Rajkumar Manoharan <rmanohar@xxxxxxxxxxxxxx> writes:
> This allows the driver to refill airtime fairness deficit
> where the driver will not access txqs by ieee80211_next_txq.
> In tx push mode data path, high priority txqs will be scheduled
> for data transmission by ieee80211_next_txq and driver will not
> prioritize txqs whereas in push-pull mode, the drivers can
> prioritize txqs and access them directly. In such mode, airtime
> deficit can not filled by ieee80211_next_txq.
>
> Signed-off-by: Rajkumar Manoharan <rmanohar@xxxxxxxxxxxxxx>
> ---
> include/net/mac80211.h | 15 +++++++++++++
> net/mac80211/tx.c | 59 +++++++++++++++++++++++++++++++++++---------------
> 2 files changed, 57 insertions(+), 17 deletions(-)
>
> diff --git a/include/net/mac80211.h b/include/net/mac80211.h
> index cc16847bd52d..a2f0b6800100 100644
> --- a/include/net/mac80211.h
> +++ b/include/net/mac80211.h
> @@ -6033,6 +6033,21 @@ bool ieee80211_schedule_txq(struct ieee80211_hw *hw,
> struct ieee80211_txq *ieee80211_next_txq(struct ieee80211_hw *hw, s8 ac);
>
> /**
> + * ieee80211_reorder_txq - change txq position in scheduling loop
> + *
> + * This function is used to reorder txq's position in scheduling loop.
> + * The txq fairness deficit will be refilled. The drivers calling this
> + * function should ensure the txq won't be accessed by ieee80211_next_txq
> + * in the same path.
> + *
> + * @hw: pointer as obtained from ieee80211_alloc_hw()
> + * @txq: pointer obtained from station or virtual interface
> + *
> + */
> +void ieee80211_reorder_txq(struct ieee80211_hw *hw,
> + struct ieee80211_txq *txq);
> +
> +/**
> * ieee80211_txq_get_depth - get pending frame/byte count of given txq
> *
> * The values are not guaranteed to be coherent with regard to each other, i.e.
> diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
> index 0af35c08e0d9..b7b2f93152f8 100644
> --- a/net/mac80211/tx.c
> +++ b/net/mac80211/tx.c
> @@ -3634,10 +3634,38 @@ static inline struct txq_info *find_txqi(struct ieee80211_local *local, s8 ac)
> return txqi;
> }
>
> +static bool ieee80211_txq_refill_deficit(struct ieee80211_local *local,
> + struct txq_info *txqi)
> +{
> + struct fq *fq = &local->fq;
> + struct sta_info *sta;
> +
> + lockdep_assert_held(&local->active_txq_lock);
> +
> + if (!txqi->txq.sta)
> + return false;
> +
> + sta = container_of(txqi->txq.sta, struct sta_info, sta);
> +
> + if (sta->airtime.deficit[txqi->txq.ac] > 0)
> + return false;
> +
> + sta->airtime.deficit[txqi->txq.ac] +=
> + IEEE80211_AIRTIME_QUANTUM * sta->airtime.weight;
> + list_move_tail(&txqi->schedule_order,
> + &local->active_txqs[txqi->txq.ac]);
This needs to check that the txq is currently at the head of
local->active_txqs[txqi->txq.ac]; otherwise fairness enforcement doesn't
work. And with this check I'm not sure the reorder function is terribly
useful for what you want to use it for?
-Toke
