250, 1600 };
109 size_to_bin(int size)
111 #if NUM_PACKET_SIZE_BINS > 1
112 if (size <= packet_size_bins[0])
115 #if NUM_PACKET_SIZE_BINS > 2
116 if (size <= packet_size_bins[1])
119 #if NUM_PACKET_SIZE_BINS > 3
120 if (size <= packet_size_bins[2])
123 #if NUM_PACKET_SIZE_BINS > 4
124 #error "add support for more packet sizes"
126 return NUM_PACKET_SIZE_BINS-1;
130 bin_to_size(int index)
132 return packet_size_bins[index];
136 ath_rate_node_init(struct ath_softc *sc, struct ath_node *an)
138 /* NB: assumed to be zero'd by caller */
142 ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an)
147 dot11rate(const HAL_RATE_TABLE *rt, int rix)
149 return rt->info[rix].phy == IEEE80211_T_HT ?
150 rt->info[rix].dot11Rate : (rt->info[rix].dot11Rate & IEEE80211_RATE_VAL) / 2;
154 dot11rate_label(const HAL_RATE_TABLE *rt, int rix)
156 return rt->info[rix].phy == IEEE80211_T_HT ? "MCS" : "Mb ";
160 * Return the rix with the lowest average_tx_time,
161 * or -1 if all the average_tx_times are 0.
164 pick_best_rate(struct ath_node *an, const HAL_RATE_TABLE *rt,
165 int size_bin, int require_acked_before)
167 struct sample_node *sn = ATH_NODE_SAMPLE(an);
168 int best_rate_rix, best_rate_tt;
174 for (mask = sn->ratemask, rix = 0; mask != 0; mask >>= 1, rix++) {
175 if ((mask & 1) == 0) /* not a supported rate */
178 /* Don't pick a non-HT rate for a HT node */
179 if ((an->an_node.ni_flags & IEEE80211_NODE_HT) &&
180 (rt->info[rix].phy != IEEE80211_T_HT)) {
184 tt = sn->stats[size_bin][rix].average_tx_time;
186 (require_acked_before &&
187 !sn->stats[size_bin][rix].packets_acked))
190 /* don't use a bit-rate that has been failing */
191 if (sn->stats[size_bin][rix].successive_failures > 3)
194 if (best_rate_tt == 0 || tt < best_rate_tt) {
199 return (best_rate_tt ? best_rate_rix : -1);
203 * Pick a good "random" bit-rate to sample other than the current one.
206 pick_sample_rate(struct sample_softc *ssc , struct ath_node *an,
207 const HAL_RATE_TABLE *rt, int size_bin)
209 #define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
210 #define MCS(ix) (rt->info[ix].dot11Rate | IEEE80211_RATE_MCS)
211 struct sample_node *sn = ATH_NODE_SAMPLE(an);
212 int current_rix, rix;
216 current_rix = sn->current_rix[size_bin];
217 if (current_rix < 0) {
218 /* no successes yet, send at the lowest bit-rate */
219 /* XXX should return MCS0 if HT */
223 current_tt = sn->stats[size_bin][current_rix].average_tx_time;
225 rix = sn->last_sample_rix[size_bin]+1; /* next sample rate */
226 mask = sn->ratemask &~ (1<<current_rix);/* don't sample current rate */
228 if ((mask & (1<<rix)) == 0) { /* not a supported rate */
230 if (++rix >= rt->rateCount)
235 /* if the node is HT and the rate isn't HT, don't bother sample */
236 if ((an->an_node.ni_flags & IEEE80211_NODE_HT) &&
237 (rt->info[rix].phy != IEEE80211_T_HT)) {
242 /* this bit-rate is always worse than the current one */
243 if (sn->stats[size_bin][rix].perfect_tx_time > current_tt) {
