Re: netconsole breaks netpoll on bridge

Stefan Priebe - Profihost AG
2014-06-16T19:05:56Z

> Am 16.06.2014 um 20:51 schrieb Cong Wang <cwang@twopensource.com>:
>
> On Mon, Jun 16, 2014 at 11:41 AM, Stefan Priebe - Profihost AG
> <s.priebe@profihost.ag> wrote:
>>
>>> Am 16.06.2014 um 20:05 schrieb Cong Wang <cwang@twopensource.com>:
>>>
>>> On Mon, Jun 16, 2014 at 5:51 AM, Stefan Priebe - Profihost AG
>>> <s.priebe@profihost.ag> wrote:
>>>> Hi,
>>>>
>>>> i'm using a vanilla 3.10.43 kernel and netconsole on top of a bridge.
>>>>
>>>> netconsole is used with vmbr0 (bridge) which is on top of bond0.
>>>>
>>>> If i want to add another bridge to vmbr0 is fails as long as netconsole
>>>> is in use.
>>>>
>>>> # brctl addif vmbr0 fwpr2004p0
>>>> can't add fwpr2004p0 to bridge vmbr0: Unknown error 524
>>>>
>>>> Kernel output:
>>>> netpoll: (null): fwpr2004p0 doesn't support polling, aborting
>>>>
>>>> If i do rmmod netconsole - everything is working fine again.
>>>
>>> This is expected, you can't add an interface which doesn't support
>>> netpoll to a bridge which is running netpoll.
>>
>> Thanks, so i can't use netconsole at a bridge used for vms?
>
> You can, but you need to make sure all the devices under
> this bridge support netpoll. Not considering mac learning,
> bridge just broadcasts all the packets to its ports, if one of them
> doesn't support netpoll, how could it work?

Ok i was trying to add a veth device so this is the problematic device.

>>> You should stop netpoll before adding it.
>>
>> How to do that? What disadvantage does this have?
>
> If you are using a redhat distro, run `service netconsole stop`.
>
> Or you can disable it via configfs, check
> Documentation/networking/netconsole.txt.

Ok but this means disabling netconsole nothing I want.

Stefan