From: Felix Fietkau Date: Sun, 7 Mar 2010 16:29:41 +0000 (+0000) Subject: mac80211: simplify minstrel_ht code, rewrite packet sampling algorithm for improved... X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=a12048b2bf1213bdafea75fb57ea0158bbaf7cae;p=openwrt%2Fstaging%2Fnbd.git mac80211: simplify minstrel_ht code, rewrite packet sampling algorithm for improved performance and a-mpdu length SVN-Revision: 20035 --- diff --git a/package/mac80211/patches/560-minstrel_ht.patch b/package/mac80211/patches/560-minstrel_ht.patch index 15ff3e6d72..bc50ca67e2 100644 --- a/package/mac80211/patches/560-minstrel_ht.patch +++ b/package/mac80211/patches/560-minstrel_ht.patch @@ -68,7 +68,7 @@ --- /dev/null +++ b/net/mac80211/rc80211_minstrel_ht.c -@@ -0,0 +1,824 @@ +@@ -0,0 +1,800 @@ +/* + * Copyright (C) 2010 Felix Fietkau + * @@ -125,9 +125,6 @@ + } \ +} + -+#define MINSTREL_INTFL_SAMPLE_SLOT0 BIT(30) -+#define MINSTREL_INTFL_SAMPLE_SLOT1 BIT(31) -+ +/* + * To enable sufficiently targeted rate sampling, MCS rates are divided into + * groups, based on the number of streams and flags (HT40, SGI) that they @@ -206,7 +203,8 @@ +static void +minstrel_calc_rate_ewma(struct minstrel_priv *mp, struct minstrel_rate_stats *mr) +{ -+ if (mr->attempts) { ++ if (unlikely(mr->attempts > 0)) { ++ mr->sample_skipped = 0; + mr->cur_prob = MINSTREL_FRAC(mr->success, mr->attempts); + if (!mr->att_hist) + mr->probability = mr->cur_prob; @@ -215,6 +213,8 @@ + mr->cur_prob, EWMA_LEVEL); + mr->att_hist += mr->attempts; + mr->succ_hist += mr->success; ++ } else { ++ mr->sample_skipped++; + } + mr->last_success = mr->success; + mr->last_attempts = mr->attempts; @@ -262,6 +262,7 @@ + int cur_prob, cur_prob_tp, cur_tp, cur_tp2; + int group, i, index; + ++ mi->sample_count = 0; + mi->max_tp_rate = 0; + mi->max_tp_rate2 = 0; + mi->max_prob_rate = 0; @@ -279,6 +280,7 @@ + mg->max_tp_rate = 0; + mg->max_tp_rate2 = 0; + mg->max_prob_rate = 0; ++ mi->sample_count++; + + for (i = 0; i < MCS_GROUP_RATES; i++) { + if (!(mg->supported & BIT(i))) @@ -309,7 +311,7 @@ + mr = minstrel_get_ratestats(mi, index); + } + -+ if (index == mg->max_tp_rate) ++ if (index >= mg->max_tp_rate) + continue; + + if (mr->cur_tp > cur_tp2) { @@ -319,6 +321,9 @@ + } + } + ++ /* try to sample up to half of the availble rates during each interval */ ++ mi->sample_count *= 4; ++ + cur_prob = 0; + cur_prob_tp = 0; + cur_tp = 0; @@ -386,7 +391,7 @@ +} + +static void -+minstrel_downgrade_rate(struct minstrel_ht_sta *mi, int *idx, int type) ++minstrel_downgrade_rate(struct minstrel_ht_sta *mi, int *idx, bool primary) +{ + int group, orig_group; + @@ -397,18 +402,14 @@ + if (!mi->groups[group].supported) + continue; + -+ if (minstrel_mcs_groups[group].streams >= ++ if (minstrel_mcs_groups[group].streams > + minstrel_mcs_groups[orig_group].streams) + continue; + -+ switch(type) { -+ case 0: ++ if (primary) + *idx = mi->groups[group].max_tp_rate; -+ break; -+ case 1: ++ else + *idx = mi->groups[group].max_tp_rate2; -+ break; -+ } + break; + } +} @@ -445,6 +446,17 @@ + mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len, + MINSTREL_FRAC(info->status.ampdu_len, 1), 90); + ++ if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) { ++ mi->sample_wait = 4 + MINSTREL_TRUNC(mi->avg_ampdu_len); ++ mi->sample_tries = 3; ++ mi->sample_count--; ++ } ++ ++ if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) { ++ mi->sample_packets += info->status.ampdu_len; ++ minstrel_next_sample_idx(mi); ++ } ++ + for (i = 0; !last; i++) { + last = (i == IEEE80211_TX_MAX_RATES - 1) || + !minstrel_ht_txstat_valid(&ar[i + 1]); @@ -452,14 +464,6 @@ + if (!minstrel_ht_txstat_valid(&ar[i])) + break; + -+ if ((i == 0 && (info->flags & MINSTREL_INTFL_SAMPLE_SLOT0)) || -+ (i == 1 && (info->flags & MINSTREL_INTFL_SAMPLE_SLOT1))) { -+ if (mi->sample_pending > 0) -+ mi->sample_pending--; -+ mi->sample_packets++; -+ minstrel_next_sample_idx(mi); -+ } -+ + group = minstrel_ht_get_group_idx(&ar[i]); + rate = &mi->groups[group].rates[ar[i].idx % 8]; + @@ -469,20 +473,19 @@ + rate->attempts += ar[i].count * info->status.ampdu_len; + } + -+ + /* + * check for sudden death of spatial multiplexing, + * downgrade to a lower number of streams if necessary. + */ + rate = minstrel_get_ratestats(mi, mi->max_tp_rate); + if (MINSTREL_FRAC(rate->success, rate->attempts) < -+ MINSTREL_FRAC(20, 100) && rate->attempts > 15) -+ minstrel_downgrade_rate(mi, &mi->max_tp_rate, 0); ++ MINSTREL_FRAC(20, 100) && rate->attempts > 30) ++ minstrel_downgrade_rate(mi, &mi->max_tp_rate, true); + + rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate2); + if (MINSTREL_FRAC(rate->success, rate->attempts) < -+ MINSTREL_FRAC(20, 100) && rate->attempts > 15) -+ minstrel_downgrade_rate(mi, &mi->max_tp_rate2, 1); ++ MINSTREL_FRAC(20, 100) && rate->attempts > 30) ++ minstrel_downgrade_rate(mi, &mi->max_tp_rate2, false); + + if (time_after(jiffies, mi->stats_update + (mp->update_interval / 2 * HZ) / 1000)) + minstrel_ht_update_stats(mp, mi); @@ -560,41 +563,21 @@ +} + +static int -+minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, -+ bool *defer) ++minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) +{ + struct minstrel_rate_stats *mr; + struct minstrel_mcs_group_data *mg; + int sample_idx = 0; -+ int sample_rate; -+ int delta; -+ -+ if (mp->has_mrr) -+ sample_rate = mp->lookaround_rate_mrr; -+ else -+ sample_rate = mp->lookaround_rate; -+ -+ delta = (mi->total_packets * sample_rate) / 100 - mi->sample_packets; -+ delta -= mi->sample_pending / 2; + -+ if (delta <= 0) ++ if (mi->sample_wait > 0) { ++ mi->sample_wait--; + return -1; -+ -+ delta -= 16; -+ if (delta > 1) { -+ /* With multi-rate retry, not every planned sample -+ * attempt actually gets used, due to the way the retry -+ * chain is set up - [max_tp,sample,prob,lowest] for -+ * sample_rate < max_tp. -+ * -+ * If there's too much sampling backlog and the link -+ * starts getting worse, minstrel would start bursting -+ * out lots of sampling frames, which would result -+ * in a large throughput loss. -+ */ -+ mi->sample_packets += delta - 1; + } + ++ if (!mi->sample_tries) ++ return -1; ++ ++ mi->sample_tries--; + mg = &mi->groups[mi->sample_group]; + sample_idx = sample_table[mg->column][mg->index]; + mr = &mg->rates[sample_idx]; @@ -605,27 +588,22 @@ + * higher than 95% to avoid wasting airtime + */ + if (!mp->has_mrr && (mr->probability > MINSTREL_FRAC(95, 100))) -+ return -1; ++ goto next; + ++ /* ++ * Make sure that lower rates