248 /* rarely sample bit-rates that fail a lot */
249 if (sn->stats[size_bin][rix].successive_failures > ssc->max_successive_failures &&
250 ticks - sn->stats[size_bin][rix].last_tx < ssc->stale_failure_timeout) {
255 /* Don't sample more than 2 rates higher for rates > 11M for non-HT rates */
256 if (! (an->an_node.ni_flags & IEEE80211_NODE_HT)) {
257 if (DOT11RATE(rix) > 2*11 && rix > current_rix + 2) {
263 sn->last_sample_rix[size_bin] = rix;
272 ath_rate_get_static_rix(struct ath_softc *sc, const struct ieee80211_node *ni)
274 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
275 #define DOT11RATE(_ix) (rt->info[(_ix)].dot11Rate & IEEE80211_RATE_VAL)
276 #define MCS(_ix) (ni->ni_htrates.rs_rates[_ix] | IEEE80211_RATE_MCS)
277 const struct ieee80211_txparam *tp = ni->ni_txparms;
280 /* Check MCS rates */
281 for (srate = ni->ni_htrates.rs_nrates - 1; srate >= 0; srate--) {
282 if (MCS(srate) == tp->ucastrate)
283 return sc->sc_rixmap[tp->ucastrate];
286 /* Check legacy rates */
287 for (srate = ni->ni_rates.rs_nrates - 1; srate >= 0; srate--) {
288 if (RATE(srate) == tp->ucastrate)
289 return sc->sc_rixmap[tp->ucastrate];
298 ath_rate_update_static_rix(struct ath_softc *sc, struct ieee80211_node *ni)
300 struct ath_node *an = ATH_NODE(ni);
301 const struct ieee80211_txparam *tp = ni->ni_txparms;
302 struct sample_node *sn = ATH_NODE_SAMPLE(an);
304 if (tp != NULL && tp->ucastrate != IEEE80211_FIXED_RATE_NONE) {
306 * A fixed rate is to be used; ucastrate is the IEEE code
307 * for this rate (sans basic bit). Check this against the
308 * negotiated rate set for the node. Note the fixed rate
309 * may not be available for various reasons so we only
310 * setup the static rate index if the lookup is successful.
312 sn->static_rix = ath_rate_get_static_rix(sc, ni);
321 ath_rate_findrate(struct ath_softc *sc, struct ath_node *an,
322 int shortPreamble, size_t frameLen,
323 u_int8_t *rix0, int *try0, u_int8_t *txrate)
325 #define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
326 #define MCS(ix) (rt->info[ix].dot11Rate | IEEE80211_RATE_MCS)
327 #define RATE(ix) (DOT11RATE(ix) / 2)
328 struct sample_node *sn = ATH_NODE_SAMPLE(an);
329 struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc);
330 struct ifnet *ifp = sc->sc_ifp;
331 struct ieee80211com *ic = ifp->if_l2com;
332 const HAL_RATE_TABLE *rt = sc->sc_currates;
333 const int size_bin = size_to_bin(frameLen);
334 int rix, mrr, best_rix, change_rates;
335 unsigned average_tx_time;
337 ath_rate_update_static_rix(sc, &an->an_node);
339 if (sn->static_rix != -1) {
340 rix = sn->static_rix;
341 *try0 = ATH_TXMAXTRY;
345 /* XXX TODO: this doesn't know about 11gn vs 11g protection; teach it */
346 mrr = sc->sc_mrretry && !(ic->ic_flags & IEEE80211_F_USEPROT);
348 best_rix = pick_best_rate(an, rt, size_bin, !mrr);
350 average_tx_time = sn->stats[size_bin][best_rix].average_tx_time;
355 * Limit the time measuring the performance of other tx
356 * rates to sample_rate% of the total transmission time.
