2 * Copyright (c) 2005 John Bicket
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer,
10 * without modification.
11 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
12 * similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
13 * redistribution must be conditioned upon including a substantially
14 * similar Disclaimer requirement for further binary redistribution.
15 * 3. Neither the names of the above-listed copyright holders nor the names
16 * of any contributors may be used to endorse or promote products derived
17 * from this software without specific prior written permission.
19 * Alternatively, this software may be distributed under the terms of the
20 * GNU General Public License ("GPL") version 2 as published by the Free
21 * Software Foundation.
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
25 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
26 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
27 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
28 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
29 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
32 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
34 * THE POSSIBILITY OF SUCH DAMAGES.
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/malloc.h>
55 #include <sys/mutex.h>
56 #include <sys/errno.h>
58 #if defined(__DragonFly__)
61 #include <machine/bus.h>
62 #include <machine/resource.h>
66 #include <sys/socket.h>
69 #include <net/if_var.h>
70 #include <net/if_media.h>
71 #include <net/if_arp.h>
72 #include <net/ethernet.h> /* XXX for ether_sprintf */
74 #include <netproto/802_11/ieee80211_var.h>
79 #include <netinet/in.h>
80 #include <netinet/if_ether.h>
83 #include <dev/netif/ath/ath/if_athvar.h>
84 #include <dev/netif/ath/ath_rate/sample/sample.h>
85 #include <dev/netif/ath/ath_hal/ah_desc.h>
86 #include <dev/netif/ath/ath_rate/sample/tx_schedules.h>
88 #if defined(__DragonFly__)
89 extern const char* ath_hal_ether_sprintf(const uint8_t *mac);
93 * This file is an implementation of the SampleRate algorithm
94 * in "Bit-rate Selection in Wireless Networks"
95 * (http://www.pdos.lcs.mit.edu/papers/jbicket-ms.ps)
97 * SampleRate chooses the bit-rate it predicts will provide the most
98 * throughput based on estimates of the expected per-packet
99 * transmission time for each bit-rate. SampleRate periodically sends
100 * packets at bit-rates other than the current one to estimate when
101 * another bit-rate will provide better performance. SampleRate
102 * switches to another bit-rate when its estimated per-packet
103 * transmission time becomes smaller than the current bit-rate's.
104 * SampleRate reduces the number of bit-rates it must sample by
105 * eliminating those that could not perform better than the one
106 * currently being used. SampleRate also stops probing at a bit-rate
107 * if it experiences several successive losses.
109 * The difference between the algorithm in the thesis and the one in this
110 * file is that the one in this file uses a ewma instead of a window.
112 * Also, this implementation tracks the average transmission time for
113 * a few different packet sizes independently for each link.
116 static void ath_rate_ctl_reset(struct ath_softc *, struct ieee80211_node *);
119 size_to_bin(int size)
121 #if NUM_PACKET_SIZE_BINS > 1
122 if (size <= packet_size_bins[0])
125 #if NUM_PACKET_SIZE_BINS > 2
126 if (size <= packet_size_bins[1])
129 #if NUM_PACKET_SIZE_BINS > 3
130 if (size <= packet_size_bins[2])
133 #if NUM_PACKET_SIZE_BINS > 4
134 #error "add support for more packet sizes"
136 return NUM_PACKET_SIZE_BINS-1;
140 ath_rate_node_init(struct ath_softc *sc, struct ath_node *an)
142 /* NB: assumed to be zero'd by caller */
146 ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an)
151 dot11rate(const HAL_RATE_TABLE *rt, int rix)
155 return rt->info[rix].phy == IEEE80211_T_HT ?
156 rt->info[rix].dot11Rate : (rt->info[rix].dot11Rate & IEEE80211_RATE_VAL) / 2;
160 dot11rate_label(const HAL_RATE_TABLE *rt, int rix)
164 return rt->info[rix].phy == IEEE80211_T_HT ? "MCS" : "Mb ";
168 * Return the rix with the lowest average_tx_time,
169 * or -1 if all the average_tx_times are 0.
172 pick_best_rate(struct ath_node *an, const HAL_RATE_TABLE *rt,
173 int size_bin, int require_acked_before)
175 struct sample_node *sn = ATH_NODE_SAMPLE(an);
176 int best_rate_rix, best_rate_tt, best_rate_pct;
183 for (mask = sn->ratemask, rix = 0; mask != 0; mask >>= 1, rix++) {
184 if ((mask & 1) == 0) /* not a supported rate */
187 /* Don't pick a non-HT rate for a HT node */
188 if ((an->an_node.ni_flags & IEEE80211_NODE_HT) &&
189 (rt->info[rix].phy != IEEE80211_T_HT)) {
193 tt = sn->stats[size_bin][rix].average_tx_time;
195 (require_acked_before &&
196 !sn->stats[size_bin][rix].packets_acked))
199 /* Calculate percentage if possible */
200 if (sn->stats[size_bin][rix].total_packets > 0) {
201 pct = sn->stats[size_bin][rix].ewma_pct;
203 /* XXX for now, assume 95% ok */
207 /* don't use a bit-rate that has been failing */
208 if (sn->stats[size_bin][rix].successive_failures > 3)
212 * For HT, Don't use a bit rate that is much more
213 * lossy than the best.
215 * XXX this isn't optimal; it's just designed to
216 * eliminate rates that are going to be obviously
219 if (an->an_node.ni_flags & IEEE80211_NODE_HT) {
220 if (best_rate_pct > (pct + 50))
225 * For non-MCS rates, use the current average txtime for
228 if (! (an->an_node.ni_flags & IEEE80211_NODE_HT)) {
229 if (best_rate_tt == 0 || tt <= best_rate_tt) {
237 * Since 2 stream rates have slightly higher TX times,
238 * allow a little bit of leeway. This should later
239 * be abstracted out and properly handled.
241 if (an->an_node.ni_flags & IEEE80211_NODE_HT) {
242 if (best_rate_tt == 0 || (tt * 8 <= best_rate_tt * 10)) {
249 return (best_rate_tt ? best_rate_rix : -1);
253 * Pick a good "random" bit-rate to sample other than the current one.
