Re: [PATCH net 1/9] virtio-net: remove the warning before XDP linearizing

From: Jason Wang
Date: Mon Dec 26 2016 - 22:08:47 EST

On 2016å12æ24æ 03:31, Daniel Borkmann wrote:
Hi Jason,

On 12/23/2016 03:37 PM, Jason Wang wrote:
Since we use EWMA to estimate the size of rx buffer. When rx buffer
size is underestimated, it's usual to have a packet with more than one
buffers. Consider this is not a bug, remove the warning and correct
the comment before XDP linearizing.

Cc: John Fastabend <john.r.fastabend@xxxxxxxxx>
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
drivers/net/virtio_net.c | 8 +-------
1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 08327e0..1067253 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -552,14 +552,8 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
struct page *xdp_page;
u32 act;

- /* No known backend devices should send packets with
- * more than a single buffer when XDP conditions are
- * met. However it is not strictly illegal so the case
- * is handled as an exception and a warning is thrown.
- */
+ /* This happens when rx buffer size is underestimated */
if (unlikely(num_buf > 1)) {
- bpf_warn_invalid_xdp_buffer();

Could you also remove the bpf_warn_invalid_xdp_buffer(), which got added
just for this?