358 if (sn->sample_tt[size_bin] < average_tx_time * (sn->packets_since_sample[size_bin]*ssc->sample_rate/100)) {
359 rix = pick_sample_rate(ssc, an, rt, size_bin);
360 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
361 &an->an_node, "size %u sample rate %d current rate %d",
362 bin_to_size(size_bin), RATE(rix),
363 RATE(sn->current_rix[size_bin]));
364 if (rix != sn->current_rix[size_bin]) {
365 sn->current_sample_rix[size_bin] = rix;
367 sn->current_sample_rix[size_bin] = -1;
369 sn->packets_since_sample[size_bin] = 0;
372 if (!sn->packets_sent[size_bin] || best_rix == -1) {
373 /* no packet has been sent successfully yet */
374 for (rix = rt->rateCount-1; rix > 0; rix--) {
375 if ((sn->ratemask & (1<<rix)) == 0)
378 * Pick the highest rate <= 36 Mbps
379 * that hasn't failed.
381 if (DOT11RATE(rix) <= 72 &&
382 sn->stats[size_bin][rix].successive_failures == 0) {
388 } else if (sn->packets_sent[size_bin] < 20) {
389 /* let the bit-rate switch quickly during the first few packets */
391 } else if (ticks - ssc->min_switch > sn->ticks_since_switch[size_bin]) {
392 /* min_switch seconds have gone by */
394 } else if (2*average_tx_time < sn->stats[size_bin][sn->current_rix[size_bin]].average_tx_time) {
395 /* the current bit-rate is twice as slow as the best one */
399 sn->packets_since_sample[size_bin]++;
402 if (best_rix != sn->current_rix[size_bin]) {
403 IEEE80211_NOTE(an->an_node.ni_vap,
404 IEEE80211_MSG_RATECTL,
406 "%s: size %d switch rate %d (%d/%d) -> %d (%d/%d) after %d packets mrr %d",
408 bin_to_size(size_bin),
409 RATE(sn->current_rix[size_bin]),
410 sn->stats[size_bin][sn->current_rix[size_bin]].average_tx_time,
411 sn->stats[size_bin][sn->current_rix[size_bin]].perfect_tx_time,
413 sn->stats[size_bin][best_rix].average_tx_time,
414 sn->stats[size_bin][best_rix].perfect_tx_time,
415 sn->packets_since_switch[size_bin],
418 sn->packets_since_switch[size_bin] = 0;
419 sn->current_rix[size_bin] = best_rix;
420 sn->ticks_since_switch[size_bin] = ticks;
422 * Set the visible txrate for this node.
424 an->an_node.ni_txrate = (rt->info[best_rix].phy == IEEE80211_T_HT) ? MCS(best_rix) : DOT11RATE(best_rix);
426 rix = sn->current_rix[size_bin];
427 sn->packets_since_switch[size_bin]++;
429 *try0 = mrr ? sn->sched[rix].t0 : ATH_TXMAXTRY;
431 KASSERT(rix >= 0 && rix < rt->rateCount, ("rix is %d", rix));
434 *txrate = rt->info[rix].rateCode
435 | (shortPreamble ? rt->info[rix].shortPreamble : 0);
436 sn->packets_sent[size_bin]++;
443 * Get the TX rates. Don't fiddle with short preamble flags for them;
444 * the caller can do that.
