From 1e9c27df7b4a59f2269b9c88a5cef1e9018e77f6 Mon Sep 17 00:00:00 2001 From: Thomas Huehn Date: Mon, 4 Mar 2013 23:30:04 +0100 Subject: mac80211: extend minstrel's rate sampling to avoid unsampled rates Minstrel's decision which rate should be directly sampled within the 1st mrr stage is limited to such rates faster than the current max throughput rate. All rates below the current max. throughput rate are indirectly sampled via the 2nd mrr stage. This approach leads to deprecated per rate statistics and therfore a deprecated mrr chain setup. This patch uses the sampling approach from minstrel_ht. A counter is added to sum all indirect sample attempts per rate. After 20 indirect sampling attempts the rate is directly sampled within the 1st mrr stage. Therefore more up-to-date statistics for all rates are maintained and used to setup the mrr chain. Acked-by: Felix Fietkau Signed-off-by: Thomas Huehn Signed-off-by: Johannes Berg --- net/mac80211/rc80211_minstrel.c | 13 +++++++++---- net/mac80211/rc80211_minstrel.h | 1 + 2 files changed, 10 insertions(+), 4 deletions(-) diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c index 152bb0e37865..aa59f2962c38 100644 --- a/net/mac80211/rc80211_minstrel.c +++ b/net/mac80211/rc80211_minstrel.c @@ -85,7 +85,8 @@ minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi) if (!usecs) usecs = 1000000; - if (mr->attempts) { + if (unlikely(mr->attempts > 0)) { + mr->sample_skipped = 0; mr->cur_prob = MINSTREL_FRAC(mr->success, mr->attempts); mr->succ_hist += mr->success; mr->att_hist += mr->attempts; @@ -93,7 +94,8 @@ minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi) mr->cur_prob, EWMA_LEVEL); mr->cur_tp = mr->probability * (1000000 / usecs); - } + } else + mr->sample_skipped++; mr->last_success = mr->success; mr->last_attempts = mr->attempts; @@ -282,9 +284,12 @@ minstrel_get_rate(void *priv, struct ieee80211_sta *sta, rate_sampling = true; /* Decide if direct ( 1st mrr stage) or indirect (2nd mrr stage) - * rate sampling method should be used */ + * rate sampling method should be used. + * Respect such rates that are not sampled for 20 interations. + */ if (mrr_capable && - msr->perfect_tx_time > mi->r[ndx].perfect_tx_time) + msr->perfect_tx_time > mi->r[ndx].perfect_tx_time && + msr->sample_skipped < 20) indirect_rate_sampling = true; if (!indirect_rate_sampling) { diff --git a/net/mac80211/rc80211_minstrel.h b/net/mac80211/rc80211_minstrel.h index 5fb5cb81d0da..200b7e3632da 100644 --- a/net/mac80211/rc80211_minstrel.h +++ b/net/mac80211/rc80211_minstrel.h @@ -43,6 +43,7 @@ struct minstrel_rate { u32 attempts; u32 last_attempts; u32 last_success; + u8 sample_skipped; /* parts per thousand */ u32 cur_prob; -- cgit v1.2.3