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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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.
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38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
42 * John Bicket's SampleRate control algorithm.
49 #include <sys/param.h>
50 #include <sys/systm.h>
51 #include <sys/sysctl.h>
52 #include <sys/kernel.h>
54 #include <sys/mutex.h>
55 #include <sys/errno.h>
57 #include <machine/bus.h>
58 #include <machine/resource.h>
61 #include <sys/socket.h>
64 #include <net/if_media.h>
65 #include <net/if_arp.h>
66 #include <net/ethernet.h> /* XXX for ether_sprintf */
68 #include <net80211/ieee80211_var.h>
73 #include <netinet/in.h>
74 #include <netinet/if_ether.h>
77 #include <dev/ath/if_athvar.h>
78 #include <dev/ath/ath_rate/sample/sample.h>
79 #include <dev/ath/ath_hal/ah_desc.h>
80 #include <dev/ath/ath_rate/sample/tx_schedules.h>
83 * This file is an implementation of the SampleRate algorithm
84 * in "Bit-rate Selection in Wireless Networks"
85 * (http://www.pdos.lcs.mit.edu/papers/jbicket-ms.ps)
87 * SampleRate chooses the bit-rate it predicts will provide the most
88 * throughput based on estimates of the expected per-packet
89 * transmission time for each bit-rate. SampleRate periodically sends
90 * packets at bit-rates other than the current one to estimate when
91 * another bit-rate will provide better performance. SampleRate
92 * switches to another bit-rate when its estimated per-packet
93 * transmission time becomes smaller than the current bit-rate's.
94 * SampleRate reduces the number of bit-rates it must sample by
95 * eliminating those that could not perform better than the one
96 * currently being used. SampleRate also stops probing at a bit-rate
97 * if it experiences several successive losses.
99 * The difference between the algorithm in the thesis and the one in this
100 * file is that the one in this file uses a ewma instead of a window.
102 * Also, this implementation tracks the average transmission time for
103 * a few different packet sizes independently for each link.
106 static void ath_rate_ctl_reset(struct ath_softc *, struct ieee80211_node *);
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 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 dot11rate(const HAL_RATE_TABLE *rt, int rix)
145 return rt->info[rix].phy == IEEE80211_T_HT ?
146 rt->info[rix].dot11Rate : (rt->info[rix].dot11Rate & IEEE80211_RATE_VAL) / 2;
150 dot11rate_label(const HAL_RATE_TABLE *rt, int rix)
154 return rt->info[rix].phy == IEEE80211_T_HT ? "MCS" : "Mb ";
158 * Return the rix with the lowest average_tx_time,
159 * or -1 if all the average_tx_times are 0.
162 pick_best_rate(struct ath_node *an, const HAL_RATE_TABLE *rt,
163 int size_bin, int require_acked_before)
165 struct sample_node *sn = ATH_NODE_SAMPLE(an);
166 int best_rate_rix, best_rate_tt, best_rate_pct;
173 for (mask = sn->ratemask, rix = 0; mask != 0; mask >>= 1, rix++) {
174 if ((mask & 1) == 0) /* not a supported rate */
177 /* Don't pick a non-HT rate for a HT node */
178 if ((an->an_node.ni_flags & IEEE80211_NODE_HT) &&
179 (rt->info[rix].phy != IEEE80211_T_HT)) {
183 tt = sn->stats[size_bin][rix].average_tx_time;
185 (require_acked_before &&
186 !sn->stats[size_bin][rix].packets_acked))
189 /* Calculate percentage if possible */
190 if (sn->stats[size_bin][rix].total_packets > 0) {
191 pct = sn->stats[size_bin][rix].ewma_pct;
193 /* XXX for now, assume 95% ok */
197 /* don't use a bit-rate that has been failing */
198 if (sn->stats[size_bin][rix].successive_failures > 3)
202 * For HT, Don't use a bit rate that is much more
203 * lossy than the best.
205 * XXX this isn't optimal; it's just designed to
206 * eliminate rates that are going to be obviously
209 if (an->an_node.ni_flags & IEEE80211_NODE_HT) {
210 if (best_rate_pct > (pct + 50))
215 * For non-MCS rates, use the current average txtime for
218 if (! (an->an_node.ni_flags & IEEE80211_NODE_HT)) {
219 if (best_rate_tt == 0 || tt <= best_rate_tt) {
227 * Since 2 stream rates have slightly higher TX times,
228 * allow a little bit of leeway. This should later
229 * be abstracted out and properly handled.
231 if (an->an_node.ni_flags & IEEE80211_NODE_HT) {
232 if (best_rate_tt == 0 || (tt * 8 <= best_rate_tt * 10)) {
239 return (best_rate_tt ? best_rate_rix : -1);
243 * Pick a good "random" bit-rate to sample other than the current one.
246 pick_sample_rate(struct sample_softc *ssc , struct ath_node *an,
247 const HAL_RATE_TABLE *rt, int size_bin)
249 #define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
250 #define MCS(ix) (rt->info[ix].dot11Rate | IEEE80211_RATE_MCS)
251 struct sample_node *sn = ATH_NODE_SAMPLE(an);
252 int current_rix, rix;
256 current_rix = sn->current_rix[size_bin];
257 if (current_rix < 0) {
258 /* no successes yet, send at the lowest bit-rate */
259 /* XXX should return MCS0 if HT */
263 current_tt = sn->stats[size_bin][current_rix].average_tx_time;
265 rix = sn->last_sample_rix[size_bin]+1; /* next sample rate */
266 mask = sn->ratemask &~ ((uint64_t) 1<<current_rix);/* don't sample current rate */
268 if ((mask & ((uint64_t) 1<<rix)) == 0) { /* not a supported rate */
270 if (++rix >= rt->rateCount)
276 * The following code stops trying to sample
277 * non-MCS rates when speaking to an MCS node.