447 ath_rate_getxtxrates(struct ath_softc *sc, struct ath_node *an,
448 uint8_t rix0, uint8_t *rix, uint8_t *try)
450 struct sample_node *sn = ATH_NODE_SAMPLE(an);
451 const struct txschedule *sched = &sn->sched[rix0];
453 KASSERT(rix0 == sched->r0, ("rix0 (%x) != sched->r0 (%x)!\n", rix0, sched->r0));
455 /* rix[0] = sched->r0; */
467 ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an,
468 struct ath_desc *ds, int shortPreamble, u_int8_t rix)
470 struct sample_node *sn = ATH_NODE_SAMPLE(an);
471 const struct txschedule *sched = &sn->sched[rix];
472 const HAL_RATE_TABLE *rt = sc->sc_currates;
473 uint8_t rix1, s1code, rix2, s2code, rix3, s3code;
475 /* XXX precalculate short preamble tables */
477 s1code = rt->info[rix1].rateCode
478 | (shortPreamble ? rt->info[rix1].shortPreamble : 0);
480 s2code = rt->info[rix2].rateCode
481 | (shortPreamble ? rt->info[rix2].shortPreamble : 0);
483 s3code = rt->info[rix3].rateCode
484 | (shortPreamble ? rt->info[rix3].shortPreamble : 0);
485 ath_hal_setupxtxdesc(sc->sc_ah, ds,
486 s1code, sched->t1, /* series 1 */
487 s2code, sched->t2, /* series 2 */
488 s3code, sched->t3); /* series 3 */
492 update_stats(struct ath_softc *sc, struct ath_node *an,
494 int rix0, int tries0,
495 int rix1, int tries1,
496 int rix2, int tries2,
497 int rix3, int tries3,
498 int short_tries, int tries, int status)
500 struct sample_node *sn = ATH_NODE_SAMPLE(an);
501 struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc);
502 const int size_bin = size_to_bin(frame_size);
503 const int size = bin_to_size(size_bin);
504 int tt, tries_so_far;
505 int is_ht40 = (an->an_node.ni_chw == 40);
507 if (!IS_RATE_DEFINED(sn, rix0))
509 tt = calc_usecs_unicast_packet(sc, size, rix0, short_tries,
510 MIN(tries0, tries) - 1, is_ht40);
511 tries_so_far = tries0;
513 if (tries1 && tries_so_far < tries) {
514 if (!IS_RATE_DEFINED(sn, rix1))
516 tt += calc_usecs_unicast_packet(sc, size, rix1, short_tries,
517 MIN(tries1 + tries_so_far, tries) - tries_so_far - 1, is_ht40);
518 tries_so_far += tries1;
521 if (tries2 && tries_so_far < tries) {
522 if (!IS_RATE_DEFINED(sn, rix2))
524 tt += calc_usecs_unicast_packet(sc, size, rix2, short_tries,
525 MIN(tries2 + tries_so_far, tries) - tries_so_far - 1, is_ht40);
526 tries_so_far += tries2;
529 if (tries3 && tries_so_far < tries) {
530 if (!IS_RATE_DEFINED(sn, rix3))
532 tt += calc_usecs_unicast_packet(sc, size, rix3, short_tries,
533 MIN(tries3 + tries_so_far, tries) - tries_so_far - 1, is_ht40);
536 if (sn->stats[size_bin][rix0].total_packets < ssc->smoothing_minpackets) {
537 /* just average the first few packets */
538 int avg_tx = sn->stats[size_bin][rix0].average_tx_time;
539 int packets = sn->stats[size_bin][rix0].total_packets;
540 sn->stats[size_bin][rix0].average_tx_time = (tt+(avg_tx*packets))/(packets+1);
543 sn->stats[size_bin][rix0].average_tx_time =
544 ((sn->stats[size_bin][rix0].average_tx_time * ssc->smoothing_rate) +
545 (tt * (100 - ssc->smoothing_rate))) / 100;
550 sn->stats[size_bin][rix0].successive_failures++;
551 for (y = size_bin+1; y < NUM_PACKET_SIZE_BINS; y++) {
553 * Also say larger packets failed since we
554 * assume if a small packet fails at a
555 * bit-rate then a larger one will also.
