[PATCH] mac80211: use coarse boottime for airtime fairness code
From: Felix Fietkau <nbd@nbd.name>
Date: 2021-12-17 11:43:10
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: Felix Fietkau <nbd@nbd.name> --- net/mac80211/tx.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 278945e3e08a..cbe7d1d00a50 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c@@ -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.
--
2.34.1