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ar9170: improve network latency

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AR9170 has the bad habit of choking when traffic builds up.
Tests have shown that this can partially be attributed to
a huge buildup of backlogged frames.

Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Christian Lamparter
2009-11-29 00:52:51 +01:00
committed by John W. Linville
parent 5e0ec31652
commit 53a76b58b6
2 changed files with 18 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/net/wireless/ath/ar9170/ar9170.h
View File

@@ -152,6 +152,8 @@ struct ar9170_sta_tid {
#define AR9170_NUM_TX_STATUS 128 #define AR9170_NUM_TX_STATUS 128
#define AR9170_NUM_TX_AGG_MAX 30 #define AR9170_NUM_TX_AGG_MAX 30
#define AR9170_NUM_TX_LIMIT_HARD AR9170_TXQ_DEPTH
#define AR9170_NUM_TX_LIMIT_SOFT (AR9170_TXQ_DEPTH - 10)
struct ar9170 { struct ar9170 {
struct ieee80211_hw *hw; struct ieee80211_hw *hw;

34
drivers/net/wireless/ath/ar9170/main.c
View File

@@ -430,7 +430,7 @@ void ar9170_tx_callback(struct ar9170 *ar, struct sk_buff *skb)
spin_lock_irqsave(&ar->tx_stats_lock, flags); spin_lock_irqsave(&ar->tx_stats_lock, flags);
ar->tx_stats[queue].len--; ar->tx_stats[queue].len--;
if (skb_queue_empty(&ar->tx_pending[queue])) { if (ar->tx_stats[queue].len < AR9170_NUM_TX_LIMIT_SOFT) {
#ifdef AR9170_QUEUE_STOP_DEBUG #ifdef AR9170_QUEUE_STOP_DEBUG
printk(KERN_DEBUG "%s: wake queue %d\n", printk(KERN_DEBUG "%s: wake queue %d\n",
wiphy_name(ar->hw->wiphy), queue); wiphy_name(ar->hw->wiphy), queue);
@@ -1716,6 +1716,21 @@ static void ar9170_tx(struct ar9170 *ar)
for (i = 0; i < __AR9170_NUM_TXQ; i++) { for (i = 0; i < __AR9170_NUM_TXQ; i++) {
spin_lock_irqsave(&ar->tx_stats_lock, flags); spin_lock_irqsave(&ar->tx_stats_lock, flags);
frames = min(ar->tx_stats[i].limit - ar->tx_stats[i].len,
skb_queue_len(&ar->tx_pending[i]));
if (remaining_space < frames) {
#ifdef AR9170_QUEUE_DEBUG
printk(KERN_DEBUG "%s: tx quota reached queue:%d, "
"remaining slots:%d, needed:%d\n",
wiphy_name(ar->hw->wiphy), i, remaining_space,
frames);
#endif /* AR9170_QUEUE_DEBUG */
frames = remaining_space;
}
ar->tx_stats[i].len += frames;
ar->tx_stats[i].count += frames;
if (ar->tx_stats[i].len >= ar->tx_stats[i].limit) { if (ar->tx_stats[i].len >= ar->tx_stats[i].limit) {
#ifdef AR9170_QUEUE_DEBUG #ifdef AR9170_QUEUE_DEBUG
printk(KERN_DEBUG "%s: queue %d full\n", printk(KERN_DEBUG "%s: queue %d full\n",
@@ -1733,25 +1748,8 @@ static void ar9170_tx(struct ar9170 *ar)
__ar9170_dump_txstats(ar); __ar9170_dump_txstats(ar);
#endif /* AR9170_QUEUE_STOP_DEBUG */ #endif /* AR9170_QUEUE_STOP_DEBUG */
ieee80211_stop_queue(ar->hw, i); ieee80211_stop_queue(ar->hw, i);
spin_unlock_irqrestore(&ar->tx_stats_lock, flags);
continue;
} }
frames = min(ar->tx_stats[i].limit - ar->tx_stats[i].len,
skb_queue_len(&ar->tx_pending[i]));
if (remaining_space < frames) {
#ifdef AR9170_QUEUE_DEBUG
printk(KERN_DEBUG "%s: tx quota reached queue:%d, "
"remaining slots:%d, needed:%d\n",
wiphy_name(ar->hw->wiphy), i, remaining_space,
frames);
#endif /* AR9170_QUEUE_DEBUG */
frames = remaining_space;
}
ar->tx_stats[i].len += frames;
ar->tx_stats[i].count += frames;
spin_unlock_irqrestore(&ar->tx_stats_lock, flags); spin_unlock_irqrestore(&ar->tx_stats_lock, flags);
if (!frames) if (!frames)