557 sn->stats[y][rix0].successive_failures++;
558 sn->stats[y][rix0].last_tx = ticks;
559 sn->stats[y][rix0].tries += tries;
560 sn->stats[y][rix0].total_packets++;
563 sn->stats[size_bin][rix0].packets_acked++;
564 sn->stats[size_bin][rix0].successive_failures = 0;
566 sn->stats[size_bin][rix0].tries += tries;
567 sn->stats[size_bin][rix0].last_tx = ticks;
568 sn->stats[size_bin][rix0].total_packets++;
570 if (rix0 == sn->current_sample_rix[size_bin]) {
571 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
573 "%s: size %d %s sample rate %d tries (%d/%d) tt %d avg_tt (%d/%d)",
576 status ? "FAIL" : "OK",
577 rix0, short_tries, tries, tt,
578 sn->stats[size_bin][rix0].average_tx_time,
579 sn->stats[size_bin][rix0].perfect_tx_time);
580 sn->sample_tt[size_bin] = tt;
581 sn->current_sample_rix[size_bin] = -1;
586 badrate(struct ifnet *ifp, int series, int hwrate, int tries, int status)
588 if_printf(ifp, "bad series%d hwrate 0x%x, tries %u ts_status 0x%x\n",
589 series, hwrate, tries, status);
593 ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an,
594 const struct ath_buf *bf)
596 struct ifnet *ifp = sc->sc_ifp;
597 struct ieee80211com *ic = ifp->if_l2com;
598 struct sample_node *sn = ATH_NODE_SAMPLE(an);
599 const struct ath_tx_status *ts = &bf->bf_status.ds_txstat;
600 const struct ath_desc *ds0 = &bf->bf_desc[0];
601 int final_rix, short_tries, long_tries, frame_size;
602 const HAL_RATE_TABLE *rt = sc->sc_currates;
605 final_rix = rt->rateCodeToIndex[ts->ts_rate];
606 short_tries = ts->ts_shortretry;
607 long_tries = ts->ts_longretry + 1;
608 frame_size = ds0->ds_ctl0 & 0x0fff; /* low-order 12 bits of ds_ctl0 */
609 if (frame_size == 0) /* NB: should not happen */
612 if (sn->ratemask == 0) {
613 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
615 "%s: size %d %s rate/try %d/%d no rates yet",
617 bin_to_size(size_to_bin(frame_size)),
618 ts->ts_status ? "FAIL" : "OK",
619 short_tries, long_tries);
622 mrr = sc->sc_mrretry && !(ic->ic_flags & IEEE80211_F_USEPROT);
623 if (!mrr || ts->ts_finaltsi == 0) {
624 if (!IS_RATE_DEFINED(sn, final_rix)) {
625 badrate(ifp, 0, ts->ts_rate, long_tries, ts->ts_status);
629 * Only one rate was used; optimize work.
631 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
632 &an->an_node, "%s: size %d (%d bytes) %s rate/try %d %s/%d/%d",
634 bin_to_size(size_to_bin(frame_size)),
636 ts->ts_status ? "FAIL" : "OK",
637 dot11rate(rt, final_rix), dot11rate_label(rt, final_rix), short_tries, long_tries);
638 update_stats(sc, an, frame_size,
639 final_rix, long_tries,
643 short_tries, long_tries, ts->ts_status);
645 int hwrates[4], tries[4], rix[4];
646 int finalTSIdx = ts->ts_finaltsi;
650 * Process intermediate rates that failed.
652 ath_hal_gettxcompletionrates(sc->sc_ah, ds0, hwrates, tries);
654 for (i = 0; i < 4; i++) {
655 rix[i] = rt->rateCodeToIndex[hwrates[i]];
658 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
660 "%s: size %d (%d bytes) finaltsidx %d tries %d %s rate/try [%d %s/%d %d %s/%d %d %s/%d %d %s/%d]",
662 bin_to_size(size_to_bin(frame_size)),
666 ts->ts_status ? "FAIL" : "OK",
667 dot11rate(rt, rix[0]), dot11rate_label(rt, rix[0]), tries[0],
668 dot11rate(rt, rix[1]), dot11rate_label(rt, rix[1]), tries[1],
669 dot11rate(rt, rix[2]), dot11rate_label(rt, rix[2]), tries[2],
670 dot11rate(rt, rix[3]), dot11rate_label(rt, rix[3]), tries[3]);
672 for (i = 0; i < 4; i++) {
673 if (tries[i] && !IS_RATE_DEFINED(sn, rix[i]))
674 badrate(ifp, 0, hwrates[i], tries[i], ts->ts_status);
678 * NB: series > 0 are not penalized for failure
679 * based on the try counts under the assumption
680 * that losses are often bursty and since we
681 * sample higher rates 1 try at a time doing so
682 * may unfairly penalize them.
