/* * Pick a non-HT rate to begin using. */ static int ath_rate_pick_seed_rate_legacy(struct ath_softc *sc, struct ath_node *an, int frameLen) { #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) int rix = -1; const HAL_RATE_TABLE *rt = sc->sc_currates; struct sample_node *sn = ATH_NODE_SAMPLE(an); const int size_bin = size_to_bin(frameLen); /* no packet has been sent successfully yet */ for (rix = rt->rateCount-1; rix > 0; rix--) { if ((sn->ratemask & (1<<rix)) == 0) continue; /* Skip HT rates */ if (rt->info[rix].phy == IEEE80211_T_HT) continue; /* * Pick the highest rate <= 36 Mbps * that hasn't failed. */ if (DOT11RATE(rix) <= 72 && sn->stats[size_bin][rix].successive_failures == 0) { break; } } return rix; #undef RATE #undef MCS #undef DOT11RATE }
/* * Pick a good "random" bit-rate to sample other than the current one. */ static __inline int pick_sample_rate(struct sample_softc *ssc , struct sample_node *sn, const HAL_RATE_TABLE *rt, int size_bin) { #define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL) int current_rix, rix; unsigned current_tt; uint32_t mask; current_rix = sn->current_rix[size_bin]; if (current_rix < 0) { /* no successes yet, send at the lowest bit-rate */ return 0; } current_tt = sn->stats[size_bin][current_rix].average_tx_time; rix = sn->last_sample_rix[size_bin]+1; /* next sample rate */ mask = sn->ratemask &~ (1<<current_rix);/* don't sample current rate */ while (mask != 0) { if ((mask & (1<<rix)) == 0) { /* not a supported rate */ nextrate: if (++rix >= rt->rateCount) rix = 0; continue; } /* this bit-rate is always worse than the current one */ if (sn->stats[size_bin][rix].perfect_tx_time > current_tt) { mask &= ~(1<<rix); goto nextrate; } /* rarely sample bit-rates that fail a lot */ if (sn->stats[size_bin][rix].successive_failures > ssc->max_successive_failures && ticks - sn->stats[size_bin][rix].last_tx < ssc->stale_failure_timeout) { mask &= ~(1<<rix); goto nextrate; } /* don't sample more than 2 rates higher for rates > 11M */ if (DOT11RATE(rix) > 2*11 && rix > current_rix + 2) { mask &= ~(1<<rix); goto nextrate; } sn->last_sample_rix[size_bin] = rix; return rix; } return current_rix; #undef DOT11RATE }
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 }
/* * Pick a good "random" bit-rate to sample other than the current one. */ static __inline int pick_sample_rate(struct sample_softc *ssc , struct ath_node *an, const HAL_RATE_TABLE *rt, int size_bin) { #define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL) #define MCS(ix) (rt->info[ix].dot11Rate | IEEE80211_RATE_MCS) struct sample_node *sn = ATH_NODE_SAMPLE(an); int current_rix, rix; unsigned current_tt; uint32_t mask; current_rix = sn->current_rix[size_bin]; if (current_rix < 0) { /* no successes yet, send at the lowest bit-rate */ /* XXX should return MCS0 if HT */ return 0; } current_tt = sn->stats[size_bin][current_rix].average_tx_time; rix = sn->last_sample_rix[size_bin]+1; /* next sample rate */ mask = sn->ratemask &~ (1<<current_rix);/* don't sample current rate */ while (mask != 0) { if ((mask & (1<<rix)) == 0) { /* not a supported rate */ nextrate: if (++rix >= rt->rateCount) rix = 0; continue; } /* if the node is HT and the rate isn't HT, don't bother sample */ if ((an->an_node.ni_flags & IEEE80211_NODE_HT) && (rt->info[rix].phy != IEEE80211_T_HT)) { mask &= ~(1<<rix); goto nextrate; } /* this bit-rate is always worse than the current one */ if (sn->stats[size_bin][rix].perfect_tx_time > current_tt) { mask &= ~(1<<rix); goto nextrate; } /* rarely sample bit-rates that fail a lot */ if (sn->stats[size_bin][rix].successive_failures > ssc->max_successive_failures && ticks - sn->stats[size_bin][rix].last_tx < ssc->stale_failure_timeout) { mask &= ~(1<<rix); goto nextrate; } /* * When doing aggregation, successive failures don't happen * as often, as sometimes some of the sub-frames get through. * * If the sample rix average tx time is greater than the * average tx time of the current rix, don't immediately use * the rate for sampling. */ if (an->an_node.ni_flags & IEEE80211_NODE_HT) { if ((sn->stats[size_bin][rix].average_tx_time * 10 > sn->stats[size_bin][current_rix].average_tx_time * 9) && (ticks - sn->stats[size_bin][rix].last_tx < ssc->stale_failure_timeout)) { mask &= ~(1<<rix); goto nextrate; } } /* * XXX TODO * For HT, limit sample somehow? */ /* Don't sample more than 2 rates higher for rates > 11M for non-HT rates */ if (! (an->an_node.ni_flags & IEEE80211_NODE_HT)) { if (DOT11RATE(rix) > 2*11 && rix > current_rix + 2) { mask &= ~(1<<rix); goto nextrate; } } sn->last_sample_rix[size_bin] = rix; return rix; } return current_rix; #undef DOT11RATE #undef MCS }
