/* * Update the EWMA percentage. * * This is a simple hack to track an EWMA based on the current * rate scenario. For the rate codes which failed, this will * record a 0% against it. For the rate code which succeeded, * EWMA will record the nbad*100/nframes percentage against it. */ static void update_ewma_stats(struct ath_softc *sc, struct ath_node *an, int frame_size, int rix0, int tries0, int rix1, int tries1, int rix2, int tries2, int rix3, int tries3, int short_tries, int tries, int status, int nframes, int nbad) { struct sample_node *sn = ATH_NODE_SAMPLE(an); struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc); const int size_bin = size_to_bin(frame_size); int tries_so_far; int pct; int rix = rix0; /* Calculate percentage based on current rate */ if (nframes == 0) nframes = nbad = 1; pct = ((nframes - nbad) * 1000) / nframes; /* Figure out which rate index succeeded */ tries_so_far = tries0; if (tries1 && tries_so_far < tries) { tries_so_far += tries1; rix = rix1; /* XXX bump ewma pct */ } if (tries2 && tries_so_far < tries) { tries_so_far += tries2; rix = rix2; /* XXX bump ewma pct */ } if (tries3 && tries_so_far < tries) { rix = rix3; /* XXX bump ewma pct */ } /* rix is the successful rate, update EWMA for final rix */ if (sn->stats[size_bin][rix].total_packets < ssc->smoothing_minpackets) { /* just average the first few packets */ int a_pct = (sn->stats[size_bin][rix].packets_acked * 1000) / (sn->stats[size_bin][rix].total_packets); sn->stats[size_bin][rix].ewma_pct = a_pct; } else { /* use a ewma */ sn->stats[size_bin][rix].ewma_pct = ((sn->stats[size_bin][rix].ewma_pct * ssc->smoothing_rate) + (pct * (100 - ssc->smoothing_rate))) / 100; } }
static void update_stats(struct ath_softc *sc, struct ath_node *an, int frame_size, int rix0, int tries0, int rix1, int tries1, int rix2, int tries2, int rix3, int tries3, int short_tries, int tries, int status, int nframes, int nbad) { struct sample_node *sn = ATH_NODE_SAMPLE(an); struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc); #ifdef IEEE80211_DEBUG const HAL_RATE_TABLE *rt = sc->sc_currates; #endif const int size_bin = size_to_bin(frame_size); const int size = bin_to_size(size_bin); int tt, tries_so_far; int is_ht40 = (an->an_node.ni_chw == 40); if (!IS_RATE_DEFINED(sn, rix0)) return; tt = calc_usecs_unicast_packet(sc, size, rix0, short_tries, MIN(tries0, tries) - 1, is_ht40); tries_so_far = tries0; if (tries1 && tries_so_far < tries) { if (!IS_RATE_DEFINED(sn, rix1)) return; tt += calc_usecs_unicast_packet(sc, size, rix1, short_tries, MIN(tries1 + tries_so_far, tries) - tries_so_far - 1, is_ht40); tries_so_far += tries1; } if (tries2 && tries_so_far < tries) { if (!IS_RATE_DEFINED(sn, rix2)) return; tt += calc_usecs_unicast_packet(sc, size, rix2, short_tries, MIN(tries2 + tries_so_far, tries) - tries_so_far - 1, is_ht40); tries_so_far += tries2; } if (tries3 && tries_so_far < tries) { if (!IS_RATE_DEFINED(sn, rix3)) return; tt += calc_usecs_unicast_packet(sc, size, rix3, short_tries, MIN(tries3 + tries_so_far, tries) - tries_so_far - 1, is_ht40); } if (sn->stats[size_bin][rix0].total_packets < ssc->smoothing_minpackets) { /* just average the first few packets */ int avg_tx = sn->stats[size_bin][rix0].average_tx_time; int packets = sn->stats[size_bin][rix0].total_packets; sn->stats[size_bin][rix0].average_tx_time = (tt+(avg_tx*packets))/(packets+nframes); } else { /* use a ewma */ sn->stats[size_bin][rix0].average_tx_time = ((sn->stats[size_bin][rix0].average_tx_time * ssc->smoothing_rate) + (tt * (100 - ssc->smoothing_rate))) / 100; } /* * XXX Don't mark the higher bit rates as also having failed; as this * unfortunately stops those rates from being tasted when trying to * TX. This happens with 11n aggregation. */ if (nframes == nbad) { #if 0 int y; #endif sn->stats[size_bin][rix0].successive_failures += nbad; #if 0 for (y = size_bin+1; y < NUM_PACKET_SIZE_BINS; y++) { /* * Also say larger packets failed since we * assume if a small packet fails at a * bit-rate then a larger one will also. */ sn->stats[y][rix0].successive_failures += nbad; sn->stats[y][rix0].last_tx = ticks; sn->stats[y][rix0].tries += tries; sn->stats[y][rix0].total_packets += nframes; } #endif } else { sn->stats[size_bin][rix0].packets_acked += (nframes - nbad); sn->stats[size_bin][rix0].successive_failures = 0; } sn->stats[size_bin][rix0].tries += tries; sn->stats[size_bin][rix0].last_tx = ticks; sn->stats[size_bin][rix0].total_packets += nframes; if (rix0 == sn->current_sample_rix[size_bin]) { IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL, &an->an_node, "%s: size %d %s sample rate %d %s tries (%d/%d) tt %d avg_tt (%d/%d) nfrm %d nbad %d", __func__, size, status ? "FAIL" : "OK", dot11rate(rt, rix0), dot11rate_label(rt, rix0), short_tries, tries, tt, sn->stats[size_bin][rix0].average_tx_time, sn->stats[size_bin][rix0].perfect_tx_time, nframes, nbad); sn->sample_tt[size_bin] = tt; sn->current_sample_rix[size_bin] = -1; } }
void ath_rate_findrate(struct ath_softc *sc, struct ath_node *an, int shortPreamble, size_t frameLen, u_int8_t *rix0, int *try0, u_int8_t *txrate) { #define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL) #define MCS(ix) (rt->info[ix].dot11Rate | IEEE80211_RATE_MCS) #define RATE(ix) (DOT11RATE(ix) / 2) struct sample_node *sn = ATH_NODE_SAMPLE(an); struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc); struct ifnet *ifp = sc->sc_ifp; struct ieee80211com *ic = ifp->if_l2com; const HAL_RATE_TABLE *rt = sc->sc_currates; const int size_bin = size_to_bin(frameLen); int rix, mrr, best_rix, change_rates; unsigned average_tx_time; ath_rate_update_static_rix(sc, &an->an_node); if (sn->static_rix != -1) { rix = sn->static_rix; *try0 = ATH_TXMAXTRY; goto done; } /* XXX TODO: this doesn't know about 11gn vs 11g protection; teach it */ mrr = sc->sc_mrretry && !(ic->ic_flags & IEEE80211_F_USEPROT); best_rix = pick_best_rate(an, rt, size_bin, !mrr); if (best_rix >= 0) { average_tx_time = sn->stats[size_bin][best_rix].average_tx_time; } else { average_tx_time = 0; } /* * Limit the time measuring the performance of other tx * rates to sample_rate% of the total transmission time. */ if (sn->sample_tt[size_bin] < average_tx_time * (sn->packets_since_sample[size_bin]*ssc->sample_rate/100)) { rix = pick_sample_rate(ssc, an, rt, size_bin); IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL, &an->an_node, "att %d sample_tt %d size %u sample rate %d %s current rate %d %s", average_tx_time, sn->sample_tt[size_bin], bin_to_size(size_bin), dot11rate(rt, rix), dot11rate_label(rt, rix), dot11rate(rt, sn->current_rix[size_bin]), dot11rate_label(rt, sn->current_rix[size_bin])); if (rix != sn->current_rix[size_bin]) { sn->current_sample_rix[size_bin] = rix; } else { sn->current_sample_rix[size_bin] = -1; } sn->packets_since_sample[size_bin] = 0; } else { change_rates = 0; if (!sn->packets_sent[size_bin] || best_rix == -1) { /* no packet has been sent successfully yet */ change_rates = 1; if (an->an_node.ni_flags & IEEE80211_NODE_HT) best_rix = ath_rate_pick_seed_rate_ht(sc, an, frameLen); else best_rix = ath_rate_pick_seed_rate_legacy(sc, an, frameLen); } else if (sn->packets_sent[size_bin] < 20) { /* let the bit-rate switch quickly during the first few packets */ IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL, &an->an_node, "%s: switching quickly..", __func__); change_rates = 1; } else if (ticks - ssc->min_switch > sn->ticks_since_switch[size_bin]) { /* min_switch seconds have gone by */ IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL, &an->an_node, "%s: min_switch %d > ticks_since_switch %d..", __func__, ticks - ssc->min_switch, sn->ticks_since_switch[size_bin]); change_rates = 1; } else if ((! (an->an_node.ni_flags & IEEE80211_NODE_HT)) && (2*average_tx_time < sn->stats[size_bin][sn->current_rix[size_bin]].average_tx_time)) { /* the current bit-rate is twice as slow as the best one */ IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL, &an->an_node, "%s: 2x att (= %d) < cur_rix att %d", __func__, 2 * average_tx_time, sn->stats[size_bin][sn->current_rix[size_bin]].average_tx_time); change_rates = 1; } else if ((an->an_node.ni_flags & IEEE80211_NODE_HT)) { int cur_rix = sn->current_rix[size_bin]; int cur_att = sn->stats[size_bin][cur_rix].average_tx_time; /* * If the node is HT, upgrade it if the MCS rate is * higher and the average tx time is within 20% of * the current rate. It can fail a little. * * This is likely not optimal! */ #if 0 printf("cur rix/att %x/%d, best rix/att %x/%d\n", MCS(cur_rix), cur_att, MCS(best_rix), average_tx_time); #endif if ((MCS(best_rix) > MCS(cur_rix)) && (average_tx_time * 8) <= (cur_att * 10)) { IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL, &an->an_node, "%s: HT: best_rix 0x%d > cur_rix 0x%x, average_tx_time %d, cur_att %d", __func__, MCS(best_rix), MCS(cur_rix), average_tx_time, cur_att); change_rates = 1; } } sn->packets_since_sample[size_bin]++; if (change_rates) { if (best_rix != sn->current_rix[size_bin]) { IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL, &an->an_node, "%s: size %d switch rate %d (%d/%d) -> %d (%d/%d) after %d packets mrr %d", __func__, bin_to_size(size_bin), RATE(sn->current_rix[size_bin]), sn->stats[size_bin][sn->current_rix[size_bin]].average_tx_time, sn->stats[size_bin][sn->current_rix[size_bin]].perfect_tx_time, RATE(best_rix), sn->stats[size_bin][best_rix].average_tx_time, sn->stats[size_bin][best_rix].perfect_tx_time, sn->packets_since_switch[size_bin], mrr); } sn->packets_since_switch[size_bin] = 0; sn->current_rix[size_bin] = best_rix; sn->ticks_since_switch[size_bin] = ticks; /* * Set the visible txrate for this node. */ an->an_node.ni_txrate = (rt->info[best_rix].phy == IEEE80211_T_HT) ? MCS(best_rix) : DOT11RATE(best_rix); } rix = sn->current_rix[size_bin]; sn->packets_since_switch[size_bin]++; } *try0 = mrr ? sn->sched[rix].t0 : ATH_TXMAXTRY; done: KASSERT(rix >= 0 && rix < rt->rateCount, ("rix is %d", rix)); *rix0 = rix; *txrate = rt->info[rix].rateCode | (shortPreamble ? rt->info[rix].shortPreamble : 0); sn->packets_sent[size_bin]++; #undef DOT11RATE #undef MCS #undef RATE }
