diff options
Diffstat (limited to 'net/mac80211/rc80211_minstrel.c')
-rw-r--r-- | net/mac80211/rc80211_minstrel.c | 127 |
1 files changed, 86 insertions, 41 deletions
diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c index 7c86a002df95..247552a7f6c2 100644 --- a/net/mac80211/rc80211_minstrel.c +++ b/net/mac80211/rc80211_minstrel.c @@ -69,14 +69,39 @@ rix_to_ndx(struct minstrel_sta_info *mi, int rix) return i; } +/* return current EMWA throughput */ +int minstrel_get_tp_avg(struct minstrel_rate *mr, int prob_ewma) +{ + int usecs; + + usecs = mr->perfect_tx_time; + if (!usecs) + usecs = 1000000; + + /* reset thr. below 10% success */ + if (mr->stats.prob_ewma < MINSTREL_FRAC(10, 100)) + return 0; + + if (prob_ewma > MINSTREL_FRAC(90, 100)) + return MINSTREL_TRUNC(100000 * (MINSTREL_FRAC(90, 100) / usecs)); + else + return MINSTREL_TRUNC(100000 * (prob_ewma / usecs)); +} + /* find & sort topmost throughput rates */ static inline void minstrel_sort_best_tp_rates(struct minstrel_sta_info *mi, int i, u8 *tp_list) { int j = MAX_THR_RATES; + struct minstrel_rate_stats *tmp_mrs = &mi->r[j - 1].stats; + struct minstrel_rate_stats *cur_mrs = &mi->r[i].stats; - while (j > 0 && mi->r[i].stats.cur_tp > mi->r[tp_list[j - 1]].stats.cur_tp) + while (j > 0 && (minstrel_get_tp_avg(&mi->r[i], cur_mrs->prob_ewma) > + minstrel_get_tp_avg(&mi->r[tp_list[j - 1]], tmp_mrs->prob_ewma))) { j--; + tmp_mrs = &mi->r[tp_list[j - 1]].stats; + } + if (j < MAX_THR_RATES - 1) memmove(&tp_list[j + 1], &tp_list[j], MAX_THR_RATES - (j + 1)); if (j < MAX_THR_RATES) @@ -127,13 +152,47 @@ minstrel_update_rates(struct minstrel_priv *mp, struct minstrel_sta_info *mi) rate_control_set_rates(mp->hw, mi->sta, ratetbl); } +/* +* Recalculate statistics and counters of a given rate +*/ +void +minstrel_calc_rate_stats(struct minstrel_rate_stats *mrs) +{ + if (unlikely(mrs->attempts > 0)) { + mrs->sample_skipped = 0; + mrs->cur_prob = MINSTREL_FRAC(mrs->success, mrs->attempts); + if (unlikely(!mrs->att_hist)) { + mrs->prob_ewma = mrs->cur_prob; + } else { + /* update exponential weighted moving variance */ + mrs->prob_ewmsd = minstrel_ewmsd(mrs->prob_ewmsd, + mrs->cur_prob, + mrs->prob_ewma, + EWMA_LEVEL); + + /*update exponential weighted moving avarage */ + mrs->prob_ewma = minstrel_ewma(mrs->prob_ewma, + mrs->cur_prob, + EWMA_LEVEL); + } + mrs->att_hist += mrs->attempts; + mrs->succ_hist += mrs->success; + } else { + mrs->sample_skipped++; + } + + mrs->last_success = mrs->success; + mrs->last_attempts = mrs->attempts; + mrs->success = 0; + mrs->attempts = 0; +} + static void minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi) { u8 tmp_tp_rate[MAX_THR_RATES]; u8 tmp_prob_rate = 0; - u32 usecs; - int i; + int i, tmp_cur_tp, tmp_prob_tp; for (i = 0; i < MAX_THR_RATES; i++) tmp_tp_rate[i] = 0; @@ -141,38 +200,15 @@ minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi) for (i = 0; i < mi->n_rates; i++) { struct minstrel_rate *mr = &mi->r[i]; struct minstrel_rate_stats *mrs = &mi->r[i].stats; + struct minstrel_rate_stats *tmp_mrs = &mi->r[tmp_prob_rate].stats; - usecs = mr->perfect_tx_time; - if (!usecs) - usecs = 1000000; - - if (unlikely(mrs->attempts > 0)) { - mrs->sample_skipped = 0; - mrs->cur_prob = MINSTREL_FRAC(mrs->success, - mrs->attempts); - mrs->succ_hist += mrs->success; - mrs->att_hist += mrs->attempts; - mrs->probability = minstrel_ewma(mrs->probability, - mrs->cur_prob, - EWMA_LEVEL); - } else - mrs->sample_skipped++; - - mrs->last_success = mrs->success; - mrs->last_attempts = mrs->attempts; - mrs->success = 0; - mrs->attempts = 