Signed-off-by: Shirley Ma <xma@xxxxxxxxxx>
---
drivers/net/virtio_net.c | 39 ++++++++++++++++++++-------------------
1 files changed, 20 insertions(+), 19 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 82dba5a..c603daa 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -23,6 +23,7 @@
#include <linux/module.h>
#include <linux/virtio.h>
#include <linux/virtio_net.h>
+#include <linux/virtio_ring.h>
#include <linux/scatterlist.h>
#include <linux/if_vlan.h>
#include <linux/slab.h>
@@ -509,19 +510,18 @@ again:
return received;
}
-static unsigned int free_old_xmit_skbs(struct virtnet_info *vi)
+static void free_old_xmit_skbs(struct virtnet_info *vi)
{
struct sk_buff *skb;
- unsigned int len, tot_sgs = 0;
+ unsigned int len;
while ((skb = virtqueue_get_buf(vi->svq, &len)) != NULL) {
pr_debug("Sent skb %p\n", skb);
vi->dev->stats.tx_bytes += skb->len;
vi->dev->stats.tx_packets++;
- tot_sgs += skb_vnet_hdr(skb)->num_sg;
dev_kfree_skb_any(skb);
}
- return tot_sgs;
+ return;
}
static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
@@ -574,11 +574,26 @@ static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct virtnet_info *vi = netdev_priv(dev);
+ bool drop;
+ bool indirect = virtio_has_feature(vi->vdev,
+ VIRTIO_RING_F_INDIRECT_DESC);
int capacity;
/* Free up any pending old buffers before queueing new ones. */
free_old_xmit_skbs(vi);
-
+ capacity = virtqueue_get_capacity(vi->svq);
+
+ /* Drop packet instead of stop queue for better performance */
+ drop = (capacity == 0 && indirect) ||
+ ((capacity < MAX_SKB_FRAGS + 2) && !indirect);
+ if (unlikely(drop)) {
+ dev->stats.tx_fifo_errors++;
+ dev_warn(&dev->dev, "Unexpected TX queue failure: %d\n",
+ capacity);
+ dev->stats.tx_dropped++;
+ kfree_skb(skb);
+ return NETDEV_TX_OK;
+ }
/* Try to transmit */
capacity = xmit_skb(vi, skb);
@@ -605,20 +620,6 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
skb_orphan(skb);
nf_reset(skb);
- /* Apparently nice girls don't return TX_BUSY; stop the queue
- * before it gets out of hand. Naturally, this wastes entries. */
- if (capacity < 2+MAX_SKB_FRAGS) {
- netif_stop_queue(dev);
- if (unlikely(!virtqueue_enable_cb(vi->svq))) {
- /* More just got used, free them then recheck. */
- capacity += free_old_xmit_skbs(vi);
- if (capacity >= 2+MAX_SKB_FRAGS) {
- netif_start_queue(dev);
- virtqueue_disable_cb(vi->svq);
- }
- }
- }
-
return NETDEV_TX_OK;
}
--
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