2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 2005 John Bicket
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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11 * notice, this list of conditions and the following disclaimer,
12 * without modification.
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16 * similar Disclaimer requirement for further binary redistribution.
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18 * of any contributors may be used to endorse or promote products derived
19 * from this software without specific prior written permission.
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.
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36 * THE POSSIBILITY OF SUCH DAMAGES.
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
44 * John Bicket's SampleRate control algorithm.
51 #include <sys/param.h>
52 #include <sys/systm.h>
53 #include <sys/sysctl.h>
54 #include <sys/kernel.h>
56 #include <sys/malloc.h>
57 #include <sys/mutex.h>
58 #include <sys/errno.h>
60 #include <machine/bus.h>
61 #include <machine/resource.h>
64 #include <sys/socket.h>
67 #include <net/if_var.h>
68 #include <net/if_media.h>
69 #include <net/if_arp.h>
70 #include <net/ethernet.h> /* XXX for ether_sprintf */
72 #include <net80211/ieee80211_var.h>
77 #include <netinet/in.h>
78 #include <netinet/if_ether.h>
81 #include <dev/ath/if_athvar.h>
82 #include <dev/ath/ath_rate/sample/sample.h>
83 #include <dev/ath/ath_hal/ah_desc.h>
84 #include <dev/ath/ath_rate/sample/tx_schedules.h>
87 * This file is an implementation of the SampleRate algorithm
88 * in "Bit-rate Selection in Wireless Networks"
89 * (http://www.pdos.lcs.mit.edu/papers/jbicket-ms.ps)
91 * SampleRate chooses the bit-rate it predicts will provide the most
92 * throughput based on estimates of the expected per-packet
93 * transmission time for each bit-rate. SampleRate periodically sends
94 * packets at bit-rates other than the current one to estimate when
95 * another bit-rate will provide better performance. SampleRate
96 * switches to another bit-rate when its estimated per-packet
97 * transmission time becomes smaller than the current bit-rate's.
98 * SampleRate reduces the number of bit-rates it must sample by
99 * eliminating those that could not perform better than the one
100 * currently being used. SampleRate also stops probing at a bit-rate
101 * if it experiences several successive losses.
103 * The difference between the algorithm in the thesis and the one in this
104 * file is that the one in this file uses a ewma instead of a window.
106 * Also, this implementation tracks the average transmission time for
107 * a few different packet sizes independently for each link.
110 static void ath_rate_ctl_reset(struct ath_softc *, struct ieee80211_node *);
113 size_to_bin(int size)
115 #if NUM_PACKET_SIZE_BINS > 1
116 if (size <= packet_size_bins[0])
119 #if NUM_PACKET_SIZE_BINS > 2
120 if (size <= packet_size_bins[1])
123 #if NUM_PACKET_SIZE_BINS > 3
124 if (size <= packet_size_bins[2])
127 #if NUM_PACKET_SIZE_BINS > 4
128 #error "add support for more packet sizes"
130 return NUM_PACKET_SIZE_BINS-1;
134 ath_rate_node_init(struct ath_softc *sc, struct ath_node *an)
136 /* NB: assumed to be zero'd by caller */
140 ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an)
145 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)
158 return rt->info[rix].phy == IEEE80211_T_HT ? "MCS" : "Mb ";
162 * Return the rix with the lowest average_tx_time,
163 * or -1 if all the average_tx_times are 0.
166 pick_best_rate(struct ath_node *an, const HAL_RATE_TABLE *rt,
167 int size_bin, int require_acked_before)
169 struct sample_node *sn = ATH_NODE_SAMPLE(an);
170 int best_rate_rix, best_rate_tt, best_rate_pct;
177 for (mask = sn->ratemask, rix = 0; mask != 0; mask >>= 1, rix++) {
178 if ((mask & 1) == 0) /* not a supported rate */
181 /* Don't pick a non-HT rate for a HT node */
182 if ((an->an_node.ni_flags & IEEE80211_NODE_HT) &&
183 (rt->info[rix].phy != IEEE80211_T_HT)) {
187 tt = sn->stats[size_bin][rix].average_tx_time;
189 (require_acked_before &&
190 !sn->stats[size_bin][rix].packets_acked))
193 /* Calculate percentage if possible */
194 if (sn->stats[size_bin][rix].total_packets > 0) {
195 pct = sn->stats[size_bin][rix].ewma_pct;
197 /* XXX for now, assume 95% ok */
201 /* don't use a bit-rate that has been failing */
202 if (sn->stats[size_bin][rix].successive_failures > 3)
206 * For HT, Don't use a bit rate that is much more
207 * lossy than the best.
209 * XXX this isn't optimal; it's just designed to
210 * eliminate rates that are going to be obviously
213 if (an->an_node.ni_flags & IEEE80211_NODE_HT) {
214 if (best_rate_pct > (pct + 50))
219 * For non-MCS rates, use the current average txtime for
222 if (! (an->an_node.ni_flags & IEEE80211_NODE_HT)) {
223 if (best_rate_tt == 0 || tt <= best_rate_tt) {
231 * Since 2 stream rates have slightly higher TX times,
232 * allow a little bit of leeway. This should later
233 * be abstracted out and properly handled.
235 if (an->an_node.ni_flags & IEEE80211_NODE_HT) {
236 if (best_rate_tt == 0 || (tt * 8 <= best_rate_tt * 10)) {
243 return (best_rate_tt ? best_rate_rix : -1);
247 * Pick a good "random" bit-rate to sample other than the current one.