278 * However, at least for CCK rates in 2.4GHz mode,
279 * the non-MCS rates MAY actually provide better
280 * PER at the very far edge of reception.
282 * However! Until ath_rate_form_aggr() grows
283 * some logic to not form aggregates if the
284 * selected rate is non-MCS, this won't work.
286 * So don't disable this code until you've taught
287 * ath_rate_form_aggr() to drop out if any of
288 * the selected rates are non-MCS.
291 /* if the node is HT and the rate isn't HT, don't bother sample */
292 if ((an->an_node.ni_flags & IEEE80211_NODE_HT) &&
293 (rt->info[rix].phy != IEEE80211_T_HT)) {
294 mask &= ~((uint64_t) 1<<rix);
299 /* this bit-rate is always worse than the current one */
300 if (sn->stats[size_bin][rix].perfect_tx_time > current_tt) {
301 mask &= ~((uint64_t) 1<<rix);
305 /* rarely sample bit-rates that fail a lot */
306 if (sn->stats[size_bin][rix].successive_failures > ssc->max_successive_failures &&
307 ticks - sn->stats[size_bin][rix].last_tx < ssc->stale_failure_timeout) {
308 mask &= ~((uint64_t) 1<<rix);
313 * For HT, only sample a few rates on either side of the
314 * current rix; there's quite likely a lot of them.
316 if (an->an_node.ni_flags & IEEE80211_NODE_HT) {
317 if (rix < (current_rix - 3) ||
318 rix > (current_rix + 3)) {
319 mask &= ~((uint64_t) 1<<rix);
324 /* Don't sample more than 2 rates higher for rates > 11M for non-HT rates */
325 if (! (an->an_node.ni_flags & IEEE80211_NODE_HT)) {
326 if (DOT11RATE(rix) > 2*11 && rix > current_rix + 2) {
327 mask &= ~((uint64_t) 1<<rix);
332 sn->last_sample_rix[size_bin] = rix;
341 ath_rate_get_static_rix(struct ath_softc *sc, const struct ieee80211_node *ni)
343 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
344 #define DOT11RATE(_ix) (rt->info[(_ix)].dot11Rate & IEEE80211_RATE_VAL)
345 #define MCS(_ix) (ni->ni_htrates.rs_rates[_ix] | IEEE80211_RATE_MCS)
346 const struct ieee80211_txparam *tp = ni->ni_txparms;
349 /* Check MCS rates */
350 for (srate = ni->ni_htrates.rs_nrates - 1; srate >= 0; srate--) {
351 if (MCS(srate) == tp->ucastrate)
352 return sc->sc_rixmap[tp->ucastrate];
355 /* Check legacy rates */
356 for (srate = ni->ni_rates.rs_nrates - 1; srate >= 0; srate--) {
357 if (RATE(srate) == tp->ucastrate)
358 return sc->sc_rixmap[tp->ucastrate];
367 ath_rate_update_static_rix(struct ath_softc *sc, struct ieee80211_node *ni)
369 struct ath_node *an = ATH_NODE(ni);
370 const struct ieee80211_txparam *tp = ni->ni_txparms;
371 struct sample_node *sn = ATH_NODE_SAMPLE(an);
373 if (tp != NULL && tp->ucastrate != IEEE80211_FIXED_RATE_NONE) {
375 * A fixed rate is to be used; ucastrate is the IEEE code
376 * for this rate (sans basic bit). Check this against the
377 * negotiated rate set for the node. Note the fixed rate
378 * may not be available for various reasons so we only
379 * setup the static rate index if the lookup is successful.
381 sn->static_rix = ath_rate_get_static_rix(sc, ni);
388 * Pick a non-HT rate to begin using.
391 ath_rate_pick_seed_rate_legacy(struct ath_softc *sc, struct ath_node *an,
394 #define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
395 #define MCS(ix) (rt->info[ix].dot11Rate | IEEE80211_RATE_MCS)
396 #define RATE(ix) (DOT11RATE(ix) / 2)
398 const HAL_RATE_TABLE *rt = sc->sc_currates;
399 struct sample_node *sn = ATH_NODE_SAMPLE(an);
400 const int size_bin = size_to_bin(frameLen);
402 /* no packet has been sent successfully yet */
403 for (rix = rt->rateCount-1; rix > 0; rix--) {
404 if ((sn->ratemask & ((uint64_t) 1<<rix)) == 0)
408 if (rt->info[rix].phy == IEEE80211_T_HT)
412 * Pick the highest rate <= 36 Mbps
413 * that hasn't failed.
415 if (DOT11RATE(rix) <= 72 &&
416 sn->stats[size_bin][rix].successive_failures == 0) {
427 * Pick a HT rate to begin using.
429 * Don't use any non-HT rates; only consider HT rates.
432 ath_rate_pick_seed_rate_ht(struct ath_softc *sc, struct ath_node *an,
435 #define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
436 #define MCS(ix) (rt->info[ix].dot11Rate | IEEE80211_RATE_MCS)
437 #define RATE(ix) (DOT11RATE(ix) / 2)
438 int rix = -1, ht_rix = -1;
439 const HAL_RATE_TABLE *rt = sc->sc_currates;
440 struct sample_node *sn = ATH_NODE_SAMPLE(an);
441 const int size_bin = size_to_bin(frameLen);
443 /* no packet has been sent successfully yet */
444 for (rix = rt->rateCount-1; rix > 0; rix--) {
445 /* Skip rates we can't use */
446 if ((sn->ratemask & ((uint64_t) 1<<rix)) == 0)
449 /* Keep a copy of the last seen HT rate index */
450 if (rt->info[rix].phy == IEEE80211_T_HT)
453 /* Skip non-HT rates */
454 if (rt->info[rix].phy != IEEE80211_T_HT)
458 * Pick a medium-speed rate regardless of stream count
459 * which has not seen any failures. Higher rates may fail;
460 * we'll try them later.
