lkml.org 
[lkml]   [2014]   [Feb]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH net-next 05/14] r8152: reduce the frequency of spin_lock
Date
Replace getting one item from a list with getting the whole list one time.

Signed-off-by: Hayes Wang <hayeswang@realtek.com>
---
drivers/net/usb/r8152.c | 47 ++++++++++++++++++++++++++++++++++++++---------
1 file changed, 38 insertions(+), 9 deletions(-)

diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index 3847c35..2a778fa 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -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++;
}
--
1.8.4.2


\
 
 \ /
  Last update: 2014-02-18 15:41    [W:0.340 / U:0.132 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site