685 update_stats(sc, an, frame_size,
690 short_tries, long_tries,
691 long_tries > tries[0]);
692 long_tries -= tries[0];
695 if (tries[1] && finalTSIdx > 0) {
696 update_stats(sc, an, frame_size,
701 short_tries, long_tries,
703 long_tries -= tries[1];
706 if (tries[2] && finalTSIdx > 1) {
707 update_stats(sc, an, frame_size,
712 short_tries, long_tries,
714 long_tries -= tries[2];
717 if (tries[3] && finalTSIdx > 2) {
718 update_stats(sc, an, frame_size,
723 short_tries, long_tries,
730 ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew)
733 ath_rate_ctl_reset(sc, &an->an_node);
736 static const struct txschedule *mrr_schedules[IEEE80211_MODE_MAX+2] = {
737 NULL, /* IEEE80211_MODE_AUTO */
738 series_11a, /* IEEE80211_MODE_11A */
739 series_11g, /* IEEE80211_MODE_11B */
740 series_11g, /* IEEE80211_MODE_11G */
741 NULL, /* IEEE80211_MODE_FH */
742 series_11a, /* IEEE80211_MODE_TURBO_A */
743 series_11g, /* IEEE80211_MODE_TURBO_G */
744 series_11a, /* IEEE80211_MODE_STURBO_A */
745 series_11na, /* IEEE80211_MODE_11NA */
746 series_11ng, /* IEEE80211_MODE_11NG */
747 series_half, /* IEEE80211_MODE_HALF */
748 series_quarter, /* IEEE80211_MODE_QUARTER */
752 * Initialize the tables for a node.
755 ath_rate_ctl_reset(struct ath_softc *sc, struct ieee80211_node *ni)
757 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
758 #define DOT11RATE(_ix) (rt->info[(_ix)].dot11Rate & IEEE80211_RATE_VAL)
759 #define MCS(_ix) (ni->ni_htrates.rs_rates[_ix] | IEEE80211_RATE_MCS)
760 struct ath_node *an = ATH_NODE(ni);
761 struct sample_node *sn = ATH_NODE_SAMPLE(an);
762 const HAL_RATE_TABLE *rt = sc->sc_currates;
765 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
767 KASSERT(sc->sc_curmode < IEEE80211_MODE_MAX+2,
768 ("curmode %u", sc->sc_curmode));
769 sn->sched = mrr_schedules[sc->sc_curmode];
770 KASSERT(sn->sched != NULL,
771 ("no mrr schedule for mode %u", sc->sc_curmode));
774 ath_rate_update_static_rix(sc, ni);
777 * Construct a bitmask of usable rates. This has all
778 * negotiated rates minus those marked by the hal as
779 * to be ignored for doing rate control.
