From: Felix Fietkau <nbd@nbd.name>
To: linux-wireless@vger.kernel.org
Cc: johannes@sipsolutions.net
Subject: [PATCH 3/4] wifi: mac80211: add AQL support for broadcast packets
Date: Mon, 23 Mar 2026 10:19:53 +0000 [thread overview]
Message-ID: <20260323101954.874299-3-nbd@nbd.name> (raw)
In-Reply-To: <20260323101954.874299-1-nbd@nbd.name>
Excessive broadcast traffic with little competing unicast traffic can easily
flood hardware queues, leading to throughput issues. Additionally, filling
the hardware queues with too many packets breaks FQ for broadcast data.
Fix this by enabling AQL for broadcast packets.
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
include/net/cfg80211.h | 1 +
include/net/mac80211.h | 2 +-
net/mac80211/debugfs.c | 13 ++++++++--
net/mac80211/ieee80211_i.h | 2 ++
net/mac80211/main.c | 1 +
net/mac80211/sta_info.c | 17 ++++++++++++-
net/mac80211/sta_info.h | 3 ++-
net/mac80211/status.c | 5 ++--
net/mac80211/tx.c | 52 ++++++++++++++++++++------------------
9 files changed, 65 insertions(+), 31 deletions(-)
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 8cd870ece351..2607b800ada5 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -3656,6 +3656,7 @@ enum wiphy_params_flags {
/* The per TXQ device queue limit in airtime */
#define IEEE80211_DEFAULT_AQL_TXQ_LIMIT_L 5000
#define IEEE80211_DEFAULT_AQL_TXQ_LIMIT_H 12000
+#define IEEE80211_DEFAULT_AQL_TXQ_LIMIT_BC 50000
/* The per interface airtime threshold to switch to lower queue limit */
#define IEEE80211_AQL_THRESHOLD 24000
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 9cc482191ab9..310546d4fca6 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1252,8 +1252,8 @@ struct ieee80211_tx_info {
status_data_idr:1,
status_data:13,
hw_queue:4,
+ tx_time_mc:1,
tx_time_est:10;
- /* 1 free bit */
union {
struct {
diff --git a/net/mac80211/debugfs.c b/net/mac80211/debugfs.c
index e8d0a8b71d59..a97d146f1445 100644
--- a/net/mac80211/debugfs.c
+++ b/net/mac80211/debugfs.c
@@ -210,11 +210,13 @@ static ssize_t aql_pending_read(struct file *file,
"VI %u us\n"
"BE %u us\n"
"BK %u us\n"
+ "BC/MC %u us\n"
"total %u us\n",
atomic_read(&local->aql_ac_pending_airtime[IEEE80211_AC_VO]),
atomic_read(&local->aql_ac_pending_airtime[IEEE80211_AC_VI]),
atomic_read(&local->aql_ac_pending_airtime[IEEE80211_AC_BE]),
atomic_read(&local->aql_ac_pending_airtime[IEEE80211_AC_BK]),
+ atomic_read(&local->aql_bc_pending_airtime),
atomic_read(&local->aql_total_pending_airtime));
return simple_read_from_buffer(user_buf, count, ppos,
buf, len);
@@ -239,7 +241,8 @@ static ssize_t aql_txq_limit_read(struct file *file,
"VO %u %u\n"
"VI %u %u\n"
"BE %u %u\n"
- "BK %u %u\n",
+ "BK %u %u\n"
+ "BC/MC %u\n",
local->aql_txq_limit_low[IEEE80211_AC_VO],
local->aql_txq_limit_high[IEEE80211_AC_VO],
local->aql_txq_limit_low[IEEE80211_AC_VI],
@@ -247,7 +250,8 @@ static ssize_t aql_txq_limit_read(struct file *file,
local->aql_txq_limit_low[IEEE80211_AC_BE],
local->aql_txq_limit_high[IEEE80211_AC_BE],
local->aql_txq_limit_low[IEEE80211_AC_BK],
- local->aql_txq_limit_high[IEEE80211_AC_BK]);
+ local->aql_txq_limit_high[IEEE80211_AC_BK],
+ local->aql_txq_limit_bc);