250 pick_sample_rate(struct sample_softc *ssc , struct ath_node *an,
251 const HAL_RATE_TABLE *rt, int size_bin)
253 #define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
254 #define MCS(ix) (rt->info[ix].dot11Rate | IEEE80211_RATE_MCS)
255 struct sample_node *sn = ATH_NODE_SAMPLE(an);
256 int current_rix, rix;
260 current_rix = sn->current_rix[size_bin];
261 if (current_rix < 0) {
262 /* no successes yet, send at the lowest bit-rate */
263 /* XXX should return MCS0 if HT */
267 current_tt = sn->stats[size_bin][current_rix].average_tx_time;
269 rix = sn->last_sample_rix[size_bin]+1; /* next sample rate */
270 mask = sn->ratemask &~ ((uint64_t) 1<<current_rix);/* don't sample current rate */
272 if ((mask & ((uint64_t) 1<<rix)) == 0) { /* not a supported rate */
274 if (++rix >= rt->rateCount)
280 * The following code stops trying to sample
281 * non-MCS rates when speaking to an MCS node.
282 * However, at least for CCK rates in 2.4GHz mode,
283 * the non-MCS rates MAY actually provide better
284 * PER at the very far edge of reception.
286 * However! Until ath_rate_form_aggr() grows
287 * some logic to not form aggregates if the
288 * selected rate is non-MCS, this won't work.
290 * So don't disable this code until you've taught
291 * ath_rate_form_aggr() to drop out if any of
292 * the selected rates are non-MCS.
295 /* if the node is HT and the rate isn't HT, don't bother sample */
296 if ((an->an_node.ni_flags & IEEE80211_NODE_HT) &&
297 (rt->info[rix].phy != IEEE80211_T_HT)) {
298 mask &= ~((uint64_t) 1<<rix);
303 /* this bit-rate is always worse than the current one */
304 if (sn->stats[size_bin][rix].perfect_tx_time > current_tt) {
305 mask &= ~((uint64_t) 1<<rix);
309 /* rarely sample bit-rates that fail a lot */
310 if (sn->stats[size_bin][rix].successive_failures > ssc->max_successive_failures &&
311 ticks - sn->stats[size_bin][rix].last_tx < ssc->stale_failure_timeout) {
312 mask &= ~((uint64_t) 1<<rix);
317 * For HT, only sample a few rates on either side of the
318 * current rix; there's quite likely a lot of them.
320 if (an->an_node.ni_flags & IEEE80211_NODE_HT) {
321 if (rix < (current_rix - 3) ||
322 rix > (current_rix + 3)) {
323 mask &= ~((uint64_t) 1<<rix);
328 /* Don't sample more than 2 rates higher for rates > 11M for non-HT rates */
329 if (! (an->an_node.ni_flags & IEEE80211_NODE_HT)) {
330 if (DOT11RATE(rix) > 2*11 && rix > current_rix + 2) {
331 mask &= ~((uint64_t) 1<<rix);
336 sn->last_sample_rix[size_bin] = rix;
345 ath_rate_get_static_rix(struct ath_softc *sc, const struct ieee80211_node *ni)
347 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
348 #define DOT11RATE(_ix) (rt->info[(_ix)].dot11Rate & IEEE80211_RATE_VAL)
349 #define MCS(_ix) (ni->ni_htrates.rs_rates[_ix] | IEEE80211_RATE_MCS)
350 const struct ieee80211_txparam *tp = ni->ni_txparms;
353 /* Check MCS rates */
354 for (srate = ni->ni_htrates.rs_nrates - 1; srate >= 0; srate--) {
355 if (MCS(srate) == tp->ucastrate)
356 return sc->sc_rixmap[tp->ucastrate];
359 /* Check legacy rates */
360 for (srate = ni->ni_rates.rs_nrates - 1; srate >= 0; srate--) {
361 if (RATE(srate) == tp->ucastrate)
362 return sc->sc_rixmap[tp->ucastrate];
371 ath_rate_update_static_rix(struct ath_softc *sc, struct ieee80211_node *ni)
373 struct ath_node *an = ATH_NODE(ni);
374 const struct ieee80211_txparam *tp = ni->ni_txparms;
375 struct sample_node *sn = ATH_NODE_SAMPLE(an);
377 if (tp != NULL && tp->ucastrate != IEEE80211_FIXED_RATE_NONE) {
379 * A fixed rate is to be used; ucastrate is the IEEE code
380 * for this rate (sans basic bit). Check this against the
381 * negotiated rate set for the node. Note the fixed rate
382 * may not be available for various reasons so we only
383 * setup the static rate index if the lookup is successful.
385 sn->static_rix = ath_rate_get_static_rix(sc, ni);
392 * Pick a non-HT rate to begin using.
395 ath_rate_pick_seed_rate_legacy(struct ath_softc *sc, struct ath_node *an,
398 #define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
399 #define MCS(ix) (rt->info[ix].dot11Rate | IEEE80211_RATE_MCS)
400 #define RATE(ix) (DOT11RATE(ix) / 2)
402 const HAL_RATE_TABLE *rt = sc->sc_currates;
403 struct sample_node *sn = ATH_NODE_SAMPLE(an);
404 const int size_bin = size_to_bin(frameLen);
406 /* no packet has been sent successfully yet */
407 for (rix = rt->rateCount-1; rix > 0; rix--) {
408 if ((sn->ratemask & ((uint64_t) 1<<rix)) == 0)
412 if (rt->info[rix].phy == IEEE80211_T_HT)
416 * Pick the highest rate <= 36 Mbps
417 * that hasn't failed.
419 if (DOT11RATE(rix) <= 72 &&
420 sn->stats[size_bin][rix].successive_failures == 0) {
431 * Pick a HT rate to begin using.
433 * Don't use any non-HT rates; only consider HT rates.
