1 /*- 2 * Copyright (c) 2005 John Bicket 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 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. 18 * 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. 22 * 23 * NO WARRANTY 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. 35 * 36 */ 37 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 40 41 /* 42 * John Bicket's SampleRate control algorithm. 43 */ 44 #include "opt_inet.h" 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/sysctl.h> 49 #include <sys/module.h> 50 #include <sys/kernel.h> 51 #include <sys/lock.h> 52 #include <sys/mutex.h> 53 #include <sys/errno.h> 54 55 #include <machine/bus.h> 56 #include <machine/resource.h> 57 #include <sys/bus.h> 58 59 #include <sys/socket.h> 60 61 #include <net/if.h> 62 #include <net/if_media.h> 63 #include <net/if_arp.h> 64 #include <net/ethernet.h> /* XXX for ether_sprintf */ 65 66 #include <net80211/ieee80211_var.h> 67 68 #include <net/bpf.h> 69 70 #ifdef INET 71 #include <netinet/in.h> 72 #include <netinet/if_ether.h> 73 #endif 74 75 #include <dev/ath/if_athvar.h> 76 #include <dev/ath/ath_rate/sample/sample.h> 77 #include <contrib/dev/ath/ah_desc.h> 78 79 #define SAMPLE_DEBUG 80 #ifdef SAMPLE_DEBUG 81 enum { 82 ATH_DEBUG_NODE = 0x00080000, /* node management */ 83 ATH_DEBUG_RATE = 0x00000010, /* rate control */ 84 ATH_DEBUG_ANY = 0xffffffff 85 }; 86 #define DPRINTF(sc, m, fmt, ...) do { \ 87 if (sc->sc_debug & (m)) \ 88 printf(fmt, __VA_ARGS__); \ 89 } while (0) 90 #else 91 #define DPRINTF(sc, m, fmt, ...) do { \ 92 (void) sc; \ 93 } while (0) 94 #endif 95 96 /* 97 * This file is an implementation of the SampleRate algorithm 98 * in "Bit-rate Selection in Wireless Networks" 99 * (http://www.pdos.lcs.mit.edu/papers/jbicket-ms.ps) 100 * 101 * SampleRate chooses the bit-rate it predicts will provide the most 102 * throughput based on estimates of the expected per-packet 103 * transmission time for each bit-rate. SampleRate periodically sends 104 * packets at bit-rates other than the current one to estimate when 105 * another bit-rate will provide better performance. SampleRate 106 * switches to another bit-rate when its estimated per-packet 107 * transmission time becomes smaller than the current bit-rate's. 108 * SampleRate reduces the number of bit-rates it must sample by 109 * eliminating those that could not perform better than the one 110 * currently being used. SampleRate also stops probing at a bit-rate 111 * if it experiences several successive losses. 112 * 113 * The difference between the algorithm in the thesis and the one in this 114 * file is that the one in this file uses a ewma instead of a window. 115 * 116 * Also, this implementation tracks the average transmission time for 117 * a few different packet sizes independently for each link. 118 */ 119 120 #define STALE_FAILURE_TIMEOUT_MS 10000 121 #define MIN_SWITCH_MS 1000 122 123 static void ath_rate_ctl_reset(struct ath_softc *, struct ieee80211_node *); 124 125 static __inline int 126 size_to_bin(int size) 127 { 128 int x = 0; 129 for (x = 0; x < NUM_PACKET_SIZE_BINS; x++) { 130 if (size <= packet_size_bins[x]) { 131 return x; 132 } 133 } 134 return