Re: Frag is bigger than frame.

[Steven Haigh <netwiz@crc.id.au>]

On 26/04/2013 1:36 AM, Wei Liu wrote:
> On Thu, Apr 25, 2013 at 4:11 PM, Wei Liu <wei.liu2@citrix.com> wrote:
>> On Thu, Apr 25, 2013 at 12:24:22PM +0100, Steven Haigh wrote:
>>> Hi all,
>>>
>>> I've noticed a couple of DomUs have networking freeze with the following
>>> getting printed to the Dom0's /var/log/messages:
>>>
>>> Apr 25 12:09:25 hosting kernel: vif vif-4-0 vif.crc: Frag is bigger than
>>> frame.
>>> Apr 25 12:09:25 hosting kernel: vif vif-4-0 vif.crc: fatal error;
>>> disabling device
>>> Apr 25 12:09:25 hosting kernel: br0: port 5(vif.crc) entered disabled state
>>>
>>> I thought this was something to do with MAX_SKB_FRAGS - however the
>>> kernel I use has this increased to 19 - so in theory I shouldn't hit
>>> this (as far as I know).
>>>
>>> Are there any other things that could trigger this?
>>>
>>
>> You're seeing a netfront bug which is fixed in that series. And it is
>> not related to MAX_SKB_FRAGS but related to GSO.
>>
>> Could you try applying my patch set "Bundle fixes for Xen netfront /
>> netback" version 7. That series has been applied to DaveM's net-next.
>>
>
> BTW with that series you should be able to get rid of the
> MAX_SKB_FRAGS -> 19 hack.

This could be quite difficult. The DomU kernel is RHEL based - and not 
easily changed without sending the patch upstream to RH - which may or 
may not apply it.

My google-fu has failed a little here - do you have a link to the 
patches? Is it against Xen or the kernel? Further, is it something that 
just altering the Dom0 part would resolve?

-- 
Steven Haigh

Email: netwiz@crc.id.au
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