256 pick_sample_rate(struct sample_softc *ssc , struct ath_node *an,
257 const HAL_RATE_TABLE *rt, int size_bin)
259 #define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
260 #define MCS(ix) (rt->info[ix].dot11Rate | IEEE80211_RATE_MCS)
261 struct sample_node *sn = ATH_NODE_SAMPLE(an);
262 int current_rix, rix;
266 current_rix = sn->current_rix[size_bin];
267 if (current_rix < 0) {
268 /* no successes yet, send at the lowest bit-rate */
269 /* XXX should return MCS0 if HT */
273 current_tt = sn->stats[size_bin][current_rix].average_tx_time;
275 rix = sn->last_sample_rix[size_bin]+1; /* next sample rate */
276 mask = sn->ratemask &~ ((uint64_t) 1<<current_rix);/* don't sample current rate */
278 if ((mask & ((uint64_t) 1<<rix)) == 0) { /* not a supported rate */
280 if (++rix >= rt->rateCount)
286 * The following code stops trying to sample
287 * non-MCS rates when speaking to an MCS node.
288 * However, at least for CCK rates in 2.4GHz mode,
289 * the non-MCS rates MAY actually provide better
290 * PER at the very far edge of reception.
292 * However! Until ath_rate_form_aggr() grows
293 * some logic to not form aggregates if the
294 * selected rate is non-MCS, this won't work.
296 * So don't disable this code until you've taught
297 * ath_rate_form_aggr() to drop out if any of
298 * the selected rates are non-MCS.
301 /* if the node is HT and the rate isn't HT, don't bother sample */
302 if ((an->an_node.ni_flags & IEEE80211_NODE_HT) &&
303 (rt->info[rix].phy != IEEE80211_T_HT)) {
304 mask &= ~((uint64_t) 1<<rix);
309 /* this bit-rate is always worse than the current one */
310 if (sn->stats[size_bin][rix].perfect_tx_time > current_tt) {
311 mask &= ~((uint64_t) 1<<rix);
315 /* rarely sample bit-rates that fail a lot */
316 if (sn->stats[size_bin][rix].successive_failures > ssc->max_successive_failures &&
317 ticks - sn->stats[size_bin][rix].last_tx < ssc->stale_failure_timeout) {
318 mask &= ~((uint64_t) 1<<rix);
323 * For HT, only sample a few rates on either side of the
324 * current rix; there's quite likely a lot of them.
326 if (an->an_node.ni_flags & IEEE80211_NODE_HT) {
327 if (rix < (current_rix - 3) ||
328 rix > (current_rix + 3)) {
329 mask &= ~((uint64_t) 1<<rix);
334 /* Don't sample more than 2 rates higher for rates > 11M for non-HT rates */
335 if (! (an->an_node.ni_flags & IEEE80211_NODE_HT)) {
336 if (DOT11RATE(rix) > 2*11 && rix > current_rix + 2) {
337 mask &= ~((uint64_t) 1<<rix);
342 sn->last_sample_rix[size_bin] = rix;
351 ath_rate_get_static_rix(struct ath_softc *sc, const struct ieee80211_node *ni)
353 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
354 #define DOT11RATE(_ix) (rt->info[(_ix)].dot11Rate & IEEE80211_RATE_VAL)
355 #define MCS(_ix) (ni->ni_htrates.rs_rates[_ix] | IEEE80211_RATE_MCS)
356 const struct ieee80211_txparam *tp = ni->ni_txparms;
359 /* Check MCS rates */
360 for (srate = ni->ni_htrates.rs_nrates - 1; srate >= 0; srate--) {
361 if (MCS(srate) == tp->ucastrate)
362 return sc->sc_rixmap[tp->ucastrate];
365 /* Check legacy rates */
366 for (srate = ni->ni_rates.rs_nrates - 1; srate >= 0; srate--) {
367 if (RATE(srate) == tp->ucastrate)
368 return sc->sc_rixmap[tp->ucastrate];
377 ath_rate_update_static_rix(struct ath_softc *sc, struct ieee80211_node *ni)
379 struct ath_node *an = ATH_NODE(ni);
380 const struct ieee80211_txparam *tp = ni->ni_txparms;
381 struct sample_node *sn = ATH_NODE_SAMPLE(an);
383 if (tp != NULL && tp->ucastrate != IEEE80211_FIXED_RATE_NONE) {
385 * A fixed rate is to be used; ucastrate is the IEEE code
386 * for this rate (sans basic bit). Check this against the
387 * negotiated rate set for the node. Note the fixed rate
388 * may not be available for various reasons so we only
389 * setup the static rate index if the lookup is successful.
391 sn->static_rix = ath_rate_get_static_rix(sc, ni);
398 * Pick a non-HT rate to begin using.
401 ath_rate_pick_seed_rate_legacy(struct ath_softc *sc, struct ath_node *an,
404 #define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
405 #define MCS(ix) (rt->info[ix].dot11Rate | IEEE80211_RATE_MCS)
406 #define RATE(ix) (DOT11RATE(ix) / 2)
408 const HAL_RATE_TABLE *rt = sc->sc_currates;
409 struct sample_node *sn = ATH_NODE_SAMPLE(an);
410 const int size_bin = size_to_bin(frameLen);
412 /* no packet has been sent successfully yet */
413 for (rix = rt->rateCount-1; rix > 0; rix--) {
414 if ((sn->ratemask & ((uint64_t) 1<<rix)) == 0)
418 if (rt->info[rix].phy == IEEE80211_T_HT)
422 * Pick the highest rate <= 36 Mbps
423 * that hasn't failed.
425 if (DOT11RATE(rix) <= 72 &&
426 sn->stats[size_bin][rix].successive_failures == 0) {
437 * Pick a HT rate to begin using.
439 * Don't use any non-HT rates; only consider HT rates.