NUM_PACKET_SIZE_BINS-1; 135 } 136 static __inline int 137 bin_to_size(int index) { 138 return packet_size_bins[index]; 139 } 140 141 static __inline int 142 rate_to_ndx(struct sample_node *sn, int rate) { 143 int x = 0; 144 for (x = 0; x < sn->num_rates; x++) { 145 if (sn->rates[x].rate == rate) { 146 return x; 147 } 148 } 149 return -1; 150 } 151 152 void 153 ath_rate_node_init(struct ath_softc *sc, struct ath_node *an) 154 { 155 DPRINTF(sc, ATH_DEBUG_NODE, "%s:\n", __func__); 156 /* NB: assumed to be zero'd by caller */ 157 } 158 159 void 160 ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an) 161 { 162 DPRINTF(sc, ATH_DEBUG_NODE, "%s:\n", __func__); 163 } 164 165 166 /* 167 * returns the ndx with the lowest average_tx_time, 168 * or -1 if all the average_tx_times are 0. 169 */ 170 static __inline int best_rate_ndx(struct sample_node *sn, int size_bin, 171 int require_acked_before) 172 { 173 int x = 0; 174 int best_rate_ndx = 0; 175 int best_rate_tt = 0; 176 for (x = 0; x < sn->num_rates; x++) { 177 int tt = sn->stats[size_bin][x].average_tx_time; 178 if (tt <= 0 || (require_acked_before && 179 !sn->stats[size_bin][x].packets_acked)) { 180 continue; 181 } 182 183 /* 9 megabits never works better than 12 */ 184 if (sn->rates[x].rate == 18) 185 continue; 186 187 /* don't use a bit-rate that has been failing */ 188 if (sn->stats[size_bin][x].successive_failures > 3) 189 continue; 190 191 if (!best_rate_tt || best_rate_tt > tt) { 192 best_rate_tt = tt; 193 best_rate_ndx = x; 194 } 195 } 196 return (best_rate_tt) ? best_rate_ndx : -1; 197 } 198 199 /* 200 * pick a good "random" bit-rate to sample other than the current one 201 */ 202 static __inline int 203 pick_sample_ndx(struct sample_node *sn, int size_bin) 204 { 205 int x = 0; 206 int current_ndx = 0; 207 unsigned current_tt = 0; 208 209 current_ndx = sn->current_rate[size_bin]; 210 if (current_ndx < 0) { 211 /* no successes yet, send at the lowest bit-rate */ 212 return 0; 213 } 214 215 current_tt = sn->stats[size_bin][current_ndx].average_tx_time; 216 217 for (x = 0; x < sn->num_rates; x++) { 218 int ndx = (sn->last_sample_ndx[size_bin]+1+x) % sn->num_rates; 219 220 /* don't sample the current bit-rate */ 221 if (ndx == current_ndx) 222 continue; 223 224 /* this bit-rate is always worse than the current one */ 225 if (sn->stats[size_bin][ndx].perfect_tx_time > current_tt) 226 continue; 227 228 /* rarely sample bit-rates that fail a lot */ 229 if (ticks - sn->stats[size_bin][ndx].last_tx < ((hz * STALE_FAILURE_TIMEOUT_MS)/1000) && 230 sn->stats[size_bin][ndx].successive_failures > 3) 231 continue; 232 233 /* don't sample more than 2 indexes higher 234 * for rates higher than 11 megabits 235 */ 236 if (sn->rates[ndx].rate > 22 && ndx > current_ndx + 2) 237 continue; 238 239 /* 9 megabits never works better than 12 */ 240 if (sn->rates[ndx].rate == 18) 241 continue; 242 243 /* if we're using 11 megabits, only sample up to 12 megabits 244 */ 245 if (sn->rates[current_ndx].rate == 22 && ndx > current_ndx + 1) 246 continue; 247 248 sn->last_sample_ndx[size_bin] = ndx; 249 return ndx; 250 } 251 return current_ndx; 252 } 253 254 void 255 ath_rate_findrate(struct ath_softc *sc, struct ath_node *an, 256 int shortPreamble, size_t frameLen, 257 u_int8_t *rix, int *try0, u_int8_t *txrate) 258 { 259 struct sample_node *sn = ATH_NODE_SAMPLE(an); 260 struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc); 261 struct ieee80211com *ic = &sc->sc_ic; 262 int ndx, size_bin, mrr, best_ndx, change_rates; 263 unsigned average_tx_time; 264 265 mrr = sc->sc_mrretry && !