783 if (ni->ni_flags & IEEE80211_NODE_HT) {
784 for (x = 0; x < ni->ni_htrates.rs_nrates; x++) {
785 rix = sc->sc_rixmap[MCS(x)];
788 /* skip rates marked broken by hal */
789 if (!rt->info[rix].valid)
791 KASSERT(rix < SAMPLE_MAXRATES,
792 ("mcs %u has rix %d", MCS(x), rix));
793 sn->ratemask |= 1<<rix;
798 for (x = 0; x < ni->ni_rates.rs_nrates; x++) {
799 rix = sc->sc_rixmap[RATE(x)];
802 /* skip rates marked broken by hal */
803 if (!rt->info[rix].valid)
805 KASSERT(rix < SAMPLE_MAXRATES,
806 ("rate %u has rix %d", RATE(x), rix));
807 sn->ratemask |= 1<<rix;
809 #ifdef IEEE80211_DEBUG
810 if (ieee80211_msg(ni->ni_vap, IEEE80211_MSG_RATECTL)) {
813 ieee80211_note(ni->ni_vap, "[%6D] %s: size 1600 rate/tt",
814 ni->ni_macaddr, ":", __func__);
815 for (mask = sn->ratemask, rix = 0; mask != 0; mask >>= 1, rix++) {
818 printf(" %d %s/%d", dot11rate(rt, rix), dot11rate_label(rt, rix),
819 calc_usecs_unicast_packet(sc, 1600, rix, 0,0,
820 (ni->ni_chw == 40)));
825 for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) {
826 int size = bin_to_size(y);
829 sn->packets_sent[y] = 0;
830 sn->current_sample_rix[y] = -1;
831 sn->last_sample_rix[y] = 0;
832 /* XXX start with first valid rate */
833 sn->current_rix[y] = ffs(sn->ratemask)-1;
836 * Initialize the statistics buckets; these are
837 * indexed by the rate code index.
839 for (rix = 0, mask = sn->ratemask; mask != 0; rix++, mask >>= 1) {
840 if ((mask & 1) == 0) /* not a valid rate */
842 sn->stats[y][rix].successive_failures = 0;
843 sn->stats[y][rix].tries = 0;
844 sn->stats[y][rix].total_packets = 0;
845 sn->stats[y][rix].packets_acked = 0;
846 sn->stats[y][rix].last_tx = 0;
848 sn->stats[y][rix].perfect_tx_time =
849 calc_usecs_unicast_packet(sc, size, rix, 0, 0,
851 sn->stats[y][rix].average_tx_time =
852 sn->stats[y][rix].perfect_tx_time;
856 /* XXX 0, num_rates-1 are wrong */
857 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
858 "%s: %d rates %d%sMbps (%dus)- %d%sMbps (%dus)", __func__,
860 DOT11RATE(0)/2, DOT11RATE(0) % 1 ? ".5" : "",
861 sn->stats[1][0].perfect_tx_time,
862 DOT11RATE(sn->num_rates-1)/2, DOT11RATE(sn->num_rates-1) % 1 ? ".5" : "",
863 sn->stats[1][sn->num_rates-1].perfect_tx_time
866 /* set the visible bit-rate */
867 if (sn->static_rix != -1)
868 ni->ni_txrate = DOT11RATE(sn->static_rix);
870 ni->ni_txrate = RATE(0);
876 sample_stats(void *arg, struct ieee80211_node *ni)
878 struct ath_softc *sc = arg;
879 const HAL_RATE_TABLE *rt = sc->sc_currates;
880 struct sample_node *sn = ATH_NODE_SAMPLE(ATH_NODE(ni));
884 printf("\n[%s] refcnt %d static_rix %d ratemask 0x%x\n",
885 ether_sprintf(ni->ni_macaddr), ieee80211_node_refcnt(ni),
886 sn->static_rix, sn->ratemask);
887 for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) {
888 printf("[%4u] cur rix %d (%d %s) since switch: packets %d ticks %u\n",
889 bin_to_size(y), sn->current_rix[y],
890 dot11rate(rt, sn->current_rix[y]),
891 dot11rate_label(rt, sn->current_rix[y]),
892 sn->packets_since_switch[y], sn->ticks_since_switch[y]);
893 printf("[%4u] last sample %d cur sample %d packets sent %d\n",
894 bin_to_size(y), sn->last_sample_rix[y],
895 sn->current_sample_rix[y], sn->packets_sent[y]);
896 printf("[%4u] packets since sample %d sample tt %u\n",