462 if (((MCS(rix) & 0x7) <= 4) &&
463 sn->stats[size_bin][rix].successive_failures == 0) {
469 * If all the MCS rates have successive failures, rix should be
470 * > 0; otherwise use the lowest MCS rix (hopefully MCS 0.)
472 return MAX(rix, ht_rix);
480 ath_rate_findrate(struct ath_softc *sc, struct ath_node *an,
481 int shortPreamble, size_t frameLen,
482 u_int8_t *rix0, int *try0, u_int8_t *txrate)
484 #define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
485 #define MCS(ix) (rt->info[ix].dot11Rate | IEEE80211_RATE_MCS)
486 #define RATE(ix) (DOT11RATE(ix) / 2)
487 struct sample_node *sn = ATH_NODE_SAMPLE(an);
488 struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc);
489 struct ifnet *ifp = sc->sc_ifp;
490 struct ieee80211com *ic = ifp->if_l2com;
491 const HAL_RATE_TABLE *rt = sc->sc_currates;
492 const int size_bin = size_to_bin(frameLen);
493 int rix, mrr, best_rix, change_rates;
494 unsigned average_tx_time;
496 ath_rate_update_static_rix(sc, &an->an_node);
498 if (sn->currates != sc->sc_currates) {
499 device_printf(sc->sc_dev, "%s: currates != sc_currates!\n",
502 *try0 = ATH_TXMAXTRY;
506 if (sn->static_rix != -1) {
507 rix = sn->static_rix;
508 *try0 = ATH_TXMAXTRY;
512 mrr = sc->sc_mrretry;
513 /* XXX check HT protmode too */
514 if (mrr && (ic->ic_flags & IEEE80211_F_USEPROT && !sc->sc_mrrprot))
517 best_rix = pick_best_rate(an, rt, size_bin, !mrr);
519 average_tx_time = sn->stats[size_bin][best_rix].average_tx_time;
524 * Limit the time measuring the performance of other tx
525 * rates to sample_rate% of the total transmission time.
527 if (sn->sample_tt[size_bin] < average_tx_time * (sn->packets_since_sample[size_bin]*ssc->sample_rate/100)) {
528 rix = pick_sample_rate(ssc, an, rt, size_bin);
529 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
530 &an->an_node, "att %d sample_tt %d size %u sample rate %d %s current rate %d %s",
532 sn->sample_tt[size_bin],
533 bin_to_size(size_bin),
535 dot11rate_label(rt, rix),
536 dot11rate(rt, sn->current_rix[size_bin]),
537 dot11rate_label(rt, sn->current_rix[size_bin]));
538 if (rix != sn->current_rix[size_bin]) {
539 sn->current_sample_rix[size_bin] = rix;
541 sn->current_sample_rix[size_bin] = -1;
543 sn->packets_since_sample[size_bin] = 0;
546 if (!sn->packets_sent[size_bin] || best_rix == -1) {
547 /* no packet has been sent successfully yet */
549 if (an->an_node.ni_flags & IEEE80211_NODE_HT)
551 ath_rate_pick_seed_rate_ht(sc, an, frameLen);
554 ath_rate_pick_seed_rate_legacy(sc, an, frameLen);
555 } else if (sn->packets_sent[size_bin] < 20) {
556 /* let the bit-rate switch quickly during the first few packets */
557 IEEE80211_NOTE(an->an_node.ni_vap,
558 IEEE80211_MSG_RATECTL, &an->an_node,
559 "%s: switching quickly..", __func__);
561 } else if (ticks - ssc->min_switch > sn->ticks_since_switch[size_bin]) {
562 /* min_switch seconds have gone by */
563 IEEE80211_NOTE(an->an_node.ni_vap,
564 IEEE80211_MSG_RATECTL, &an->an_node,
565 "%s: min_switch %d > ticks_since_switch %d..",
566 __func__, ticks - ssc->min_switch, sn->ticks_since_switch[size_bin]);
568 } else if ((! (an->an_node.ni_flags & IEEE80211_NODE_HT)) &&
569 (2*average_tx_time < sn->stats[size_bin][sn->current_rix[size_bin]].average_tx_time)) {
570 /* the current bit-rate is twice as slow as the best one */
571 IEEE80211_NOTE(an->an_node.ni_vap,
572 IEEE80211_MSG_RATECTL, &an->an_node,
573 "%s: 2x att (= %d) < cur_rix att %d",
575 2 * average_tx_time, sn->stats[size_bin][sn->current_rix[size_bin]].average_tx_time);
577 } else if ((an->an_node.ni_flags & IEEE80211_NODE_HT)) {
578 int cur_rix = sn->current_rix[size_bin];
579 int cur_att = sn->stats[size_bin][cur_rix].average_tx_time;
581 * If the node is HT, upgrade it if the MCS rate is
582 * higher and the average tx time is within 20% of
583 * the current rate. It can fail a little.
585 * This is likely not optimal!
