From patchwork Fri Sep 7 22:22:50 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= X-Patchwork-Id: 10592631 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B04A014BD for ; Fri, 7 Sep 2018 22:23:00 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A0F6B281E1 for ; Fri, 7 Sep 2018 22:23:00 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 95383252D5; Fri, 7 Sep 2018 22:23:00 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8EF0B28421 for ; Fri, 7 Sep 2018 22:22:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726687AbeIHDF7 (ORCPT ); Fri, 7 Sep 2018 23:05:59 -0400 Received: from mail.toke.dk ([52.28.52.200]:34863 "EHLO mail.toke.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726597AbeIHDF6 (ORCPT ); Fri, 7 Sep 2018 23:05:58 -0400 Subject: [PATCH RFC v3 1/4] mac80211: Add TXQ scheduling API DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=toke.dk; s=20161023; t=1536358970; bh=E2rCLzWH9BWbkqK2xM7zaA/x/1Ho0Li63OrCPFkJKzw=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=N9XTatH/GaBdBNtHoJTg4b4Hc96ExtUovSQfsBt2hsPJTwS2iVza6KufHfSvcFnCf oLCJk7zVyN2kfraWOYIsx3BPKSMHPcO/fBcYHXDnjuNO9P4BD/NxB8/fJnhfcaHSBC gyFcebW+bI0jzSWxnUvUwS36rCJI5WrVWkM3ykiIROnMgvKjP8csEhud/DSkkAwZgj jcrczT30NJU1XnEFVDYtoCL2ZLdl5cd3XYK941yTiNrsFxqw7w1N1KudFvF7Ywi7jq euAdRgicGdI2Ue4eD+28vELx9LuKme1c8MHd463UoiawYdiS3Jde9OIQ1WGGhTb0H2 /dl6+RPdJs9iw== From: Toke =?utf-8?q?H=C3=B8iland-J=C3=B8rgensen?= To: linux-wireless@vger.kernel.org, make-wifi-fast@lists.bufferbloat.net Cc: Rajkumar Manoharan , Felix Fietkau Date: Sat, 08 Sep 2018 00:22:50 +0200 X-Clacks-Overhead: GNU Terry Pratchett Message-ID: <153635897010.14170.2992498632345986102.stgit@alrua-x1> In-Reply-To: <153635803319.14170.10011969968767927187.stgit@alrua-x1> References: <153635803319.14170.10011969968767927187.stgit@alrua-x1> MIME-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This adds an API to mac80211 to handle scheduling of TXQs and changes the interface between driver and mac80211 for TXQ handling as follows: - The wake_tx_queue callback interface includes only the ac number instead of the TXQ. The driver is expected to retrieve TXQs from ieee80211_next_txq() - Two new mac80211 functions are added: ieee80211_next_txq() and ieee80211_schedule_txq(). The former returns the next TXQ that should be scheduled, and is how the driver gets a queue to pull packets from. The latter is called internally by mac80211 to start scheduling a queue, and the driver is supposed to call it to re-schedule the TXQ after it is finished pulling packets from it (unless the queue emptied). Drivers can optionally filter TXQs on ac to support per-AC hardware queue designs. Usage of the new API is optional, so drivers can be ported one at a time. Signed-off-by: Toke Høiland-Jørgensen --- include/net/mac80211.h | 45 ++++++++++++++++++++++++++++++--- net/mac80211/agg-tx.c | 2 + net/mac80211/driver-ops.h | 7 +++++ net/mac80211/ieee80211_i.h | 9 +++++++ net/mac80211/main.c | 4 +++ net/mac80211/sta_info.c | 2 + net/mac80211/tx.c | 60 +++++++++++++++++++++++++++++++++++++++++++- 7 files changed, 122 insertions(+), 7 deletions(-) diff --git a/include/net/mac80211.h b/include/net/mac80211.h index c4fadbafbf21..ff413d9caa50 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -108,9 +108,16 @@ * The driver is expected to initialize its private per-queue data for stations * and interfaces in the .add_interface and .sta_add ops. * - * The driver can't access the queue directly. To dequeue a frame, it calls - * ieee80211_tx_dequeue(). Whenever mac80211 adds a new frame to a queue, it - * calls the .wake_tx_queue driver op. + * The driver can't access the queue directly. To dequeue a frame from a + * txq, it calls ieee80211_tx_dequeue(). Whenever mac80211 adds a new frame to a + * queue, it calls the .wake_tx_queue driver op. + * + * Drivers can optionally delegate responsibility for