diff mbox series

[v2,1/4] mac80211: call ieee80211_tx_h_rate_ctrl() when dequeue

Message ID 2176023d8f13d82d093452e1c105609396c30622.1622164961.git.ryder.lee@mediatek.com (mailing list archive)
State Superseded
Delegated to: Johannes Berg
Headers show
Series [v2,1/4] mac80211: call ieee80211_tx_h_rate_ctrl() when dequeue | expand

Commit Message

Ryder Lee May 28, 2021, 6:05 a.m. UTC 
Make ieee80211_tx_h_rate_ctrl() get called on dequeue to improve
performance since it reduces the turnaround time for rate control.

Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
---
change since v2 - roll ieee80211_tx_h_rate_ctrl checks into one condition
---
 net/mac80211/tx.c | 52 ++++++++++++++++++++++++++---------------------
 1 file changed, 29 insertions(+), 23 deletions(-)

Comments

Felix Fietkau June 10, 2021, 11:10 a.m. UTC | #1 
On 2021-05-28 08:05, Ryder Lee wrote:
> Make ieee80211_tx_h_rate_ctrl() get called on dequeue to improve
> performance since it reduces the turnaround time for rate control.
> 
> Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
For the mac80211 patches:
Acked-by: Felix Fietkau <nbd@nbd.name>
Ryder Lee June 16, 2021, 10:45 p.m. UTC | #2 
On Thu, 2021-06-10 at 13:10 +0200, Felix Fietkau wrote:
> On 2021-05-28 08:05, Ryder Lee wrote:
> > Make ieee80211_tx_h_rate_ctrl() get called on dequeue to improve
> > performance since it reduces the turnaround time for rate control.
> > 
> > Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
> For the mac80211 patches:
> Acked-by: Felix Fietkau <nbd@nbd.name>

Hi Johannes,

Does this series look okay to you?

Ryder
Felix Fietkau June 17, 2021, 10:50 a.m. UTC | #3 
On 2021-05-28 08:05, Ryder Lee wrote:
> Make ieee80211_tx_h_rate_ctrl() get called on dequeue to improve
> performance since it reduces the turnaround time for rate control.
> 
> Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
> ---
> change since v2 - roll ieee80211_tx_h_rate_ctrl checks into one condition
There were some OpenWrt crash reported which appear to be related to
this patch. I was able to reproduce a deadlock with ath9k, and I'm
currently looking into it.

- Felix
Felix Fietkau June 17, 2021, 5:59 p.m. UTC | #4 
On 2021-06-17 12:50, Felix Fietkau wrote:
> 
> On 2021-05-28 08:05, Ryder Lee wrote:
>> Make ieee80211_tx_h_rate_ctrl() get called on dequeue to improve
>> performance since it reduces the turnaround time for rate control.
>> 
>> Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
>> ---
>> change since v2 - roll ieee80211_tx_h_rate_ctrl checks into one condition
> There were some OpenWrt crash reported which appear to be related to
> this patch. I was able to reproduce a deadlock with ath9k, and I'm
> currently looking into it.
Some more information about the crash:
- ath9k calls ieee80211_tx_dequeue with the tx queue lock held
- ieee80211_tx_dequeue calls minstrel get_rate
- get_rate calls minstrel_aggr_check
- minstrel_aggr check calls ieee80211_start_tx_ba_session
- ieee80211_start_tx_ba_session tries to send a frame
- ath9k tries to acquire the tx lock it already holds

I've fixed this in v3 by moving the logic of minstrel_aggr_check into
mac80211

- Felix
diff mbox series

Patch

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 0b719f3d2dec..d3016c3a3069 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1768,8 +1768,6 @@  static int invoke_tx_handlers_early(struct ieee80211_tx_data *tx)
 	CALL_TXH(ieee80211_tx_h_ps_buf);
 	CALL_TXH(ieee80211_tx_h_check_control_port_protocol);
 	CALL_TXH(ieee80211_tx_h_select_key);
-	if (!ieee80211_hw_check(&tx->local->hw, HAS_RATE_CONTROL))
-		CALL_TXH(ieee80211_tx_h_rate_ctrl);
 
  txh_done:
 	if (unlikely(res == TX_DROP)) {
@@ -1802,6 +1800,9 @@  static int invoke_tx_handlers_late(struct ieee80211_tx_data *tx)
 		goto txh_done;
 	}
 