588 printf("cur rix/att %x/%d, best rix/att %x/%d\n",
589 MCS(cur_rix), cur_att, MCS(best_rix), average_tx_time);
591 if ((MCS(best_rix) > MCS(cur_rix)) &&
592 (average_tx_time * 8) <= (cur_att * 10)) {
593 IEEE80211_NOTE(an->an_node.ni_vap,
594 IEEE80211_MSG_RATECTL, &an->an_node,
595 "%s: HT: best_rix 0x%d > cur_rix 0x%x, average_tx_time %d, cur_att %d",
597 MCS(best_rix), MCS(cur_rix), average_tx_time, cur_att);
602 sn->packets_since_sample[size_bin]++;
605 if (best_rix != sn->current_rix[size_bin]) {
606 IEEE80211_NOTE(an->an_node.ni_vap,
607 IEEE80211_MSG_RATECTL,
609 "%s: size %d switch rate %d (%d/%d) -> %d (%d/%d) after %d packets mrr %d",
611 bin_to_size(size_bin),
612 RATE(sn->current_rix[size_bin]),
613 sn->stats[size_bin][sn->current_rix[size_bin]].average_tx_time,
614 sn->stats[size_bin][sn->current_rix[size_bin]].perfect_tx_time,
616 sn->stats[size_bin][best_rix].average_tx_time,
617 sn->stats[size_bin][best_rix].perfect_tx_time,
618 sn->packets_since_switch[size_bin],
621 sn->packets_since_switch[size_bin] = 0;
622 sn->current_rix[size_bin] = best_rix;
623 sn->ticks_since_switch[size_bin] = ticks;
625 * Set the visible txrate for this node.
627 an->an_node.ni_txrate = (rt->info[best_rix].phy == IEEE80211_T_HT) ? MCS(best_rix) : DOT11RATE(best_rix);
629 rix = sn->current_rix[size_bin];
630 sn->packets_since_switch[size_bin]++;
632 *try0 = mrr ? sn->sched[rix].t0 : ATH_TXMAXTRY;
636 * This bug totally sucks and should be fixed.
638 * For now though, let's not panic, so we can start to figure
639 * out how to better reproduce it.
641 if (rix < 0 || rix >= rt->rateCount) {
642 printf("%s: ERROR: rix %d out of bounds (rateCount=%d)\n",
646 rix = 0; /* XXX just default for now */
648 KASSERT(rix >= 0 && rix < rt->rateCount, ("rix is %d", rix));
651 *txrate = rt->info[rix].rateCode
652 | (shortPreamble ? rt->info[rix].shortPreamble : 0);
653 sn->packets_sent[size_bin]++;
660 * Get the TX rates. Don't fiddle with short preamble flags for them;
661 * the caller can do that.
664 ath_rate_getxtxrates(struct ath_softc *sc, struct ath_node *an,
665 uint8_t rix0, struct ath_rc_series *rc)
667 struct sample_node *sn = ATH_NODE_SAMPLE(an);
668 const struct txschedule *sched = &sn->sched[rix0];
670 KASSERT(rix0 == sched->r0, ("rix0 (%x) != sched->r0 (%x)!\n",
673 rc[0].flags = rc[1].flags = rc[2].flags = rc[3].flags = 0;
675 rc[0].rix = sched->r0;
676 rc[1].rix = sched->r1;
677 rc[2].rix = sched->r2;
678 rc[3].rix = sched->r3;
680 rc[0].tries = sched->t0;
681 rc[1].tries = sched->t1;
682 rc[2].tries = sched->t2;
683 rc[3].tries = sched->t3;
687 ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an,
688 struct ath_desc *ds, int shortPreamble, u_int8_t rix)
690 struct sample_node *sn = ATH_NODE_SAMPLE(an);
691 const struct txschedule *sched = &sn->sched[rix];
692 const HAL_RATE_TABLE *rt = sc->sc_currates;
693 uint8_t rix1, s1code, rix2, s2code, rix3, s3code;
695 /* XXX precalculate short preamble tables */
697 s1code = rt->info[rix1].rateCode
698 | (shortPreamble ? rt->info[rix1].shortPreamble : 0);
700 s2code = rt->info[rix2].rateCode
701 | (shortPreamble ? rt->info[rix2].shortPreamble : 0);
703 s3code = rt->info[rix3].rateCode
704 | (shortPreamble ? rt->info[rix3].shortPreamble : 0);
705 ath_hal_setupxtxdesc(sc->sc_ah, ds,
706 s1code, sched->t1, /* series 1 */
707 s2code, sched->t2, /* series 2 */
708 s3code, sched->t3); /* series 3 */
712 update_stats(struct ath_softc *sc, struct ath_node *an,
714 int rix0, int tries0,
715 int rix1, int tries1,
716 int rix2, int tries2,
717 int rix3, int tries3,
718 int short_tries, int tries, int status,
719 int nframes, int nbad)
721 struct sample_node *sn = ATH_NODE_SAMPLE(an);
722 struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc);
723 #ifdef IEEE80211_DEBUG
724 const HAL_RATE_TABLE *rt = sc->sc_currates;
726 const int size_bin = size_to_bin(frame_size);
727 const int size = bin_to_size(size_bin);
728 int tt, tries_so_far;
729 int is_ht40 = (an->an_node.ni_chw == 40);
732 if (!IS_RATE_DEFINED(sn, rix0))
734 tt = calc_usecs_unicast_packet(sc, size, rix0, short_tries,
735 MIN(tries0, tries) - 1, is_ht40);
736 tries_so_far = tries0;
738 if (tries1 && tries_so_far < tries) {
739 if (!IS_RATE_DEFINED(sn, rix1))
741 tt += calc_usecs_unicast_packet(sc, size, rix1, short_tries,
742 MIN(tries1 + tries_so_far, tries) - tries_so_far - 1, is_ht40);
743 tries_so_far += tries1;
746 if (tries2 && tries_so_far < tries) {
747 if (!IS_RATE_DEFINED(sn, rix2))
749 tt += calc_usecs_unicast_packet(sc, size, rix2, short_tries,
750 MIN(tries2 + tries_so_far, tries) - tries_so_far - 1, is_ht40);
751 tries_so_far += tries2;
754 if (tries3 && tries_so_far < tries) {
755 if (!IS_RATE_DEFINED(sn, rix3))
757 tt += calc_usecs_unicast_packet(sc, size, rix3, short_tries,
758 MIN(tries3 + tries_so_far, tries) - tries_so_far - 1, is_ht40);
761 if (sn->stats[size_bin][rix0].total_packets < ssc->smoothing_minpackets) {
762 /* just average the first few packets */
763 int avg_tx = sn->stats[size_bin][rix0].average_tx_time;
764 int packets = sn->stats[size_bin][rix0].total_packets;
765 sn->stats[size_bin][rix0].average_tx_time = (tt+(avg_tx*packets))/(packets+nframes);
768 sn->stats[size_bin][rix0].average_tx_time =
769 ((sn->stats[size_bin][rix0].average_tx_time * ssc->smoothing_rate) +
770 (tt * (100 - ssc->smoothing_rate))) / 100;
774 * XXX Don't mark the higher bit rates as also having failed; as this
775 * unfortunately stops those rates from being tasted when trying to
776 * TX. This happens with 11n aggregation.
