From 5b989c18dab2e82bac8a5564a174794bf84b20e6 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Fri, 15 Mar 2019 11:03:35 +0100 Subject: mac80211: rework locking for txq scheduling / airtime fairness MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Holding the lock around the entire duration of tx scheduling can create some nasty lock contention, especially when processing airtime information from the tx status or the rx path. Improve locking by only holding the active_txq_lock for lookups / scheduling list modifications. Signed-off-by: Felix Fietkau Acked-by: Toke Høiland-Jørgensen Signed-off-by: Johannes Berg --- include/net/mac80211.h | 49 +++++++++++++++++++------------------------------ 1 file changed, 19 insertions(+), 30 deletions(-) (limited to 'include') diff --git a/include/net/mac80211.h b/include/net/mac80211.h index ac2ed8ec662b..616998252dc7 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -6231,8 +6231,6 @@ struct sk_buff *ieee80211_tx_dequeue(struct ieee80211_hw *hw, * @hw: pointer as obtained from ieee80211_alloc_hw() * @ac: AC number to return packets from. * - * Should only be called between calls to ieee80211_txq_schedule_start() - * and ieee80211_txq_schedule_end(). * Returns the next txq if successful, %NULL if no queue is eligible. If a txq * is returned, it should be returned with ieee80211_return_txq() after the * driver has finished scheduling it. @@ -6240,51 +6238,42 @@ struct sk_buff *ieee80211_tx_dequeue(struct ieee80211_hw *hw, struct ieee80211_txq *ieee80211_next_txq(struct ieee80211_hw *hw, u8 ac); /** - * ieee80211_return_txq - return a TXQ previously acquired by ieee80211_next_txq() - * - * @hw: pointer as obtained from ieee80211_alloc_hw() - * @txq: pointer obtained from station or virtual interface - * - * Should only be called between calls to ieee80211_txq_schedule_start() - * and ieee80211_txq_schedule_end(). - */ -void ieee80211_return_txq(struct ieee80211_hw *hw, struct ieee80211_txq *txq); - -/** - * ieee80211_txq_schedule_start - acquire locks for safe scheduling of an AC + * ieee80211_txq_schedule_start - start new scheduling round for TXQs * * @hw: pointer as obtained from ieee80211_alloc_hw() * @ac: AC number to acquire locks for * - * Acquire locks needed to schedule TXQs from the given AC. Should be called - * before ieee80211_next_txq() or ieee80211_return_txq(). + * Should be called before ieee80211_next_txq() or ieee80211_return_txq(). + * The driver must not call multiple TXQ scheduling rounds concurrently. */ -void ieee80211_txq_schedule_start(struct ieee80211_hw *hw, u8 ac) - __acquires(txq_lock); +void ieee80211_txq_schedule_start(struct ieee80211_hw *hw, u8 ac); + +/* (deprecated) */ +static inline void ieee80211_txq_schedule_end(struct ieee80211_hw *hw, u8 ac) +{ +} /** - * ieee80211_txq_schedule_end - release locks for safe scheduling of an AC + * ieee80211_schedule_txq - schedule a TXQ for transmission * * @hw: pointer as obtained from ieee80211_alloc_hw() - * @ac: AC number to acquire locks for + * @txq: pointer obtained from station or virtual interface * - * Release locks previously acquired by ieee80211_txq_schedule_end(). + * Schedules a TXQ for transmission if it is not already scheduled. */ -void ieee80211_txq_schedule_end(struct ieee80211_hw *hw, u8 ac) - __releases(txq_lock); +void ieee80211_schedule_txq(struct ieee80211_hw *hw, struct ieee80211_txq *txq); /** - * ieee80211_schedule_txq - schedule a TXQ for transmission + * ieee80211_return_txq - return a TXQ previously acquired by ieee80211_next_txq() * * @hw: pointer as obtained from ieee80211_alloc_hw() * @txq: pointer obtained from station or virtual interface - * - * Schedules a TXQ for transmission if it is not already scheduled. Takes a - * lock, which means it must *not* be called between - * ieee80211_txq_schedule_start() and ieee80211_txq_schedule_end() */ -void ieee80211_schedule_txq(struct ieee80211_hw *hw, struct ieee80211_txq *txq) - __acquires(txq_lock) __releases(txq_lock); +static inline void +ieee80211_return_txq(struct ieee80211_hw *hw, struct ieee80211_txq *txq) +{ + ieee80211_schedule_txq(hw, txq); +} /** * ieee80211_txq_may_transmit - check whether TXQ is allowed to transmit -- cgit From a58d7525b8014115d57fd30186a84f6d30783f2c Mon Sep 17 00:00:00 2001 From: Stanislaw Gruszka Date: Tue, 12 Mar 2019 10:51:40 +0100 Subject: cfg80211: add ratelimited variants of err and warn wiphy_{err,warn}_ratelimited will be used by rt2x00 Signed-off-by: Stanislaw Gruszka Signed-off-by: Johannes Berg --- include/net/cfg80211.