/* * 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) #define DOT11RATE(_ix) (rt->info[(_ix)].dot11Rate & IEEE80211_RATE_VAL) struct ath_node *an = ATH_NODE(ni); const struct ieee80211_txparam *tp = ni->ni_txparms; struct sample_node *sn = ATH_NODE_SAMPLE(an); const HAL_RATE_TABLE *rt = sc->sc_currates; #ifdef IEEE80211_DEBUG char ethstr[ETHER_ADDRSTRLEN + 1]; #endif int x, y, srate, rix; KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode)); KASSERT(sc->sc_curmode < IEEE80211_MODE_MAX+2, ("curmode %u", sc->sc_curmode)); sn->sched = mrr_schedules[sc->sc_curmode]; KASSERT(sn->sched != NULL, ("no mrr schedule for mode %u", sc->sc_curmode)); sn->static_rix = -1; if (tp != NULL && tp->ucastrate != IEEE80211_FIXED_RATE_NONE) { /* * A fixed rate is to be used; ucastrate is the IEEE code * for this rate (sans basic bit). Check this against the * negotiated rate set for the node. Note the fixed rate * may not be available for various reasons so we only * setup the static rate index if the lookup is successful. * XXX handle MCS */ for (srate = ni->ni_rates.rs_nrates - 1; srate >= 0; srate--) if (RATE(srate) == tp->ucastrate) { sn->static_rix = sc->sc_rixmap[tp->ucastrate]; break; } #ifdef IEEE80211_DEBUG if (sn->static_rix == -1) { IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, "%s: ucastrate %u not found, nrates %u", __func__, tp->ucastrate, ni->ni_rates.rs_nrates); } #endif } /* * Construct a bitmask of usable rates. This has all * negotiated rates minus those marked by the hal as * to be ignored for doing rate control. */ sn->ratemask = 0; for (x = 0; x < ni->ni_rates.rs_nrates; x++) { rix = sc->sc_rixmap[RATE(x)]; if (rix == 0xff) continue; /* skip rates marked broken by hal */ if (!rt->info[rix].valid) continue; KASSERT(rix < SAMPLE_MAXRATES, ("rate %u has rix %d", RATE(x), rix)); sn->ratemask |= 1<<rix; } #ifdef IEEE80211_DEBUG if (ieee80211_msg(ni->ni_vap, IEEE80211_MSG_RATECTL)) { uint32_t mask; ieee80211_note(ni->ni_vap, "[%s] %s: size 1600 rate/tt", kether_ntoa(ni->ni_macaddr, ethstr), __func__); for (mask = sn->ratemask, rix = 0; mask != 0; mask >>= 1, rix++) { if ((mask & 1) == 0) continue; kprintf(" %d/%d", DOT11RATE(rix) / 2, calc_usecs_unicast_packet(sc, 1600, rix, 0,0)); } kprintf("\n"); }
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 }
/* * Pick a good "random" bit-rate to sample other than the current one. */ static __inline int pick_sample_rate(struct sample_softc *ssc , struct ath_node *an, const HAL_RATE_TABLE *rt, int size_bin) { #define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL) #define MCS(ix) (rt->info[ix].dot11Rate | IEEE80211_RATE_MCS) struct sample_node *sn = ATH_NODE_SAMPLE(an); int current_rix, rix; unsigned current_tt; uint64_t mask; current_rix = sn->current_rix[size_bin]; if (current_rix < 0) { /* no successes yet, send at the lowest bit-rate */ /* XXX should return MCS0 if HT */ return 0; } current_tt = sn->stats[size_bin][current_rix].average_tx_time; rix = sn->last_sample_rix[size_bin]+1; /* next sample rate */ mask = sn->ratemask &~ ((uint64_t) 1<<current_rix);/* don't sample current rate */ while (mask != 0) { if ((mask & ((uint64_t) 1<<rix)) == 0) { /* not a supported rate */ nextrate: if (++rix >= rt->rateCount) rix = 0; continue; } /* * The following code stops trying to sample * non-MCS rates when speaking to an MCS node. * However, at least for CCK rates in 2.4GHz mode, * the non-MCS rates MAY actually provide better * PER at the very far edge of reception. * * However! Until ath_rate_form_aggr() grows * some logic to not form aggregates if the * selected rate is non-MCS, this won't work. * * So don't disable this code until you've taught * ath_rate_form_aggr() to drop out if any of * the selected rates are non-MCS. */ #if 1 /* if the node is HT and the rate isn't HT, don't bother sample */ if ((an->an_node.ni_flags & IEEE80211_NODE_HT) && (rt->info[rix].phy != IEEE80211_T_HT)) { mask &= ~((uint64_t) 1<<rix); goto nextrate; } #endif /* this bit-rate is always worse than the current one */ if (sn->stats[size_bin][rix].perfect_tx_time > current_tt) { mask &= ~((uint64_t) 1<<rix); goto nextrate; } /* rarely sample bit-rates that fail a lot */ if (sn->stats[size_bin][rix].successive_failures > ssc->max_successive_failures && ticks - sn->stats[size_bin][rix].last_tx < ssc->stale_failure_timeout) { mask &= ~((uint64_t) 1<<rix); goto nextrate; } /* * For HT, only sample a few rates on either side of the * current rix; there's quite likely a lot of them. */ if (an->an_node.ni_flags & IEEE80211_NODE_HT) { if (rix < (current_rix - 3) || rix > (current_rix + 3)) { mask &= ~((uint64_t) 1<<rix); goto nextrate; } } /* Don't sample more than 2 rates higher for rates > 11M for non-HT rates */ if (! (an->an_node.ni_flags & IEEE80211_NODE_HT)) { if (DOT11RATE(rix) > 2*11 && rix > current_rix + 2) { mask &= ~((uint64_t) 1<<rix); goto nextrate; } } sn->last_sample_rix[size_bin] = rix; return rix; } return current_rix; #undef DOT11RATE #undef MCS }