0; - - /* Update throughput per rate, reset thr. below 10% success */ - if (mrs->probability < MINSTREL_FRAC(10, 100)) - mrs->cur_tp = 0; - else - mrs->cur_tp = mrs->probability * (1000000 / usecs); + /* Update statistics of success probability per rate */ + minstrel_calc_rate_stats(mrs); /* Sample less often below the 10% chance of success. * Sample less often above the 95% chance of success. */ - if (mrs->probability > MINSTREL_FRAC(95, 100) || - mrs->probability < MINSTREL_FRAC(10, 100)) { + if (mrs->prob_ewma > MINSTREL_FRAC(95, 100) || + mrs->prob_ewma < MINSTREL_FRAC(10, 100)) { mr->adjusted_retry_count = mrs->retry_count >> 1; if (mr->adjusted_retry_count > 2) mr->adjusted_retry_count = 2; @@ -192,11 +228,14 @@ minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi) * choose the maximum throughput rate as max_prob_rate * (2) if all success probabilities < 95%, the rate with * highest success probability is chosen as max_prob_rate */ - if (mrs->probability >= MINSTREL_FRAC(95, 100)) { - if (mrs->cur_tp >= mi->r[tmp_prob_rate].stats.cur_tp) + if (mrs->prob_ewma >= MINSTREL_FRAC(95, 100)) { + tmp_cur_tp = minstrel_get_tp_avg(mr, mrs->prob_ewma); + tmp_prob_tp = minstrel_get_tp_avg(&mi->r[tmp_prob_rate], + tmp_mrs->prob_ewma); + if (tmp_cur_tp >= tmp_prob_tp) tmp_prob_rate = i; } else { - if (mrs->probability >= mi->r[tmp_prob_rate].stats.probability) + if (mrs->prob_ewma >= tmp_mrs->prob_ewma) tmp_prob_rate = i; } } @@ -215,7 +254,7 @@ minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi) #endif /* Reset update timer */ - mi->stats_update = jiffies; + mi->last_stats_update = jiffies; minstrel_update_rates(mp, mi); } @@ -253,7 +292,7 @@ minstrel_tx_status(void *priv, struct ieee80211_supported_band *sband, if (mi->sample_deferred > 0) mi->sample_deferred--; - if (time_after(jiffies, mi->stats_update + + if (time_after(jiffies, mi->last_stats_update + (mp->update_interval * HZ) / 1000)) minstrel_update_stats(mp, mi); } @@ -373,7 +412,7 @@ minstrel_get_rate(void *priv, struct ieee80211_sta *sta, rate++; mi->sample_deferred++; } else { - if (!msr->sample_limit != 0) + if (!msr->sample_limit) return; mi->sample_packets++; @@ -385,7 +424,7 @@ minstrel_get_rate(void *priv, struct ieee80211_sta *sta, * has a probability of >95%, we shouldn't be attempting * to use it, as this only wastes precious airtime */ if (!mrr_capable && - (mi->r[ndx].stats.probability > MINSTREL_FRAC(95, 100))) + (mi->r[ndx].stats.prob_ewma > MINSTREL_FRAC(95, 100))) return; mi->prev_sample = true; @@ -519,7 +558,7 @@ minstrel_rate_init(void *priv, struct ieee80211_supported_band *sband, } mi->n_rates = n; - mi->stats_update = jiffies; + mi->last_stats_update = jiffies; init_sample_table(mi); minstrel_update_rates(mp, mi); @@ -553,7 +592,7 @@ minstrel_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp) if (!mi->sample_table) goto error1; - mi->stats_update = jiffies; + mi->last_stats_update = jiffies; return mi; error1: @@ -663,12 +702,18 @@ minstrel_free(void *priv) static u32 minstrel_get_expected_throughput(void *priv_sta) { struct minstrel_sta_info *mi = priv_sta; + struct minstrel_rate_stats *tmp_mrs; int idx = mi->max_tp_rate[0]; + int tmp_cur_tp; /* convert pkt per sec in kbps (1200 is the average pkt size used for * computing cur_tp */ - return MINSTREL_TRUNC(mi->r[idx].stats.cur_tp) * 1200 * 8 / 1024; + tmp_mrs = &mi->r[idx].stats; + tmp_cur_tp = minstrel_get_tp_avg(&mi->r[idx], tmp_mrs->prob_ewma); + tmp_cur_tp = tmp_cur_tp * 1200 * 8 / 1024; + + return tmp_cur_tp; } const struct rate_control_ops mac80211_minstrel = { |