100% CPU load with device scanning enabled

[Maria Matejka]

Hello!

Just shortly, I was trying BIRD in QEMUs connected via OVS bridges 
several years ago. It was even worse, I went to some segfaults in OVS.
(A week later, one of my friends told me that it was an embargoed bug.)
I didn't try any more, it wasn't feasible.

I'd like to promise that I'd look into it, anyway I'm busy a lot and 
I'll surely forget your issue in ten minutes. If you don't hear me until 
next Monday, please ping me.

Maria

On 5/6/19 9:33 PM, Saso Tavcar wrote:
> The best solution would be a good OVS routing table patch as quoted.
> 
> Maybe BIRD developers can help, since they are native C developers.
> 
> We also tried bird on native (K)VM network interfaces. Since they are 
> some kind of SW
> emulation too, we hit on unrecoverable network IRQ problems, thus 
> overloaded OVS is
> still better solution for us.
> 
> Regards,
> saso
> 
>> On 6 May 2019, at 21:01, Kees Meijs <kees at nefos.nl 
>> <mailto:kees at nefos.nl>> wrote:
>>
>> Hi Saso,
>>
>> Thank you very much. OVS is new in the mix (we're not replacing Quagga 
>> alone) as well. Obviously we didn't expect this to happen.
>>
>> I'll see if patching OVS in Debian in a similar way works for us or if 
>> another approach fits better (i.e. maybe not using OVS at all).
>>
>> If you'll know of a better more upgrade-and-maintainance-proof 
>> solution I would welcome more information.
>>
>> Regards,
>> Kees
>>
>> On 06-05-19 20:40, Saso Tavcar wrote:
>>> this is an OVS issue, already discussed:
>>>
>>> https://mail.openvswitch.org/pipermail/ovs-discuss/2016-November/043007.html
>>> ...
>>> _https://mail.openvswitch.org/pipermail/ovs-discuss/2016-November/043063.html_
>>> _
>>> _
>>> Official OVS quote:
>>> >/We'd accept patches to improve OVS's routing table code. It's not />/designed to scale to 1,800,000 routes. We'd also take code to suppress />/the routing table code in cases where it isn't actually needed, since />/it's not always needed. But we can't take a patch to just delete it; />/I'm sure you understand./
>>> I tried to apply this patch at that time, but was already useless for 
>>> newer versions:
>>>
>>> _https://mail.openvswitch.org/pipermail/ovs-discuss/attachments/20161123/5379b333/attachment.bin_
>>>
>>> Our workaround was to scale VM with 3 vCPU-s, since our average 
>>> system load is 1.5 for BGP.
>>>
>>> You can see what is happening:
>>>
>>
>