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From: Daniel Borkmann <daniel@iogearbox•net>
To: Jason Wang <jasowang@redhat•com>,
	mst@redhat•com, virtualization@lists•linux-foundation.org,
	netdev@vger•kernel.org, linux-kernel@vger•kernel.org
Cc: john.r.fastabend@intel•com
Subject: Re: [PATCH net 1/9] virtio-net: remove the warning before XDP linearizing
Date: Fri, 23 Dec 2016 20:31:53 +0100	[thread overview]
Message-ID: <585D7BA9.50509@iogearbox.net> (raw)
In-Reply-To: <1482503852-12438-2-git-send-email-jasowang@redhat.com>

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@intel•com>
> Signed-off-by: Jason Wang <jasowang@redhat•com>
> ---
>   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?

Thanks.

>   			/* linearize data for XDP */
>   			xdp_page = xdp_linearize_page(rq, num_buf,
>   						      page, offset, &len);
>

  reply	other threads:[~2016-12-23 19:31 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-12-23 14:37 [PATCH net 0/9] several fixups for virtio-net XDP Jason Wang
2016-12-23 14:37 ` [PATCH net 1/9] virtio-net: remove the warning before XDP linearizing Jason Wang
2016-12-23 19:31   ` Daniel Borkmann [this message]
2016-12-27  3:08     ` Jason Wang
2016-12-23 14:37 ` [PATCH net 2/9] virtio-net: correctly xmit linearized page on XDP_TX Jason Wang
2016-12-23 15:47   ` John Fastabend
2016-12-23 14:37 ` [PATCH net 3/9] virtio-net: fix page miscount during XDP linearizing Jason Wang
2016-12-23 15:54   ` John Fastabend
2016-12-26  2:30     ` Jason Wang
2016-12-23 14:37 ` [PATCH net 4/9] virtio-net: correctly handle XDP_PASS for linearized packets Jason Wang
2016-12-23 15:57   ` John Fastabend
2016-12-26  2:34     ` Jason Wang
2016-12-23 14:37 ` [PATCH net 5/9] virtio-net: unbreak csumed packets for XDP_PASS Jason Wang
2016-12-23 15:58   ` John Fastabend
2016-12-23 14:37 ` [PATCH net 6/9] virtio-net: make rx buf size estimation works for XDP Jason Wang
2016-12-23 16:02   ` John Fastabend
2016-12-23 14:37 ` [PATCH net 7/9] virtio-net: forbid XDP when VIRTIO_NET_F_GUEST_UFO is support Jason Wang
2016-12-23 16:02   ` John Fastabend
2016-12-23 16:10     ` John Fastabend
2016-12-26  2:38       ` Jason Wang
2016-12-23 14:37 ` [PATCH net 8/9] virtio-net: remove big packet XDP codes Jason Wang
2016-12-23 14:37 ` [PATCH net 9/9] virtio-net: XDP support for small buffers Jason Wang
2016-12-23 16:51   ` John Fastabend
2017-01-02 22:43   ` John Fastabend
2017-01-03  6:16     ` Jason Wang
2017-01-03 16:40       ` John Fastabend
2017-01-04  3:05         ` Jason Wang
2016-12-23 17:10 ` [PATCH net 0/9] several fixups for virtio-net XDP John Fastabend
2016-12-26  2:39   ` Jason Wang
2016-12-23 18:49 ` David Miller

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