Return-path: Received: from mail-lf0-f45.google.com ([209.85.215.45]:34871 "EHLO mail-lf0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932374AbcA0OZK (ORCPT ); Wed, 27 Jan 2016 09:25:10 -0500 Received: by mail-lf0-f45.google.com with SMTP id c192so7030166lfe.2 for ; Wed, 27 Jan 2016 06:25:08 -0800 (PST) From: Michal Kazior To: linux-wireless@vger.kernel.org Cc: johannes@sipsolutions.net, Michal Kazior Subject: [PATCH v2] mac80211: expose txq queue depth and size to drivers Date: Wed, 27 Jan 2016 15:26:12 +0100 Message-Id: <1453904772-25289-1-git-send-email-michal.kazior@tieto.com> (sfid-20160127_152514_390328_392A884C) In-Reply-To: <1453382588-27105-1-git-send-email-michal.kazior@tieto.com> References: <1453382588-27105-1-git-send-email-michal.kazior@tieto.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: This will allow drivers to make more educated decisions whether to defer transmission or not. Relying on wake_tx_queue() call count implicitly was not possible because it could be called without queued frame count actually changing on software tx aggregation start/stop code paths. It was also not possible to know how long byte-wise queue was without dequeueing. Signed-off-by: Michal Kazior --- Notes: v2: * export a dedicated API call to get both frame/byte counts to reduce redundancy and offer possible synchronized reads in the future [Felix] include/net/mac80211.h | 15 +++++++++++++++ net/mac80211/ieee80211_i.h | 1 + net/mac80211/iface.c | 1 + net/mac80211/sta_info.c | 1 + net/mac80211/tx.c | 8 +++++++- net/mac80211/util.c | 14 ++++++++++++++ 6 files changed, 39 insertions(+), 1 deletion(-) diff --git a/include/net/mac80211.h b/include/net/mac80211.h index 31337f81ec03..6617516a276f 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -5594,4 +5594,19 @@ void ieee80211_unreserve_tid(struct ieee80211_sta *sta, u8 tid); */ struct sk_buff *ieee80211_tx_dequeue(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. + * txq state can change half-way of this function and the caller may end up + * with "new" frame_cnt and "old" byte_cnt or vice-versa. + * + * @txq: pointer obtained from station or virtual interface + * @frame_cnt: pointer to store frame count + * @byte_cnt: pointer to store byte count + */ +void ieee80211_txq_get_depth(struct ieee80211_txq *txq, + unsigned long *frame_cnt, + unsigned long *byte_cnt); #endif /* MAC80211_H */ diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index a29f61dc9c06..a96f8c0461f6 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -804,6 +804,7 @@ enum txq_info_flags { struct txq_info { struct sk_buff_head queue; unsigned long flags; + unsigned long byte_cnt; /* keep last! */ struct ieee80211_txq txq; diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index 0451f120746e..453b4e741780 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -979,6 +979,7 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata, spin_lock_bh(&txqi->queue.lock); ieee80211_purge_tx_queue(&local->hw, &txqi->queue); + txqi->byte_cnt = 0; spin_unlock_bh(&txqi->queue.lock); atomic_set(&sdata->txqs_len[txqi->txq.ac], 0); diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c index 7e007cf12cb2..e1d9ccc5d197 100644 --- a/net/mac80211/sta_info.c +++ b/net/mac80211/sta_info.c @@ -116,6 +116,7 @@ static void __cleanup_single_sta(struct sta_info *sta) ieee80211_purge_tx_queue(&local->hw, &txqi->queue); atomic_sub(n, &sdata->txqs_len[txqi->txq.ac]); + txqi->byte_cnt = 0; } } diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 3311ce0f3d6c..af584f7cdd63 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -1266,7 +1266,11 @@ static void ieee80211_drv_tx(struct ieee80211_local *local, if (atomic_read(&sdata->txqs_len[ac]) >= local->hw.txq_ac_max_pending) netif_stop_subqueue(sdata->dev, ac); - skb_queue_tail(&txqi->queue, skb); + spin_lock_bh(&txqi->queue.lock); + txqi->byte_cnt += skb->len; + __skb_queue_tail(&txqi->queue, skb); + spin_unlock_bh(&txqi->queue.lock); + drv_wake_tx_queue(local, txqi); return; @@ -1294,6 +1298,8 @@ struct sk_buff *ieee80211_tx_dequeue(struct ieee80211_hw *hw, if (!skb) goto out; + txqi->byte_cnt -= skb->len; + atomic_dec(&sdata->txqs_len[ac]); if (__netif_subqueue_stopped(sdata->dev, ac)) ieee80211_propagate_queue_wake(local, sdata->vif.hw_queue[ac]); diff --git a/net/mac80211/util.c b/net/mac80211/util.c index fb90d9c5df59..091f3dd62ad1 100644 --- a/net/mac80211/util.c +++ b/net/mac80211/util.c @@ -3368,3 +3368,17 @@ void ieee80211_init_tx_queue(struct ieee80211_sub_if_data *sdata, txqi->txq.ac = IEEE80211_AC_BE; } } + +void ieee80211_txq_get_depth(struct ieee80211_txq *txq, + unsigned long *frame_cnt, + unsigned long *byte_cnt) +{ + struct txq_info *txqi = to_txq_info(txq); + + if (frame_cnt) + *frame_cnt = txqi->queue.qlen; + + if (byte_cnt) + *byte_cnt = txqi->byte_cnt; +} +EXPORT_SYMBOL(ieee80211_txq_get_depth); -- 2.1.4