778 if (nframes == nbad) {
782 sn->stats[size_bin][rix0].successive_failures += nbad;
784 for (y = size_bin+1; y < NUM_PACKET_SIZE_BINS; y++) {
786 * Also say larger packets failed since we
787 * assume if a small packet fails at a
788 * bit-rate then a larger one will also.
790 sn->stats[y][rix0].successive_failures += nbad;
791 sn->stats[y][rix0].last_tx = ticks;
792 sn->stats[y][rix0].tries += tries;
793 sn->stats[y][rix0].total_packets += nframes;
797 sn->stats[size_bin][rix0].packets_acked += (nframes - nbad);
798 sn->stats[size_bin][rix0].successive_failures = 0;
800 sn->stats[size_bin][rix0].tries += tries;
801 sn->stats[size_bin][rix0].last_tx = ticks;
802 sn->stats[size_bin][rix0].total_packets += nframes;
804 /* update EWMA for this rix */
806 /* Calculate percentage based on current rate */
809 pct = ((nframes - nbad) * 1000) / nframes;
811 if (sn->stats[size_bin][rix0].total_packets <
812 ssc->smoothing_minpackets) {
813 /* just average the first few packets */
814 int a_pct = (sn->stats[size_bin][rix0].packets_acked * 1000) /
815 (sn->stats[size_bin][rix0].total_packets);
816 sn->stats[size_bin][rix0].ewma_pct = a_pct;
819 sn->stats[size_bin][rix0].ewma_pct =
820 ((sn->stats[size_bin][rix0].ewma_pct * ssc->smoothing_rate) +
821 (pct * (100 - ssc->smoothing_rate))) / 100;
825 if (rix0 == sn->current_sample_rix[size_bin]) {
826 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
828 "%s: size %d %s sample rate %d %s tries (%d/%d) tt %d avg_tt (%d/%d) nfrm %d nbad %d",
831 status ? "FAIL" : "OK",
833 dot11rate_label(rt, rix0),
834 short_tries, tries, tt,
835 sn->stats[size_bin][rix0].average_tx_time,
836 sn->stats[size_bin][rix0].perfect_tx_time,
838 sn->sample_tt[size_bin] = tt;
839 sn->current_sample_rix[size_bin] = -1;
844 badrate(struct ifnet *ifp, int series, int hwrate, int tries, int status)
846 if_printf(ifp, "bad series%d hwrate 0x%x, tries %u ts_status 0x%x\n",
847 series, hwrate, tries, status);
851 ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an,
852 const struct ath_rc_series *rc, const struct ath_tx_status *ts,
853 int frame_size, int nframes, int nbad)
855 struct ifnet *ifp = sc->sc_ifp;
856 struct ieee80211com *ic = ifp->if_l2com;
857 struct sample_node *sn = ATH_NODE_SAMPLE(an);
858 int final_rix, short_tries, long_tries;
859 const HAL_RATE_TABLE *rt = sc->sc_currates;
860 int status = ts->ts_status;
863 final_rix = rt->rateCodeToIndex[ts->ts_rate];
864 short_tries = ts->ts_shortretry;
865 long_tries = ts->ts_longretry + 1;
868 device_printf(sc->sc_dev, "%s: nframes=0?\n", __func__);
872 if (frame_size == 0) /* NB: should not happen */
875 if (sn->ratemask == 0) {
876 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
878 "%s: size %d %s rate/try %d/%d no rates yet",
880 bin_to_size(size_to_bin(frame_size)),
881 status ? "FAIL" : "OK",
882 short_tries, long_tries);
885 mrr = sc->sc_mrretry;
886 /* XXX check HT protmode too */
887 if (mrr && (ic->ic_flags & IEEE80211_F_USEPROT && !sc->sc_mrrprot))
890 if (!mrr || ts->ts_finaltsi == 0) {
891 if (!IS_RATE_DEFINED(sn, final_rix)) {
892 device_printf(sc->sc_dev, "%s: ts_rate=%d ts_finaltsi=%d\n",
893 __func__, ts->ts_rate, ts->ts_finaltsi);
894 badrate(ifp, 0, ts->ts_rate, long_tries, status);
898 * Only one rate was used; optimize work.
900 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
901 &an->an_node, "%s: size %d (%d bytes) %s rate/short/long %d %s/%d/%d nframes/nbad [%d/%d]",
903 bin_to_size(size_to_bin(frame_size)),
905 status ? "FAIL" : "OK",
906 dot11rate(rt, final_rix), dot11rate_label(rt, final_rix),
907 short_tries, long_tries, nframes, nbad);
908 update_stats(sc, an, frame_size,
909 final_rix, long_tries,
913 short_tries, long_tries, status,
917 int finalTSIdx = ts->ts_finaltsi;
921 * Process intermediate rates that failed.