442 ath_rate_pick_seed_rate_ht(struct ath_softc *sc, struct ath_node *an,
445 #define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
446 #define MCS(ix) (rt->info[ix].dot11Rate | IEEE80211_RATE_MCS)
447 #define RATE(ix) (DOT11RATE(ix) / 2)
448 int rix = -1, ht_rix = -1;
449 const HAL_RATE_TABLE *rt = sc->sc_currates;
450 struct sample_node *sn = ATH_NODE_SAMPLE(an);
451 const int size_bin = size_to_bin(frameLen);
453 /* no packet has been sent successfully yet */
454 for (rix = rt->rateCount-1; rix > 0; rix--) {
455 /* Skip rates we can't use */
456 if ((sn->ratemask & ((uint64_t) 1<<rix)) == 0)
459 /* Keep a copy of the last seen HT rate index */
460 if (rt->info[rix].phy == IEEE80211_T_HT)
463 /* Skip non-HT rates */
464 if (rt->info[rix].phy != IEEE80211_T_HT)
468 * Pick a medium-speed rate regardless of stream count
469 * which has not seen any failures. Higher rates may fail;
470 * we'll try them later.
472 if (((MCS(rix) & 0x7) <= 4) &&
473 sn->stats[size_bin][rix].successive_failures == 0) {
479 * If all the MCS rates have successive failures, rix should be
480 * > 0; otherwise use the lowest MCS rix (hopefully MCS 0.)
482 return MAX(rix, ht_rix);
490 ath_rate_findrate(struct ath_softc *sc, struct ath_node *an,
491 int shortPreamble, size_t frameLen,
492 u_int8_t *rix0, int *try0, u_int8_t *txrate)
494 #define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
495 #define MCS(ix) (rt->info[ix].dot11Rate | IEEE80211_RATE_MCS)
496 #define RATE(ix) (DOT11RATE(ix) / 2)
497 struct sample_node *sn = ATH_NODE_SAMPLE(an);
498 struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc);
499 struct ieee80211com *ic = &sc->sc_ic;
500 const HAL_RATE_TABLE *rt = sc->sc_currates;
501 const int size_bin = size_to_bin(frameLen);
502 int rix, mrr, best_rix, change_rates;
503 unsigned average_tx_time;
505 ath_rate_update_static_rix(sc, &an->an_node);
507 if (sn->currates != sc->sc_currates) {
508 device_printf(sc->sc_dev, "%s: currates != sc_currates!\n",
511 *try0 = ATH_TXMAXTRY;
515 if (sn->static_rix != -1) {
516 rix = sn->static_rix;
517 *try0 = ATH_TXMAXTRY;
521 mrr = sc->sc_mrretry;
522 /* XXX check HT protmode too */
523 if (mrr && (ic->ic_flags & IEEE80211_F_USEPROT && !sc->sc_mrrprot))
526 best_rix = pick_best_rate(an, rt, size_bin, !mrr);
528 average_tx_time = sn->stats[size_bin][best_rix].average_tx_time;
533 * Limit the time measuring the performance of other tx
534 * rates to sample_rate% of the total transmission time.
536 if (sn->sample_tt[size_bin] < average_tx_time * (sn->packets_since_sample[size_bin]*ssc->sample_rate/100)) {
537 rix = pick_sample_rate(ssc, an, rt, size_bin);
538 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
539 &an->an_node, "att %d sample_tt %d size %u sample rate %d %s current rate %d %s",
541 sn->sample_tt[size_bin],
542 bin_to_size(size_bin),
544 dot11rate_label(rt, rix),
545 dot11rate(rt, sn->current_rix[size_bin]),
546 dot11rate_label(rt, sn->current_rix[size_bin]));
547 if (rix != sn->current_rix[size_bin]) {
548 sn->current_sample_rix[size_bin] = rix;
550 sn->current_sample_rix[size_bin] = -1;
552 sn->packets_since_sample[size_bin] = 0;
555 if (!sn->packets_sent[size_bin] || best_rix == -1) {
556 /* no packet has been sent successfully yet */
558 if (an->an_node.ni_flags & IEEE80211_NODE_HT)
560 ath_rate_pick_seed_rate_ht(sc, an, frameLen);
563 ath_rate_pick_seed_rate_legacy(sc, an, frameLen);
564 } else if (sn->packets_sent[size_bin] < 20) {
565 /* let the bit-rate switch quickly during the first few packets */
566 IEEE80211_NOTE(an->an_node.ni_vap,
567 IEEE80211_MSG_RATECTL, &an->an_node,
568 "%s: switching quickly..", __func__);
570 } else if (ticks - ssc->min_switch > sn->ticks_since_switch[size_bin]) {
571 /* min_switch seconds have gone by */
572 IEEE80211_NOTE(an->an_node.ni_vap,
573 IEEE80211_MSG_RATECTL, &an->an_node,
574 "%s: min_switch %d > ticks_since_switch %d..",
575 __func__, ticks - ssc->min_switch, sn->ticks_since_switch[size_bin]);
577 } else if ((! (an->an_node.ni_flags & IEEE80211_NODE_HT)) &&
578 (2*average_tx_time < sn->stats[size_bin][sn->current_rix[size_bin]].average_tx_time)) {
579 /* the current bit-rate is twice as slow as the best one */
580 IEEE80211_NOTE(an->an_node.ni_vap,
581 IEEE80211_MSG_RATECTL, &an->an_node,
582 "%s: 2x att (= %d) < cur_rix att %d",
584 2 * average_tx_time, sn->stats[size_bin][sn->current_rix[size_bin]].average_tx_time);
586 } else if ((an->an_node.ni_flags & IEEE80211_NODE_HT)) {
587 int cur_rix = sn->current_rix[size_bin];
588 int cur_att = sn->stats[size_bin][cur_rix].average_tx_time;
590 * If the node is HT, upgrade it if the MCS rate is
591 * higher and the average tx time is within 20% of
592 * the current rate. It can fail a little.
594 * This is likely not optimal!