897 bin_to_size(y), sn->packets_since_sample[y],
900 for (mask = sn->ratemask, rix = 0; mask != 0; mask >>= 1, rix++) {
903 for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) {
904 if (sn->stats[y][rix].total_packets == 0)
906 printf("[%2u %s:%4u] %8d:%-8d (%3d%%) T %8d F %4d avg %5u last %u\n",
907 dot11rate(rt, rix), dot11rate_label(rt, rix),
909 sn->stats[y][rix].total_packets,
910 sn->stats[y][rix].packets_acked,
911 (100*sn->stats[y][rix].packets_acked)/sn->stats[y][rix].total_packets,
912 sn->stats[y][rix].tries,
913 sn->stats[y][rix].successive_failures,
914 sn->stats[y][rix].average_tx_time,
915 ticks - sn->stats[y][rix].last_tx);
921 ath_rate_sysctl_stats(SYSCTL_HANDLER_ARGS)
923 struct ath_softc *sc = arg1;
924 struct ifnet *ifp = sc->sc_ifp;
925 struct ieee80211com *ic = ifp->if_l2com;
929 error = sysctl_handle_int(oidp, &v, 0, req);
930 if (error || !req->newptr)
932 ieee80211_iterate_nodes(&ic->ic_sta, sample_stats, sc);
937 ath_rate_sysctl_smoothing_rate(SYSCTL_HANDLER_ARGS)
939 struct sample_softc *ssc = arg1;
942 rate = ssc->smoothing_rate;
943 error = sysctl_handle_int(oidp, &rate, 0, req);
944 if (error || !req->newptr)
946 if (!(0 <= rate && rate < 100))
948 ssc->smoothing_rate = rate;
949 ssc->smoothing_minpackets = 100 / (100 - rate);
954 ath_rate_sysctl_sample_rate(SYSCTL_HANDLER_ARGS)
956 struct sample_softc *ssc = arg1;
959 rate = ssc->sample_rate;
960 error = sysctl_handle_int(oidp, &rate, 0, req);
961 if (error || !req->newptr)
963 if (!(2 <= rate && rate <= 100))
965 ssc->sample_rate = rate;
970 ath_rate_sysctlattach(struct ath_softc *sc, struct sample_softc *ssc)
972 struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev);
973 struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev);
975 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
976 "smoothing_rate", CTLTYPE_INT | CTLFLAG_RW, ssc, 0,
977 ath_rate_sysctl_smoothing_rate, "I",
978 "sample: smoothing rate for avg tx time (%%)");
979 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
980 "sample_rate", CTLTYPE_INT | CTLFLAG_RW, ssc, 0,
981 ath_rate_sysctl_sample_rate, "I",
982 "sample: percent air time devoted to sampling new rates (%%)");
983 /* XXX max_successive_failures, stale_failure_timeout, min_switch */
984 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
985 "sample_stats", CTLTYPE_INT | CTLFLAG_RW, sc, 0,
986 ath_rate_sysctl_stats, "I", "sample: print statistics");
989 struct ath_ratectrl *
990 ath_rate_attach(struct ath_softc *sc)
992 struct sample_softc *ssc;
994 ssc = malloc(sizeof(struct sample_softc), M_DEVBUF, M_NOWAIT|M_ZERO);
997 ssc->arc.arc_space = sizeof(struct sample_node);
998 ssc->smoothing_rate = 95; /* ewma percentage ([0..99]) */
999 ssc->smoothing_minpackets = 100 / (100 - ssc->smoothing_rate);
1000 ssc->sample_rate = 10; /* %time to try diff tx rates */
1001 ssc->max_successive_failures = 3; /* threshold for rate sampling*/
1002 ssc->stale_failure_timeout = 10 * hz; /* 10 seconds */
1003 ssc->min_switch = hz; /* 1 second */
1004 ath_rate_sysctlattach(sc, ssc);
1009 ath_rate_detach(struct ath_ratectrl *arc)
1011 struct sample_softc *ssc = (struct sample_softc *) arc;
1013 free(ssc, M_DEVBUF);