/*- * Copyright (c) 2005 John Bicket * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer, * without modification. * 2. Redistributions in binary form must reproduce at minimum a disclaimer * similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any * redistribution must be conditioned upon including a substantially * similar Disclaimer requirement for further binary redistribution. * 3. Neither the names of the above-listed copyright holders nor the names * of any contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * Alternatively, this software may be distributed under the terms of the * GNU General Public License ("GPL") version 2 as published by the Free * Software Foundation. * * NO WARRANTY * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF * THE POSSIBILITY OF SUCH DAMAGES. */ #include __FBSDID("$FreeBSD$"); /* * John Bicket's SampleRate control algorithm. */ #include "opt_inet.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* XXX for ether_sprintf */ #include #include #ifdef INET #include #include #endif #include #include #include #define SAMPLE_DEBUG #ifdef SAMPLE_DEBUG enum { ATH_DEBUG_RATE = 0x00000010, /* rate control */ }; #define DPRINTF(sc, _fmt, ...) do { \ if (sc->sc_debug & ATH_DEBUG_RATE) \ printf(_fmt, __VA_ARGS__); \ } while (0) #else #define DPRINTF(sc, _fmt, ...) #endif /* * This file is an implementation of the SampleRate algorithm * in "Bit-rate Selection in Wireless Networks" * (http://www.pdos.lcs.mit.edu/papers/jbicket-ms.ps) * * SampleRate chooses the bit-rate it predicts will provide the most * throughput based on estimates of the expected per-packet * transmission time for each bit-rate. SampleRate periodically sends * packets at bit-rates other than the current one to estimate when * another bit-rate will provide better performance. SampleRate * switches to another bit-rate when its estimated per-packet * transmission time becomes smaller than the current bit-rate's. * SampleRate reduces the number of bit-rates it must sample by * eliminating those that could not perform better than the one * currently being used. SampleRate also stops probing at a bit-rate * if it experiences several successive losses. * * The difference between the algorithm in the thesis and the one in this * file is that the one in this file uses a ewma instead of a window. * */ #define STALE_FAILURE_TIMEOUT_MS 10000 static void ath_rate_ctl_reset(struct ath_softc *, struct ieee80211_node *); static __inline int size_to_bin(int size) { int x = 0; for (x = 0; x < NUM_PACKET_SIZE_BINS; x++) { if (size <= packet_size_bins[x]) { return x; } } return NUM_PACKET_SIZE_BINS-1; } static __inline int bin_to_size(int index) { return packet_size_bins[index]; } static __inline int rate_to_ndx(struct sample_node *sn, int rate) { int x = 0; for (x = 0; x < sn->num_rates; x++) { if (sn->rates[x].rate == rate) { return x; } } return -1; } /* * Setup rate codes for management/control frames. We force * all such frames to the lowest rate. */ static void ath_rate_setmgtrates(struct ath_softc *sc, struct ath_node *an) { const HAL_RATE_TABLE *rt = sc->sc_currates; /* setup rates for management frames */ /* XXX management/control frames always go at lowest speed */ an->an_tx_mgtrate = rt->info[0].rateCode; an->an_tx_mgtratesp = an->an_tx_mgtrate | rt->info[0].shortPreamble; } void ath_rate_node_init(struct ath_softc *sc, struct ath_node *an) { DPRINTF(sc, "%s:\n", __func__); /* NB: assumed to be zero'd by caller */ ath_rate_setmgtrates(sc, an); } void ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an) { DPRINTF(sc, "%s:\n", __func__); } /* * returns the ndx with the lowest