597 kprintf("cur rix/att %x/%d, best rix/att %x/%d\n",
598 MCS(cur_rix), cur_att, MCS(best_rix), average_tx_time);
600 if ((MCS(best_rix) > MCS(cur_rix)) &&
601 (average_tx_time * 8) <= (cur_att * 10)) {
602 IEEE80211_NOTE(an->an_node.ni_vap,
603 IEEE80211_MSG_RATECTL, &an->an_node,
604 "%s: HT: best_rix 0x%d > cur_rix 0x%x, average_tx_time %d, cur_att %d",
606 MCS(best_rix), MCS(cur_rix), average_tx_time, cur_att);
611 sn->packets_since_sample[size_bin]++;
614 if (best_rix != sn->current_rix[size_bin]) {
615 IEEE80211_NOTE(an->an_node.ni_vap,
616 IEEE80211_MSG_RATECTL,
618 "%s: size %d switch rate %d (%d/%d) -> %d (%d/%d) after %d packets mrr %d",
620 bin_to_size(size_bin),
621 RATE(sn->current_rix[size_bin]),
622 sn->stats[size_bin][sn->current_rix[size_bin]].average_tx_time,
623 sn->stats[size_bin][sn->current_rix[size_bin]].perfect_tx_time,
625 sn->stats[size_bin][best_rix].average_tx_time,
626 sn->stats[size_bin][best_rix].perfect_tx_time,
627 sn->packets_since_switch[size_bin],
630 sn->packets_since_switch[size_bin] = 0;
631 sn->current_rix[size_bin] = best_rix;
632 sn->ticks_since_switch[size_bin] = ticks;
634 * Set the visible txrate for this node.
636 an->an_node.ni_txrate = (rt->info[best_rix].phy == IEEE80211_T_HT) ? MCS(best_rix) : DOT11RATE(best_rix);
638 rix = sn->current_rix[size_bin];
639 sn->packets_since_switch[size_bin]++;
641 *try0 = mrr ? sn->sched[rix].t0 : ATH_TXMAXTRY;
645 * This bug totally sucks and should be fixed.
647 * For now though, let's not panic, so we can start to figure
648 * out how to better reproduce it.
650 if (rix < 0 || rix >= rt->rateCount) {
651 kprintf("%s: ERROR: rix %d out of bounds (rateCount=%d)\n",
655 rix = 0; /* XXX just default for now */
657 KASSERT(rix >= 0 && rix < rt->rateCount, ("rix is %d", rix));
660 *txrate = rt->info[rix].rateCode
661 | (shortPreamble ? rt->info[rix].shortPreamble : 0);
662 sn->packets_sent[size_bin]++;
669 * Get the TX rates. Don't fiddle with short preamble flags for them;
670 * the caller can do that.
673 ath_rate_getxtxrates(struct ath_softc *sc, struct ath_node *an,
674 uint8_t rix0, struct ath_rc_series *rc)
676 struct sample_node *sn = ATH_NODE_SAMPLE(an);
677 const struct txschedule *sched = &sn->sched[rix0];
679 KASSERT(rix0 == sched->r0, ("rix0 (%x) != sched->r0 (%x)!\n",
682 rc[0].flags = rc[1].flags = rc[2].flags = rc[3].flags = 0;
684 rc[0].rix = sched->r0;
685 rc[1].rix = sched->r1;
686 rc[2].rix = sched->r2;
687 rc[3].rix = sched->r3;
689 rc[0].tries = sched->t0;
690 rc[1].tries = sched->t1;
691 rc[2].tries = sched->t2;
692 rc[3].tries = sched->t3;
696 ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an,
697 struct ath_desc *ds, int shortPreamble, u_int8_t rix)
699 struct sample_node *sn = ATH_NODE_SAMPLE(an);
700 const struct txschedule *sched = &sn->sched[rix];
701 const HAL_RATE_TABLE *rt = sc->sc_currates;
702 uint8_t rix1, s1code, rix2, s2code, rix3, s3code;
704 /* XXX precalculate short preamble tables */
706 s1code = rt->info[rix1].rateCode
707 | (shortPreamble ? rt->info[rix1].shortPreamble : 0);
709 s2code = rt->info[rix2].rateCode
710 | (shortPreamble ? rt->info[rix2].shortPreamble : 0);
712 s3code = rt->info[rix3].rateCode
713 | (shortPreamble ? rt->info[rix3].shortPreamble : 0);
714 ath_hal_setupxtxdesc(sc->sc_ah, ds,
715 s1code, sched->t1, /* series 1 */
716 s2code, sched->t2, /* series 2 */
717 s3code, sched->t3); /* series 3 */
721 update_stats(struct ath_softc *sc, struct ath_node *an,
723 int rix0, int tries0,
724 int rix1, int tries1,
725 int rix2, int tries2,
726 int rix3, int tries3,
727 int short_tries, int tries, int status,
728 int nframes, int nbad)
730 struct sample_node *sn = ATH_NODE_SAMPLE(an);
731 struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc);
732 #ifdef IEEE80211_DEBUG
733 const HAL_RATE_TABLE *rt = sc->sc_currates;
735 const int size_bin = size_to_bin(frame_size);
736 const int size = bin_to_size(size_bin);
737 int tt, tries_so_far;
738 int is_ht40 = (an->an_node.ni_chw == 40);
741 if (!IS_RATE_DEFINED(sn, rix0))
743 tt = calc_usecs_unicast_packet(sc, size, rix0, short_tries,
744 MIN(tries0, tries) - 1, is_ht40);
745 tries_so_far = tries0;
747 if (tries1 && tries_so_far < tries) {
748 if (!IS_RATE_DEFINED(sn, rix1))
750 tt += calc_usecs_unicast_packet(sc, size, rix1, short_tries,
751 MIN(tries1 + tries_so_far, tries) - tries_so_far - 1, is_ht40);
752 tries_so_far += tries1;
755 if (tries2 && tries_so_far < tries) {
756 if (!IS_RATE_DEFINED(sn, rix2))
758 tt += calc_usecs_unicast_packet(sc, size, rix2, short_tries,
759 MIN(tries2 + tries_so_far, tries) - tries_so_far - 1, is_ht40);
760 tries_so_far += tries2;
763 if (tries3 && tries_so_far < tries) {
764 if (!IS_RATE_DEFINED(sn, rix3))
766 tt += calc_usecs_unicast_packet(sc, size, rix3, short_tries,
767 MIN(tries3 + tries_so_far, tries) - tries_so_far - 1, is_ht40);
770 if (sn->stats[size_bin][rix0].total_packets < ssc->smoothing_minpackets) {
771 /* just average the first few packets */
772 int avg_tx = sn->stats[size_bin][rix0].average_tx_time;
773 int packets = sn->stats[size_bin][rix0].total_packets;
774 sn->stats[size_bin][rix0].average_tx_time = (tt+(avg_tx*packets))/(packets+nframes);
777 sn->stats[size_bin][rix0].average_tx_time =
778 ((sn->stats[size_bin][rix0].average_tx_time * ssc->smoothing_rate) +
779 (tt * (100 - ssc->smoothing_rate))) / 100;
783 * XXX Don't mark the higher bit rates as also having failed; as this
784 * unfortunately stops those rates from being tasted when trying to
785 * TX. This happens with 11n aggregation.