get sampled only occasionally, ++ * if the link is working perfectly. ++ */ + if (minstrel_get_duration(sample_idx) > -+ minstrel_get_duration(mi->max_tp_rate)) { -+ /* -+ * Make sure that lower rates get sampled occasionally, even -+ * if the link is working perfectly. Some drivers such as ath9k -+ * severely limit aggregation size if the MRR chain contains low -+ * rates -+ * -+ * If the lower rate has already been tried a few times, there's -+ * no point in forcing it to be sampled again, so skip to the -+ * next sampling index after applying this one in the tx control -+ */ -+ if (mr->att_hist > 15) { -+ *defer = true; -+ minstrel_next_sample_idx(mi); -+ } -+ } ++ minstrel_get_duration(mi->max_tp_rate) && ++ mr->sample_skipped < 10) ++ goto next; + + return sample_idx; ++ ++next: ++ minstrel_next_sample_idx(mi); ++ return -1; +} + +static void @@ -657,7 +635,6 @@ + struct minstrel_ht_sta_priv *msp = priv_sta; + struct minstrel_ht_sta *mi = &msp->ht; + struct minstrel_priv *mp = priv; -+ bool sample_defer = false; + int sample_idx; + + if (rate_control_send_low(sta, priv_sta, txrc)) @@ -668,22 +645,13 @@ + + minstrel_aggr_check(mp, sta, txrc->skb); + -+ sample_idx = minstrel_get_sample_rate(mp, mi, &sample_defer); ++ sample_idx = minstrel_get_sample_rate(mp, mi); + if (sample_idx >= 0) { -+ if (sample_defer) { -+ minstrel_ht_set_rate(mp, mi, &ar[0], mi->max_tp_rate, -+ txrc, false, false); -+ minstrel_ht_set_rate(mp, mi, &ar[1], sample_idx, -+ txrc, true, true); -+ info->flags |= MINSTREL_INTFL_SAMPLE_SLOT1; -+ } else { -+ minstrel_ht_set_rate(mp, mi, &ar[0], sample_idx, -+ txrc, true, false); -+ minstrel_ht_set_rate(mp, mi, &ar[1], mi->max_tp_rate, -+ txrc, false, true); -+ info->flags |= MINSTREL_INTFL_SAMPLE_SLOT0; -+ } -+ mi->sample_pending++; ++ minstrel_ht_set_rate(mp, mi, &ar[0], sample_idx, ++ txrc, true, false); ++ minstrel_ht_set_rate(mp, mi, &ar[1], mi->max_tp_rate, ++ txrc, false, true); ++ info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE; + } else { + minstrel_ht_set_rate(mp, mi, &ar[0], mi->max_tp_rate, + txrc, false, false); @@ -698,21 +666,58 @@ + mi->total_packets++; + + /* wraparound */ -+ if (mi->total_packets >= 100000) { ++ if (mi->total_packets == ~0) { + mi->total_packets = 0; + mi->sample_packets = 0; -+ mi->sample_pending = 0; + } +} + +static void -+minstrel_ht_update_cap(struct minstrel_ht_sta *mi, struct ieee80211_sta *sta, -+ enum nl80211_channel_type oper_chan_type) ++minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband, ++ struct ieee80211_sta *sta, void *priv_sta, ++ enum nl80211_channel_type oper_chan_type) +{ ++ struct minstrel_priv *mp = priv; ++ struct minstrel_ht_sta_priv *msp = priv_sta; ++ struct minstrel_ht_sta *mi = &msp->ht; + struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs; ++ struct ieee80211_local *local = hw_to_local(mp->hw); + u16 sta_cap = sta->ht_cap.cap; ++ int ack_dur; + int i; + ++ /* fall back to the old minstrel for legacy stations */ ++ if (sta && !sta->ht_cap.ht_supported) { ++ msp->is_ht = false; ++ memset(&msp->legacy, 0, sizeof(msp->legacy)); ++ msp->legacy.r = msp->ratelist; ++ msp->legacy.sample_table = msp->sample_table; ++ return mac80211_minstrel.rate_init(priv, sband, sta, &msp->legacy); ++ } ++ ++ BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != ++ MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS); ++ ++ msp->is_ht = true; ++ memset(mi, 0, sizeof(*mi)); ++ mi->stats_update = jiffies; ++ ++ ack_dur = ieee80211_frame_duration(local, 10, 60, 1, 1); ++ mi->overhead = ieee80211_frame_duration(local, 0, 60, 1, 1) + ack_dur; ++ mi->overhead_rtscts = mi->overhead + 2 * ack_dur; ++ ++ mi->avg_ampdu_len = MINSTREL_FRAC(1, 1); ++ ++ /* When using MRR, sample more on the first attempt, without delay */ ++ if (mp->has_mrr) { ++ mi->sample_count = 16; ++ mi->sample_wait = 0; ++ } else { ++ mi->sample_count = 8; ++ mi->sample_wait = 8; ++ } ++ mi->sample_tries = 4; ++ + if (oper_chan_type != NL80211_CHAN_HT40MINUS && + oper_chan_type != NL80211_CHAN_HT40PLUS) + sta_cap &= ~IEEE80211_HT_CAP_SUP_WIDTH_20_40; @@ -744,34 +749,8 @@ + struct ieee80211_sta *sta, void *priv_sta) +{ + struct minstrel_priv *mp = priv; -+ struct minstrel_ht_sta_priv *msp = priv_sta; -+ struct minstrel_ht_sta *mi = &msp->ht; -+ struct ieee80211_local *local = hw_to_local(mp->hw); -+ int ack_dur; -+ -+ /* fall back to the old minstrel for legacy stations */ -+ if (sta && !sta->ht_cap.ht_supported) { -+ msp->is_ht = false; -+ memset(&msp->legacy, 0, sizeof(msp->legacy)); -+ msp->legacy.r = msp->ratelist; -+ msp->legacy.sample_table = msp->sample_table; -+ return mac80211_minstrel.rate_init(priv, sband, sta, &msp->legacy); -+ } -+ -+ BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != -+ MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS); -+ -+ msp->is_ht = true; -+ memset(mi, 0, sizeof(*mi)); -+ mi->stats_update = jiffies; + -+ ack_dur = ieee80211_frame_duration(local, 10, 60, 1, 1); -+ mi->overhead = ieee80211_frame_duration(local, 0, 60, 1, 1) + ack_dur; -+ mi->overhead_rtscts = mi->overhead + 2 * ack_dur; -+ -+ mi->avg_ampdu_len = MINSTREL_FRAC(1, 1); -+ -+ minstrel_ht_update_cap(mi, sta, mp->hw->conf.channel_type); ++ minstrel_ht_update_caps(priv, sband, sta, priv_sta, mp->hw->conf.channel_type); +} + +static void @@ -779,10 +758,7 @@ + struct ieee80211_sta *sta, void *priv_sta, + u32 changed, enum nl80211_channel_type oper_chan_type) +{ -+ struct minstrel_ht_sta_priv *msp = priv_sta; -+ struct minstrel_ht_sta *mi = &msp->ht; -+ -+ minstrel_ht_update_cap(mi, sta, oper_chan_type); ++ minstrel_ht_update_caps(priv, sband, sta, priv_sta, oper_chan_type); +} + +static void * @@ -895,7 +871,7 @@ +} --- /dev/null +++ b/net/mac80211/rc80211_minstrel_ht.h -@@ -0,0 +1,115 @@ +@@ -0,0 +1,120 @@ +/* + * Copyright (C) 2010 Felix Fietkau + * @@ -942,9 +918,11 @@ + unsigned int cur_prob, probability; + + /* maximum retry counts */ -+ bool retry_updated; + unsigned int retry_count; + unsigned int retry_count_rtscts; ++ ++ bool retry_updated; ++ u8 sample_skipped; +}; + +struct minstrel_mcs_group_data { @@ -985,10 +963,13 @@ + + unsigned int total_packets; + unsigned int sample_packets; -+ unsigned int sample_pending; ++ ++ u8 sample_wait; ++ u8 sample_tries; ++ u8 sample_count; + + /* current MCS group to be sampled */ -+ unsigned int sample_group; ++ u8 sample_group; + + /* MCS rate group info and statistics */ + struct minstrel_mcs_group_data groups[MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS];