Return-path: Received: from nbd.name ([46.4.11.11]:56821 "EHLO nbd.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753277Ab3CCLtz (ORCPT ); Sun, 3 Mar 2013 06:49:55 -0500 From: Felix Fietkau To: linux-wireless@vger.kernel.org Cc: johannes@sipsolutions.net Subject: [PATCH 1/2] mac80211/minstrel_ht: increase sampling frequency of some slower rates Date: Sun, 3 Mar 2013 12:49:51 +0100 Message-Id: <1362311392-83648-1-git-send-email-nbd@openwrt.org> (sfid-20130303_125004_774796_2DABCAF2) Sender: linux-wireless-owner@vger.kernel.org List-ID: If a rate is below the max_tp_rate, sample it frequently if: - it is above max_tp_rate2, or - it is above max_prob_rate and is a candidate for max_prob_rate (has fewer streams than max_tp_rate). This helps the retry chain recover more quickly from bad statistics caused by collisions or interference, and slightly reduces throughput fluctuations with higher rates. Signed-off-by: Felix Fietkau --- net/mac80211/rc80211_minstrel_ht.c | 20 ++++++++++++-------- net/mac80211/rc80211_minstrel_ht.h | 1 + 2 files changed, 13 insertions(+), 8 deletions(-) diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c index 4d35bc5..1b69924 100644 --- a/net/mac80211/rc80211_minstrel_ht.c +++ b/net/mac80211/rc80211_minstrel_ht.c @@ -246,7 +246,6 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) struct minstrel_rate_stats *mr; int cur_prob, cur_prob_tp, cur_tp, cur_tp2; int group, i, index; - int prob_max_streams = 1; if (mi->ampdu_packets > 0) { mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len, @@ -330,7 +329,7 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) cur_tp2 = cur_tp; mi->max_tp_rate = mg->max_tp_rate; cur_tp = mr->cur_tp; - prob_max_streams = minstrel_mcs_groups[group].streams - 1; + mi->max_prob_streams = minstrel_mcs_groups[group].streams - 1; } mr = minstrel_get_ratestats(mi, mg->max_tp_rate2); @@ -340,8 +339,8 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) } } - if (prob_max_streams < 1) - prob_max_streams = 1; + if (mi->max_prob_streams < 1) + mi->max_prob_streams = 1; for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) { mg = &mi->groups[group]; @@ -349,7 +348,7 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) continue; mr = minstrel_get_ratestats(mi, mg->max_prob_rate); if (cur_prob_tp < mr->cur_tp && - minstrel_mcs_groups[group].streams <= prob_max_streams) { + minstrel_mcs_groups[group].streams <= mi->max_prob_streams) { mi->max_prob_rate = mg->max_prob_rate; cur_prob = mr->cur_prob; cur_prob_tp = mr->cur_tp; @@ -630,6 +629,7 @@ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) { struct minstrel_rate_stats *mr; struct minstrel_mcs_group_data *mg; + unsigned int sample_dur, sample_group; int sample_idx = 0; if (mi->sample_wait > 0) { @@ -644,7 +644,8 @@ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) mg = &mi->groups[mi->sample_group]; sample_idx = sample_table[mg->column][mg->index]; mr = &mg->rates[sample_idx]; - sample_idx += mi->sample_group * MCS_GROUP_RATES; + sample_group = mi->sample_group; + sample_idx += sample_group * MCS_GROUP_RATES; minstrel_next_sample_idx(mi); /* @@ -665,8 +666,11 @@ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) * 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)) { + sample_dur = minstrel_get_duration(sample_idx); + if (sample_dur >= minstrel_get_duration(mi->max_tp_rate2) && + (mi->max_prob_streams < + minstrel_mcs_groups[sample_group].streams || + sample_dur >= minstrel_get_duration(mi->max_prob_rate))) { if (mr->sample_skipped < 20) return -1; diff --git a/net/mac80211/rc80211_minstrel_ht.h b/net/mac80211/rc80211_minstrel_ht.h index 302dbd5..c6d6a0d 100644 --- a/net/mac80211/rc80211_minstrel_ht.h +++ b/net/mac80211/rc80211_minstrel_ht.h @@ -85,6 +85,7 @@ struct minstrel_ht_sta { /* best probability rate */ unsigned int max_prob_rate; + unsigned int max_prob_streams; /* time of last status update */ unsigned long stats_update; -- 1.8.0.2