static void update_stats(struct ath_softc *sc, struct ath_node *an, int frame_size, int rix0, int tries0, int rix1, int tries1, int rix2, int tries2, int rix3, 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); const int size_bin = size_to_bin(frame_size); const int size = bin_to_size(size_bin); int tt, tries_so_far; if (!IS_RATE_DEFINED(sn, rix0)) return; tt = calc_usecs_unicast_packet(sc, size, rix0, short_tries, MIN(tries0, tries) - 1); tries_so_far = tries0; if (tries1 && tries_so_far < tries) { if (!IS_RATE_DEFINED(sn, rix1)) return; tt += calc_usecs_unicast_packet(sc, size, rix1, short_tries, MIN(tries1 + tries_so_far, tries) - tries_so_far - 1); tries_so_far += tries1; } if (tries2 && tries_so_far < tries) { if (!IS_RATE_DEFINED(sn, rix2)) return; tt += calc_usecs_unicast_packet(sc, size, rix2, short_tries, MIN(tries2 + tries_so_far, tries) - tries_so_far - 1); tries_so_far += tries2; } if (tries3 && tries_so_far < tries) { if (!IS_RATE_DEFINED(sn, rix3)) return; tt += calc_usecs_unicast_packet(sc, size, rix3, short_tries, MIN(tries3 + tries_so_far, tries) - tries_so_far - 1); } if (sn->stats[size_bin][rix0].total_packets < ssc->smoothing_minpackets) { /* just average the first few packets */ int avg_tx = sn->stats[size_bin][rix0].average_tx_time; int packets = sn->stats[size_bin][rix0].total_packets; sn->stats[size_bin][rix0].average_tx_time = (tt+(avg_tx*packets))/(packets+1); } else { /* use a ewma */ sn->stats[size_bin][rix0].average_tx_time = ((sn->stats[size_bin][rix0].average_tx_time * ssc->smoothing_rate) + (tt * (100 - ssc->smoothing_rate))) / 100; } if (status != 0) { int y; sn->stats[size_bin][rix0].successive_failures++; for (y = size_bin+1; y < NUM_PACKET_SIZE_BINS; y++) { /* * Also say larger packets failed since we * assume if a small packet fails at a * bit-rate then a larger one will also. */ sn->stats[y][rix0].successive_failures++; sn->stats[y][rix0].last_tx = ticks; sn->stats[y][rix0].tries += tries; sn->stats[y][rix0].total_packets++; } } else { sn->stats[size_bin][rix0].packets_acked++; sn->stats[size_bin][rix0].successive_failures = 0; } sn->stats[size_bin][rix0].tries += tries; sn->stats[size_bin][rix0].last_tx = ticks; sn->stats[size_bin][rix0].total_packets++; if (rix0 == sn->current_sample_rix[size_bin]) { IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL, &an->an_node, "%s: size %d %s sample rate %d tries (%d/%d) tt %d avg_tt (%d/%d)", __func__, size, status ? "FAIL" : "OK", rix0, short_tries, tries, tt, sn->stats[size_bin][rix0].average_tx_time, sn->stats[size_bin][rix0].perfect_tx_time); sn->sample_tt[size_bin] = tt; sn->current_sample_rix[size_bin] = -1; } }
void ath_rate_findrate(struct ath_softc *sc, struct ath_node *an, int shortPreamble, size_t frameLen, u_int8_t *rix0, int *try0, u_int8_t *txrate) { #define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL) #define RATE(ix) (DOT11RATE(ix) / 2) struct sample_node *sn = ATH_NODE_SAMPLE(an); struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc); struct ifnet *ifp = sc->sc_ifp; struct ieee80211com *ic = ifp->if_l2com; const HAL_RATE_TABLE *rt = sc->sc_currates; const int size_bin = size_to_bin(frameLen); int rix, mrr, best_rix, change_rates; unsigned average_tx_time; if (sn->static_rix != -1) { rix = sn->static_rix; *try0 = ATH_TXMAXTRY; goto done; } mrr = sc->sc_mrretry && !