436 ath_rate_pick_seed_rate_ht(struct ath_softc *sc, struct ath_node *an,
439 #define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
440 #define MCS(ix) (rt->info[ix].dot11Rate | IEEE80211_RATE_MCS)
441 #define RATE(ix) (DOT11RATE(ix) / 2)
442 int rix = -1, ht_rix = -1;
443 const HAL_RATE_TABLE *rt = sc->sc_currates;
444 struct sample_node *sn = ATH_NODE_SAMPLE(an);
445 const int size_bin = size_to_bin(frameLen);
447 /* no packet has been sent successfully yet */
448 for (rix = rt->rateCount-1; rix > 0; rix--) {
449 /* Skip rates we can't use */
450 if ((sn->ratemask & ((uint64_t) 1<<rix)) == 0)
453 /* Keep a copy of the last seen HT rate index */
454 if (rt->info[rix].phy == IEEE80211_T_HT)
457 /* Skip non-HT rates */
458 if (rt->info[rix].phy != IEEE80211_T_HT)
462 * Pick a medium-speed rate regardless of stream count
463 * which has not seen any failures. Higher rates may fail;
464 * we'll try them later.
466 if (((MCS(rix) & 0x7) <= 4) &&
467 sn->stats[size_bin][rix].successive_failures == 0) {
473 * If all the MCS rates have successive failures, rix should be
474 * > 0; otherwise use the lowest MCS rix (hopefully MCS 0.)
476 return MAX(rix, ht_rix);
484 ath_rate_findrate(struct ath_softc *sc, struct ath_node *an,
485 int shortPreamble, size_t frameLen,
486 u_int8_t *rix0, int *try0, u_int8_t *txrate)
488 #define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
489 #define MCS(ix) (rt->info[ix].dot11Rate | IEEE80211_RATE_MCS)
490 #define RATE(ix) (DOT11RATE(ix) / 2)
491 struct sample_node *sn = ATH_NODE_SAMPLE(an);
492 struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc);
493 struct ieee80211com *ic = &sc->sc_ic;
494 const HAL_RATE_TABLE *rt = sc->sc_currates;
495 const int size_bin = size_to_bin(frameLen);
496 int rix, mrr, best_rix, change_rates;
497 unsigned average_tx_time;
499 ath_rate_update_static_rix(sc, &an->an_node);
501 if (sn->currates != sc->sc_currates) {
502 device_printf(sc->sc_dev, "%s: currates != sc_currates!\n",
505 *try0 = ATH_TXMAXTRY;
509 if (sn->static_rix != -1) {
510 rix = sn->static_rix;
511 *try0 = ATH_TXMAXTRY;
515 mrr = sc->sc_mrretry;
516 /* XXX check HT protmode too */
517 if (mrr && (ic->ic_flags & IEEE80211_F_USEPROT && !sc->sc_mrrprot))
520 best_rix = pick_best_rate(an, rt, size_bin, !mrr);
522 average_tx_time = sn->stats[size_bin][best_rix].average_tx_time;
527 * Limit the time measuring the performance of other tx
528 * rates to sample_rate% of the total transmission time.
530 if (sn->sample_tt[size_bin] < average_tx_time * (sn->packets_since_sample[size_bin]*ssc->sample_rate/100)) {
531 rix = pick_sample_rate(ssc, an, rt, size_bin);
532 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
533 &an->an_node, "att %d sample_tt %d size %u sample rate %d %s current rate %d %s",
535 sn->sample_tt[size_bin],
536 bin_to_size(size_bin),
538 dot11rate_label(rt, rix),
539 dot11rate(rt, sn->current_rix[size_bin]),
540 dot11rate_label(rt, sn->current_rix[size_bin]));
541 if (rix != sn->current_rix[size_bin]) {
542 sn->current_sample_rix[size_bin] = rix;
544 sn->current_sample_rix[size_bin] = -1;
546 sn->packets_since_sample[size_bin] = 0;
549 if (!sn->packets_sent[size_bin] || best_rix == -1) {
550 /* no packet has been sent successfully yet */
552 if (an->an_node.ni_flags & IEEE80211_NODE_HT)
554 ath_rate_pick_seed_rate_ht(sc, an, frameLen);
557 ath_rate_pick_seed_rate_legacy(sc, an, frameLen);
558 } else if (sn->packets_sent[size_bin] < 20) {
559 /* let the bit-rate switch quickly during the first few packets */
560 IEEE80211_NOTE(an->an_node.ni_vap,
561 IEEE80211_MSG_RATECTL, &an->an_node,
562 "%s: switching quickly..", __func__);
564 } else if (ticks - ssc->min_switch > sn->ticks_since_switch[size_bin]) {
565 /* min_switch seconds have gone by */
566 IEEE80211_NOTE(an->an_node.ni_vap,
567 IEEE80211_MSG_RATECTL, &an->an_node,
568 "%s: min_switch %d > ticks_since_switch %d..",
569 __func__, ticks - ssc->min_switch, sn->ticks_since_switch[size_bin]);
571 } else if ((! (an->an_node.ni_flags & IEEE80211_NODE_HT)) &&
572 (2*average_tx_time < sn->stats[size_bin][sn->current_rix[size_bin]].average_tx_time)) {
573 /* the current bit-rate is twice as slow as the best one */
574 IEEE80211_NOTE(an->an_node.ni_vap,
575 IEEE80211_MSG_RATECTL, &an->an_node,
576 "%s: 2x att (= %d) < cur_rix att %d",
578 2 * average_tx_time, sn->stats[size_bin][sn->current_rix[size_bin]].average_tx_time);
580 } else if ((an->an_node.ni_flags & IEEE80211_NODE_HT)) {
581 int cur_rix = sn->current_rix[size_bin];
582 int cur_att = sn->stats[size_bin][cur_rix].average_tx_time;
584 * If the node is HT, upgrade it if the MCS rate is
585 * higher and the average tx time is within 20% of
586 * the current rate. It can fail a little.
588 * This is likely not optimal!
