package/kernel/mac80211/patches/subsys/305-mac80211-increase-quantum-for-airtime-scheduler.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Date: Sun, 26 Jun 2022 11:43:25 +0200
   3 Subject: [PATCH] mac80211: increase quantum for airtime scheduler
   4
   5 Given the typical AQL budget and queue length, a quantum of 256 with the
   6 default station weight often requires iterating over all queues frequently,
   7 until one of them becomes eligible.
   8 Improve performance by using 8 times station weight as scheduler quantum
   9
  10 Signed-off-by: Felix Fietkau <nbd@nbd.name>
  11 ---
  12
  13 --- a/net/mac80211/ieee80211_i.h
  14 +++ b/net/mac80211/ieee80211_i.h
  15 @@ -92,6 +92,8 @@ extern const u8 ieee80211_ac_to_qos_mask
  16   */
  17  #define AIRTIME_ACTIVE_DURATION (HZ / 10)
  18
  19 +#define AIRTIME_QUANTUM_SHIFT  3
  20 +
  21  struct ieee80211_bss {
  22         u32 device_ts_beacon, device_ts_presp;
  23
  24 --- a/net/mac80211/tx.c
  25 +++ b/net/mac80211/tx.c
  26 @@ -4060,7 +4060,7 @@ struct ieee80211_txq *ieee80211_next_txq
  27
  28                 if (deficit < 0)
  29                         sta->airtime[txqi->txq.ac].deficit +=
  30 -                               sta->airtime_weight;
  31 +                               sta->airtime_weight << AIRTIME_QUANTUM_SHIFT;
  32
  33                 if (deficit < 0 || !aql_check) {
  34                         list_move_tail(&txqi->schedule_order,
  35 @@ -4203,7 +4203,8 @@ bool ieee80211_txq_may_transmit(struct i
  36                 }
  37                 sta = container_of(iter->txq.sta, struct sta_info, sta);
  38                 if (ieee80211_sta_deficit(sta, ac) < 0)
  39 -                       sta->airtime[ac].deficit += sta->airtime_weight;
  40 +                       sta->airtime[ac].deficit += sta->airtime_weight <<
  41 +                                                   AIRTIME_QUANTUM_SHIFT;
  42                 list_move_tail(&iter->schedule_order, &local->active_txqs[ac]);
  43         }
  44
  45 @@ -4211,7 +4212,7 @@ bool ieee80211_txq_may_transmit(struct i
  46         if (sta->airtime[ac].deficit >= 0)
  47                 goto out;
  48
  49 -       sta->airtime[ac].deficit += sta->airtime_weight;
  50 +       sta->airtime[ac].deficit += sta->airtime_weight << AIRTIME_QUANTUM_SHIFT;
  51         list_move_tail(&txqi->schedule_order, &local->active_txqs[ac]);
  52         spin_unlock_bh(&local->active_txq_lock[ac]);
  53