(ic->ic_flags & IEEE80211_F_USEPROT); best_rix = pick_best_rate(sn, rt, size_bin, !mrr); if (best_rix >= 0) { average_tx_time = sn->stats[size_bin][best_rix].average_tx_time; } else { average_tx_time = 0; } /* * Limit the time measuring the performance of other tx * rates to sample_rate% of the total transmission time. */ if (sn->sample_tt[size_bin] < average_tx_time * (sn->packets_since_sample[size_bin]*ssc->sample_rate/100)) { rix = pick_sample_rate(ssc, sn, rt, size_bin); IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL, &an->an_node, "size %u sample rate %d current rate %d", bin_to_size(size_bin), RATE(rix), RATE(sn->current_rix[size_bin])); if (rix != sn->current_rix[size_bin]) { sn->current_sample_rix[size_bin] = rix; } else { sn->current_sample_rix[size_bin] = -1; } sn->packets_since_sample[size_bin] = 0; } else { change_rates = 0; if (!sn->packets_sent[size_bin] || best_rix == -1) { /* no packet has been sent successfully yet */ for (rix = rt->rateCount-1; rix > 0; rix--) { if ((sn->ratemask & (1<<rix)) == 0) continue; /* * Pick the highest rate <= 36 Mbps * that hasn't failed. */ if (DOT11RATE(rix) <= 72 && sn->stats[size_bin][rix].successive_failures == 0) { break; } } change_rates = 1; best_rix = rix; } else if (sn->packets_sent[size_bin] < 20) { /* let the bit-rate switch quickly during the first few packets */ change_rates = 1; } else if (ticks - ssc->min_switch > sn->ticks_since_switch[size_bin]) { /* min_switch seconds have gone by */ change_rates = 1; } else if (2*average_tx_time < sn->stats[size_bin][sn->current_rix[size_bin]].average_tx_time) { /* the current bit-rate is twice as slow as the best one */ change_rates = 1; } sn->packets_since_sample[size_bin]++; if (change_rates) { if (best_rix != sn->current_rix[size_bin]) { IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL, &an->an_node, "%s: size %d switch rate %d (%d/%d) -> %d (%d/%d) after %d packets mrr %d", __func__, bin_to_size(size_bin), RATE(sn->current_rix[size_bin]), sn->stats[size_bin][sn->current_rix[size_bin]].average_tx_time, sn->stats[size_bin][sn->current_rix[size_bin]].perfect_tx_time, RATE(best_rix), sn->stats[size_bin][best_rix].average_tx_time, sn->stats[size_bin][best_rix].perfect_tx_time, sn->packets_since_switch[size_bin], mrr); } sn->packets_since_switch[size_bin] = 0; sn->current_rix[size_bin] = best_rix; sn->ticks_since_switch[size_bin] = ticks; /* * Set the visible txrate for this node. */ an->an_node.ni_txrate = DOT11RATE(best_rix); } rix = sn->current_rix[size_bin]; sn->packets_since_switch[size_bin]++; } *try0 = mrr ? sn->sched[rix].t0 : ATH_TXMAXTRY; done: KASSERT(rix >= 0 && rix < rt->rateCount, ("rix is %d", rix)); *rix0 = rix; *txrate = rt->info[rix].rateCode | (shortPreamble ? rt->info[rix].shortPreamble : 0); sn->packets_sent[size_bin]++; #undef DOT11RATE #undef RATE }
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); if (!(0 <= ndx0 && ndx0 < sn->num_rates)) { printf("%s: bogus ndx0 %d, max %u, mode %u\n", __func__, ndx0, sn->num_rates, sc->sc_curmode); return; } rate = sn->rates[ndx0].rate; tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx0].rix, short_tries, MIN(tries0, tries) - 1); tries_so_far += tries0; if (tries1 && tries0 < tries) { if (!(0 <= ndx1 && ndx1 < sn->num_rates)) { printf("%s: bogus ndx1 %d, max %u, mode %u\n", __func__, ndx1, sn->num_rates, sc->sc_curmode); return; } tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx1].rix, short_tries, MIN(tries1 + tries_so_far, tries) - tries_so_far - 1); } tries_so_far += tries1; if (tries2 && tries0 + tries1 < tries) { if (!