591 printf("cur rix/att %x/%d, best rix/att %x/%d\n",
592 MCS(cur_rix), cur_att, MCS(best_rix), average_tx_time);
594 if ((MCS(best_rix) > MCS(cur_rix)) &&
595 (average_tx_time * 8) <= (cur_att * 10)) {
596 IEEE80211_NOTE(an->an_node.ni_vap,
597 IEEE80211_MSG_RATECTL, &an->an_node,
598 "%s: HT: best_rix 0x%d > cur_rix 0x%x, average_tx_time %d, cur_att %d",
600 MCS(best_rix), MCS(cur_rix), average_tx_time, cur_att);
605 sn->packets_since_sample[size_bin]++;
608 if (best_rix != sn->current_rix[size_bin]) {
609 IEEE80211_NOTE(an->an_node.ni_vap,
610 IEEE80211_MSG_RATECTL,
612 "%s: size %d switch rate %d (%d/%d) -> %d (%d/%d) after %d packets mrr %d",
614 bin_to_size(size_bin),
615 RATE(sn->current_rix[size_bin]),
616 sn->stats[size_bin][sn->current_rix[size_bin]].average_tx_time,
617 sn->stats[size_bin][sn->current_rix[size_bin]].perfect_tx_time,
619 sn->stats[size_bin][best_rix].average_tx_time,
620 sn->stats[size_bin][best_rix].perfect_tx_time,
621 sn->packets_since_switch[size_bin],
624 sn->packets_since_switch[size_bin] = 0;
625 sn->current_rix[size_bin] = best_rix;
626 sn->ticks_since_switch[size_bin] = ticks;
628 * Set the visible txrate for this node.
630 an->an_node.ni_txrate = (rt->info[best_rix].phy == IEEE80211_T_HT) ? MCS(best_rix) : DOT11RATE(best_rix);
632 rix = sn->current_rix[size_bin];
633 sn->packets_since_switch[size_bin]++;
635 *try0 = mrr ? sn->sched[rix].t0 : ATH_TXMAXTRY;
639 * This bug totally sucks and should be fixed.
641 * For now though, let's not panic, so we can start to figure
642 * out how to better reproduce it.
644 if (rix < 0 || rix >= rt->rateCount) {
645 printf("%s: ERROR: rix %d out of bounds (rateCount=%d)\n",
649 rix = 0; /* XXX just default for now */
651 KASSERT(rix >= 0 && rix < rt->rateCount, ("rix is %d", rix));
654 *txrate = rt->info[rix].rateCode
655 | (shortPreamble ? rt->info[rix].shortPreamble : 0);
656 sn->packets_sent[size_bin]++;
663 * Get the TX rates. Don't fiddle with short preamble flags for them;
664 * the caller can do that.
667 ath_rate_getxtxrates(struct ath_softc *sc, struct ath_node *an,
668 uint8_t rix0, struct ath_rc_series *rc)
670 struct sample_node *sn = ATH_NODE_SAMPLE(an);
671 const struct txschedule *sched = &sn->sched[rix0];
673 KASSERT(rix0 == sched->r0, ("rix0 (%x) != sched->r0 (%x)!\n",
676 rc[0].flags = rc[1].flags = rc[2].flags = rc[3].flags = 0;
678 rc[0].rix = sched->r0;
679 rc[1].rix = sched->r1;
680 rc[2].rix = sched->r2;
681 rc[3].rix = sched->r3;
683 rc[0].tries = sched->t0;
684 rc[1].tries = sched->t1;
685 rc[2].tries = sched->t2;
686 rc[3].tries = sched->t3;
690 ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an,
691 struct ath_desc *ds, int shortPreamble, u_int8_t rix)
693 struct sample_node *sn = ATH_NODE_SAMPLE(an);
694 const struct txschedule *sched = &sn->sched[rix];
695 const HAL_RATE_TABLE *rt = sc->sc_currates;
696 uint8_t rix1, s1code, rix2, s2code, rix3, s3code;
698 /* XXX precalculate short preamble tables */
700 s1code = rt->info[rix1].rateCode
701 | (shortPreamble ? rt->info[rix1].shortPreamble : 0);
703 s2code = rt->info[rix2].rateCode
704 | (shortPreamble ? rt->info[rix2].shortPreamble : 0);
706 s3code = rt->info[rix3].rateCode
707 | (shortPreamble ? rt->info[rix3].shortPreamble : 0);
708 ath_hal_setupxtxdesc(sc->sc_ah, ds,
709 s1code, sched->t1, /* series 1 */
710 s2code, sched->t2, /* series 2 */
711 s3code, sched->t3); /* series 3 */
715 update_stats(struct ath_softc *sc, struct ath_node *an,
717 int rix0, int tries0,
718 int rix1, int tries1,
719 int rix2, int tries2,
720 int rix3, int tries3,
721 int short_tries, int tries, int status,
722 int nframes, int nbad)
724 struct sample_node *sn = ATH_NODE_SAMPLE(an);
725 struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc);
726 #ifdef IEEE80211_DEBUG
727 const HAL_RATE_TABLE *rt = sc->sc_currates;
729 const int size_bin = size_to_bin(frame_size);
730 const int size = bin_to_size(size_bin);
731 int tt, tries_so_far;
732 int is_ht40 = (an->an_node.ni_chw == 40);
735 if (!IS_RATE_DEFINED(sn, rix0))
737 tt = calc_usecs_unicast_packet(sc, size, rix0, short_tries,
738 MIN(tries0, tries) - 1, is_ht40);
739 tries_so_far = tries0;
741 if (tries1 && tries_so_far < tries) {
742 if (!IS_RATE_DEFINED(sn, rix1))
744 tt += calc_usecs_unicast_packet(sc, size, rix1, short_tries,
745 MIN(tries1 + tries_so_far, tries) - tries_so_far - 1, is_ht40);
746 tries_so_far += tries1;
749 if (tries2 && tries_so_far < tries) {
750 if (!IS_RATE_DEFINED(sn, rix2))
752 tt += calc_usecs_unicast_packet(sc, size, rix2, short_tries,
753 MIN(tries2 + tries_so_far, tries) - tries_so_far - 1, is_ht40);
754 tries_so_far += tries2;
757 if (tries3 && tries_so_far < tries) {
758 if (!IS_RATE_DEFINED(sn, rix3))
760 tt += calc_usecs_unicast_packet(sc, size, rix3, short_tries,
761 MIN(tries3 + tries_so_far, tries) - tries_so_far - 1, is_ht40);
764 if (sn->stats[size_bin][rix0].total_packets < ssc->smoothing_minpackets) {
765 /* just average the first few packets */
766 int avg_tx = sn->stats[size_bin][rix0].average_tx_time;
767 int packets = sn->stats[size_bin][rix0].total_packets;
768 sn->stats[size_bin][rix0].average_tx_time = (tt+(avg_tx*packets))/(packets+nframes);
771 sn->stats[size_bin][rix0].average_tx_time =
772 ((sn->stats[size_bin][rix0].average_tx_time * ssc->smoothing_rate) +
773 (tt * (100 - ssc->smoothing_rate))) / 100;
777 * XXX Don't mark the higher bit rates as also having failed; as this
778 * unfortunately stops those rates from being tasted when trying to
779 * TX. This happens with 11n aggregation.