average_tx_time, * or -1 if all the average_tx_times are 0. */ static __inline int best_rate_ndx(struct sample_node *sn, int size_bin, int require_acked_before) { int x = 0; int best_rate_ndx = 0; int best_rate_tt = 0; for (x = 0; x < sn->num_rates; x++) { int tt = sn->stats[size_bin][x].average_tx_time; if (tt <= 0 || (require_acked_before && !sn->stats[size_bin][x].packets_acked)) { continue; } if (!best_rate_tt || best_rate_tt > tt) { best_rate_tt = tt; best_rate_ndx = x; } } return (best_rate_tt) ? best_rate_ndx : -1; } /* * pick a ndx s.t. the perfect_tx_time * is less than the best bit-rate's average_tx_time * and the ndx has not had four successive failures. */ static __inline int pick_sample_ndx(struct sample_node *sn, int size_bin) { int x = 0; int current_ndx = 0; unsigned current_tt = 0; current_ndx = sn->current_rate[size_bin]; if (current_ndx < 0) { /* no successes yet, send at the lowest bit-rate */ return 0; } current_tt = sn->stats[size_bin][current_ndx].average_tx_time; for (x = 0; x < sn->num_rates; x++) { int ndx = (sn->last_sample_ndx[size_bin] + 1 + x) % sn->num_rates; /* * clear any stale stuff out. */ if (ticks - sn->stats[size_bin][ndx].last_tx > ((hz * STALE_FAILURE_TIMEOUT_MS)/1000)) { sn->stats[size_bin][ndx].average_tx_time = sn->stats[size_bin][ndx].perfect_tx_time; sn->stats[size_bin][ndx].successive_failures = 0; sn->stats[size_bin][ndx].tries = 0; sn->stats[size_bin][ndx].total_packets = 0; sn->stats[size_bin][ndx].packets_acked = 0; } if (ndx != current_ndx && sn->stats[size_bin][ndx].perfect_tx_time < current_tt && sn->stats[size_bin][ndx].successive_failures < 4) { sn->last_sample_ndx[size_bin] = ndx; return ndx; } } return current_ndx; } void ath_rate_findrate(struct ath_softc *sc, struct ath_node *an, int shortPreamble, size_t frameLen, u_int8_t *rix, int *try0, u_int8_t *txrate) { struct sample_node *sn = ATH_NODE_SAMPLE(an); struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc); struct ieee80211com *ic = &sc->sc_ic; int ndx, size_bin, mrr, best_ndx; unsigned average_tx_time; mrr = sc->sc_mrretry && !(ic->ic_flags & IEEE80211_F_USEPROT) && !(frameLen > ic->ic_rtsthreshold); size_bin = size_to_bin(frameLen); best_ndx = best_rate_ndx(sn, size_bin, !mrr); if (best_ndx >= 0) { average_tx_time = sn->stats[size_bin][best_ndx].average_tx_time; } else { average_tx_time = 0; } if (sn->static_rate_ndx != -1) { ndx = sn->static_rate_ndx; *try0 = ATH_TXMAXTRY; } else { ndx = 0; *try0 = mrr ? 2 : ATH_TXMAXTRY; DPRINTF(sc, "%s: %s size %d mrr %d packets_sent %d best_ndx %d " "sample tt %d packets since %d\n" , __func__, ether_sprintf(an->an_node.ni_macaddr) , packet_size_bins[size_bin] , mrr , sn->packets_sent[size_bin] , best_ndx , sn->sample_tt[size_bin] , sn->packets_since_sample[size_bin] ); if (!sn->packets_sent[size_bin]) { /* no packets sent */ if (best_ndx == -1) { ndx = sn->num_rates - 1; if (sc->sc_curmode != IEEE80211_MODE_11B) { for (; ndx >= 0 && sn->rates[ndx].rate > 72; ndx--) ; } } else { ndx = best_ndx; } } else if (best_ndx == -1) { /* no packet has succeeded yet */ if (mrr) { /* * no packet has succeeded, try the * highest bitrate that hasn't failed */ for (ndx = sn->num_rates-1; ndx >= 0; ndx--) { if (sn->stats[size_bin][ndx].successive_failures == 0) { break; } } } else { ndx = sn->num_rates - 1; if (sc->sc_curmode != IEEE80211_MODE_11B) { for (; ndx >= 0 && sn->rates[ndx].rate > 72; ndx--) ; } } } else if (sn->sample_tt[size_bin] < (sn->packets_since_sample[size_bin]*ssc->ath_sample_rate/100) * average_tx_time && sn->packets_since_sample[size_bin] > 15) { /* * we want to limit the time measuring the performance * of other