Skip to content
Snippets Groups Projects
Unverified Commit ea5ebd9c authored by David Bauer's avatar David Bauer Committed by GitHub
Browse files

mac80211: add AQL support for broadcast packets (#3208)


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: default avatarFelix Fietkau <nbd@nbd.name>
Signed-off-by: default avatarDavid Bauer <mail@david-bauer.net>
parent 0bbe55ca
No related branches found
Tags experimental-2024-03-29-base
No related merge requests found
From: Felix Fietkau <nbd@nbd.name>
Date: Fri, 9 Feb 2024 20:47:39 +0100
Subject: mac80211: add AQL support for broadcast/multicast packets
Should improve performance/reliability with lots of mcast packets
Signed-off-by: Felix Fietkau <nbd@nbd.name>
(cherry picked from commit 95e633efbd1b4ffbbfc2d8abba2b05291f6e9903)
diff --git a/package/kernel/mac80211/patches/subsys/330-mac80211-add-AQL-support-for-broadcast-packets.patch b/package/kernel/mac80211/patches/subsys/330-mac80211-add-AQL-support-for-broadcast-packets.patch
new file mode 100644
index 0000000000000000000000000000000000000000..9095f4916f1a80fee004bbef4d37c26899969f5a
--- /dev/null
+++ b/package/kernel/mac80211/patches/subsys/330-mac80211-add-AQL-support-for-broadcast-packets.patch
@@ -0,0 +1,226 @@
+From: Felix Fietkau <nbd@nbd.name>
+Date: Fri, 9 Feb 2024 19:43:40 +0100
+Subject: [PATCH] mac80211: add AQL support for broadcast packets
+
+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>
+---
+
+--- a/include/net/cfg80211.h
++++ b/include/net/cfg80211.h
+@@ -3158,6 +3158,7 @@ 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
+--- a/net/mac80211/debugfs.c
++++ b/net/mac80211/debugfs.c
+@@ -215,11 +215,13 @@ static ssize_t aql_pending_read(struct f
+ "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);
+@@ -245,7 +247,8 @@ static ssize_t aql_txq_limit_read(struct
+ "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],
+@@ -253,7 +256,8 @@ static ssize_t aql_txq_limit_read(struct
+ 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);
+ }
+@@ -279,6 +283,11 @@ static ssize_t aql_txq_limit_write(struc
+ 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;
+
+--- a/net/mac80211/ieee80211_i.h
++++ b/net/mac80211/ieee80211_i.h
+@@ -1300,10 +1300,12 @@ struct ieee80211_local {
+ u16 schedule_round[IEEE80211_NUM_ACS];
+
+ 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;
+--- a/net/mac80211/main.c
++++ b/net/mac80211/main.c
+@@ -789,6 +789,7 @@ struct ieee80211_hw *ieee80211_alloc_hw_
+ 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]);
+--- a/net/mac80211/sta_info.c
++++ b/net/mac80211/sta_info.c
+@@ -2166,28 +2166,27 @@ void ieee80211_sta_update_pending_airtim
+ struct sta_info *sta, u8 ac,
+ u16 tx_airtime, bool tx_completed)
+ {
++ atomic_t *counter;
+ int tx_pending;
+
+ if (!wiphy_ext_feature_isset(local->hw.wiphy, NL80211_EXT_FEATURE_AQL))
+ return;
+
+- if (!tx_completed) {
+- if (sta)
+- atomic_add(tx_airtime,
+- &sta->airtime[ac].aql_tx_pending);
++ if (sta)
++ counter = &sta->airtime[ac].aql_tx_pending;
++ else
++ counter = &local->aql_bc_pending_airtime;
+
++ if (!tx_completed) {
++ atomic_add(tx_airtime, counter);
+ atomic_add(tx_airtime, &local->aql_total_pending_airtime);
+ atomic_add(tx_airtime, &local->aql_ac_pending_airtime[ac]);
+ return;
+ }
+
+- if (sta) {
+- tx_pending = atomic_sub_return(tx_airtime,
+- &sta->airtime[ac].aql_tx_pending);
+- if (tx_pending < 0)
+- atomic_cmpxchg(&sta->airtime[ac].aql_tx_pending,
+- tx_pending, 0);
+- }
++ tx_pending = atomic_sub_return(tx_airtime, counter);
++ if (tx_pending < 0)
++ atomic_cmpxchg(counter, tx_pending, 0);
+
+ atomic_sub(tx_airtime, &local->aql_total_pending_airtime);
+ tx_pending = atomic_sub_return(tx_airtime,
+--- a/net/mac80211/tx.c
++++ b/net/mac80211/tx.c
+@@ -3957,9 +3957,8 @@ begin:
+ encap_out:
+ IEEE80211_SKB_CB(skb)->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,
+@@ -4025,6 +4024,7 @@ struct ieee80211_txq *ieee80211_next_txq
+ 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]);
+
+@@ -4048,26 +4048,26 @@ struct ieee80211_txq *ieee80211_next_txq
+ 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 << AIRTIME_QUANTUM_SHIFT;
+-
+- 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;
+
+@@ -4132,7 +4132,8 @@ bool ieee80211_txq_airtime_check(struct
+ 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;
+@@ -4181,15 +4182,15 @@ bool ieee80211_txq_may_transmit(struct i
+
+ 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)
0% Loading or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment