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authorMark McLoughlin <markmc@redhat.com>2008-11-17 01:39:18 -0500
committerDavid S. Miller <davem@davemloft.net>2008-11-17 01:39:18 -0500
commit0a888fd1f6320d1d9318c58de9bca3cef41546d6 (patch)
treee1ff542e6c8acba415d67a3764e4124849801805 /drivers/net/virtio_net.c
parent908cd2dabbfbbefb02f6b908a1188a62e685136a (diff)
virtio_net: Recycle some more rx buffer pages
Each time we re-fill the recv queue with buffers, we allocate one too many skbs and free it again when adding fails. We should recycle the pages allocated in this case. A previous version of this patch made trim_pages() trim trailing unused pages from skbs with some paged data, but this actually caused a barely measurable slowdown. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (use netdev_priv) Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/virtio_net.c')
-rw-r--r--drivers/net/virtio_net.c22
1 files changed, 13 insertions, 9 deletions
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index ede0a80045b3..f5207ef21a91 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -82,6 +82,16 @@ static void give_a_page(struct virtnet_info *vi, struct page *page)
82 vi->pages = page; 82 vi->pages = page;
83} 83}
84 84
85static void trim_pages(struct virtnet_info *vi, struct sk_buff *skb)
86{
87 unsigned int i;
88
89 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
90 give_a_page(vi, skb_shinfo(skb)->frags[i].page);
91 skb_shinfo(skb)->nr_frags = 0;
92 skb->data_len = 0;
93}
94
85static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask) 95static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask)
86{ 96{
87 struct page *p = vi->pages; 97 struct page *p = vi->pages;
@@ -121,15 +131,8 @@ static void receive_skb(struct net_device *dev, struct sk_buff *skb,
121 } 131 }
122 len -= sizeof(struct virtio_net_hdr); 132 len -= sizeof(struct virtio_net_hdr);
123 133
124 if (len <= MAX_PACKET_LEN) { 134 if (len <= MAX_PACKET_LEN)
125 unsigned int i; 135 trim_pages(netdev_priv(dev), skb);
126
127 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
128 give_a_page(netdev_priv(dev),
129 skb_shinfo(skb)->frags[i].page);
130 skb->data_len = 0;
131 skb_shinfo(skb)->nr_frags = 0;
132 }
133 136
134 err = pskb_trim(skb, len); 137 err = pskb_trim(skb, len);
135 if (err) { 138 if (err) {
@@ -233,6 +236,7 @@ static void try_fill_recv(struct virtnet_info *vi)
233 err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, num, skb); 236 err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, num, skb);
234 if (err) { 237 if (err) {
235 skb_unlink(skb, &vi->recv); 238 skb_unlink(skb, &vi->recv);
239 trim_pages(vi, skb);
236 kfree_skb(skb); 240 kfree_skb(skb);
237 break; 241 break;
238 } 242 }