787 if (nframes == nbad) {
791 sn->stats[size_bin][rix0].successive_failures += nbad;
793 for (y = size_bin+1; y < NUM_PACKET_SIZE_BINS; y++) {
795 * Also say larger packets failed since we
796 * assume if a small packet fails at a
797 * bit-rate then a larger one will also.
799 sn->stats[y][rix0].successive_failures += nbad;
800 sn->stats[y][rix0].last_tx = ticks;
801 sn->stats[y][rix0].tries += tries;
802 sn->stats[y][rix0].total_packets += nframes;
806 sn->stats[size_bin][rix0].packets_acked += (nframes - nbad);
807 sn->stats[size_bin][rix0].successive_failures = 0;
809 sn->stats[size_bin][rix0].tries += tries;
810 sn->stats[size_bin][rix0].last_tx = ticks;
811 sn->stats[size_bin][rix0].total_packets += nframes;
813 /* update EWMA for this rix */
815 /* Calculate percentage based on current rate */
818 pct = ((nframes - nbad) * 1000) / nframes;
820 if (sn->stats[size_bin][rix0].total_packets <
821 ssc->smoothing_minpackets) {
822 /* just average the first few packets */
823 int a_pct = (sn->stats[size_bin][rix0].packets_acked * 1000) /
824 (sn->stats[size_bin][rix0].total_packets);
825 sn->stats[size_bin][rix0].ewma_pct = a_pct;
828 sn->stats[size_bin][rix0].ewma_pct =
829 ((sn->stats[size_bin][rix0].ewma_pct * ssc->smoothing_rate) +
830 (pct * (100 - ssc->smoothing_rate))) / 100;
834 if (rix0 == sn->current_sample_rix[size_bin]) {
835 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
837 "%s: size %d %s sample rate %d %s tries (%d/%d) tt %d avg_tt (%d/%d) nfrm %d nbad %d",
840 status ? "FAIL" : "OK",
842 dot11rate_label(rt, rix0),
843 short_tries, tries, tt,
844 sn->stats[size_bin][rix0].average_tx_time,
845 sn->stats[size_bin][rix0].perfect_tx_time,
847 sn->sample_tt[size_bin] = tt;
848 sn->current_sample_rix[size_bin] = -1;
853 badrate(struct ath_softc *sc, int series, int hwrate, int tries, int status)
856 device_printf(sc->sc_dev,
857 "bad series%d hwrate 0x%x, tries %u ts_status 0x%x\n",
858 series, hwrate, tries, status);
862 ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an,
863 const struct ath_rc_series *rc, const struct ath_tx_status *ts,
864 int frame_size, int nframes, int nbad)
866 struct ieee80211com *ic = &sc->sc_ic;
867 struct sample_node *sn = ATH_NODE_SAMPLE(an);
868 int final_rix, short_tries, long_tries;
869 const HAL_RATE_TABLE *rt = sc->sc_currates;
870 int status = ts->ts_status;
873 final_rix = rt->rateCodeToIndex[ts->ts_rate];
874 short_tries = ts->ts_shortretry;
875 long_tries = ts->ts_longretry + 1;
878 device_printf(sc->sc_dev, "%s: nframes=0?\n", __func__);
882 if (frame_size == 0) /* NB: should not happen */
885 if (sn->ratemask == 0) {
886 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
888 "%s: size %d %s rate/try %d/%d no rates yet",
890 bin_to_size(size_to_bin(frame_size)),
891 status ? "FAIL" : "OK",
892 short_tries, long_tries);
895 mrr = sc->sc_mrretry;
896 /* XXX check HT protmode too */
897 if (mrr && (ic->ic_flags & IEEE80211_F_USEPROT && !sc->sc_mrrprot))
900 if (!mrr || ts->ts_finaltsi == 0) {
901 if (!IS_RATE_DEFINED(sn, final_rix)) {
902 device_printf(sc->sc_dev,
903 "%s: ts_rate=%d ts_finaltsi=%d, final_rix=%d\n",
904 __func__, ts->ts_rate, ts->ts_finaltsi, final_rix);
905 badrate(sc, 0, ts->ts_rate, long_tries, status);
909 * Only one rate was used; optimize work.
911 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
912 &an->an_node, "%s: size %d (%d bytes) %s rate/short/long %d %s/%d/%d nframes/nbad [%d/%d]",
914 bin_to_size(size_to_bin(frame_size)),
916 status ? "FAIL" : "OK",
917 dot11rate(rt, final_rix), dot11rate_label(rt, final_rix),
918 short_tries, long_tries, nframes, nbad);
919 update_stats(sc, an, frame_size,
920 final_rix, long_tries,
924 short_tries, long_tries, status,
928 int finalTSIdx = ts->ts_finaltsi;
932 * Process intermediate rates that failed.