return simple_read_from_buffer(user_buf, count, ppos,
buf, len);
}
@@ -273,6 +277,11 @@ static ssize_t aql_txq_limit_write(struct file *file,
else
buf[count] = '\0';
+ if (sscanf(buf, "mcast %u", &q_limit_low) == 1) {
+ local->aql_txq_limit_bc = q_limit_low;
+ return count;
+ }
+
if (sscanf(buf, "%u %u %u", &ac, &q_limit_low, &q_limit_high) != 3)
return -EINVAL;
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index b0dc93399e95..7ce39d19274f 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1427,10 +1427,12 @@ struct ieee80211_local {
spinlock_t handle_wake_tx_queue_lock;
u16 airtime_flags;
+ u32 aql_txq_limit_bc;
u32 aql_txq_limit_low[IEEE80211_NUM_ACS];
u32 aql_txq_limit_high[IEEE80211_NUM_ACS];
u32 aql_threshold;
atomic_t aql_total_pending_airtime;
+ atomic_t aql_bc_pending_airtime;
atomic_t aql_ac_pending_airtime[IEEE80211_NUM_ACS];
const struct ieee80211_ops *ops;
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index d1bb6353908d..a05e3f6cb43c 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -984,6 +984,7 @@ struct ieee80211_hw *ieee80211_alloc_hw_nm(size_t priv_data_len,
spin_lock_init(&local->rx_path_lock);
spin_lock_init(&local->queue_stop_reason_lock);
+ local->aql_txq_limit_bc = IEEE80211_DEFAULT_AQL_TXQ_LIMIT_BC;
for (i = 0; i < IEEE80211_NUM_ACS; i++) {
INIT_LIST_HEAD(&local->active_txqs[i]);
spin_lock_init(&local->active_txq_lock[i]);
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 912f00d905b8..12696c242537 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -2443,13 +2443,28 @@ EXPORT_SYMBOL(ieee80211_sta_recalc_aggregates);
void ieee80211_sta_update_pending_airtime(struct ieee80211_local *local,
struct sta_info *sta, u8 ac,
- u16 tx_airtime, bool tx_completed)
+ u16 tx_airtime, bool tx_completed,
+ bool mcast)
{
int tx_pending;
if (!wiphy_ext_feature_isset(local->hw.wiphy, NL80211_EXT_FEATURE_AQL))
return;
+ if (mcast) {
+ if (!tx_completed) {
+ atomic_add(tx_airtime, &local->aql_bc_pending_airtime);
+ return;
+ }
+
+ tx_pending = atomic_sub_return(tx_airtime,
+ &local->aql_bc_pending_airtime);
+ if (tx_pending < 0)
+ atomic_cmpxchg(&local->aql_bc_pending_airtime,
+ tx_pending, 0);
+ return;
+ }
+
if (!tx_completed) {
if (sta)
atomic_add(tx_airtime,
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 58ccbea7f6f6..eea7eff35463 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -147,7 +147,8 @@ struct airtime_info {
void ieee80211_sta_update_pending_airtime(struct ieee80211_local *local,
struct sta_info *sta, u8 ac,
- u16 tx_airtime, bool tx_completed);
+ u16 tx_airtime, bool tx_completed,
+ bool mcast);
struct sta_info;
diff --git a/net/mac80211/status.c b/net/mac80211/status.c
index 4b38aa0e902a..ccc37c4d843d 100644
--- a/net/mac80211/status.c
+++ b/net/mac80211/status.c
@@ -751,7 +751,7 @@ static void ieee80211_report_used_skb(struct ieee80211_local *local,
ieee80211_sta_update_pending_airtime(local, sta,
skb_get_queue_mapping(skb),
tx_time_est,
- true);
+ true, info->tx_time_mc);
rcu_read_unlock();
}
@@ -1160,10 +1160,11 @@ void ieee80211_tx_status_ext(struct ieee80211_hw *hw,
/* Do this here to avoid the expensive lookup of the sta
* in ieee80211_report_used_skb().
