package/kernel/mac80211/patches/subsys/332-v6.0-mac80211-consider-aql_tx_pending-when-checking-airti.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Date: Mon, 20 Jun 2022 14:59:09 +0200
   3 Subject: [PATCH] mac80211: consider aql_tx_pending when checking airtime
   4  deficit
   5
   6 When queueing packets for a station, deficit only gets added once the packets
   7 have been transmitted, which could be much later. During that time, a lot of
   8 temporary unfairness could happen, which could lead to bursty behavior.
   9 Fix this by subtracting the aql_tx_pending when checking the deficit in tx
  10 scheduling.
  11
  12 Signed-off-by: Felix Fietkau <nbd@nbd.name>
  13 ---
  14
  15 --- a/net/mac80211/tx.c
  16 +++ b/net/mac80211/tx.c
  17 @@ -3817,6 +3817,13 @@ out:
  18  }
  19  EXPORT_SYMBOL(ieee80211_tx_dequeue);
  20
  21 +static inline s32 ieee80211_sta_deficit(struct sta_info *sta, u8 ac)
  22 +{
  23 +       struct airtime_info *air_info = &sta->airtime[ac];
  24 +
  25 +       return air_info->deficit - atomic_read(&air_info->aql_tx_pending);
  26 +}
  27 +
  28  struct ieee80211_txq *ieee80211_next_txq(struct ieee80211_hw *hw, u8 ac)
  29  {
  30         struct ieee80211_local *local = hw_to_local(hw);
  31 @@ -3847,7 +3854,7 @@ struct ieee80211_txq *ieee80211_next_txq
  32                 struct sta_info *sta = container_of(txqi->txq.sta,
  33                                                     struct sta_info, sta);
  34                 bool aql_check = ieee80211_txq_airtime_check(hw, &txqi->txq);
  35 -               s32 deficit = sta->airtime[txqi->txq.ac].deficit;
  36 +               s32 deficit = ieee80211_sta_deficit(sta, txqi->txq.ac);
  37
  38                 if (aql_check)
  39                         found_eligible_txq = true;
  40 @@ -3972,7 +3979,7 @@ bool ieee80211_txq_may_transmit(struct i
  41                         continue;
  42                 }
  43                 sta = container_of(iter->txq.sta, struct sta_info, sta);
  44 -               if (sta->airtime[ac].deficit < 0)
  45 +               if (ieee80211_sta_deficit(sta, ac) < 0)
  46                         sta->airtime[ac].deficit += sta->airtime_weight;
  47                 list_move_tail(&iter->schedule_order, &local->active_txqs[ac]);
  48         }