bit-rates to ath_sample_rate% of the * total transmission time. */ ndx = pick_sample_ndx(sn, size_bin); if (ndx != sn->current_rate[size_bin]) { DPRINTF(sc, "%s: %s size %d last sample tt %d sampling %d packets since %d\n", __func__, ether_sprintf(an->an_node.ni_macaddr), packet_size_bins[size_bin], sn->sample_tt[size_bin], sn->rates[ndx].rate, sn->packets_since_sample[size_bin]); sn->current_sample_ndx[size_bin] = ndx; } else { sn->current_sample_ndx[size_bin] = -1; } sn->packets_since_sample[size_bin] = 0; } else { sn->packets_since_sample[size_bin]++; /* * don't switch bit-rates every packet. only * switch during the first few packets we send * or after 100 packets, or if the current * bit-rate begins to perform twice as bad as * another one. */ if (sn->packets_sent[size_bin] < 20 || ticks - ((hz*2000)/1000) > sn->jiffies_since_switch[size_bin] || average_tx_time * 2 < sn->stats[size_bin][sn->current_rate[size_bin]].average_tx_time ) { if (sn->packets_sent[size_bin] > 20) { DPRINTF(sc, "%s: %s size %d switch rate %d (%d/%d) -> %d (%d/%d) after %d packets mmr %d\n", __func__, ether_sprintf(an->an_node.ni_macaddr), packet_size_bins[size_bin], sn->rates[sn->current_rate[size_bin]].rate, sn->stats[size_bin][sn->current_rate[size_bin]].average_tx_time, sn->stats[size_bin][sn->current_rate[size_bin]].perfect_tx_time, sn->rates[best_ndx].rate, sn->stats[size_bin][best_ndx].average_tx_time, sn->stats[size_bin][best_ndx].perfect_tx_time, sn->packets_since_switch[size_bin], mrr); } sn->packets_since_switch[size_bin] = 0; sn->current_rate[size_bin] = best_ndx; sn->jiffies_since_switch[size_bin] = ticks; } ndx = sn->current_rate[size_bin]; sn->packets_since_switch[size_bin]++; } } if (ndx < 0) { ndx = 0; } *rix = sn->rates[ndx].rix; if (shortPreamble) { *txrate = sn->rates[ndx].shortPreambleRateCode; } else { *txrate = sn->rates[ndx].rateCode; } sn->packets_sent[size_bin]++; an->an_node.ni_txrate = ndx; } void ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an, struct ath_desc *ds, int shortPreamble, u_int8_t rix) { struct sample_node *sn = ATH_NODE_SAMPLE(an); int rateCode = -1; int frame_size, size_bin, best_ndx, ndx; frame_size = ds->ds_ctl0 & 0x0fff; /* low-order 12 bits of ds_ctl0 */ KASSERT(frame_size != 0, ("no frame size")); size_bin = size_to_bin(frame_size); best_ndx = best_rate_ndx(sn, size_bin, 0); if (best_ndx == -1 || !sn->stats[size_bin][best_ndx].packets_acked) { /* * no packet has succeeded, so also try at the * lowest bitate. */ ndx = 0; } else { /* * we're trying a different bit-rate, and it could be lossy, * so if it fails try at the best bit-rate. */ ndx = best_ndx; } KASSERT(0 <= ndx && ndx < IEEE80211_RATE_MAXSIZE, ("invalid ndx %d", ndx)); if (shortPreamble) { rateCode = sn->rates[ndx].shortPreambleRateCode; } else { rateCode = sn->rates[ndx].rateCode; } ath_hal_setupxtxdesc(sc->sc_ah, ds , rateCode, 3 /* series 1 */ , sn->rates[0].rateCode, 3 /* series 2 */ , 0, 0 /* series 3 */ ); } static void update_stats(struct ath_softc *sc, struct ath_node *an, int frame_size, int ndx0, int tries0, int ndx1, int tries1, int ndx2, int tries2, int ndx3, int tries3, int short_tries, int tries, int status) { struct sample_node *sn = ATH_NODE_SAMPLE(an); struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc); int tt = 0; int tries_so_far = 0; int size_bin = 0; int size = 0; int rate = 0; size_bin = size_to_bin(frame_size); size = bin_to_size(size_bin); rate = sn->rates[ndx0].rate; tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx0].rix, short_tries-1, MIN(tries0, tries) - 1); tries_so_far += tries0; if (tries1 && tries0 < tries) { tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx1].rix, short_tries-1, MIN(tries1 + tries_so_far, tries) - tries_so_far - 1); } tries_so_far += tries1; if (tries2 && tries0 + tries1 < tries) { tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx2].rix, short_tries-1, MIN(tries2 + tries_so_far, tries) - tries_so_far - 1); } tries_so_far += tries2; if (tries3 && tries0 + tries1 + tries2 < tries) { tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx3].rix, short_tries-1, MIN(tries3 + tries_so_far, tries) - tries_so_far - 1); } #ifdef SAMPLE_DEBUG if (short_tries + tries > 3 || status) { DPRINTF(sc, "%s: %s size %d rate %d ndx %d tries (%d/%d) tries0 %d tt %d avg_tt %d perfect_tt %d status %d\n", __func__, ether_sprintf(an->an_node.ni_macaddr), size, rate, ndx0, short_tries, tries, tries0, tt, sn->stats[size_bin][ndx0].average_tx_time, sn->stats[size_bin][ndx0].perfect_tx_time, status); } #endif /* SAMPLE_DEBUG */ if (sn->stats[size_bin][ndx0].total_packets < (100 / (100 - ssc->ath_smoothing_rate))) { /* just average the first few packets */ int avg_tx = sn->stats[size_bin][ndx0].average_tx_time; int packets = sn->stats[size_bin][ndx0].total_packets; sn->stats[size_bin][ndx0].average_tx_time = (tt+(avg_tx*packets))/(packets+1); } else { /* use a ewma */ sn->stats[size_bin][ndx0].average_tx_time = ((sn->stats[size_bin][ndx0].average_tx_time * ssc->ath_smoothing_rate) + (tt * (100 - ssc->ath_smoothing_rate))) / 100; } if (status) { /* * this packet failed - count this as a failure * for larger packets also, since we assume * if a small packet fails at a lower bit-rate * then a larger one will also. */ int y; for (y = size_bin; y < NUM_PACKET_SIZE_BINS; y++) { sn->stats[y][ndx0].successive_failures++; sn->stats[y][ndx0].last_tx = ticks; } } else { sn->stats[size_bin][ndx0].packets_acked++; sn->stats[size_bin][ndx0].successive_failures = 0; } sn->stats[size_bin][ndx0].tries += tries; sn->stats[size_bin][ndx0].last_tx = ticks; sn->stats[size_bin][ndx0].total_packets++; if (ndx0 == sn->current_sample_ndx[size_bin]) { DPRINTF(sc, "%s: %s size %d sample rate %d tries (%d/%d) tt %d avg_tt (%d/%d) status %d\n", __func__, ether_sprintf(an->an_node.ni_macaddr), size, rate, short_tries, tries, tt, sn->stats[size_bin][ndx0].average_tx_time, sn->stats[size_bin][ndx0].perfect_tx_time, status); sn->sample_tt[size_bin] = tt; sn->current_sample_ndx[size_bin] = -1; } } void ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an, const struct ath_desc *ds, const struct ath_desc *ds0) { struct sample_node *sn = ATH_NODE_SAMPLE(an); const struct ar5212_desc *ads = (const struct ar5212_desc *)&ds->ds_ctl0; int final_rate, short_tries, long_tries, frame_size; int ndx = -1; final_rate = sc->sc_hwmap[ds->ds_txstat.ts_rate &~ HAL_TXSTAT_ALTRATE].ieeerate; short_tries = ds->ds_txstat.ts_shortretry + 1; long_tries = ds->ds_txstat.ts_longretry + 1; frame_size = ds0->ds_ctl0 & 0x0fff; /* low-order 12 bits of ds_ctl0 */ if (frame_size == 0) /* NB: should not happen */ frame_size = 1500; if (sn->num_rates <= 0) { DPRINTF(sc, "%s: %s size %d status %d rate/try %d/%d " "no rates yet\n", __func__, ether_sprintf(an->an_node.ni_macaddr), bin_to_size(size_to_bin(frame_size)), ds->ds_txstat.ts_status, short_tries, long_tries); return; } if (sc->sc_mrretry && ds->ds_txstat.ts_status) { /* this packet failed */ DPRINTF(sc, "%s: %s size %d rate/try %d/%d %d/%d %d/%d %d/%d status %s retries (%d/%d)\n", __func__, ether_sprintf(an->an_node.ni_macaddr), bin_to_size(size_to_bin(frame_size)), sc->sc_hwmap[ads->xmit_rate0].ieeerate, ads->xmit_tries0, sc->sc_hwmap[ads->xmit_rate1].ieeerate, ads->xmit_tries1, sc->sc_hwmap[ads->xmit_rate2].ieeerate, ads->xmit_tries2, sc->sc_hwmap[ads->xmit_rate3].ieeerate, ads->xmit_tries3, ds->ds_txstat.ts_status ? "FAIL" : "OK", short_tries, long_tries); } if (!