(ic->ic_flags & IEEE80211_F_USEPROT); 266 size_bin = size_to_bin(frameLen); 267 best_ndx = best_rate_ndx(sn, size_bin, !mrr); 268 269 if (best_ndx >= 0) { 270 average_tx_time = sn->stats[size_bin][best_ndx].average_tx_time; 271 } else { 272 average_tx_time = 0; 273 } 274 275 if (sn->static_rate_ndx != -1) { 276 ndx = sn->static_rate_ndx; 277 *try0 = ATH_TXMAXTRY; 278 } else { 279 *try0 = mrr ? 2 : ATH_TXMAXTRY; 280 281 if (sn->sample_tt[size_bin] < average_tx_time * (sn->packets_since_sample[size_bin]*ssc->ath_sample_rate/100)) { 282 /* 283 * we want to limit the time measuring the performance 284 * of other bit-rates to ath_sample_rate% of the 285 * total transmission time. 286 */ 287 ndx = pick_sample_ndx(sn, size_bin); 288 if (ndx != sn->current_rate[size_bin]) { 289 sn->current_sample_ndx[size_bin] = ndx; 290 } else { 291 sn->current_sample_ndx[size_bin] = -1; 292 } 293 sn->packets_since_sample[size_bin] = 0; 294 295 } else { 296 change_rates = 0; 297 if (!sn->packets_sent[size_bin] || best_ndx == -1) { 298 /* no packet has been sent successfully yet */ 299 for (ndx = sn->num_rates-1; ndx > 0; ndx--) { 300 /* 301 * pick the highest rate <= 36 Mbps 302 * that hasn't failed. 303 */ 304 if (sn->rates[ndx].rate <= 72 && 305 sn->stats[size_bin][ndx].successive_failures == 0) { 306 break; 307 } 308 } 309 change_rates = 1; 310 best_ndx = ndx; 311 } else if (sn->packets_sent[size_bin] < 20) { 312 /* let the bit-rate switch quickly during the first few packets */ 313 change_rates = 1; 314 } else if (ticks - ((hz*MIN_SWITCH_MS)/1000) > sn->ticks_since_switch[size_bin]) { 315 /* 2 seconds have gone by */ 316 change_rates = 1; 317 } else if (average_tx_time * 2 < sn->stats[size_bin][sn->current_rate[size_bin]].average_tx_time) { 318 /* the current bit-rate is twice as slow as the best one */ 319 change_rates = 1; 320 } 321 322 sn->packets_since_sample[size_bin]++; 323 324 if (change_rates) { 325 if (best_ndx != sn->current_rate[size_bin]) { 326 DPRINTF(sc, ATH_DEBUG_RATE, 327 "%s: %s size %d switch rate %d (%d/%d) -> %d (%d/%d) after %d packets mrr %d\n", 328 __func__, 329 ether_sprintf(an->an_node.ni_macaddr), 330 packet_size_bins[size_bin], 331 sn->rates[sn->current_rate[size_bin]].rate, 332 sn->stats[size_bin][sn->current_rate[size_bin]].average_tx_time, 333 sn->stats[size_bin][sn->current_rate[size_bin]].perfect_tx_time, 334 sn->rates[best_ndx].rate, 335 sn->stats[size_bin][best_ndx].average_tx_time, 336 sn->stats[size_bin][best_ndx].perfect_tx_time, 337 sn->packets_since_switch[size_bin], 338 mrr); 339 } 340 sn->packets_since_switch[size_bin] = 0; 341 sn->current_rate[size_bin] = best_ndx; 342 sn->ticks_since_switch[size_bin] = ticks; 343 } 344 ndx = sn->current_rate[size_bin]; 345 sn->packets_since_switch[size_bin]++; 346 if (size_bin == 0) { 347 /* 348 * set the visible txrate for this node 349 * to the rate of small packets 350 */ 351 an->an_node.ni_txrate = ndx; 352 } 353 } 354 } 355 356 KASSERT(ndx >= 0 && ndx < sn->num_rates, ("ndx is %d", ndx)); 357 358 *rix = sn->rates[ndx].rix; 359 if (shortPreamble) { 360 *txrate = sn->rates[ndx].shortPreambleRateCode; 361 } else { 362 *txrate = sn->rates[ndx].rateCode; 363 } 364 sn->packets_sent[size_bin]++; 365 } 366 367 void 368 ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an, 369 struct ath_desc *ds, int shortPreamble, u_int8_t rix) 370 { 371 struct sample_node *sn = ATH_NODE_SAMPLE(an); 372 int rateCode = -1; 373 int frame_size = 0; 374 int size_bin = 0; 375 int ndx = 0; 376 377 size_bin = size_to_bin(frame_size); // TODO: it's correct that frame_size alway 0 ? 378 ndx = sn->current_rate[size_bin]; /* retry at the current bit-rate */ 379 380 if (!sn->stats[size_bin][ndx].packets_acked) { 381 ndx = 0; /* use the lowest bit-rate */ 382 } 383 384 if (shortPreamble) { 385 rateCode = sn->rates[ndx].shortPreambleRateCode; 386 } else { 387 rateCode = sn->rates[ndx].rateCode; 388 } 389 ath_hal_setupxtxdesc(sc->sc_ah, ds 390 , rateCode, 3 /* series 1 */ 391 , sn->rates[0].rateCode, 3 /* series 2 */ 392 , 0, 0 /* series 3 */ 393 ); 394 } 395 396 static void 397 update_stats(struct ath_softc *sc, struct ath_node *an, 398 int frame_size, 399 int ndx0, int tries0, 400 int ndx1, int tries1, 401 int ndx2, int tries2, 402 int ndx3, int tries3, 403 int short_tries, int tries, int status) 404 { 405 struct sample_node *sn = ATH_NODE_SAMPLE(an); 406 struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc); 407 int tt = 0; 408 int tries_so_far = 0; 409 int size_bin = 0; 410 int size = 0; 411 int rate = 0; 412 413 size_bin = size_to_bin(frame_size); 414 size = bin_to_size(size_bin); 415 416 if (!(0 <= ndx0 && ndx0 < sn->num_rates)) { 417 printf("%s: bogus ndx0 %d, max %u, mode %u\n", 418 __func__, ndx0, sn->num_rates, sc->sc_curmode); 419 return; 420 } 421 rate = sn->rates[ndx0].rate; 422 423 tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx0].rix, 424 short_tries, 425 MIN(tries0, tries) - 1); 426 tries_so_far += tries0; 427 if (tries1 && tries0 < tries) { 428 if (!(0 <= ndx1 && ndx1 < sn->num_rates)) { 429 printf("%s: bogus ndx1 %d, max %u, mode %u\n", 430 __func__, ndx1, sn->num_rates, sc->sc_curmode); 431 return; 432 } 433 tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx1].rix, 434 short_tries, 435 MIN(tries1 + tries_so_far, tries) - tries_so_far - 1); 436 } 437 tries_so_far += tries1; 438 439 if (tries2 && tries0 + tries1 < tries) { 440 if (!(0 <= ndx2 && ndx2 < sn->num_rates)) { 441 printf("%s: bogus ndx2 %d, max %u, mode %u\n", 442 __func__, ndx2, sn->num_rates, sc->sc_curmode); 443 return; 444 } 445 tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx2].rix, 446 short_tries, 447 MIN(tries2 + tries_so_far, tries) - tries_so_far - 1); 448 } 449 450 tries_so_far += tries2; 451 452 if (tries3 && tries0 + tries1 + tries2 < tries) { 453 if (!