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authorXuan Zhuo <xuanzhuo@linux.alibaba.com>2023-05-08 09:14:03 +0300
committerJakub Kicinski <kuba@kernel.org>2023-05-10 05:44:26 +0300
commit363d8ce4b94719a87dad865e2829f1dba0f7ef71 (patch)
treed023fc957ad518e3ac37fe0b22464153654fe464 /drivers/net/virtio_net.c
parent559ae55cfc334c91c62d2ea054a3345611363ee0 (diff)
downloadlinux-363d8ce4b94719a87dad865e2829f1dba0f7ef71.tar.xz
virtio_net: mergeable xdp: put old page immediately
In the xdp implementation of virtio-net mergeable, it always checks whether two page is used and a page is selected to release. This is complicated for the processing of action, and be careful. In the entire process, we have such principles: * If xdp_page is used (PASS, TX, Redirect), then we release the old page. * If it is a drop case, we will release two. The old page obtained from buf is release inside err_xdp, and xdp_page needs be relased by us. But in fact, when we allocate a new page, we can release the old page immediately. Then just one is using, we just need to release the new page for drop case. On the drop path, err_xdp will release the variable "page", so we only need to let "page" point to the new xdp_page in advance. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/net/virtio_net.c')
-rw-r--r--drivers/net/virtio_net.c19
1 files changed, 7 insertions, 12 deletions
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index a12ae26db0e2..e9ee4fd5fe5f 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1249,6 +1249,9 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
if (!xdp_page)
goto err_xdp;
offset = VIRTIO_XDP_HEADROOM;
+
+ put_page(page);
+ page = xdp_page;
} else if (unlikely(headroom < virtnet_get_headroom(vi))) {
xdp_room = SKB_DATA_ALIGN(VIRTIO_XDP_HEADROOM +
sizeof(struct skb_shared_info));
@@ -1263,11 +1266,12 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
page_address(page) + offset, len);
frame_sz = PAGE_SIZE;
offset = VIRTIO_XDP_HEADROOM;
- } else {
- xdp_page = page;
+
+ put_page(page);
+ page = xdp_page;
}
- data = page_address(xdp_page) + offset;
+ data = page_address(page) + offset;
err = virtnet_build_xdp_buff_mrg(dev, vi, rq, &xdp, data, len, frame_sz,
&num_buf, &xdp_frags_truesz, stats);
if (unlikely(err))
@@ -1282,8 +1286,6 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
if (unlikely(!head_skb))
goto err_xdp_frags;
- if (unlikely(xdp_page != page))
- put_page(page);
rcu_read_unlock();
return head_skb;
case XDP_TX:
@@ -1301,8 +1303,6 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
goto err_xdp_frags;
}
*xdp_xmit |= VIRTIO_XDP_TX;
- if (unlikely(xdp_page != page))
- put_page(page);
rcu_read_unlock();
goto xdp_xmit;
case XDP_REDIRECT:
@@ -1311,8 +1311,6 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
if (err)
goto err_xdp_frags;
*xdp_xmit |= VIRTIO_XDP_REDIR;
- if (unlikely(xdp_page != page))
- put_page(page);
rcu_read_unlock();
goto xdp_xmit;
default:
@@ -1325,9 +1323,6 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
goto err_xdp_frags;
}
err_xdp_frags:
- if (unlikely(xdp_page != page))
- __free_pages(xdp_page, 0);
-
if (xdp_buff_has_frags(&xdp)) {
shinfo = xdp_get_shared_info_from_buff(&xdp);
for (i = 0; i < shinfo->nr_frags; i++) {