935 IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
937 "%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]",
939 bin_to_size(size_to_bin(frame_size)),
944 status ? "FAIL" : "OK",
945 dot11rate(rt, rc[0].rix),
946 dot11rate_label(rt, rc[0].rix), rc[0].tries,
947 dot11rate(rt, rc[1].rix),
948 dot11rate_label(rt, rc[1].rix), rc[1].tries,
949 dot11rate(rt, rc[2].rix),
950 dot11rate_label(rt, rc[2].rix), rc[2].tries,
951 dot11rate(rt, rc[3].rix),
952 dot11rate_label(rt, rc[3].rix), rc[3].tries,
955 for (i = 0; i < 4; i++) {
956 if (rc[i].tries && !IS_RATE_DEFINED(sn, rc[i].rix))
957 badrate(sc, 0, rc[i].ratecode, rc[i].tries,
962 * NB: series > 0 are not penalized for failure
963 * based on the try counts under the assumption
964 * that losses are often bursty and since we
965 * sample higher rates 1 try at a time doing so
966 * may unfairly penalize them.
969 update_stats(sc, an, frame_size,
970 rc[0].rix, rc[0].tries,
971 rc[1].rix, rc[1].tries,
972 rc[2].rix, rc[2].tries,
973 rc[3].rix, rc[3].tries,
974 short_tries, long_tries,
975 long_tries > rc[0].tries,
977 long_tries -= rc[0].tries;
980 if (rc[1].tries && finalTSIdx > 0) {
981 update_stats(sc, an, frame_size,
982 rc[1].rix, rc[1].tries,
983 rc[2].rix, rc[2].tries,
984 rc[3].rix, rc[3].tries,
986 short_tries, long_tries,
989 long_tries -= rc[1].tries;
992 if (rc[2].tries && finalTSIdx > 1) {
993 update_stats(sc, an, frame_size,
994 rc[2].rix, rc[2].tries,
995 rc[3].rix, rc[3].tries,
998 short_tries, long_tries,
1001 long_tries -= rc[2].tries;
1004 if (rc[3].tries && finalTSIdx > 2) {
1005 update_stats(sc, an, frame_size,
1006 rc[3].rix, rc[3].tries,
1010 short_tries, long_tries,
1018 ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew)
1021 ath_rate_ctl_reset(sc, &an->an_node);
1024 static const struct txschedule *mrr_schedules[IEEE80211_MODE_MAX+2] = {
1025 NULL, /* IEEE80211_MODE_AUTO */
1026 series_11a, /* IEEE80211_MODE_11A */
1027 series_11g, /* IEEE80211_MODE_11B */
1028 series_11g, /* IEEE80211_MODE_11G */
1029 NULL, /* IEEE80211_MODE_FH */
1030 series_11a, /* IEEE80211_MODE_TURBO_A */
1031 series_11g, /* IEEE80211_MODE_TURBO_G */
1032 series_11a, /* IEEE80211_MODE_STURBO_A */
1033 series_11na, /* IEEE80211_MODE_11NA */
1034 series_11ng, /* IEEE80211_MODE_11NG */
1035 series_half, /* IEEE80211_MODE_HALF */
1036 series_quarter, /* IEEE80211_MODE_QUARTER */
1040 * Initialize the tables for a node.
1043 ath_rate_ctl_reset(struct ath_softc *sc, struct ieee80211_node *ni)
1045 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
1046 #define DOT11RATE(_ix) (rt->info[(_ix)].dot11Rate & IEEE80211_RATE_VAL)
1047 #define MCS(_ix) (ni->ni_htrates.rs_rates[_ix] | IEEE80211_RATE_MCS)
1048 struct ath_node *an = ATH_NODE(ni);
1049 struct sample_node *sn = ATH_NODE_SAMPLE(an);
1050 const HAL_RATE_TABLE *rt = sc->sc_currates;
1053 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
1055 KASSERT(sc->sc_curmode < IEEE80211_MODE_MAX+2,
1056 ("curmode %u", sc->sc_curmode));
1058 sn->sched = mrr_schedules[sc->sc_curmode];
1059 KASSERT(sn->sched != NULL,
1060 ("no mrr schedule for mode %u", sc->sc_curmode));
1062 sn->static_rix = -1;
1063 ath_rate_update_static_rix(sc, ni);
1065 sn->currates = sc->sc_currates;
1068 * Construct a bitmask of usable rates. This has all
1069 * negotiated rates minus those marked by the hal as
1070 * to be ignored for doing rate control.
1074 if (ni->ni_flags & IEEE80211_NODE_HT) {
1075 for (x = 0; x < ni->ni_htrates.rs_nrates; x++) {
1076 rix = sc->sc_rixmap[MCS(x)];
1079 /* skip rates marked broken by hal */
1080 if (!rt->info[rix].valid)
1082 KASSERT(rix < SAMPLE_MAXRATES,
1083 ("mcs %u has rix %d", MCS(x), rix));
1084 sn->ratemask |= (uint64_t) 1<<rix;
1089 for (x = 0; x < ni->ni_rates.rs_nrates; x++) {
1090 rix = sc->sc_rixmap[RATE(x)];
1093 /* skip rates marked broken by hal */
1094 if (!rt->info[rix].valid)
1096 KASSERT(rix < SAMPLE_MAXRATES,
1097 ("rate %u has rix %d", RATE(x), rix));
1098 sn->ratemask |= (uint64_t) 1<<rix;
1100 #ifdef IEEE80211_DEBUG
1101 if (ieee80211_msg(ni->ni_vap, IEEE80211_MSG_RATECTL)) {
1104 #if defined(__DragonFly__)
1105 ieee80211_note(ni->ni_vap, "[%s] %s: size 1600 rate/tt",
1106 ath_hal_ether_sprintf(ni->ni_macaddr), __func__);
1108 ieee80211_note(ni->ni_vap, "[%6D] %s: size 1600 rate/tt",
1109 ni->ni_macaddr, ":", __func__);
1111 for (mask = sn->ratemask, rix = 0; mask != 0; mask >>= 1, rix++) {
1112 if ((mask & 1) == 0)
1114 kprintf(" %d %s/%d", dot11rate(rt, rix), dot11rate_label(rt, rix),
1115 calc_usecs_unicast_packet(sc, 1600, rix, 0,0,
1116 (ni->ni_chw == 40)));
1121 for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) {
1122 int size = bin_to_size(y);
1125 sn->packets_sent[y] = 0;
1126 sn->current_sample_rix[y] = -1;
1127 sn->last_sample_rix[y] = 0;
1128 /* XXX start with first valid rate */
1129 sn->current_rix[y] = ffs(sn->ratemask)-1;
1132 * Initialize the statistics buckets; these are
1133 * indexed by the rate code index.