(0 <= ndx3 && ndx3 < sn->num_rates)) { 454 printf("%s: bogus ndx3 %d, max %u, mode %u\n", 455 __func__, ndx3, sn->num_rates, sc->sc_curmode); 456 return; 457 } 458 tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx3].rix, 459 short_tries, 460 MIN(tries3 + tries_so_far, tries) - tries_so_far - 1); 461 } 462 if (sn->stats[size_bin][ndx0].total_packets < (100 / (100 - ssc->ath_smoothing_rate))) { 463 /* just average the first few packets */ 464 int avg_tx = sn->stats[size_bin][ndx0].average_tx_time; 465 int packets = sn->stats[size_bin][ndx0].total_packets; 466 sn->stats[size_bin][ndx0].average_tx_time = (tt+(avg_tx*packets))/(packets+1); 467 } else { 468 /* use a ewma */ 469 sn->stats[size_bin][ndx0].average_tx_time = 470 ((sn->stats[size_bin][ndx0].average_tx_time * ssc->ath_smoothing_rate) + 471 (tt * (100 - ssc->ath_smoothing_rate))) / 100; 472 } 473 474 if (status) { 475 int y; 476 sn->stats[size_bin][ndx0].successive_failures++; 477 for (y = size_bin+1; y < NUM_PACKET_SIZE_BINS; y++) { 478 /* also say larger packets failed since we 479 * assume if a small packet fails at a lower 480 * bit-rate then a larger one will also. 481 */ 482 sn->stats[y][ndx0].successive_failures++; 483 sn->stats[y][ndx0].last_tx = ticks; 484 sn->stats[y][ndx0].tries += tries; 485 sn->stats[y][ndx0].total_packets++; 486 } 487 } else { 488 sn->stats[size_bin][ndx0].packets_acked++; 489 sn->stats[size_bin][ndx0].successive_failures = 0; 490 } 491 sn->stats[size_bin][ndx0].tries += tries; 492 sn->stats[size_bin][ndx0].last_tx = ticks; 493 sn->stats[size_bin][ndx0].total_packets++; 494 495 496 if (ndx0 == sn->current_sample_ndx[size_bin]) { 497 DPRINTF(sc, ATH_DEBUG_RATE, 498 "%s: %s size %d %s sample rate %d tries (%d/%d) tt %d avg_tt (%d/%d)\n", 499 __func__, ether_sprintf(an->an_node.ni_macaddr), 500 size, 501 status ? "FAIL" : "OK", 502 rate, short_tries, tries, tt, 503 sn->stats[size_bin][ndx0].average_tx_time, 504 sn->stats[size_bin][ndx0].perfect_tx_time); 505 sn->sample_tt[size_bin] = tt; 506 sn->current_sample_ndx[size_bin] = -1; 507 } 508 } 509 510 void 511 ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an, 512 const struct ath_buf *bf) 513 { 514 struct ieee80211com *ic = &sc->sc_ic; 515 struct sample_node *sn = ATH_NODE_SAMPLE(an); 516 const struct ath_tx_status *ts = &bf->bf_status.ds_txstat; 517 const struct ath_desc *ds0 = &bf->bf_desc[0]; 518 int final_rate, short_tries, long_tries, frame_size; 519 int mrr; 520 521 final_rate = sc->sc_hwmap[ts->ts_rate &~ HAL_TXSTAT_ALTRATE].ieeerate; 522 short_tries = ts->ts_shortretry; 523 long_tries = ts->ts_longretry + 1; 524 frame_size = ds0->ds_ctl0 & 0x0fff; /* low-order 12 bits of ds_ctl0 */ 525 if (frame_size == 0) /* NB: should not happen */ 526 frame_size = 1500; 527 528 if (sn->num_rates <= 0) { 529 DPRINTF(sc, ATH_DEBUG_RATE, 530 "%s: %s size %d %s rate/try %d/%d no rates yet\n", 531 __func__, ether_sprintf(an->an_node.ni_macaddr), 532 bin_to_size(size_to_bin(frame_size)), 533 ts->ts_status ? "FAIL" : "OK", 534 short_tries, long_tries); 535 return; 536 } 537 mrr = sc->sc_mrretry && !(ic->ic_flags & IEEE80211_F_USEPROT); 538 if (!mrr || !