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

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Date:   Tue, 27 Dec 2016 11:08:34 +0800
From:   Jason Wang <jasowang@...hat.com>
To:     Daniel Borkmann <daniel@...earbox.net>, mst@...hat.com,
        virtualization@...ts.linux-foundation.org, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org
Cc:     john.r.fastabend@...el.com
Subject: Re: [PATCH net 1/9] virtio-net: remove the warning before XDP
 linearizing



On 2016年12月24日 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@...el.com>
>> Signed-off-by: Jason Wang <jasowang@...hat.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. 

Posted.

Thanks