781 * This is valid for higher CCK rates, higher OFDM rates, and higher
782 * HT rates within the current number of streams (eg MCS0..7, 8..15,
785 if (nframes == nbad) {
789 sn->stats[size_bin][rix0].successive_failures += nbad;
791 for (y = size_bin+1; y < NUM_PACKET_SIZE_BINS; y++) {
793 * Also say larger packets failed since we
794 * assume if a small packet fails at a
795 * bit-rate then a larger one will also.
797 sn->stats[y][rix0].successive_failures += nbad;
798 sn->stats[y][rix0].last_tx = ticks;
799 sn->stats[y][rix0].tries += tries;
800 sn->stats[y][rix0].total_packets += nframes;
804 sn->stats[size_bin][rix0].packets_acked += (nframes - nbad);
805 sn->stats[size_bin][rix0].successive_failures = 0;
807 sn->stats[size_bin][rix0].tries += tries;
808 sn->stats[size_bin][rix0].last_tx = ticks;
809 sn->stats[size_bin][rix0].total_packets += nframes;
811 /* update EWMA for this rix */
813 /* Calculate percentage based on current rate */
816 pct = ((nframes - nbad) * 1000) / nframes;
818 if (sn->stats[size_bin][rix0].total_packets <
819 ssc->smoothing_minpackets) {
820 /* just average the first few packets */
821 int a_pct = (sn->stats[size_bin][rix0].packets_acked * 1000) /
822 (sn->stats[size_bin][rix0].total_packets);
823 sn->stats[size_bin][rix0].ewma_pct = a_pct;
826 sn->stats[size_bin][rix0].ewma_pct =
827 ((sn->stats[size_bin][rix0].ewma_pct * ssc->smoothing_rate) +
828 (pct * (100 - ssc->smoothing_rate))) / 100;
832 if (rix0 == sn->current_sample_rix[size_bin]) {
833 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
835 "%s: size %d %s sample rate %d %s tries (%d/%d) tt %d avg_tt (%d/%d) nfrm %d nbad %d",
838 status ? "FAIL" : "OK",
840 dot11rate_label(rt, rix0),
841 short_tries, tries, tt,
842 sn->stats[size_bin][rix0].average_tx_time,
843 sn->stats[size_bin][rix0].perfect_tx_time,
845 sn->sample_tt[size_bin] = tt;
846 sn->current_sample_rix[size_bin] = -1;
851 badrate(struct ath_softc *sc, int series, int hwrate, int tries, int status)
854 device_printf(sc->sc_dev,
855 "bad series%d hwrate 0x%x, tries %u ts_status 0x%x\n",
856 series, hwrate, tries, status);
860 ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an,
861 const struct ath_rc_series *rc, const struct ath_tx_status *ts,
862 int frame_size, int nframes, int nbad)
864 struct ieee80211com *ic = &sc->sc_ic;
865 struct sample_node *sn = ATH_NODE_SAMPLE(an);
866 int final_rix, short_tries, long_tries;
867 const HAL_RATE_TABLE *rt = sc->sc_currates;
868 int status = ts->ts_status;
871 final_rix = rt->rateCodeToIndex[ts->ts_rate];
872 short_tries = ts->ts_shortretry;
873 long_tries = ts->ts_longretry + 1;
876 device_printf(sc->sc_dev, "%s: nframes=0?\n", __func__);
880 if (frame_size == 0) /* NB: should not happen */
883 if (sn->ratemask == 0) {
884 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
886 "%s: size %d %s rate/try %d/%d no rates yet",
888 bin_to_size(size_to_bin(frame_size)),
889 status ? "FAIL" : "OK",
890 short_tries, long_tries);
893 mrr = sc->sc_mrretry;
894 /* XXX check HT protmode too */
895 if (mrr && (ic->ic_flags & IEEE80211_F_USEPROT && !sc->sc_mrrprot))
898 if (!mrr || ts->ts_finaltsi == 0) {
899 if (!IS_RATE_DEFINED(sn, final_rix)) {
900 device_printf(sc->sc_dev,
901 "%s: ts_rate=%d ts_finaltsi=%d, final_rix=%d\n",
902 __func__, ts->ts_rate, ts->ts_finaltsi, final_rix);
903 badrate(sc, 0, ts->ts_rate, long_tries, status);
907 * Only one rate was used; optimize work.
