[PATCH v2] mac80211: expose txq queue depth and size to drivers
From: Michal Kazior <hidden>
Date: 2016-01-27 14:25:10
Subsystem:
mac80211, the rest · Maintainers:
Johannes Berg, Linus Torvalds
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 <redacted>
---
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