Commit d84130a1 authored by hayeswang's avatar hayeswang Committed by David S. Miller
Browse files

r8152: reduce the frequency of spin_lock 



Replace getting one item from a list with getting the whole list one time.

Signed-off-by: default avatarHayes Wang <hayeswang@realtek.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8a91c824

drivers/net/usb/r8152.c

+38 −9
Original line number Diff line number Diff line
@@ -1299,9 +1299,16 @@ r8152_tx_csum(struct r8152 *tp, struct tx_desc *desc, struct sk_buff *skb) 


static int r8152_tx_agg_fill(struct r8152 *tp, struct tx_agg *agg)

{

	struct sk_buff_head skb_head, *tx_queue = &tp->tx_queue;

	unsigned long flags;

	int remain;

	u8 *tx_data;



	__skb_queue_head_init(&skb_head);

	spin_lock_irqsave(&tx_queue->lock, flags);

	skb_queue_splice_init(tx_queue, &skb_head);

	spin_unlock_irqrestore(&tx_queue->lock, flags);



	tx_data = agg->head;

	agg->skb_num = agg->skb_len = 0;

	remain = rx_buf_sz;
@@ -1311,14 +1318,14 @@ static int r8152_tx_agg_fill(struct r8152 *tp, struct tx_agg *agg) 
		struct sk_buff *skb;

		unsigned int len;



		skb = skb_dequeue(&tp->tx_queue);

		skb = __skb_dequeue(&skb_head);

		if (!skb)

			break;



		remain -= sizeof(*tx_desc);

		len = skb->len;

		if (remain < len) {

			skb_queue_head(&tp->tx_queue, skb);

			__skb_queue_head(&skb_head, skb);

			break;

		}
@@ -1336,6 +1343,12 @@ static int r8152_tx_agg_fill(struct r8152 *tp, struct tx_agg *agg) 
		remain = rx_buf_sz - (int)(tx_agg_align(tx_data) - agg->head);

	}



	if (!skb_queue_empty(&skb_head)) {

		spin_lock_irqsave(&tx_queue->lock, flags);

		skb_queue_splice(&skb_head, tx_queue);

		spin_unlock_irqrestore(&tx_queue->lock, flags);

	}



	netif_tx_lock(tp->netdev);



	if (netif_queue_stopped(tp->netdev) &&
@@ -1354,10 +1367,17 @@ static int r8152_tx_agg_fill(struct r8152 *tp, struct tx_agg *agg) 
static void rx_bottom(struct r8152 *tp)

{

	unsigned long flags;

	struct list_head *cursor, *next;

	struct list_head *cursor, *next, rx_queue;



	if (list_empty(&tp->rx_done))

		return;



	INIT_LIST_HEAD(&rx_queue);

	spin_lock_irqsave(&tp->rx_lock, flags);

	list_for_each_safe(cursor, next, &tp->rx_done) {

	list_splice_init(&tp->rx_done, &rx_queue);

	spin_unlock_irqrestore(&tp->rx_lock, flags);



	list_for_each_safe(cursor, next, &rx_queue) {

		struct rx_desc *rx_desc;

		struct rx_agg *agg;

		int len_used = 0;
@@ -1366,7 +1386,6 @@ static void rx_bottom(struct r8152 *tp) 
		int ret;



		list_del_init(cursor);

		spin_unlock_irqrestore(&tp->rx_lock, flags);



		agg = list_entry(cursor, struct rx_agg, list);

		urb = agg->urb;
@@ -1416,13 +1435,13 @@ static void rx_bottom(struct r8152 *tp) 


submit:

		ret = r8152_submit_rx(tp, agg, GFP_ATOMIC);

		spin_lock_irqsave(&tp->rx_lock, flags);

		if (ret && ret != -ENODEV) {

			list_add_tail(&agg->list, next);

			spin_lock_irqsave(&tp->rx_lock, flags);

			list_add_tail(&agg->list, &tp->rx_done);

			spin_unlock_irqrestore(&tp->rx_lock, flags);

			tasklet_schedule(&tp->tl);

		}

	}

	spin_unlock_irqrestore(&tp->rx_lock, flags);

}



static void tx_bottom(struct r8152 *tp)
@@ -1496,9 +1515,19 @@ int r8152_submit_rx(struct r8152 *tp, struct rx_agg *agg, gfp_t mem_flags) 
static void rtl_drop_queued_tx(struct r8152 *tp)

{

	struct net_device_stats *stats = &tp->netdev->stats;

	struct sk_buff_head skb_head, *tx_queue = &tp->tx_queue;

	unsigned long flags;

	struct sk_buff *skb;



	while ((skb = skb_dequeue(&tp->tx_queue))) {

	if (skb_queue_empty(tx_queue))

		return;



	__skb_queue_head_init(&skb_head);

	spin_lock_irqsave(&tx_queue->lock, flags);

	skb_queue_splice_init(tx_queue, &skb_head);

	spin_unlock_irqrestore(&tx_queue->lock, flags);



	while ((skb = __skb_dequeue(&skb_head))) {

		dev_kfree_skb(skb);

		stats->tx_dropped++;

	}