From: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
To: netdev@vger.kernel.org
Cc: "Michael S. Tsirkin" <mst@redhat.com>,
Jason Wang <jasowang@redhat.com>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Jesper Dangaard Brouer <hawk@kernel.org>,
John Fastabend <john.fastabend@gmail.com>,
virtualization@lists.linux-foundation.org, bpf@vger.kernel.org
Subject: [PATCH net-next 1/8] virtio_net: mergeable xdp: put old page immediately
Date: Wed, 22 Mar 2023 11:03:01 +0800 [thread overview]
Message-ID: <20230322030308.16046-2-xuanzhuo@linux.alibaba.com> (raw)
In-Reply-To: <20230322030308.16046-1-xuanzhuo@linux.alibaba.com>
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>
---
drivers/net/virtio_net.c | 15 ++++++---------
1 file changed, 6 insertions(+), 9 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index e2560b6f7980..4d2bf1ce0730 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1245,6 +1245,9 @@ 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));
@@ -1259,6 +1262,9 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
page_address(page) + offset, len);
frame_sz = PAGE_SIZE;
offset = VIRTIO_XDP_HEADROOM;
+
+ put_page(page);
+ page = xdp_page;
} else {
xdp_page = page;
}
@@ -1278,8 +1284,6 @@ 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:
@@ -1297,8 +1301,6 @@ 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:
@@ -1307,8 +1309,6 @@ 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:
@@ -1321,9 +1321,6 @@ 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++) {
--
2.32.0.3.g01195cf9f
next prev parent reply other threads:[~2023-03-22 3:03 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-22 3:03 [PATCH net-next 0/8] virtio_net: refactor xdp codes Xuan Zhuo
2023-03-22 3:03 ` Xuan Zhuo [this message]
2023-03-22 8:22 ` [PATCH net-next 1/8] virtio_net: mergeable xdp: put old page immediately Yunsheng Lin
2023-03-23 1:36 ` Xuan Zhuo
2023-03-23 3:38 ` Yunsheng Lin
2023-03-23 3:45 ` Xuan Zhuo
2023-03-23 5:38 ` Jason Wang
2023-03-23 5:58 ` Xuan Zhuo
2023-03-22 3:03 ` [PATCH net-next 2/8] virtio_net: mergeable xdp: introduce mergeable_xdp_prepare Xuan Zhuo
2023-03-22 11:52 ` Yunsheng Lin
2023-03-23 1:45 ` Xuan Zhuo
2023-03-23 4:45 ` Yunsheng Lin
2023-03-23 4:52 ` Jakub Kicinski
2023-03-23 5:40 ` Jason Wang
2023-03-23 7:24 ` Yunsheng Lin
2023-03-23 11:04 ` Xuan Zhuo
2023-03-23 10:59 ` Xuan Zhuo
2023-03-22 3:03 ` [PATCH net-next 3/8] virtio_net: introduce virtnet_xdp_handler() to seprate the logic of run xdp Xuan Zhuo
2023-03-22 3:03 ` [PATCH net-next 4/8] virtio_net: separate the logic of freeing xdp shinfo Xuan Zhuo
2023-03-22 3:03 ` [PATCH net-next 5/8] virtio_net: separate the logic of freeing the rest mergeable buf Xuan Zhuo
2023-03-22 3:03 ` [PATCH net-next 6/8] virtio_net: auto release xdp shinfo Xuan Zhuo
2023-03-22 3:03 ` [PATCH net-next 7/8] virtio_net: introduce receive_mergeable_xdp() Xuan Zhuo
2023-03-22 23:43 ` kernel test robot
2023-03-22 3:03 ` [PATCH net-next 8/8] virtio_net: introduce receive_small_xdp() Xuan Zhuo
2023-03-23 2:06 ` kernel test robot
2023-03-22 3:34 ` [PATCH net-next 0/8] virtio_net: refactor xdp codes Michael S. Tsirkin
2023-03-22 3:40 ` Xuan Zhuo
2023-03-22 3:53 ` Michael S. Tsirkin
2023-03-22 3:56 ` Xuan Zhuo
2023-03-22 3:59 ` Jakub Kicinski
2023-03-28 12:04 Xuan Zhuo
2023-03-28 12:04 ` [PATCH net-next 1/8] virtio_net: mergeable xdp: put old page immediately Xuan Zhuo
2023-03-31 9:01 ` Jason Wang
2023-04-03 4:11 ` Xuan Zhuo
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