*/
+ bool mcast = IEEE80211_SKB_CB(skb)->tx_time_mc;
ieee80211_sta_update_pending_airtime(local, sta,
skb_get_queue_mapping(skb),
tx_time_est,
- true);
+ true, mcast);
ieee80211_info_set_tx_time_est(IEEE80211_SKB_CB(skb), 0);
}
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 3844c7fbb8a8..04a3ea9beae5 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -3987,20 +3987,20 @@ struct sk_buff *ieee80211_tx_dequeue(struct ieee80211_hw *hw,
encap_out:
info->control.vif = vif;
- if (tx.sta &&
- wiphy_ext_feature_isset(local->hw.wiphy, NL80211_EXT_FEATURE_AQL)) {
- bool ampdu = txq->ac != IEEE80211_AC_VO;
+ if (wiphy_ext_feature_isset(local->hw.wiphy, NL80211_EXT_FEATURE_AQL)) {
+ bool ampdu = txq->sta && txq->ac != IEEE80211_AC_VO;
u32 airtime;
airtime = ieee80211_calc_expected_tx_airtime(hw, vif, txq->sta,
skb->len, ampdu);
- if (airtime) {
- airtime = ieee80211_info_set_tx_time_est(info, airtime);
- ieee80211_sta_update_pending_airtime(local, tx.sta,
- txq->ac,
- airtime,
- false);
- }
+ if (!airtime)
+ return skb;
+
+ airtime = ieee80211_info_set_tx_time_est(info, airtime);
+ info->tx_time_mc = !tx.sta;
+ ieee80211_sta_update_pending_airtime(local, tx.sta, txq->ac,
+ airtime, false,
+ info->tx_time_mc);
}
return skb;
@@ -4052,6 +4052,7 @@ struct ieee80211_txq *ieee80211_next_txq(struct ieee80211_hw *hw, u8 ac)
struct ieee80211_txq *ret = NULL;
struct txq_info *txqi = NULL, *head = NULL;
bool found_eligible_txq = false;
+ bool aql_check;
spin_lock_bh(&local->active_txq_lock[ac]);
@@ -4075,26 +4076,28 @@ struct ieee80211_txq *ieee80211_next_txq(struct ieee80211_hw *hw, u8 ac)
if (!head)
head = txqi;
+ aql_check = ieee80211_txq_airtime_check(hw, &txqi->txq);
+ if (aql_check)
+ found_eligible_txq = true;
+
if (txqi->txq.sta) {
struct sta_info *sta = container_of(txqi->txq.sta,
struct sta_info, sta);
- bool aql_check = ieee80211_txq_airtime_check(hw, &txqi->txq);
- s32 deficit = ieee80211_sta_deficit(sta, txqi->txq.ac);
- if (aql_check)
- found_eligible_txq = true;
-
- if (deficit < 0)
+ if (ieee80211_sta_deficit(sta, txqi->txq.ac) < 0) {
sta->airtime[txqi->txq.ac].deficit +=
sta->airtime_weight;
- if (deficit < 0 || !aql_check) {
- list_move_tail(&txqi->schedule_order,
- &local->active_txqs[txqi->txq.ac]);
- goto begin;
+ aql_check = false;
}
}
+ if (!aql_check) {
+ list_move_tail(&txqi->schedule_order,
+ &local->active_txqs[txqi->txq.ac]);
+ goto begin;
+ }
+
if (txqi->schedule_round == local->schedule_round[ac])
goto out;
@@ -4161,7 +4164,8 @@ bool ieee80211_txq_airtime_check(struct ieee80211_hw *hw,
return true;
if (!txq->sta)
- return true;
+ return atomic_read(&local->aql_bc_pending_airtime) <
+ local->aql_txq_limit_bc;
if (unlikely(txq->tid == IEEE80211_NUM_TIDS))
return true;
@@ -4210,15 +4214,15 @@ bool ieee80211_txq_may_transmit(struct ieee80211_hw *hw,
spin_lock_bh(&local->active_txq_lock[ac]);
- if (!txqi->txq.sta)
- goto out;
-
if (list_empty(&txqi->schedule_order))
goto out;
if (!ieee80211_txq_schedule_airtime_check(local, ac))
goto out;
+ if (!txqi->txq.sta)
+ goto out;
+
list_for_each_entry_safe(iter, tmp, &local->active_txqs[ac],
schedule_order) {
if (iter == txqi)
--
2.51.0
next prev parent reply other threads:[~2026-03-23 10:19 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-23 10:19 [PATCH 1/4] wifi: mac80211: factor out part of ieee80211_calc_expected_tx_airtime Felix Fietkau
2026-03-23 10:19 ` [PATCH 2/4] wifi: mac80211: estimate expected throughput if not provided by driver/rc Felix Fietkau
2026-03-23 10:35 ` Johannes Berg
2026-03-23 10:19 ` Felix Fietkau [this message]
2026-03-23 10:38 ` [PATCH 3/4] wifi: mac80211: add AQL support for broadcast packets Johannes Berg
2026-03-23 10:19 ` [PATCH 4/4] wifi: mac80211: add ieee80211_txq_aql_pending() Felix Fietkau
2026-03-23 10:39 ` Johannes Berg
2026-03-23 10:43 ` Felix Fietkau
2026-03-23 10:55 ` Johannes Berg
2026-03-23 16:00 ` [PATCH 1/4] wifi: mac80211: factor out part of ieee80211_calc_expected_tx_airtime Pablo MARTIN-GOMEZ
2026-03-25 3:58 ` Felix Fietkau
2026-03-25 11:21 ` Pablo MARTIN-GOMEZ
2026-03-25 11:41 ` Felix Fietkau
2026-03-25 13:05 ` Pablo MARTIN-GOMEZ
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