Commit 6a789ba6 authored by Felix Fietkau's avatar Felix Fietkau Committed by Johannes Berg
Browse files

mac80211: use coarse boottime for airtime fairness code 



The time values used by the airtime fairness code only need to be accurate
enough to cover station activity detection.
Using ktime_get_coarse_boottime_ns instead of ktime_get_boottime_ns will
drop the accuracy down to jiffies intervals, but at the same time saves
a lot of CPU cycles in a hot path

Signed-off-by: default avatarFelix Fietkau <nbd@nbd.name>
Acked-by: default avatarToke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20211217114258.14619-1-nbd@nbd.name


Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 75c5bd68

net/mac80211/tx.c

+5 −5
Original line number Diff line number Diff line
@@ -3821,7 +3821,7 @@ struct ieee80211_txq *ieee80211_next_txq(struct ieee80211_hw *hw, u8 ac) 
{

	struct ieee80211_local *local = hw_to_local(hw);

	struct airtime_sched_info *air_sched;

	u64 now = ktime_get_boottime_ns();

	u64 now = ktime_get_coarse_boottime_ns();

	struct ieee80211_txq *ret = NULL;

	struct airtime_info *air_info;

	struct txq_info *txqi = NULL;
@@ -3948,7 +3948,7 @@ void ieee80211_update_airtime_weight(struct ieee80211_local *local, 
	u64 weight_sum = 0;



	if (unlikely(!now))

		now = ktime_get_boottime_ns();

		now = ktime_get_coarse_boottime_ns();



	lockdep_assert_held(&air_sched->lock);
@@ -3974,7 +3974,7 @@ void ieee80211_schedule_txq(struct ieee80211_hw *hw, 
	struct ieee80211_local *local = hw_to_local(hw);

	struct txq_info *txqi = to_txq_info(txq);

	struct airtime_sched_info *air_sched;

	u64 now = ktime_get_boottime_ns();

	u64 now = ktime_get_coarse_boottime_ns();

	struct airtime_info *air_info;

	u8 ac = txq->ac;

	bool was_active;
@@ -4032,7 +4032,7 @@ static void __ieee80211_unschedule_txq(struct ieee80211_hw *hw, 


	if (!purge)

		airtime_set_active(air_sched, air_info,

				   ktime_get_boottime_ns());

				   ktime_get_coarse_boottime_ns());



	rb_erase_cached(&txqi->schedule_order,

			&air_sched->active_txqs);
@@ -4120,7 +4120,7 @@ bool ieee80211_txq_may_transmit(struct ieee80211_hw *hw, 
	if (RB_EMPTY_NODE(&txqi->schedule_order))

		goto out;



	now = ktime_get_boottime_ns();

	now = ktime_get_coarse_boottime_ns();



	/* Like in ieee80211_next_txq(), make sure the first station in the

	 * scheduling order is eligible for transmission to avoid starvation.