(0 <= ndx2 && ndx2 < sn->num_rates)) { printf("%s: bogus ndx2 %d, max %u, mode %u\n", __func__, ndx2, sn->num_rates, sc->sc_curmode); return; } tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx2].rix, short_tries, MIN(tries2 + tries_so_far, tries) - tries_so_far - 1); } tries_so_far += tries2; if (tries3 && tries0 + tries1 + tries2 < tries) { if (!(0 <= ndx3 && ndx3 < sn->num_rates)) { printf("%s: bogus ndx3 %d, max %u, mode %u\n", __func__, ndx3, sn->num_rates, sc->sc_curmode); return; } tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx3].rix, short_tries, MIN(tries3 + tries_so_far, tries) - tries_so_far - 1); } 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) { int y; sn->stats[size_bin][ndx0].successive_failures++; for (y = size_bin+1; y < NUM_PACKET_SIZE_BINS; y++) { /* also say larger packets failed since we * assume if a small packet fails at a lower * bit-rate then a larger one will also. */ sn->stats[y][ndx0].successive_failures++; sn->stats[y][ndx0].last_tx = ticks; sn->stats[y][ndx0].tries += tries; sn->stats[y][ndx0].total_packets++; } } 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, ATH_DEBUG_RATE, "%s: %s size %d %s sample rate %d tries (%d/%d) tt %d avg_tt (%d/%d)\n", __func__, ether_sprintf(an->an_node.ni_macaddr), size, status ? "FAIL" : "OK", rate, short_tries, tries, tt, sn->stats[size_bin][ndx0].average_tx_time, sn->stats[size_bin][ndx0].perfect_tx_time); sn->sample_tt[size_bin] = tt; sn->current_sample_ndx[size_bin] = -1; } }
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, change_rates; unsigned average_tx_time; mrr = sc->sc_mrretry && !(ic->ic_flags & IEEE80211_F_USEPROT); 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 { *try0 = mrr ? 2 : ATH_TXMAXTRY; if (sn->sample_tt[size_bin] < average_tx_time * (sn->packets_since_sample[size_bin]*ssc->ath_sample_rate/100)) { /* * 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]) { sn->current_sample_ndx[size_bin] = ndx; } else { sn->current_sample_ndx[size_bin] = -1; } sn->packets_since_sample[size_bin] = 0; } else { change_rates = 0; if (!sn->packets_sent[size_bin] || best_ndx == -1) { /* no packet has been sent successfully yet */ for (ndx = sn->num_rates-1; ndx > 0; ndx--) { /* * pick the highest rate <= 36 Mbps * that hasn't failed. */ if (sn->rates[ndx].rate <= 72 && sn->stats[size_bin][ndx].successive_failures == 0) { break; } } change_rates = 1; best_ndx = ndx; } else if (sn->packets_sent[size_bin] < 20) { /* let the bit-rate switch quickly during the first few packets */ change_rates = 1; } else if (ticks - ((hz*MIN_SWITCH_MS)/1000) > sn->ticks_since_switch[size_bin]) { /* 2 seconds have gone by */ change_rates = 1; } else if (average_tx_time * 2 < sn->stats[size_bin][sn->current_rate[size_bin]].average_tx_time) { /* the current bit-rate is twice as slow as the best one */ change_rates = 1; } sn->packets_since_sample[size_bin]++; if (change_rates) { if (best_ndx != sn->current_rate[size_bin]) { DPRINTF(sc, ATH_DEBUG_RATE, "%s: %s size %d switch rate %d (%d/%d) -> %d (%d/%d) after %d packets mrr %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->ticks_since_switch[size_bin] = ticks; } ndx = sn->current_rate[size_bin]; sn->packets_since_switch[size_bin]++; if (size_bin == 0) { /* * set the visible txrate for this node * to the rate of small packets */ an->an_node.ni_txrate = ndx; } } } KASSERT(ndx >= 0 && ndx < sn->num_rates, ("ndx is %d", ndx)); *rix = sn->rates[ndx].rix; if (shortPreamble) { *txrate = sn->rates[ndx].shortPreambleRateCode; } else { *txrate = sn->rates[ndx].rateCode; } sn->packets_sent[size_bin]++; }