1135 for (rix = 0, mask = sn->ratemask; mask != 0; rix++, mask >>= 1) {
1136 if ((mask & 1) == 0) /* not a valid rate */
1138 sn->stats[y][rix].successive_failures = 0;
1139 sn->stats[y][rix].tries = 0;
1140 sn->stats[y][rix].total_packets = 0;
1141 sn->stats[y][rix].packets_acked = 0;
1142 sn->stats[y][rix].last_tx = 0;
1143 sn->stats[y][rix].ewma_pct = 0;
1145 sn->stats[y][rix].perfect_tx_time =
1146 calc_usecs_unicast_packet(sc, size, rix, 0, 0,
1147 (ni->ni_chw == 40));
1148 sn->stats[y][rix].average_tx_time =
1149 sn->stats[y][rix].perfect_tx_time;
1153 /* XXX 0, num_rates-1 are wrong */
1154 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
1155 "%s: %d rates %d%sMbps (%dus)- %d%sMbps (%dus)", __func__,
1157 DOT11RATE(0)/2, DOT11RATE(0) % 1 ? ".5" : "",
1158 sn->stats[1][0].perfect_tx_time,
1159 DOT11RATE(sn->num_rates-1)/2, DOT11RATE(sn->num_rates-1) % 1 ? ".5" : "",
1160 sn->stats[1][sn->num_rates-1].perfect_tx_time
1163 /* set the visible bit-rate */
1164 if (sn->static_rix != -1)
1165 ni->ni_txrate = DOT11RATE(sn->static_rix);
1167 ni->ni_txrate = RATE(0);
1173 * Fetch the statistics for the given node.
1175 * The ieee80211 node must be referenced and unlocked, however the ath_node
1178 * The main difference here is that we convert the rate indexes
1179 * to 802.11 rates, or the userland output won't make much sense
1180 * as it has no access to the rix table.
1183 ath_rate_fetch_node_stats(struct ath_softc *sc, struct ath_node *an,
1184 struct ath_rateioctl *rs)
1186 struct sample_node *sn = ATH_NODE_SAMPLE(an);
1187 const HAL_RATE_TABLE *rt = sc->sc_currates;
1188 struct ath_rateioctl_tlv av;
1189 struct ath_rateioctl_rt *tv;
1193 ATH_NODE_LOCK_ASSERT(an);
1196 * Ensure there's enough space for the statistics.
1199 sizeof(struct ath_rateioctl_tlv) +
1200 sizeof(struct ath_rateioctl_rt) +
1201 sizeof(struct ath_rateioctl_tlv) +
1202 sizeof(struct sample_node)) {
1203 device_printf(sc->sc_dev, "%s: len=%d, too short\n",
1210 * Take a temporary copy of the sample node state so we can
1211 * modify it before we copy it.
1213 #if defined(__DragonFly__)
1214 tv = kmalloc(sizeof(struct ath_rateioctl_rt), M_TEMP,
1215 M_INTWAIT | M_ZERO);
1217 tv = malloc(sizeof(struct ath_rateioctl_rt), M_TEMP,
1225 * Populate the rate table mapping TLV.
1227 tv->nentries = rt->rateCount;
1228 for (y = 0; y < rt->rateCount; y++) {
1229 tv->ratecode[y] = rt->info[y].dot11Rate & IEEE80211_RATE_VAL;
1230 if (rt->info[y].phy == IEEE80211_T_HT)
1231 tv->ratecode[y] |= IEEE80211_RATE_MCS;
1236 * First TLV - rate code mapping
1238 av.tlv_id = ATH_RATE_TLV_RATETABLE;
1239 av.tlv_len = sizeof(struct ath_rateioctl_rt);
1240 copyout(&av, rs->buf + o, sizeof(struct ath_rateioctl_tlv));
1241 o += sizeof(struct ath_rateioctl_tlv);
1242 copyout(tv, rs->buf + o, sizeof(struct ath_rateioctl_rt));
1243 o += sizeof(struct ath_rateioctl_rt);
1246 * Second TLV - sample node statistics
1248 av.tlv_id = ATH_RATE_TLV_SAMPLENODE;
1249 av.tlv_len = sizeof(struct sample_node);
1250 copyout(&av, rs->buf + o, sizeof(struct ath_rateioctl_tlv));
1251 o += sizeof(struct ath_rateioctl_tlv);
1254 * Copy the statistics over to the provided buffer.
