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| author | Xuan Zhuo <xuanzhuo@linux.alibaba.com> | 2023-05-08 09:14:03 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2023-05-10 05:44:26 +0300 |
| commit | 363d8ce4b94719a87dad865e2829f1dba0f7ef71 (patch) | |
| tree | d023fc957ad518e3ac37fe0b22464153654fe464 /drivers/net/virtio_net.c | |
| parent | 559ae55cfc334c91c62d2ea054a3345611363ee0 (diff) | |
| download | linux-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.c | 19 |
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++) { |