mt76: dma: reduce lock contention in mt76_dma_tx_cleanup

Instead of taking q->lock for every single cleaned up frame, batch up to
16 cleaned up frames before taking it.

Signed-off-by: Felix Fietkau <[email protected]>
This commit is contained in:
Felix Fietkau
2022-03-19 23:24:57 +01:00
parent 0b1deb9292
commit 2e51013b38
+23 -3
View File
@@ -233,7 +233,9 @@ static void
mt76_dma_tx_cleanup(struct mt76_dev *dev, struct mt76_queue *q, bool flush)
{
struct mt76_queue_entry entry;
int done = 0;
int last;
int tail;
if (!q || !q->ndesc)
return;
@@ -244,21 +246,39 @@ mt76_dma_tx_cleanup(struct mt76_dev *dev, struct mt76_queue *q, bool flush)
else
last = readl(&q->regs->dma_idx);
while (q->queued > 0 && q->tail != last) {
tail = q->tail;
while (q->queued - done > 0 && tail != last) {
mt76_dma_tx_cleanup_idx(dev, q, q->tail, &entry);
mt76_queue_tx_complete(dev, q, &entry);
if (entry.skb)
dev->drv->tx_complete_skb(dev, &entry);
tail = (tail + 1) % q->ndesc;
done++;
if (entry.txwi) {
if (!(dev->drv->drv_flags & MT_DRV_TXWI_NO_FREE))
mt76_put_txwi(dev, entry.txwi);
}
if (!flush && q->tail == last)
if (!flush && tail == last)
last = readl(&q->regs->dma_idx);
if (done > 16) {
spin_lock_bh(&q->lock);
q->queued -= done;
q->tail = tail;
spin_unlock_bh(&q->lock);
done = 0;
}
}
spin_unlock_bh(&q->cleanup_lock);
if (done) {
spin_lock_bh(&q->lock);
q->queued -= done;
q->tail = tail;
spin_unlock_bh(&q->lock);
}
if (flush) {
spin_lock_bh(&q->lock);
mt76_dma_sync_idx(dev, q);