scheduling queues to + * mac80211, to take advantage of airtime fairness accounting. In this case, to + * obtain the next queue to pull frames from, the driver calls + * ieee80211_next_txq(). The driver is then expected to re-schedule the txq + * using ieee80211_schedule_txq() if it is still active after the driver has + * finished pulling packets from it. * * For AP powersave TIM handling, the driver only needs to indicate if it has * buffered packets in the driver specific data structures by calling @@ -6045,13 +6052,43 @@ void ieee80211_unreserve_tid(struct ieee80211_sta *sta, u8 tid); * ieee80211_tx_dequeue - dequeue a packet from a software tx queue * * @hw: pointer as obtained from ieee80211_alloc_hw() - * @txq: pointer obtained from station or virtual interface + * @txq: pointer obtained from station or virtual interface, or from + * ieee80211_next_txq() * * Returns the skb if successful, %NULL if no frame was available. */ struct sk_buff *ieee80211_tx_dequeue(struct ieee80211_hw *hw, struct ieee80211_txq *txq); +/** + * ieee80211_schedule_txq - add txq to scheduling loop + * + * @hw: pointer as obtained from ieee80211_alloc_hw() + * @txq: pointer obtained from station or virtual interface + * + * Returns %true if the txq was actually added to the scheduling, + * %false otherwise. + */ +bool ieee80211_schedule_txq(struct ieee80211_hw *hw, + struct ieee80211_txq *txq); + +/** + * ieee80211_next_txq - get next tx queue to pull packets from + * + * @hw: pointer as obtained from ieee80211_alloc_hw() + * @ac: AC number to return packets from. + * @first: Setting this to true signifies the start of a new scheduling round. + * Each TXQ will only be returned at most exactly once in each round. + * + * Returns the next txq if successful, %NULL if no queue is eligible. If a txq + * is returned, it will have been removed from the scheduler queue and needs to + * be re-scheduled with ieee80211_schedule_txq() to continue to be active. Note + * that the driver is responsible for locking to ensuring two different threads + * don't schedule the same AC simultaneously. + */ +struct ieee80211_txq *ieee80211_next_txq(struct ieee80211_hw *hw, s8 ac, + bool first); + /** * ieee80211_txq_get_depth - get pending frame/byte count of given txq * diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c index 69e831bc317b..e94b1a0407af 100644 --- a/net/mac80211/agg-tx.c +++ b/net/mac80211/agg-tx.c @@ -229,7 +229,7 @@ ieee80211_agg_start_txq(struct sta_info *sta, int tid, bool enable) clear_bit(IEEE80211_TXQ_STOP, &txqi->flags); local_bh_disable(); rcu_read_lock(); - drv_wake_tx_queue(sta->sdata->local, txqi); + schedule_and_wake_txq(sta->sdata->local, txqi); rcu_read_unlock(); local_bh_enable(); } diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h index e42c641b6190..f1578c394f75 100644 --- a/net/mac80211/driver-ops.h +++ b/net/mac80211/driver-ops.h @@ -1173,6 +1173,13 @@ static inline void drv_wake_tx_queue(struct ieee80211_local *local, local->ops->wake_tx_queue(&local->hw, &txq->txq); } +static inline void schedule_and_wake_txq(struct ieee80211_local *local, + struct txq_info *txqi) +{ + ieee80211_schedule_txq(&local->hw, &txqi->txq); + drv_wake_tx_queue(local, txqi); +} + static inline int drv_can_aggregate_in_amsdu(struct ieee80211_local *local, struct sk_buff *head, struct sk_buff *skb) diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index f40a2167935f..75f9c9ab364f 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -829,6 +829,8 @@ enum txq_info_flags { * a fq_flow which is already owned by a different tin * @def_cvars: codel vars for @def_flow * @frags: used to keep fragments created after dequeue + * @schedule_order: used with ieee80211_local->active_txqs + * @schedule_round: counter to prevent infinite loops on TXQ scheduling */ struct txq_info { struct fq_tin tin; @@ -836,6 +838,8 @@ struct txq_info { struct