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include') diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h index bb307a11ee63..13bfeb712d36 100644 --- a/include/net/cfg80211.h +++ b/include/net/cfg80211.h @@ -7183,6 +7183,11 @@ void cfg80211_pmsr_complete(struct wireless_dev *wdev, #define wiphy_info(wiphy, format, args...) \ dev_info(&(wiphy)->dev, format, ##args) +#define wiphy_err_ratelimited(wiphy, format, args...) \ + dev_err_ratelimited(&(wiphy)->dev, format, ##args) +#define wiphy_warn_ratelimited(wiphy, format, args...) \ + dev_warn_ratelimited(&(wiphy)->dev, format, ##args) + #define wiphy_debug(wiphy, format, args...) \ wiphy_printk(KERN_DEBUG, wiphy, format, ##args) -- cgit From 2b4a66980217332d91ab1785e1750857d6d52bc8 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Mon, 18 Mar 2019 12:00:58 +0100 Subject: mac80211: make ieee80211_schedule_txq schedule empty TXQs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently there is no way for the driver to signal to mac80211 that it should schedule a TXQ even if there are no packets on the mac80211 part of that queue. This is problematic if the driver has an internal retry queue to deal with software A-MPDU retry. This patch changes the behavior of ieee80211_schedule_txq to always schedule the queue, as its only user (ath9k) seems to expect such behavior already: it calls this function on tx status and on powersave wakeup whenever its internal retry queue is not empty. Also add an extra argument to ieee80211_return_txq to get the same behavior. This fixes an issue on ath9k where tx queues with packets to retry (and no new packets in mac80211) would not get serviced. Fixes: 89cea7493a346 ("ath9k: Switch to mac80211 TXQ scheduling and airtime APIs") Signed-off-by: Felix Fietkau Acked-by: Toke Høiland-Jørgensen Signed-off-by: Johannes Berg --- include/net/mac80211.h | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) (limited to 'include') diff --git a/include/net/mac80211.h b/include/net/mac80211.h index 616998252dc7..112dc18c658f 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -6253,26 +6253,42 @@ static inline void ieee80211_txq_schedule_end(struct ieee80211_hw *hw, u8 ac) { } +void __ieee80211_schedule_txq(struct ieee80211_hw *hw, + struct ieee80211_txq *txq, bool force); + /** * ieee80211_schedule_txq - schedule a TXQ for transmission * * @hw: pointer as obtained from ieee80211_alloc_hw() * @txq: pointer obtained from station or virtual interface * - * Schedules a TXQ for transmission if it is not already scheduled. + * Schedules a TXQ for transmission if it is not already scheduled, + * even if mac80211 does not have any packets buffered. + * + * The driver may call this function if it has buffered packets for + * this TXQ internally. */ -void ieee80211_schedule_txq(struct ieee80211_hw *hw, struct ieee80211_txq *txq); +static inline void +ieee80211_schedule_txq(struct ieee80211_hw *hw, struct ieee80211_txq *txq) +{ + __ieee80211_schedule_txq(hw, txq, true); +} /** * ieee80211_return_txq - return a TXQ previously acquired by ieee80211_next_txq() * * @hw: pointer as obtained from ieee80211_alloc_hw() * @txq: pointer obtained from station or virtual interface + * @force: schedule txq even if mac80211 does not have any buffered packets. + * + * The driver may set force=true if it has buffered packets for this TXQ + * internally. */ static inline void -ieee80211_return_txq(struct ieee80211_hw *hw, struct ieee80211_txq *txq) +ieee80211_return_txq(struct ieee80211_hw *hw, struct ieee80211_txq *txq, + bool force) { - ieee80211_schedule_txq(hw, txq); + __ieee80211_schedule_txq(hw, txq, force); } /** -- cgit