package/kernel/mac80211/patches/subsys/333-mac80211-keep-recently-active-tx-queues-in-schedulin.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Date: Mon, 20 Jun 2022 20:52:50 +0200
   3 Subject: [PATCH] mac80211: keep recently active tx queues in scheduling
   4  list
   5
   6 This allows proper deficit accounting to ensure that they don't carry their
   7 deficit until the next time they become active
   8
   9 Signed-off-by: Felix Fietkau <nbd@nbd.name>
  10 ---
  11
  12 --- a/net/mac80211/ieee80211_i.h
  13 +++ b/net/mac80211/ieee80211_i.h
  14 @@ -83,6 +83,13 @@ extern const u8 ieee80211_ac_to_qos_mask
  15
  16  #define IEEE80211_MAX_NAN_INSTANCE_ID 255
  17
  18 +
  19 +/*
  20 + * Keep a station's queues on the active list for deficit accounting purposes
  21 + * if it was active or queued during the last 100ms
  22 + */
  23 +#define AIRTIME_ACTIVE_DURATION (HZ / 10)
  24 +
  25  struct ieee80211_bss {
  26         u32 device_ts_beacon, device_ts_presp;
  27
  28 --- a/net/mac80211/sta_info.h
  29 +++ b/net/mac80211/sta_info.h
  30 @@ -138,6 +138,7 @@ enum ieee80211_agg_stop_reason {
  31  struct airtime_info {
  32         u64 rx_airtime;
  33         u64 tx_airtime;
  34 +       u32 last_active;
  35         s32 deficit;
  36         atomic_t aql_tx_pending; /* Estimated airtime for frames pending */
  37         u32 aql_limit_low;
  38 --- a/net/mac80211/tx.c
  39 +++ b/net/mac80211/tx.c
  40 @@ -3824,6 +3824,36 @@ static inline s32 ieee80211_sta_deficit(
  41         return air_info->deficit - atomic_read(&air_info->aql_tx_pending);
  42  }
  43
  44 +static void
  45 +ieee80211_txq_set_active(struct txq_info *txqi)
  46 +{
  47 +       struct sta_info *sta;
  48 +
  49 +       if (!txqi->txq.sta)
  50 +               return;
  51 +
  52 +       sta = container_of(txqi->txq.sta, struct sta_info, sta);
  53 +       sta->airtime[txqi->txq.ac].last_active = (u32)jiffies;
  54 +}
  55 +
  56 +static bool
  57 +ieee80211_txq_keep_active(struct txq_info *txqi)
  58 +{
  59 +       struct sta_info *sta;
  60 +       u32 diff;
  61 +
  62 +       if (!txqi->txq.sta)
  63 +               return false;
  64 +
  65 +       sta = container_of(txqi->txq.sta, struct sta_info, sta);
  66 +       if (ieee80211_sta_deficit(sta, txqi->txq.ac) >= 0)
  67 +               return false;
  68 +
  69 +       diff = (u32)jiffies - sta->airtime[txqi->txq.ac].last_active;
  70 +
  71 +       return diff <= AIRTIME_ACTIVE_DURATION;
  72 +}
  73 +
  74  struct ieee80211_txq *ieee80211_next_txq(struct ieee80211_hw *hw, u8 ac)
  75  {
  76         struct ieee80211_local *local = hw_to_local(hw);
  77 @@ -3870,7 +3900,6 @@ struct ieee80211_txq *ieee80211_next_txq
  78                 }
  79         }
  80
  81 -
  82         if (txqi->schedule_round == local->schedule_round[ac])
  83                 goto out;
  84
  85 @@ -3890,12 +3919,13 @@ void __ieee80211_schedule_txq(struct iee
  86  {
  87         struct ieee80211_local *local = hw_to_local(hw);
  88         struct txq_info *txqi = to_txq_info(txq);
  89 +       bool has_queue;
  90
  91         spin_lock_bh(&local->active_txq_lock[txq->ac]);
  92
  93 +       has_queue = force || txq_has_queue(txq);
  94         if (list_empty(&txqi->schedule_order) &&
  95 -           (force || !skb_queue_empty(&txqi->frags) ||
  96 -            txqi->tin.backlog_packets)) {
  97 +           (has_queue || ieee80211_txq_keep_active(txqi))) {
  98                 /* If airtime accounting is active, always enqueue STAs at the
  99                  * head of the list to ensure that they only get moved to the
 100                  * back by the airtime DRR scheduler once they have a negative
 101 @@ -3903,7 +3933,7 @@ void __ieee80211_schedule_txq(struct iee
 102                  * get immediately moved to the back of the list on the next
 103                  * call to ieee80211_next_txq().
 104                  */
 105 -               if (txqi->txq.sta && local->airtime_flags &&
 106 +               if (txqi->txq.sta && local->airtime_flags && has_queue &&
 107                     wiphy_ext_feature_isset(local->hw.wiphy,
 108                                             NL80211_EXT_FEATURE_AIRTIME_FAIRNESS))
 109                         list_add(&txqi->schedule_order,
 110 @@ -3911,6 +3941,8 @@ void __ieee80211_schedule_txq(struct iee
 111                 else
 112                         list_add_tail(&txqi->schedule_order,
 113                                       &local->active_txqs[txq->ac]);
 114 +               if (has_queue)
 115 +                       ieee80211_txq_set_active(txqi);
 116         }
 117
 118         spin_unlock_bh(&local->active_txq_lock[txq->ac]);