924 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
926 "%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]",
928 bin_to_size(size_to_bin(frame_size)),
933 status ? "FAIL" : "OK",
934 dot11rate(rt, rc[0].rix),
935 dot11rate_label(rt, rc[0].rix), rc[0].tries,
936 dot11rate(rt, rc[1].rix),
937 dot11rate_label(rt, rc[1].rix), rc[1].tries,
938 dot11rate(rt, rc[2].rix),
939 dot11rate_label(rt, rc[2].rix), rc[2].tries,
940 dot11rate(rt, rc[3].rix),
941 dot11rate_label(rt, rc[3].rix), rc[3].tries,
944 for (i = 0; i < 4; i++) {
945 if (rc[i].tries && !IS_RATE_DEFINED(sn, rc[i].rix))
946 badrate(ifp, 0, rc[i].ratecode, rc[i].tries,
951 * NB: series > 0 are not penalized for failure
952 * based on the try counts under the assumption
953 * that losses are often bursty and since we
954 * sample higher rates 1 try at a time doing so
955 * may unfairly penalize them.
958 update_stats(sc, an, frame_size,
959 rc[0].rix, rc[0].tries,
960 rc[1].rix, rc[1].tries,
961 rc[2].rix, rc[2].tries,
962 rc[3].rix, rc[3].tries,
963 short_tries, long_tries,
964 long_tries > rc[0].tries,
966 long_tries -= rc[0].tries;
969 if (rc[1].tries && finalTSIdx > 0) {
970 update_stats(sc, an, frame_size,
971 rc[1].rix, rc[1].tries,
972 rc[2].rix, rc[2].tries,
973 rc[3].rix, rc[3].tries,
975 short_tries, long_tries,
978 long_tries -= rc[1].tries;
981 if (rc[2].tries && finalTSIdx > 1) {
982 update_stats(sc, an, frame_size,
983 rc[2].rix, rc[2].tries,
984 rc[3].rix, rc[3].tries,
987 short_tries, long_tries,
990 long_tries -= rc[2].tries;
993 if (rc[3].tries && finalTSIdx > 2) {
994 update_stats(sc, an, frame_size,
995 rc[3].rix, rc[3].tries,
999 short_tries, long_tries,
1007 ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew)
1010 ath_rate_ctl_reset(sc, &an->an_node);
1013 static const struct txschedule *mrr_schedules[IEEE80211_MODE_MAX+2] = {
1014 NULL, /* IEEE80211_MODE_AUTO */
1015 series_11a, /* IEEE80211_MODE_11A */
1016 series_11g, /* IEEE80211_MODE_11B */
1017 series_11g, /* IEEE80211_MODE_11G */
1018 NULL, /* IEEE80211_MODE_FH */
1019 series_11a, /* IEEE80211_MODE_TURBO_A */
1020 series_11g, /* IEEE80211_MODE_TURBO_G */
1021 series_11a, /* IEEE80211_MODE_STURBO_A */
1022 series_11na, /* IEEE80211_MODE_11NA */
1023 series_11ng, /* IEEE80211_MODE_11NG */
1024 series_half, /* IEEE80211_MODE_HALF */
1025 series_quarter, /* IEEE80211_MODE_QUARTER */
1029 * Initialize the tables for a node.
1032 ath_rate_ctl_reset(struct ath_softc *sc, struct ieee80211_node *ni)
1034 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
1035 #define DOT11RATE(_ix) (rt->info[(_ix)].dot11Rate & IEEE80211_RATE_VAL)
1036 #define MCS(_ix) (ni->ni_htrates.rs_rates[_ix] | IEEE80211_RATE_MCS)
1037 struct ath_node *an = ATH_NODE(ni);
1038 struct sample_node *sn = ATH_NODE_SAMPLE(an);
1039 const HAL_RATE_TABLE *rt = sc->sc_currates;
1042 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
1044 KASSERT(sc->sc_curmode < IEEE80211_MODE_MAX+2,
1045 ("curmode %u", sc->sc_curmode));
1047 sn->sched = mrr_schedules[sc->sc_curmode];
1048 KASSERT(sn->sched != NULL,
1049 ("no mrr schedule for mode %u", sc->sc_curmode));
1051 sn->static_rix = -1;
1052 ath_rate_update_static_rix(sc, ni);
1054 sn->currates = sc->sc_currates;
1057 * Construct a bitmask of usable rates. This has all
1058 * negotiated rates minus those marked by the hal as
1059 * to be ignored for doing rate control.