codel_vars def_cvars; struct codel_stats cstats; struct sk_buff_head frags; + struct list_head schedule_order; + u16 schedule_round; unsigned long flags; /* keep last! */ @@ -1127,6 +1131,11 @@ struct ieee80211_local { struct codel_vars *cvars; struct codel_params cparams; + /* protects active_txqs and txqi->schedule_order */ + spinlock_t active_txq_lock; + struct list_head active_txqs[IEEE80211_NUM_ACS]; + u16 schedule_round[IEEE80211_NUM_ACS]; + const struct ieee80211_ops *ops; /* diff --git a/net/mac80211/main.c b/net/mac80211/main.c index 77381017bac7..c6d88758cbb7 100644 --- a/net/mac80211/main.c +++ b/net/mac80211/main.c @@ -663,6 +663,10 @@ struct ieee80211_hw *ieee80211_alloc_hw_nm(size_t priv_data_len, spin_lock_init(&local->rx_path_lock); spin_lock_init(&local->queue_stop_reason_lock); + for (i = 0; i < IEEE80211_NUM_ACS; i++) + INIT_LIST_HEAD(&local->active_txqs[i]); + spin_lock_init(&local->active_txq_lock); + INIT_LIST_HEAD(&local->chanctx_list); mutex_init(&local->chanctx_mtx); diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c index fb8c2252ac0e..c2f5cb7df54f 100644 --- a/net/mac80211/sta_info.c +++ b/net/mac80211/sta_info.c @@ -1249,7 +1249,7 @@ void ieee80211_sta_ps_deliver_wakeup(struct sta_info *sta) if (!sta->sta.txq[i] || !txq_has_queue(sta->sta.txq[i])) continue; - drv_wake_tx_queue(local, to_txq_info(sta->sta.txq[i])); + schedule_and_wake_txq(local, to_txq_info(sta->sta.txq[i])); } skb_queue_head_init(&pending); diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index c42bfa1dcd2c..8bcc447e2cbc 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -1445,6 +1445,7 @@ void ieee80211_txq_init(struct ieee80211_sub_if_data *sdata, codel_vars_init(&txqi->def_cvars); codel_stats_init(&txqi->cstats); __skb_queue_head_init(&txqi->frags); + INIT_LIST_HEAD(&txqi->schedule_order); txqi->txq.vif = &sdata->vif; @@ -1485,6 +1486,9 @@ void ieee80211_txq_purge(struct ieee80211_local *local, fq_tin_reset(fq, tin, fq_skb_free_func); ieee80211_purge_tx_queue(&local->hw, &txqi->frags); + spin_lock_bh(&local->active_txq_lock); + list_del_init(&txqi->schedule_order); + spin_unlock_bh(&local->active_txq_lock); } void ieee80211_txq_set_params(struct ieee80211_local *local) @@ -1601,7 +1605,7 @@ static bool ieee80211_queue_skb(struct ieee80211_local *local, ieee80211_txq_enqueue(local, txqi, skb); spin_unlock_bh(&fq->lock); - drv_wake_tx_queue(local, txqi); + schedule_and_wake_txq(local, txqi); return true; } @@ -3623,6 +3627,60 @@ struct sk_buff *ieee80211_tx_dequeue(struct ieee80211_hw *hw, } EXPORT_SYMBOL(ieee80211_tx_dequeue); +bool ieee80211_schedule_txq(struct ieee80211_hw *hw, + struct ieee80211_txq *txq) +{ + struct ieee80211_local *local = hw_to_local(hw); + struct txq_info *txqi = to_txq_info(txq); + bool ret = false; + + spin_lock_bh(&local->active_txq_lock); + + if (list_empty(&txqi->schedule_order)) { + list_add_tail(&txqi->schedule_order, + &local->active_txqs[txq->ac]); + ret = true; + } + + spin_unlock_bh(&local->active_txq_lock); + + return ret; +} +EXPORT_SYMBOL(ieee80211_schedule_txq); + +struct ieee80211_txq *ieee80211_next_txq(struct ieee80211_hw *hw, s8 ac, + bool first) +{ + struct ieee80211_local *local = hw_to_local(hw); + struct txq_info *txqi = NULL; + + spin_lock_bh(&local->active_txq_lock); + + if (first) + local->schedule_round[ac]++; + + if (list_empty(&local->active_txqs[ac])) + goto out; + + txqi = list_first_entry(&local->active_txqs[ac], + struct txq_info, + schedule_order); + + if (txqi->schedule_round == local->schedule_round[ac]) + txqi = NULL; + else + list_del_init(&txqi->schedule_order); + out: + spin_unlock_bh(&local->active_txq_lock); + + if (!txqi) + return NULL; + + txqi->schedule_round = local->schedule_round[ac]; + return &txqi->txq; +} +EXPORT_SYMBOL(ieee80211_next_txq); + void __ieee80211_subif_start_xmit(struct sk_buff *skb, struct net_device *dev, u32 info_flags)