(ds->ds_txstat.ts_rate & HAL_TXSTAT_ALTRATE)) { /* only one rate was used */ ndx = rate_to_ndx(sn, final_rate); DPRINTF(sc, "%s: %s size %d status %d rate/try %d/%d/%d\n", __func__, ether_sprintf(an->an_node.ni_macaddr), bin_to_size(size_to_bin(frame_size)), ds->ds_txstat.ts_status, ndx, short_tries, long_tries); if (ndx >= 0 && ndx < sn->num_rates) { update_stats(sc, an, frame_size, ndx, long_tries, 0, 0, 0, 0, 0, 0, short_tries, long_tries, ds->ds_txstat.ts_status); } } else { int rate0, tries0, ndx0; int rate1, tries1, ndx1; int rate2, tries2, ndx2; int rate3, tries3, ndx3; int finalTSIdx = ads->final_ts_index; /* * Process intermediate rates that failed. */ rate0 = sc->sc_hwmap[ads->xmit_rate0].ieeerate; tries0 = ads->xmit_tries0; ndx0 = rate_to_ndx(sn, rate0); rate1 = sc->sc_hwmap[ads->xmit_rate1].ieeerate; tries1 = ads->xmit_tries1; ndx1 = rate_to_ndx(sn, rate1); rate2 = sc->sc_hwmap[ads->xmit_rate2].ieeerate; tries2 = ads->xmit_tries2; ndx2 = rate_to_ndx(sn, rate2); rate3 = sc->sc_hwmap[ads->xmit_rate3].ieeerate; tries3 = ads->xmit_tries3; ndx3 = rate_to_ndx(sn, rate3); #if 1 DPRINTF(sc, "%s: %s size %d finaltsidx %d tries %d status %d rate/try %d/%d %d/%d %d/%d %d/%d\n", __func__, ether_sprintf(an->an_node.ni_macaddr), bin_to_size(size_to_bin(frame_size)), finalTSIdx, long_tries, ds->ds_txstat.ts_status, rate0, tries0, rate1, tries1, rate2, tries2, rate3, tries3); #endif if (tries0) { update_stats(sc, an, frame_size, ndx0, tries0, ndx1, tries1, ndx2, tries2, ndx3, tries3, short_tries, ds->ds_txstat.ts_longretry + 1, ds->ds_txstat.ts_status); } if (tries1 && finalTSIdx > 0) { update_stats(sc, an, frame_size, ndx1, tries1, ndx2, tries2, ndx3, tries3, 0, 0, short_tries, ds->ds_txstat.ts_longretry + 1 - tries0, ds->ds_txstat.ts_status); } if (tries2 && finalTSIdx > 1) { update_stats(sc, an, frame_size, ndx2, tries2, ndx3, tries3, 0, 0, 0, 0, short_tries, ds->ds_txstat.ts_longretry + 1 - tries0 - tries1, ds->ds_txstat.ts_status); } if (tries3 && finalTSIdx > 2) { update_stats(sc, an, frame_size, ndx3, tries3, 0, 0, 0, 0, 0, 0, short_tries, ds->ds_txstat.ts_longretry + 1 - tries0 - tries1 - tries2, ds->ds_txstat.ts_status); } } } void ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew) { DPRINTF(sc, "%s: %s isnew %d\n", __func__, ether_sprintf(an->an_node.ni_macaddr), isnew); if (isnew) ath_rate_ctl_reset(sc, &an->an_node); } /* * Initialize the tables for a node. */ static void ath_rate_ctl_reset(struct ath_softc *sc, struct ieee80211_node *ni) { #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL) struct ieee80211com *ic = &sc->sc_ic; struct ath_node *an = ATH_NODE(ni); struct sample_node *sn = ATH_NODE_SAMPLE(an); const HAL_RATE_TABLE *rt = sc->sc_currates; int x, y, srate; KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode)); sn->static_rate_ndx = -1; if (ic->ic_fixed_rate != IEEE80211_FIXED_RATE_NONE) { /* * A fixed rate is to be used; ic_fixed_rate is an * index into the supported rate set. Convert this * to the index into the negotiated rate set for * the node. We know the rate is there because the * rate set is checked when the station associates. */ const struct ieee80211_rateset *rs = &ic->ic_sup_rates[ic->ic_curmode]; int r = rs->rs_rates[ic->ic_fixed_rate] & IEEE80211_RATE_VAL; /* NB: the rate set is assumed sorted */ srate = ni->ni_rates.rs_nrates - 1; for (; srate >= 0 && RATE(srate) != r; srate--) ; KASSERT(srate >= 0, ("fixed rate %d not in rate set", ic->ic_fixed_rate)); sn->static_rate_ndx = srate; } DPRINTF(sc, "%s: %s size 1600 rate/tt", __func__, ether_sprintf(ni->ni_macaddr)); sn->num_rates = ni->ni_rates.rs_nrates; for (x = 0; x < ni->ni_rates.rs_nrates; x++) { sn->rates[x].rate = ni->ni_rates.rs_rates[x] & IEEE80211_RATE_VAL; sn->rates[x].rix = sc->sc_rixmap[sn->rates[x].rate]; if (sn->rates[x].rix == 0xff) { DPRINTF(sc, "%s: ignore bogus rix at %d\n", __func__, x); continue; } sn->rates[x].rateCode = rt->info[sn->rates[x].rix].rateCode; sn->rates[x].shortPreambleRateCode = rt->info[sn->rates[x].rix].rateCode | rt->info[sn->rates[x].rix].shortPreamble; DPRINTF(sc, " %d/%d", sn->rates[x].rate, calc_usecs_unicast_packet(sc, 1600, sn->rates[x].rix, 0,0)); } DPRINTF(sc, "%s\n", ""); /* set the visible bit-rate to the lowest one available */ ni->ni_txrate = 0; sn->num_rates = ni->ni_rates.rs_nrates; for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) { int size = bin_to_size(y); sn->packets_sent[y] = 0; sn->current_sample_ndx[y] = -1; sn->last_sample_ndx[y] = 0; for (x = 0; x < ni->ni_rates.rs_nrates; x++) { sn->stats[y][x].successive_failures = 0; sn->stats[y][x].tries = 0; sn->stats[y][x].total_packets = 0; sn->stats[y][x].packets_acked = 0; sn->stats[y][x].last_tx = 0; sn->stats[y][x].perfect_tx_time = calc_usecs_unicast_packet(sc, size, sn->rates[x].rix, 0, 0); sn->stats[y][x].average_tx_time = sn->stats[y][x].perfect_tx_time; } } #undef RATE } static void rate_cb(void *arg, struct ieee80211_node *ni) { struct ath_softc *sc = arg; ath_rate_newassoc(sc, ATH_NODE(ni), 1); } /* * Reset the rate control state for each 802.11 state transition. */ void ath_rate_newstate(struct ath_softc *sc, enum ieee80211_state state) { struct ieee80211com *ic = &sc->sc_ic; if (state == IEEE80211_S_RUN) { if (ic->ic_opmode != IEEE80211_M_STA) { /* * Sync rates for associated stations and neighbors. */ ieee80211_iterate_nodes(&ic->ic_sta, rate_cb, sc); } ath_rate_newassoc(sc, ATH_NODE(ic->ic_bss), 1); } } static void ath_rate_sysctlattach(struct ath_softc *sc, struct sample_softc *osc) { struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev); struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev); /* XXX bounds check [0..100] */ SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, "smoothing_rate", CTLFLAG_RW, &osc->ath_smoothing_rate, 0, "rate control: retry threshold to credit rate raise (%%)"); /* XXX bounds check [2..100] */ SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, "sample_rate", CTLFLAG_RW, &osc->ath_sample_rate,0, "rate control: # good periods before raising rate"); } struct ath_ratectrl * ath_rate_attach(struct ath_softc *sc) { struct sample_softc *osc; DPRINTF(sc, "%s:\n", __func__); osc = malloc(sizeof(struct sample_softc), M_DEVBUF, M_NOWAIT|M_ZERO); if (osc == NULL) return NULL; osc->arc.arc_space = sizeof(struct sample_node); osc->ath_smoothing_rate = 95; /* ewma percentage (out of 100) */ osc->ath_sample_rate = 10; /* send a different bit-rate 1/X packets */ ath_rate_sysctlattach(sc, osc); return &osc->arc; } void ath_rate_detach(struct ath_ratectrl *arc) { struct sample_softc *osc = (struct sample_softc *) arc; free(osc, M_DEVBUF); } /* * Module glue. */ static int sample_modevent(module_t mod, int type, void *unused) { switch (type) { case MOD_LOAD: if (bootverbose) printf("ath_rate: version 1.2 \n"); return 0; case MOD_UNLOAD: return 0; } return EINVAL; } static moduledata_t sample_mod = { "ath_rate", sample_modevent, 0 }; DECLARE_MODULE(ath_rate, sample_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST); MODULE_VERSION(ath_rate, 1); MODULE_DEPEND(ath_rate, ath_hal, 1, 1, 1); /* Atheros HAL */ MODULE_DEPEND(ath_rate, wlan, 1, 1, 1);