1063 if (ni->ni_flags & IEEE80211_NODE_HT) {
1064 for (x = 0; x < ni->ni_htrates.rs_nrates; x++) {
1065 rix = sc->sc_rixmap[MCS(x)];
1068 /* skip rates marked broken by hal */
1069 if (!rt->info[rix].valid)
1071 KASSERT(rix < SAMPLE_MAXRATES,
1072 ("mcs %u has rix %d", MCS(x), rix));
1073 sn->ratemask |= (uint64_t) 1<<rix;
1078 for (x = 0; x < ni->ni_rates.rs_nrates; x++) {
1079 rix = sc->sc_rixmap[RATE(x)];
1082 /* skip rates marked broken by hal */
1083 if (!rt->info[rix].valid)
1085 KASSERT(rix < SAMPLE_MAXRATES,
1086 ("rate %u has rix %d", RATE(x), rix));
1087 sn->ratemask |= (uint64_t) 1<<rix;
1089 #ifdef IEEE80211_DEBUG
1090 if (ieee80211_msg(ni->ni_vap, IEEE80211_MSG_RATECTL)) {
1093 ieee80211_note(ni->ni_vap, "[%6D] %s: size 1600 rate/tt",
1094 ni->ni_macaddr, ":", __func__);
1095 for (mask = sn->ratemask, rix = 0; mask != 0; mask >>= 1, rix++) {
1096 if ((mask & 1) == 0)
1098 printf(" %d %s/%d", dot11rate(rt, rix), dot11rate_label(rt, rix),
1099 calc_usecs_unicast_packet(sc, 1600, rix, 0,0,
1100 (ni->ni_chw == 40)));
1105 for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) {
1106 int size = bin_to_size(y);
1109 sn->packets_sent[y] = 0;
1110 sn->current_sample_rix[y] = -1;
1111 sn->last_sample_rix[y] = 0;
1112 /* XXX start with first valid rate */
1113 sn->current_rix[y] = ffs(sn->ratemask)-1;
1116 * Initialize the statistics buckets; these are
1117 * indexed by the rate code index.
1119 for (rix = 0, mask = sn->ratemask; mask != 0; rix++, mask >>= 1) {
1120 if ((mask & 1) == 0) /* not a valid rate */
1122 sn->stats[y][rix].successive_failures = 0;
1123 sn->stats[y][rix].tries = 0;
1124 sn->stats[y][rix].total_packets = 0;
1125 sn->stats[y][rix].packets_acked = 0;
1126 sn->stats[y][rix].last_tx = 0;
1127 sn->stats[y][rix].ewma_pct = 0;
1129 sn->stats[y][rix].perfect_tx_time =
1130 calc_usecs_unicast_packet(sc, size, rix, 0, 0,
1131 (ni->ni_chw == 40));
1132 sn->stats[y][rix].average_tx_time =
1133 sn->stats[y][rix].perfect_tx_time;
1137 /* XXX 0, num_rates-1 are wrong */
1138 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
1139 "%s: %d rates %d%sMbps (%dus)- %d%sMbps (%dus)", __func__,
1141 DOT11RATE(0)/2, DOT11RATE(0) % 1 ? ".5" : "",
1142 sn->stats[1][0].perfect_tx_time,
1143 DOT11RATE(sn->num_rates-1)/2, DOT11RATE(sn->num_rates-1) % 1 ? ".5" : "",
1144 sn->stats[1][sn->num_rates-1].perfect_tx_time
1147 /* set the visible bit-rate */
1148 if (sn->static_rix != -1)
1149 ni->ni_txrate = DOT11RATE(sn->static_rix);
1151 ni->ni_txrate = RATE(0);
1157 * Fetch the statistics for the given node.
1159 * The ieee80211 node must be referenced and unlocked, however the ath_node
1162 * The main difference here is that we convert the rate indexes
1163 * to 802.11 rates, or the userland output won't make much sense
1164 * as it has no access to the rix table.
1167 ath_rate_fetch_node_stats(struct ath_softc *sc, struct ath_node *an,
1168 struct ath_rateioctl *rs)
1170 struct sample_node *sn = ATH_NODE_SAMPLE(an);
1171 const HAL_RATE_TABLE *rt = sc->sc_currates;
1172 struct ath_rateioctl_tlv av;
1173 struct ath_rateioctl_rt *tv;
1177 ATH_NODE_LOCK_ASSERT(an);
1180 * Ensure there's enough space for the statistics.
1183 sizeof(struct ath_rateioctl_tlv) +
1184 sizeof(struct ath_rateioctl_rt) +
1185 sizeof(struct ath_rateioctl_tlv) +
1186 sizeof(struct sample_node)) {
1187 device_printf(sc->sc_dev, "%s: len=%d, too short\n",
1194 * Take a temporary copy of the sample node state so we can
1195 * modify it before we copy it.
1197 tv = malloc(sizeof(struct ath_rateioctl_rt), M_TEMP,
1204 * Populate the rate table mapping TLV.
1206 tv->nentries = rt->rateCount;
1207 for (y = 0; y < rt->rateCount; y++) {
1208 tv->ratecode[y] = rt->info[y].dot11Rate & IEEE80211_RATE_VAL;
1209 if (rt->info[y].phy == IEEE80211_T_HT)
1210 tv->ratecode[y] |= IEEE80211_RATE_MCS;
1215 * First TLV - rate code mapping
1217 av.tlv_id = ATH_RATE_TLV_RATETABLE;
1218 av.tlv_len = sizeof(struct ath_rateioctl_rt);
1219 copyout(&av, rs->buf + o, sizeof(struct ath_rateioctl_tlv));
1220 o += sizeof(struct ath_rateioctl_tlv);
1221 copyout(tv, rs->buf + o, sizeof(struct ath_rateioctl_rt));
1222 o += sizeof(struct ath_rateioctl_rt);
1225 * Second TLV - sample node statistics
1227 av.tlv_id = ATH_RATE_TLV_SAMPLENODE;
1228 av.tlv_len = sizeof(struct sample_node);
1229 copyout(&av, rs->buf + o, sizeof(struct ath_rateioctl_tlv));
1230 o += sizeof(struct ath_rateioctl_tlv);
1233 * Copy the statistics over to the provided buffer.