1256 copyout(sn, rs->buf + o, sizeof(struct sample_node));
1257 o += sizeof(struct sample_node);
1265 sample_stats(void *arg, struct ieee80211_node *ni)
1267 struct ath_softc *sc = arg;
1268 const HAL_RATE_TABLE *rt = sc->sc_currates;
1269 struct sample_node *sn = ATH_NODE_SAMPLE(ATH_NODE(ni));
1273 kprintf("\n[%s] refcnt %d static_rix (%d %s) ratemask 0x%jx\n",
1274 ether_sprintf(ni->ni_macaddr), ieee80211_node_refcnt(ni),
1275 dot11rate(rt, sn->static_rix),
1276 dot11rate_label(rt, sn->static_rix),
1277 (uintmax_t)sn->ratemask);
1278 for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) {
1279 kprintf("[%4u] cur rix %d (%d %s) since switch: packets %d ticks %u\n",
1280 bin_to_size(y), sn->current_rix[y],
1281 dot11rate(rt, sn->current_rix[y]),
1282 dot11rate_label(rt, sn->current_rix[y]),
1283 sn->packets_since_switch[y], sn->ticks_since_switch[y]);
1284 kprintf("[%4u] last sample (%d %s) cur sample (%d %s) packets sent %d\n",
1286 dot11rate(rt, sn->last_sample_rix[y]),
1287 dot11rate_label(rt, sn->last_sample_rix[y]),
1288 dot11rate(rt, sn->current_sample_rix[y]),
1289 dot11rate_label(rt, sn->current_sample_rix[y]),
1290 sn->packets_sent[y]);
1291 kprintf("[%4u] packets since sample %d sample tt %u\n",
1292 bin_to_size(y), sn->packets_since_sample[y],
1295 for (mask = sn->ratemask, rix = 0; mask != 0; mask >>= 1, rix++) {
1296 if ((mask & 1) == 0)
1298 for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) {
1299 if (sn->stats[y][rix].total_packets == 0)
1301 kprintf("[%2u %s:%4u] %8ju:%-8ju (%3d%%) (EWMA %3d.%1d%%) T %8ju F %4d avg %5u last %u\n",
1302 dot11rate(rt, rix), dot11rate_label(rt, rix),
1304 (uintmax_t) sn->stats[y][rix].total_packets,
1305 (uintmax_t) sn->stats[y][rix].packets_acked,
1306 (int) ((sn->stats[y][rix].packets_acked * 100ULL) /
1307 sn->stats[y][rix].total_packets),
1308 sn->stats[y][rix].ewma_pct / 10,
1309 sn->stats[y][rix].ewma_pct % 10,
1310 (uintmax_t) sn->stats[y][rix].tries,
1311 sn->stats[y][rix].successive_failures,
1312 sn->stats[y][rix].average_tx_time,
1313 ticks - sn->stats[y][rix].last_tx);
1319 ath_rate_sysctl_stats(SYSCTL_HANDLER_ARGS)
1321 struct ath_softc *sc = arg1;
1322 struct ieee80211com *ic = &sc->sc_ic;
1326 error = sysctl_handle_int(oidp, &v, 0, req);
1327 if (error || !req->newptr)
1329 ieee80211_iterate_nodes(&ic->ic_sta, sample_stats, sc);
1334 ath_rate_sysctl_smoothing_rate(SYSCTL_HANDLER_ARGS)
1336 struct sample_softc *ssc = arg1;
1339 rate = ssc->smoothing_rate;
1340 error = sysctl_handle_int(oidp, &rate, 0, req);
1341 if (error || !req->newptr)
1343 if (!(0 <= rate && rate < 100))
1345 ssc->smoothing_rate = rate;
1346 ssc->smoothing_minpackets = 100 / (100 - rate);
1351 ath_rate_sysctl_sample_rate(SYSCTL_HANDLER_ARGS)
1353 struct sample_softc *ssc = arg1;
1356 rate = ssc->sample_rate;
1357 error = sysctl_handle_int(oidp, &rate, 0, req);
1358 if (error || !req->newptr)
1360 if (!(2 <= rate && rate <= 100))
1362 ssc->sample_rate = rate;
1367 ath_rate_sysctlattach(struct ath_softc *sc, struct sample_softc *ssc)
1369 struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev);
1370 struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev);
1372 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
1373 "smoothing_rate", CTLTYPE_INT | CTLFLAG_RW, ssc, 0,
1374 ath_rate_sysctl_smoothing_rate, "I",
1375 "sample: smoothing rate for avg tx time (%%)");
1376 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
1377 "sample_rate", CTLTYPE_INT | CTLFLAG_RW, ssc, 0,
1378 ath_rate_sysctl_sample_rate, "I",
1379 "sample: percent air time devoted to sampling new rates (%%)");
1380 /* XXX max_successive_failures, stale_failure_timeout, min_switch */
1381 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
1382 "sample_stats", CTLTYPE_INT | CTLFLAG_RW, sc, 0,
1383 ath_rate_sysctl_stats, "I", "sample: print statistics");
1386 struct ath_ratectrl *
1387 ath_rate_attach(struct ath_softc *sc)
1389 struct sample_softc *ssc;
1391 #if defined(__DragonFly__)
1392 ssc = kmalloc(sizeof(struct sample_softc), M_DEVBUF, M_INTWAIT|M_ZERO);
1394 ssc = malloc(sizeof(struct sample_softc), M_DEVBUF, M_NOWAIT|M_ZERO);
1398 ssc->arc.arc_space = sizeof(struct sample_node);
1399 ssc->smoothing_rate = 75; /* ewma percentage ([0..99]) */
1400 ssc->smoothing_minpackets = 100 / (100 - ssc->smoothing_rate);
1401 ssc->sample_rate = 10; /* %time to try diff tx rates */
1402 ssc->max_successive_failures = 3; /* threshold for rate sampling*/
1403 ssc->stale_failure_timeout = 10 * hz; /* 10 seconds */
1404 ssc->min_switch = hz; /* 1 second */
1405 ath_rate_sysctlattach(sc, ssc);
1410 ath_rate_detach(struct ath_ratectrl *arc)
1412 struct sample_softc *ssc = (struct sample_softc *) arc;
1414 kfree(ssc, M_DEVBUF);
1417 #if defined(__DragonFly__)
1423 sample_modevent(module_t mod, int type, void *unused)
1427 wlan_serialize_enter();
1432 kprintf("ath_rate: <SampleRate bit-rate "
1433 "selection algorithm>\n");
1444 wlan_serialize_exit();
1449 static moduledata_t sample_mod = {
1455 DECLARE_MODULE(ath_rate, sample_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
1456 MODULE_VERSION(ath_rate, 1);
1457 MODULE_DEPEND(ath_rate, ath_hal, 1, 1, 1);
1458 MODULE_DEPEND(ath_rate, wlan, 1, 1, 1);