909 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
910 &an->an_node, "%s: size %d (%d bytes) %s rate/short/long %d %s/%d/%d nframes/nbad [%d/%d]",
912 bin_to_size(size_to_bin(frame_size)),
914 status ? "FAIL" : "OK",
915 dot11rate(rt, final_rix), dot11rate_label(rt, final_rix),
916 short_tries, long_tries, nframes, nbad);
917 update_stats(sc, an, frame_size,
918 final_rix, long_tries,
922 short_tries, long_tries, status,
926 int finalTSIdx = ts->ts_finaltsi;
930 * Process intermediate rates that failed.
933 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
935 "%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]",
937 bin_to_size(size_to_bin(frame_size)),
942 status ? "FAIL" : "OK",
943 dot11rate(rt, rc[0].rix),
944 dot11rate_label(rt, rc[0].rix), rc[0].tries,
945 dot11rate(rt, rc[1].rix),
946 dot11rate_label(rt, rc[1].rix), rc[1].tries,
947 dot11rate(rt, rc[2].rix),
948 dot11rate_label(rt, rc[2].rix), rc[2].tries,
949 dot11rate(rt, rc[3].rix),
950 dot11rate_label(rt, rc[3].rix), rc[3].tries,
953 for (i = 0; i < 4; i++) {
954 if (rc[i].tries && !IS_RATE_DEFINED(sn, rc[i].rix))
955 badrate(sc, 0, rc[i].ratecode, rc[i].tries,
960 * NB: series > 0 are not penalized for failure
961 * based on the try counts under the assumption
962 * that losses are often bursty and since we
963 * sample higher rates 1 try at a time doing so
964 * may unfairly penalize them.
967 update_stats(sc, an, frame_size,
968 rc[0].rix, rc[0].tries,
969 rc[1].rix, rc[1].tries,
970 rc[2].rix, rc[2].tries,
971 rc[3].rix, rc[3].tries,
972 short_tries, long_tries,
973 long_tries > rc[0].tries,
975 long_tries -= rc[0].tries;
978 if (rc[1].tries && finalTSIdx > 0) {
979 update_stats(sc, an, frame_size,
980 rc[1].rix, rc[1].tries,
981 rc[2].rix, rc[2].tries,
982 rc[3].rix, rc[3].tries,
984 short_tries, long_tries,
987 long_tries -= rc[1].tries;
990 if (rc[2].tries && finalTSIdx > 1) {
991 update_stats(sc, an, frame_size,
992 rc[2].rix, rc[2].tries,
993 rc[3].rix, rc[3].tries,
996 short_tries, long_tries,
999 long_tries -= rc[2].tries;
1002 if (rc[3].tries && finalTSIdx > 2) {
1003 update_stats(sc, an, frame_size,
1004 rc[3].rix, rc[3].tries,
1008 short_tries, long_tries,
1016 ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew)
1019 ath_rate_ctl_reset(sc, &an->an_node);
1023 ath_rate_update_rx_rssi(struct ath_softc *sc, struct ath_node *an, int rssi)
1028 static const struct txschedule *mrr_schedules[IEEE80211_MODE_MAX+2] = {
1029 NULL, /* IEEE80211_MODE_AUTO */
1030 series_11a, /* IEEE80211_MODE_11A */
1031 series_11g, /* IEEE80211_MODE_11B */
1032 series_11g, /* IEEE80211_MODE_11G */
1033 NULL, /* IEEE80211_MODE_FH */
1034 series_11a, /* IEEE80211_MODE_TURBO_A */
1035 series_11g, /* IEEE80211_MODE_TURBO_G */
1036 series_11a, /* IEEE80211_MODE_STURBO_A */
1037 series_11na, /* IEEE80211_MODE_11NA */
1038 series_11ng, /* IEEE80211_MODE_11NG */
1039 series_half, /* IEEE80211_MODE_HALF */
1040 series_quarter, /* IEEE80211_MODE_QUARTER */
1044 * Initialize the tables for a node.
1047 ath_rate_ctl_reset(struct ath_softc *sc, struct ieee80211_node *ni)
1049 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
1050 #define DOT11RATE(_ix) (rt->info[(_ix)].dot11Rate & IEEE80211_RATE_VAL)
1051 #define MCS(_ix) (ni->ni_htrates.rs_rates[_ix] | IEEE80211_RATE_MCS)
1052 struct ath_node *an = ATH_NODE(ni);
1053 struct sample_node *sn = ATH_NODE_SAMPLE(an);
1054 const HAL_RATE_TABLE *rt = sc->sc_currates;
1057 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
1059 KASSERT(sc->sc_curmode < IEEE80211_MODE_MAX+2,
1060 ("curmode %u", sc->sc_curmode));
1062 sn->sched = mrr_schedules[sc->sc_curmode];
1063 KASSERT(sn->sched != NULL,
1064 ("no mrr schedule for mode %u", sc->sc_curmode));
1066 sn->static_rix = -1;
1067 ath_rate_update_static_rix(sc, ni);
1069 sn->currates = sc->sc_currates;
1072 * Construct a bitmask of usable rates. This has all
1073 * negotiated rates minus those marked by the hal as
1074 * to be ignored for doing rate control.
