From 3ff901cb5df1d2102e924d75d91347a2a3070fa5 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Fri, 24 Jul 2020 20:28:16 +0200 Subject: [PATCH] mac80211: improve AQL tx airtime estimation AQL does not take into account that most HT/VHT/HE traffic is A-MPDU aggregated. Because of that, the per-packet airtime overhead is vastly overestimated. Improve it by assuming an average aggregation length of 16 for non-legacy traffic if not using the VO AC queue. This should improve performance with high data rates, especially with multiple stations Signed-off-by: Felix Fietkau Link: https://lore.kernel.org/r/20200724182816.18678-1-nbd@nbd.name Signed-off-by: Johannes Berg --- net/mac80211/airtime.c | 24 ++++++++++++++++++++---- net/mac80211/ieee80211_i.h | 2 +- net/mac80211/tx.c | 3 ++- 3 files changed, 23 insertions(+), 6 deletions(-) diff --git a/net/mac80211/airtime.c b/net/mac80211/airtime.c index 9fc2968856c0..366f76c9003d 100644 --- a/net/mac80211/airtime.c +++ b/net/mac80211/airtime.c @@ -551,7 +551,7 @@ EXPORT_SYMBOL_GPL(ieee80211_calc_tx_airtime); u32 ieee80211_calc_expected_tx_airtime(struct ieee80211_hw *hw, struct ieee80211_vif *vif, struct ieee80211_sta *pubsta, - int len) + int len, bool ampdu) { struct ieee80211_supported_band *sband; struct ieee80211_chanctx_conf *conf; @@ -572,10 +572,26 @@ u32 ieee80211_calc_expected_tx_airtime(struct ieee80211_hw *hw, if (pubsta) { struct sta_info *sta = container_of(pubsta, struct sta_info, sta); + struct ieee80211_tx_rate *rate = &sta->tx_stats.last_rate; + u32 airtime; - return ieee80211_calc_tx_airtime_rate(hw, - &sta->tx_stats.last_rate, - band, len); + if (!(rate->flags & (IEEE80211_TX_RC_VHT_MCS | + IEEE80211_TX_RC_MCS))) + ampdu = false; + + /* + * Assume that HT/VHT transmission on any AC except VO will + * use aggregation. Since we don't have reliable reporting + * of aggregation length, assume an average of 16. + * This will not be very accurate, but much better than simply + * assuming un-aggregated tx. + */ + airtime = ieee80211_calc_tx_airtime_rate(hw, rate, band, + ampdu ? len * 16 : len); + if (ampdu) + airtime /= 16; + + return airtime; } if (!conf) diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index ec1a71ac65f2..28b154c6e72d 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -2290,7 +2290,7 @@ extern const struct ethtool_ops ieee80211_ethtool_ops; u32 ieee80211_calc_expected_tx_airtime(struct ieee80211_hw *hw, struct ieee80211_vif *vif, struct ieee80211_sta *pubsta, - int len); + int len, bool ampdu); #ifdef CONFIG_MAC80211_NOINLINE #define debug_noinline noinline #else diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 0d0e901b1d4c..7c0abe477b03 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -3722,10 +3722,11 @@ encap_out: if (vif && wiphy_ext_feature_isset(local->hw.wiphy, NL80211_EXT_FEATURE_AQL)) { + bool ampdu = txq->ac != IEEE80211_AC_VO; u32 airtime; airtime = ieee80211_calc_expected_tx_airtime(hw, vif, txq->sta, - skb->len); + skb->len, ampdu); if (airtime) { airtime = ieee80211_info_set_tx_time_est(info, airtime); ieee80211_sta_update_pending_airtime(local, tx.sta,