+	if (!ieee80211_hw_check(&tx->local->hw, HAS_RATE_CONTROL))
+		CALL_TXH(ieee80211_tx_h_rate_ctrl);
+
 	CALL_TXH(ieee80211_tx_h_michael_mic_add);
 	CALL_TXH(ieee80211_tx_h_sequence);
 	CALL_TXH(ieee80211_tx_h_fragment);
@@ -3369,15 +3370,21 @@  static bool ieee80211_amsdu_aggregate(struct ieee80211_sub_if_data *sdata,
  * Can be called while the sta lock is held. Anything that can cause packets to
  * be generated will cause deadlock!
  */
-static void ieee80211_xmit_fast_finish(struct ieee80211_sub_if_data *sdata,
-				       struct sta_info *sta, u8 pn_offs,
-				       struct ieee80211_key *key,
-				       struct sk_buff *skb)
+static ieee80211_tx_result
+ieee80211_xmit_fast_finish(struct ieee80211_sub_if_data *sdata,
+			   struct sta_info *sta, u8 pn_offs,
+			   struct ieee80211_key *key,
+			   struct ieee80211_tx_data *tx)
 {
+	struct sk_buff *skb = tx->skb;
 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 	struct ieee80211_hdr *hdr = (void *)skb->data;
 	u8 tid = IEEE80211_NUM_TIDS;
 
+	if (!ieee80211_hw_check(&tx->local->hw, HAS_RATE_CONTROL) &&
+	    ieee80211_tx_h_rate_ctrl(tx) != TX_CONTINUE)
+		return TX_DROP;
+
 	if (key)
 		info->control.hw_key = &key->conf;
 
@@ -3426,6 +3433,8 @@  static void ieee80211_xmit_fast_finish(struct ieee80211_sub_if_data *sdata,
 			break;
 		}
 	}
+
+	return TX_CONTINUE;
 }
 
 static bool ieee80211_xmit_fast(struct ieee80211_sub_if_data *sdata,
@@ -3529,24 +3538,17 @@  static bool ieee80211_xmit_fast(struct ieee80211_sub_if_data *sdata,
 	tx.sta = sta;
 	tx.key = fast_tx->key;
 
-	if (!ieee80211_hw_check(&local->hw, HAS_RATE_CONTROL)) {
-		tx.skb = skb;
-		r = ieee80211_tx_h_rate_ctrl(&tx);
-		skb = tx.skb;
-		tx.skb = NULL;
-
-		if (r != TX_CONTINUE) {
-			if (r != TX_QUEUED)
-				kfree_skb(skb);
-			return true;
-		}
-	}
-
 	if (ieee80211_queue_skb(local, sdata, sta, skb))
 		return true;
 
-	ieee80211_xmit_fast_finish(sdata, sta, fast_tx->pn_offs,
-				   fast_tx->key, skb);
+	tx.skb = skb;
+	r = ieee80211_xmit_fast_finish(sdata, sta, fast_tx->pn_offs,
+				       fast_tx->key, &tx);
+	tx.skb = NULL;
+	if (r == TX_DROP) {
+		kfree_skb(skb);
+		return true;
+	}
 
 	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
 		sdata = container_of(sdata->bss,
@@ -3663,8 +3665,12 @@  struct sk_buff *ieee80211_tx_dequeue(struct ieee80211_hw *hw,
 		    (tx.key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV))
 			pn_offs = ieee80211_hdrlen(hdr->frame_control);
 
-		ieee80211_xmit_fast_finish(sta->sdata, sta, pn_offs,
-					   tx.key, skb);
+		r = ieee80211_xmit_fast_finish(sta->sdata, sta, pn_offs,
+					       tx.key, &tx);
+		if (r != TX_CONTINUE) {
+			ieee80211_free_txskb(&local->hw, skb);
+			goto begin;
+		}
 	} else {
 		if (invoke_tx_handlers_late(&tx))
 			goto begin;