1078 if (ni->ni_flags & IEEE80211_NODE_HT) {
1079 for (x = 0; x < ni->ni_htrates.rs_nrates; x++) {
1080 rix = sc->sc_rixmap[MCS(x)];
1083 /* skip rates marked broken by hal */
1084 if (!rt->info[rix].valid)
1086 KASSERT(rix < SAMPLE_MAXRATES,
1087 ("mcs %u has rix %d", MCS(x), rix));
1088 sn->ratemask |= (uint64_t) 1<<rix;
1093 for (x = 0; x < ni->ni_rates.rs_nrates; x++) {
1094 rix = sc->sc_rixmap[RATE(x)];
1097 /* skip rates marked broken by hal */
1098 if (!rt->info[rix].valid)
1100 KASSERT(rix < SAMPLE_MAXRATES,
1101 ("rate %u has rix %d", RATE(x), rix));
1102 sn->ratemask |= (uint64_t) 1<<rix;
1104 #ifdef IEEE80211_DEBUG
1105 if (ieee80211_msg(ni->ni_vap, IEEE80211_MSG_RATECTL)) {
1108 ieee80211_note(ni->ni_vap, "[%6D] %s: size 1600 rate/tt",
1109 ni->ni_macaddr, ":", __func__);
1110 for (mask = sn->ratemask, rix = 0; mask != 0; mask >>= 1, rix++) {
1111 if ((mask & 1) == 0)
1113 printf(" %d %s/%d", dot11rate(rt, rix), dot11rate_label(rt, rix),
1114 calc_usecs_unicast_packet(sc, 1600, rix, 0,0,
1115 (ni->ni_chw == 40)));
1120 for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) {
1121 int size = bin_to_size(y);
1124 sn->packets_sent[y] = 0;
1125 sn->current_sample_rix[y] = -1;
1126 sn->last_sample_rix[y] = 0;
1127 /* XXX start with first valid rate */
1128 sn->current_rix[y] = ffs(sn->ratemask)-1;
1131 * Initialize the statistics buckets; these are
1132 * indexed by the rate code index.
1134 for (rix = 0, mask = sn->ratemask; mask != 0; rix++, mask >>= 1) {
1135 if ((mask & 1) == 0) /* not a valid rate */
1137 sn->stats[y][rix].successive_failures = 0;
1138 sn->stats[y][rix].tries = 0;
1139 sn->stats[y][rix].total_packets = 0;
1140 sn->stats[y][rix].packets_acked = 0;
1141 sn->stats[y][rix].last_tx = 0;
1142 sn->stats[y][rix].ewma_pct = 0;
1144 sn->stats[y][rix].perfect_tx_time =
1145 calc_usecs_unicast_packet(sc, size, rix, 0, 0,
1146 (ni->ni_chw == 40));
1147 sn->stats[y][rix].average_tx_time =
1148 sn->stats[y][rix].perfect_tx_time;
1152 /* XXX 0, num_rates-1 are wrong */
1153 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
1154 "%s: %d rates %d%sMbps (%dus)- %d%sMbps (%dus)", __func__,
1156 DOT11RATE(0)/2, DOT11RATE(0) % 1 ? ".5" : "",
1157 sn->stats[1][0].perfect_tx_time,
1158 DOT11RATE(sn->num_rates-1)/2, DOT11RATE(sn->num_rates-1) % 1 ? ".5" : "",
1159 sn->stats[1][sn->num_rates-1].perfect_tx_time
1162 /* set the visible bit-rate */
1163 if (sn->static_rix != -1)
1164 ni->ni_txrate = DOT11RATE(sn->static_rix);
1166 ni->ni_txrate = RATE(0);
1172 * Fetch the statistics for the given node.
1174 * The ieee80211 node must be referenced and unlocked, however the ath_node
1177 * The main difference here is that we convert the rate indexes
1178 * to 802.11 rates, or the userland output won't make much sense
1179 * as it has no access to the rix table.
1182 ath_rate_fetch_node_stats(struct ath_softc *sc, struct ath_node *an,
1183 struct ath_rateioctl *rs)
1185 struct sample_node *sn = ATH_NODE_SAMPLE(an);
1186 const HAL_RATE_TABLE *rt = sc->sc_currates;
1187 struct ath_rateioctl_tlv av;
1188 struct ath_rateioctl_rt *tv;
1192 ATH_NODE_LOCK_ASSERT(an);
1195 * Ensure there's enough space for the statistics.
1198 sizeof(struct ath_rateioctl_tlv) +
1199 sizeof(struct ath_rateioctl_rt) +
1200 sizeof(struct ath_rateioctl_tlv) +
1201 sizeof(struct sample_node)) {
1202 device_printf(sc->sc_dev, "%s: len=%d, too short\n",
1209 * Take a temporary copy of the sample node state so we can
1210 * modify it before we copy it.
1212 tv = malloc(sizeof(struct ath_rateioctl_rt), M_TEMP,
1219 * Populate the rate table mapping TLV.
1221 tv->nentries = rt->rateCount;
1222 for (y = 0; y < rt->rateCount; y++) {
1223 tv->ratecode[y] = rt->info[y].dot11Rate & IEEE80211_RATE_VAL;
1224 if (rt->info[y].phy == IEEE80211_T_HT)
1225 tv->ratecode[y] |= IEEE80211_RATE_MCS;
1230 * First TLV - rate code mapping
1232 av.tlv_id = ATH_RATE_TLV_RATETABLE;
1233 av.tlv_len = sizeof(struct ath_rateioctl_rt);
1234 copyout(&av, rs->buf + o, sizeof(struct ath_rateioctl_tlv));
1235 o += sizeof(struct ath_rateioctl_tlv);
1236 copyout(tv, rs->buf + o, sizeof(struct ath_rateioctl_rt));
1237 o += sizeof(struct ath_rateioctl_rt);
1240 * Second TLV - sample node statistics
1242 av.tlv_id = ATH_RATE_TLV_SAMPLENODE;
1243 av.tlv_len = sizeof(struct sample_node);
1244 copyout(&av, rs->buf + o, sizeof(struct ath_rateioctl_tlv));
1245 o += sizeof(struct ath_rateioctl_tlv);
1248 * Copy the statistics over to the provided buffer.