(ts->ts_rate & HAL_TXSTAT_ALTRATE)) { 539 int ndx = rate_to_ndx(sn, final_rate); 540 541 /* 542 * Only one rate was used; optimize work. 543 */ 544 DPRINTF(sc, ATH_DEBUG_RATE, 545 "%s: %s size %d %s rate/try %d/%d/%d\n", 546 __func__, ether_sprintf(an->an_node.ni_macaddr), 547 bin_to_size(size_to_bin(frame_size)), 548 ts->ts_status ? "FAIL" : "OK", 549 final_rate, short_tries, long_tries); 550 update_stats(sc, an, frame_size, 551 ndx, long_tries, 552 0, 0, 553 0, 0, 554 0, 0, 555 short_tries, long_tries, ts->ts_status); 556 } else { 557 int hwrate0, rate0, tries0, ndx0; 558 int hwrate1, rate1, tries1, ndx1; 559 int hwrate2, rate2, tries2, ndx2; 560 int hwrate3, rate3, tries3, ndx3; 561 int finalTSIdx = ts->ts_finaltsi; 562 563 /* 564 * Process intermediate rates that failed. 565 */ 566 if (sc->sc_ah->ah_magic != 0x20065416) { 567 hwrate0 = MS(ds0->ds_ctl3, AR_XmitRate0); 568 hwrate1 = MS(ds0->ds_ctl3, AR_XmitRate1); 569 hwrate2 = MS(ds0->ds_ctl3, AR_XmitRate2); 570 hwrate3 = MS(ds0->ds_ctl3, AR_XmitRate3); 571 } else { 572 hwrate0 = MS(ds0->ds_ctl3, AR5416_XmitRate0); 573 hwrate1 = MS(ds0->ds_ctl3, AR5416_XmitRate1); 574 hwrate2 = MS(ds0->ds_ctl3, AR5416_XmitRate2); 575 hwrate3 = MS(ds0->ds_ctl3, AR5416_XmitRate3); 576 } 577 578 rate0 = sc->sc_hwmap[hwrate0].ieeerate; 579 tries0 = MS(ds0->ds_ctl2, AR_XmitDataTries0); 580 ndx0 = rate_to_ndx(sn, rate0); 581 582 rate1 = sc->sc_hwmap[hwrate1].ieeerate; 583 tries1 = MS(ds0->ds_ctl2, AR_XmitDataTries1); 584 ndx1 = rate_to_ndx(sn, rate1); 585 586 rate2 = sc->sc_hwmap[hwrate2].ieeerate; 587 tries2 = MS(ds0->ds_ctl2, AR_XmitDataTries2); 588 ndx2 = rate_to_ndx(sn, rate2); 589 590 rate3 = sc->sc_hwmap[hwrate3].ieeerate; 591 tries3 = MS(ds0->ds_ctl2, AR_XmitDataTries3); 592 ndx3 = rate_to_ndx(sn, rate3); 593 594 DPRINTF(sc, ATH_DEBUG_RATE, 595 "%s: %s size %d finaltsidx %d tries %d %s rate/try [%d/%d %d/%d %d/%d %d/%d]\n", 596 __func__, ether_sprintf(an->an_node.ni_macaddr), 597 bin_to_size(size_to_bin(frame_size)), 598 finalTSIdx, 599 long_tries, 600 ts->ts_status ? "FAIL" : "OK", 601 rate0, tries0, 602 rate1, tries1, 603 rate2, tries2, 604 rate3, tries3); 605 606 /* 607 * NB: series > 0 are not penalized for failure 608 * based on the try counts under the assumption 609 * that losses are often bursty and since we 610 * sample higher rates 1 try at a time doing so 611 * may unfairly penalize them. 612 */ 613 if (tries0) { 614 update_stats(sc, an, frame_size, 615 ndx0, tries0, 616 ndx1, tries1, 617 ndx2, tries2, 618 ndx3, tries3, 619 short_tries, long_tries, 620 long_tries > tries0); 621 long_tries -= tries0; 622 } 623 624 if (tries1 && finalTSIdx > 0) { 625 update_stats(sc, an, frame_size, 626 ndx1, tries1, 627 ndx2, tries2, 628 ndx3, tries3, 629 0, 0, 630 short_tries, long_tries, 631 ts->ts_status); 632 long_tries -= tries1; 633 } 634 635 if (tries2 && finalTSIdx > 1) { 636 update_stats(sc, an, frame_size, 637 ndx2, tries2, 638 ndx3, tries3, 639 0, 0, 640 0, 0, 641 short_tries, long_tries, 642 ts->ts_status); 643 long_tries -= tries2; 644 } 645 646 if (tries3 && finalTSIdx > 2) { 647 update_stats(sc, an, frame_size, 648 ndx3, tries3, 649 0, 0, 650 0, 0, 651 0, 0, 652 short_tries, long_tries, 653 ts->ts_status); 654 } 655 } 656 } 657 658 void 659 ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew) 660 { 661 DPRINTF(sc, ATH_DEBUG_NODE, "%s: %s isnew %d\n", __func__, 662 ether_sprintf(an->an_node.ni_macaddr), isnew); 663 if (isnew) 664 ath_rate_ctl_reset(sc, &an->an_node); 665 } 666 667 /* 668 * Initialize the tables for a node. 669 */ 670 static void 671 ath_rate_ctl_reset(struct ath_softc *sc, struct ieee80211_node *ni) 672 { 673 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL) 674 struct ieee80211com *ic = &sc->sc_ic; 675 struct ath_node *an = ATH_NODE(ni); 676 struct sample_node *sn = ATH_NODE_SAMPLE(an); 677 const HAL_RATE_TABLE *rt = sc->sc_currates; 678 int x, y, srate; 679 680 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode)); 681 sn->static_rate_ndx = -1; 682 if (ic->ic_fixed_rate != IEEE80211_FIXED_RATE_NONE) { 683 /* 684 * A fixed rate is to be used; ic_fixed_rate is the 685 * IEEE code for this rate (sans basic bit). Convert this 686 * to the index into the negotiated rate set for 687 * the node. 688 */ 689 /* NB: the rate set is assumed sorted */ 690 srate = ni->ni_rates.rs_nrates - 1; 691 for (; srate >= 0 && RATE(srate) != ic->ic_fixed_rate; srate--) 692 ; 693 /* 694 * The fixed rate may not be available due to races 695 * and mode settings. Also orphaned nodes created in 696 * adhoc mode may not have any rate set so this lookup 697 * can fail. 698 */ 699 if (srate >= 0) 700 sn->static_rate_ndx = srate; 701 } 702 703 DPRINTF(sc, ATH_DEBUG_RATE, "%s: %s size 1600 rate/tt", 704 __func__, ether_sprintf(ni->ni_macaddr)); 705 706 sn->num_rates = ni->ni_rates.rs_nrates; 707 for (x = 0; x < ni->ni_rates.rs_nrates; x++) { 708 sn->rates[x].rate = ni->ni_rates.rs_rates[x] & IEEE80211_RATE_VAL; 709 sn->rates[x].rix = sc->sc_rixmap[sn->rates[x].rate]; 710 if (sn->rates[x].rix == 0xff) { 711 DPRINTF(sc, ATH_DEBUG_RATE, 712 "%s: ignore bogus rix at %d\n", __func__, x); 713 continue; 714 } 715 sn->rates[x].rateCode = rt->info[sn->rates[x].rix].rateCode; 716 sn->rates[x].shortPreambleRateCode = 717 rt->info[sn->rates[x].rix].rateCode | 718 rt->info[sn->rates[x].rix].shortPreamble; 719 720 DPRINTF(sc, ATH_DEBUG_RATE, " %d/%d", sn->rates[x].rate, 721 calc_usecs_unicast_packet(sc, 1600, sn->rates[x].rix, 0,0)); 722 } 723 DPRINTF(sc, ATH_DEBUG_RATE, "%s\n", ""); 724 725 /* set the visible bit-rate to the lowest one available */ 726 ni->ni_txrate = 0; 727 sn->num_rates = ni->ni_rates.rs_nrates; 728 729 for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) { 730 int size = bin_to_size(y); 731 int ndx = 0; 732 sn->packets_sent[y] = 0; 733 sn->current_sample_ndx[y] = -1; 734 sn->last_sample_ndx[y] = 0; 735 736 for (x = 0; x < ni->ni_rates.rs_nrates; x++) { 737 sn->stats[y][x].successive_failures = 0; 738 sn->stats[y][x].tries = 0; 739 sn->stats[y][x].total_packets = 0; 740 sn->stats[y][x].packets_acked = 0; 741 sn->stats[y][x].last_tx = 0; 742 743 sn->stats[y][x].perfect_tx_time = 744 calc_usecs_unicast_packet(sc, size, 745 sn->rates[x].rix, 746 0, 0); 747 sn->stats[y][x].average_tx_time = sn->stats[y][x].perfect_tx_time; 748 } 749 750 /* set the initial rate */ 751 for (ndx = sn->num_rates-1; ndx > 0; ndx--) { 752 if (sn->rates[ndx].rate <= 72) { 753 break; 754 } 755 } 756 sn->current_rate[y] = ndx; 757 } 758 759 DPRINTF(sc, ATH_DEBUG_RATE, 760 "%s: %s %d rates %d%sMbps (%dus)- %d%sMbps (%dus)\n", 761 __func__, ether_sprintf(ni->ni_macaddr), 762 sn->num_rates, 763 sn->rates[0].rate/2, sn->rates[0].rate % 0x1 ? ".5" : "", 764 sn->stats[1][0].perfect_tx_time, 765 sn->rates[sn->num_rates-1].rate/2, 766 sn->rates[sn->num_rates-1].rate % 0x1 ? ".5" : "", 767 sn->stats[1][sn->num_rates-1].perfect_tx_time 768 ); 769 770 if (sn->static_rate_ndx != -1) 771 ni->ni_txrate = sn->static_rate_ndx; 772 else 773 ni->ni_txrate = sn->current_rate[0]; 774 #undef RATE 775 } 776 777 static void 778 rate_cb(void *arg, struct ieee80211_node *ni) 779 { 780 struct ath_softc *sc = arg; 781 782 ath_rate_newassoc(sc, ATH_NODE(ni), 1); 783 } 784 785 /* 786 * Reset the rate control state for each 802.11 state transition. 787 */ 788 void 789 ath_rate_newstate(struct ath_softc *sc, enum ieee80211_state state) 790 { 791 struct ieee80211com *ic = &sc->sc_ic; 792 793 if (state == IEEE80211_S_RUN) { 794 if (ic->ic_opmode != IEEE80211_M_STA) { 795 /* 796 * Sync rates for associated stations and neighbors. 797 */ 798 ieee80211_iterate_nodes(&ic->ic_sta, rate_cb, sc); 799 } 800 ath_rate_newassoc(sc, ATH_NODE(ic->ic_bss), 1); 801 } 802 } 803 804 static void 805 ath_rate_sysctlattach(struct ath_softc *sc, struct sample_softc *osc) 806 { 807 struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev); 808 struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev); 809 810 /* XXX bounds check [0..100] */ 811 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 812 "smoothing_rate", CTLFLAG_RW, &osc->ath_smoothing_rate, 0, 813 "rate control: retry threshold to credit rate raise (%%)"); 814 /* XXX bounds check [2..100] */ 815 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 816 "sample_rate", CTLFLAG_RW, &osc->ath_sample_rate,0, 817 "rate control: # good periods before raising rate"); 818 } 819 820 struct ath_ratectrl * 821 ath_rate_attach(struct ath_softc *sc) 822 { 823 struct sample_softc *osc; 824 825 DPRINTF(sc, ATH_DEBUG_ANY, "%s:\n", __func__); 826 osc = malloc(sizeof(struct sample_softc), M_DEVBUF, M_NOWAIT|M_ZERO); 827 if (osc == NULL) 828 return NULL; 829 osc->arc.arc_space = sizeof(struct sample_node); 830 osc->ath_smoothing_rate = 95; /* ewma percentage (out of 100) */ 831 osc->ath_sample_rate = 10; /* send a different bit-rate 1/X packets */ 832 ath_rate_sysctlattach(sc, osc); 833 return &osc->arc; 834 } 835 836 void 837 ath_rate_detach(struct ath_ratectrl *arc) 838 { 839 struct sample_softc *osc = (struct sample_softc *) arc; 840 841 free(osc, M_DEVBUF); 842 } 843 844 /* 845 * Module glue. 846 */ 847 static int 848 sample_modevent(module_t mod, int type, void *unused) 849 { 850 switch (type) { 851 case MOD_LOAD: 852 if (bootverbose) 853 printf("ath_rate: version 1.2 <SampleRate bit-rate selection algorithm>\n"); 854 return 0; 855 case MOD_UNLOAD: 856 return 0; 857 } 858 return EINVAL; 859 } 860 861 static moduledata_t sample_mod = { 862 "ath_rate", 863 sample_modevent, 864 0 865 }; 866 DECLARE_MODULE(ath_rate, sample_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST); 867 MODULE_VERSION(ath_rate, 1); 868 MODULE_DEPEND(ath_rate, ath_hal, 1, 1, 1); /* Atheros HAL */ 869 MODULE_DEPEND(ath_rate, wlan, 1, 1, 1); 870