2023-12-06 06:13:40

by Dmitry Antipov

Subject: [PATCH] wifi: mac80211: cleanup airtime arithmetic with ieee80211_sta_keep_active()

Prefer native jiffies-wide 'unsigned long' for the 'last_active' field of
'struct airtime_info' and introduce 'ieee80211_sta_keep_active()' for airtime
check in 'ieee80211_txq_keep_active()' and 'ieee80211_sta_register_airtime()'.

Signed-off-by: Dmitry Antipov <[email protected]>
---
net/mac80211/ieee80211_i.h | 13 ++++++++-----
net/mac80211/sta_info.c | 4 +---
net/mac80211/sta_info.h | 2 +-
net/mac80211/tx.c | 7 ++-----
4 files changed, 12 insertions(+), 14 deletions(-)

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 84df104f272b..d284dd570190 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -92,11 +92,14 @@ enum ieee80211_status_data {
IEEE80211_STATUS_SUBDATA_MASK = 0xff0,
};

-/*
- * Keep a station's queues on the active list for deficit accounting purposes
- * if it was active or queued during the last 100ms
- */
-#define AIRTIME_ACTIVE_DURATION (HZ / 10)
+static inline bool
+ieee80211_sta_keep_active(struct sta_info *sta, u8 ac)
+{
+ /* Keep a station's queues on the active list for deficit accounting
+ * purposes if it was active or queued during the last 100ms.
+ */
+ return time_before_eq(jiffies, sta->airtime[ac].last_active + HZ / 10);
+}

struct ieee80211_bss {
u32 device_ts_beacon, device_ts_presp;
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 0ba613dd1cc4..27ccdfea5c6a 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -2268,7 +2268,6 @@ void ieee80211_sta_register_airtime(struct ieee80211_sta *pubsta, u8 tid,
struct ieee80211_local *local = sta->sdata->local;
u8 ac = ieee80211_ac_from_tid(tid);
u32 airtime = 0;
- u32 diff;

if (sta->local->airtime_flags & AIRTIME_USE_TX)
airtime += tx_airtime;
@@ -2279,8 +2278,7 @@ void ieee80211_sta_register_airtime(struct ieee80211_sta *pubsta, u8 tid,
sta->airtime[ac].tx_airtime += tx_airtime;
sta->airtime[ac].rx_airtime += rx_airtime;

- diff = (u32)jiffies - sta->airtime[ac].last_active;
- if (diff <= AIRTIME_ACTIVE_DURATION)
+ if (ieee80211_sta_keep_active(sta, ac))
sta->airtime[ac].deficit -= airtime;

spin_unlock_bh(&local->active_txq_lock[ac]);
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 7acf2223e47a..5ef1554f991f 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -138,7 +138,7 @@ enum ieee80211_agg_stop_reason {
struct airtime_info {
u64 rx_airtime;
u64 tx_airtime;
- u32 last_active;
+ unsigned long last_active;
s32 deficit;
atomic_t aql_tx_pending; /* Estimated airtime for frames pending */
u32 aql_limit_low;
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index ed4fdf655343..314998fdb1a5 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -4013,14 +4013,13 @@ ieee80211_txq_set_active(struct txq_info *txqi)
return;

sta = container_of(txqi->txq.sta, struct sta_info, sta);
- sta->airtime[txqi->txq.ac].last_active = (u32)jiffies;
+ sta->airtime[txqi->txq.ac].last_active = jiffies;
}

static bool
ieee80211_txq_keep_active(struct txq_info *txqi)
{
struct sta_info *sta;
- u32 diff;

if (!txqi->txq.sta)
return false;
@@ -4029,9 +4028,7 @@ ieee80211_txq_keep_active(struct txq_info *txqi)
if (ieee80211_sta_deficit(sta, txqi->txq.ac) >= 0)
return false;

- diff = (u32)jiffies - sta->airtime[txqi->txq.ac].last_active;
-
- return diff <= AIRTIME_ACTIVE_DURATION;
+ return ieee80211_sta_keep_active(sta, txqi->txq.ac);
}

struct ieee80211_txq *ieee80211_next_txq(struct ieee80211_hw *hw, u8 ac)
--
2.43.0

2023-12-06 22:52:55

by Toke Høiland-Jørgensen

Subject: Re: [PATCH] wifi: mac80211: cleanup airtime arithmetic with ieee80211_sta_keep_active()

Dmitry Antipov <[email protected]> writes:

> Prefer native jiffies-wide 'unsigned long' for the 'last_active' field of
> 'struct airtime_info' and introduce 'ieee80211_sta_keep_active()' for airtime
> check in 'ieee80211_txq_keep_active()' and 'ieee80211_sta_register_airtime()'.
>
> Signed-off-by: Dmitry Antipov <[email protected]>

Sure, this seems like a reasonable cleanup!

Reviewed-by: Toke Høiland-Jørgensen <[email protected]>