1250 copyout(sn, rs->buf + o, sizeof(struct sample_node));
1251 o += sizeof(struct sample_node);
1259 sample_stats(void *arg, struct ieee80211_node *ni)
1261 struct ath_softc *sc = arg;
1262 const HAL_RATE_TABLE *rt = sc->sc_currates;
1263 struct sample_node *sn = ATH_NODE_SAMPLE(ATH_NODE(ni));
1267 printf("\n[%s] refcnt %d static_rix (%d %s) ratemask 0x%jx\n",
1268 ether_sprintf(ni->ni_macaddr), ieee80211_node_refcnt(ni),
1269 dot11rate(rt, sn->static_rix),
1270 dot11rate_label(rt, sn->static_rix),
1271 (uintmax_t)sn->ratemask);
1272 for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) {
1273 printf("[%4u] cur rix %d (%d %s) since switch: packets %d ticks %u\n",
1274 bin_to_size(y), sn->current_rix[y],
1275 dot11rate(rt, sn->current_rix[y]),
1276 dot11rate_label(rt, sn->current_rix[y]),
1277 sn->packets_since_switch[y], sn->ticks_since_switch[y]);
1278 printf("[%4u] last sample (%d %s) cur sample (%d %s) packets sent %d\n",
1280 dot11rate(rt, sn->last_sample_rix[y]),
1281 dot11rate_label(rt, sn->last_sample_rix[y]),
1282 dot11rate(rt, sn->current_sample_rix[y]),
1283 dot11rate_label(rt, sn->current_sample_rix[y]),
1284 sn->packets_sent[y]);
1285 printf("[%4u] packets since sample %d sample tt %u\n",
1286 bin_to_size(y), sn->packets_since_sample[y],
1289 for (mask = sn->ratemask, rix = 0; mask != 0; mask >>= 1, rix++) {
1290 if ((mask & 1) == 0)
1292 for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) {
1293 if (sn->stats[y][rix].total_packets == 0)
1295 printf("[%2u %s:%4u] %8ju:%-8ju (%3d%%) (EWMA %3d.%1d%%) T %8ju F %4d avg %5u last %u\n",
1296 dot11rate(rt, rix), dot11rate_label(rt, rix),
1298 (uintmax_t) sn->stats[y][rix].total_packets,
1299 (uintmax_t) sn->stats[y][rix].packets_acked,
1300 (int) ((sn->stats[y][rix].packets_acked * 100ULL) /
1301 sn->stats[y][rix].total_packets),
1302 sn->stats[y][rix].ewma_pct / 10,
1303 sn->stats[y][rix].ewma_pct % 10,
1304 (uintmax_t) sn->stats[y][rix].tries,
1305 sn->stats[y][rix].successive_failures,
1306 sn->stats[y][rix].average_tx_time,
1307 ticks - sn->stats[y][rix].last_tx);
1313 ath_rate_sysctl_stats(SYSCTL_HANDLER_ARGS)
1315 struct ath_softc *sc = arg1;
1316 struct ieee80211com *ic = &sc->sc_ic;
1320 error = sysctl_handle_int(oidp, &v, 0, req);
1321 if (error || !req->newptr)
1323 ieee80211_iterate_nodes(&ic->ic_sta, sample_stats, sc);
1328 ath_rate_sysctl_smoothing_rate(SYSCTL_HANDLER_ARGS)
1330 struct sample_softc *ssc = arg1;
1333 rate = ssc->smoothing_rate;
1334 error = sysctl_handle_int(oidp, &rate, 0, req);
1335 if (error || !req->newptr)
1337 if (!(0 <= rate && rate < 100))
1339 ssc->smoothing_rate = rate;
1340 ssc->smoothing_minpackets = 100 / (100 - rate);
1345 ath_rate_sysctl_sample_rate(SYSCTL_HANDLER_ARGS)
1347 struct sample_softc *ssc = arg1;
1350 rate = ssc->sample_rate;
1351 error = sysctl_handle_int(oidp, &rate, 0, req);
1352 if (error || !req->newptr)
1354 if (!(2 <= rate && rate <= 100))
1356 ssc->sample_rate = rate;
1361 ath_rate_sysctlattach(struct ath_softc *sc, struct sample_softc *ssc)
1363 struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev);
1364 struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev);
1366 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
1367 "smoothing_rate", CTLTYPE_INT | CTLFLAG_RW, ssc, 0,
1368 ath_rate_sysctl_smoothing_rate, "I",
1369 "sample: smoothing rate for avg tx time (%%)");
1370 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
1371 "sample_rate", CTLTYPE_INT | CTLFLAG_RW, ssc, 0,
1372 ath_rate_sysctl_sample_rate, "I",
1373 "sample: percent air time devoted to sampling new rates (%%)");
1374 /* XXX max_successive_failures, stale_failure_timeout, min_switch */
1375 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
1376 "sample_stats", CTLTYPE_INT | CTLFLAG_RW, sc, 0,
1377 ath_rate_sysctl_stats, "I", "sample: print statistics");
1380 struct ath_ratectrl *
1381 ath_rate_attach(struct ath_softc *sc)
1383 struct sample_softc *ssc;
1385 ssc = malloc(sizeof(struct sample_softc), M_DEVBUF, M_NOWAIT|M_ZERO);
1388 ssc->arc.arc_space = sizeof(struct sample_node);
1389 ssc->smoothing_rate = 75; /* ewma percentage ([0..99]) */
1390 ssc->smoothing_minpackets = 100 / (100 - ssc->smoothing_rate);
1391 ssc->sample_rate = 10; /* %time to try diff tx rates */
1392 ssc->max_successive_failures = 3; /* threshold for rate sampling*/
1393 ssc->stale_failure_timeout = 10 * hz; /* 10 seconds */
1394 ssc->min_switch = hz; /* 1 second */
1395 ath_rate_sysctlattach(sc, ssc);
1400 ath_rate_detach(struct ath_ratectrl *arc)
1402 struct sample_softc *ssc = (struct sample_softc *) arc;
1404 free(ssc, M_DEVBUF);