1235 copyout(sn, rs->buf + o, sizeof(struct sample_node));
1236 o += sizeof(struct sample_node);
1244 sample_stats(void *arg, struct ieee80211_node *ni)
1246 struct ath_softc *sc = arg;
1247 const HAL_RATE_TABLE *rt = sc->sc_currates;
1248 struct sample_node *sn = ATH_NODE_SAMPLE(ATH_NODE(ni));
1252 printf("\n[%s] refcnt %d static_rix (%d %s) ratemask 0x%jx\n",
1253 ether_sprintf(ni->ni_macaddr), ieee80211_node_refcnt(ni),
1254 dot11rate(rt, sn->static_rix),
1255 dot11rate_label(rt, sn->static_rix),
1256 (uintmax_t)sn->ratemask);
1257 for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) {
1258 printf("[%4u] cur rix %d (%d %s) since switch: packets %d ticks %u\n",
1259 bin_to_size(y), sn->current_rix[y],
1260 dot11rate(rt, sn->current_rix[y]),
1261 dot11rate_label(rt, sn->current_rix[y]),
1262 sn->packets_since_switch[y], sn->ticks_since_switch[y]);
1263 printf("[%4u] last sample (%d %s) cur sample (%d %s) packets sent %d\n",
1265 dot11rate(rt, sn->last_sample_rix[y]),
1266 dot11rate_label(rt, sn->last_sample_rix[y]),
1267 dot11rate(rt, sn->current_sample_rix[y]),
1268 dot11rate_label(rt, sn->current_sample_rix[y]),
1269 sn->packets_sent[y]);
1270 printf("[%4u] packets since sample %d sample tt %u\n",
1271 bin_to_size(y), sn->packets_since_sample[y],
1274 for (mask = sn->ratemask, rix = 0; mask != 0; mask >>= 1, rix++) {
1275 if ((mask & 1) == 0)
1277 for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) {
1278 if (sn->stats[y][rix].total_packets == 0)
1280 printf("[%2u %s:%4u] %8ju:%-8ju (%3d%%) (EWMA %3d.%1d%%) T %8ju F %4d avg %5u last %u\n",
1281 dot11rate(rt, rix), dot11rate_label(rt, rix),
1283 (uintmax_t) sn->stats[y][rix].total_packets,
1284 (uintmax_t) sn->stats[y][rix].packets_acked,
1285 (int) ((sn->stats[y][rix].packets_acked * 100ULL) /
1286 sn->stats[y][rix].total_packets),
1287 sn->stats[y][rix].ewma_pct / 10,
1288 sn->stats[y][rix].ewma_pct % 10,
1289 (uintmax_t) sn->stats[y][rix].tries,
1290 sn->stats[y][rix].successive_failures,
1291 sn->stats[y][rix].average_tx_time,
1292 ticks - sn->stats[y][rix].last_tx);
1298 ath_rate_sysctl_stats(SYSCTL_HANDLER_ARGS)
1300 struct ath_softc *sc = arg1;
1301 struct ifnet *ifp = sc->sc_ifp;
1302 struct ieee80211com *ic = ifp->if_l2com;
1306 error = sysctl_handle_int(oidp, &v, 0, req);
1307 if (error || !req->newptr)
1309 ieee80211_iterate_nodes(&ic->ic_sta, sample_stats, sc);
1314 ath_rate_sysctl_smoothing_rate(SYSCTL_HANDLER_ARGS)
1316 struct sample_softc *ssc = arg1;
1319 rate = ssc->smoothing_rate;
1320 error = sysctl_handle_int(oidp, &rate, 0, req);
1321 if (error || !req->newptr)
1323 if (!(0 <= rate && rate < 100))
1325 ssc->smoothing_rate = rate;
1326 ssc->smoothing_minpackets = 100 / (100 - rate);
1331 ath_rate_sysctl_sample_rate(SYSCTL_HANDLER_ARGS)
1333 struct sample_softc *ssc = arg1;
1336 rate = ssc->sample_rate;
1337 error = sysctl_handle_int(oidp, &rate, 0, req);
1338 if (error || !req->newptr)
1340 if (!(2 <= rate && rate <= 100))
1342 ssc->sample_rate = rate;
1347 ath_rate_sysctlattach(struct ath_softc *sc, struct sample_softc *ssc)
1349 struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev);
1350 struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev);
1352 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
1353 "smoothing_rate", CTLTYPE_INT | CTLFLAG_RW, ssc, 0,
1354 ath_rate_sysctl_smoothing_rate, "I",
1355 "sample: smoothing rate for avg tx time (%%)");
1356 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
1357 "sample_rate", CTLTYPE_INT | CTLFLAG_RW, ssc, 0,
1358 ath_rate_sysctl_sample_rate, "I",
1359 "sample: percent air time devoted to sampling new rates (%%)");
1360 /* XXX max_successive_failures, stale_failure_timeout, min_switch */
1361 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
1362 "sample_stats", CTLTYPE_INT | CTLFLAG_RW, sc, 0,
1363 ath_rate_sysctl_stats, "I", "sample: print statistics");
1366 struct ath_ratectrl *
1367 ath_rate_attach(struct ath_softc *sc)
1369 struct sample_softc *ssc;
1371 ssc = malloc(sizeof(struct sample_softc), M_DEVBUF, M_NOWAIT|M_ZERO);
1374 ssc->arc.arc_space = sizeof(struct sample_node);
1375 ssc->smoothing_rate = 75; /* ewma percentage ([0..99]) */
1376 ssc->smoothing_minpackets = 100 / (100 - ssc->smoothing_rate);
1377 ssc->sample_rate = 10; /* %time to try diff tx rates */
1378 ssc->max_successive_failures = 3; /* threshold for rate sampling*/
1379 ssc->stale_failure_timeout = 10 * hz; /* 10 seconds */
1380 ssc->min_switch = hz; /* 1 second */
1381 ath_rate_sysctlattach(sc, ssc);
1386 ath_rate_detach(struct ath_ratectrl *arc)
1388 struct sample_softc *ssc = (struct sample_softc *) arc;
1390 free(ssc, M_DEVBUF);