mac80211: increase airtime scheduler quantum

improves performance by requiring fewer iterations over tx queues

Signed-off-by: Felix Fietkau <nbd@nbd.name>
This commit is contained in:
Felix Fietkau 2022-06-26 11:47:12 +02:00
parent 78b7be9f6c
commit 7bf5233a2a

View File

@ -0,0 +1,53 @@
From: Felix Fietkau <nbd@nbd.name>
Date: Sun, 26 Jun 2022 11:43:25 +0200
Subject: [PATCH] mac80211: increase quantum for airtime scheduler
Given the typical AQL budget and queue length, a quantum of 256 with the
default station weight often requires iterating over all queues frequently,
until one of them becomes eligible.
Improve performance by using 8 times station weight as scheduler quantum
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -90,6 +90,8 @@ extern const u8 ieee80211_ac_to_qos_mask
*/
#define AIRTIME_ACTIVE_DURATION (HZ / 10)
+#define AIRTIME_QUANTUM_SHIFT 3
+
struct ieee80211_bss {
u32 device_ts_beacon, device_ts_presp;
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -3894,7 +3894,7 @@ struct ieee80211_txq *ieee80211_next_txq
if (deficit < 0)
sta->airtime[txqi->txq.ac].deficit +=
- sta->airtime_weight;
+ sta->airtime_weight << AIRTIME_QUANTUM_SHIFT;
if (deficit < 0 || !aql_check) {
list_move_tail(&txqi->schedule_order,
@@ -4037,7 +4037,8 @@ bool ieee80211_txq_may_transmit(struct i
}
sta = container_of(iter->txq.sta, struct sta_info, sta);
if (ieee80211_sta_deficit(sta, ac) < 0)
- sta->airtime[ac].deficit += sta->airtime_weight;
+ sta->airtime[ac].deficit += sta->airtime_weight <<
+ AIRTIME_QUANTUM_SHIFT;
list_move_tail(&iter->schedule_order, &local->active_txqs[ac]);
}
@@ -4045,7 +4046,7 @@ bool ieee80211_txq_may_transmit(struct i
if (sta->airtime[ac].deficit >= 0)
goto out;
- sta->airtime[ac].deficit += sta->airtime_weight;
+ sta->airtime[ac].deficit += sta->airtime_weight << AIRTIME_QUANTUM_SHIFT;
list_move_tail(&txqi->schedule_order, &local->active_txqs[ac]);
spin_unlock_bh(&local->active_txq_lock[ac]);