Wed, Aug 28, 2019 at 11:26:03PM CEST, dsah...@gmail.com wrote:
>On 8/28/19 4:37 AM, Jiri Pirko wrote:
>> Tue, Aug 06, 2019 at 09:15:17PM CEST, dsah...@kernel.org wrote:
>>> From: David Ahern <dsah...@gmail.com>
>>>
>>> Prior to the commit in the fixes tag, the resource controller in netdevsim
>>> tracked fib entries and rules per network namespace. Restore that behavior.
>>
>> David, please help me understand. If the counters are per-device, not
>> per-netns, they are both the same. If we have device (devlink instance)
>> is in a netns and take only things happening in this netns into account,
>> it should count exactly the same amount of fib entries, doesn't it?
>
>if you are only changing where the counters are stored - net_generic vs
>devlink private - then yes, they should be equivalent.
Okay.
>
>>
>> I re-thinked the devlink netns patchset and currently I'm going in
>> slightly different direction. I'm having netns as an attribute of
>> devlink reload. So all the port netdevices and everything gets
>> re-instantiated into new netns. Works fine with mlxsw. There we also
>> re-register the fib notifier.
>>
>> I think that this can work for your usecase in netdevsim too:
>> 1) devlink instance is registering a fib notifier to track all fib
>> entries in a namespace it belongs to. The counters are per-device -
>> counting fib entries in a namespace the device is in.
>> 2) another devlink instance can do the same tracking in the same
>> namespace. No problem, it's a separate counter, but the numbers are
>> the same. One can set different limits to different devlink
>> instances, but you can have only one. That is the bahaviour you have
>> now.
>> 3) on devlink reload, netdevsim re-instantiates ports and re-registers
>> fib notifier
>> 4) on devlink reload with netns change, all should be fine as the
>> re-registered fib nofitier replays the entries. The ports are
>> re-instatiated in new netns.
>>
>> This way, we would get consistent behaviour between netdevsim and real
>> devices (mlxsw), correct devlink-netns implementation (you also
>> suggested to move ports to the namespace). Everyone should be happy.
>>
>> What do you think?
>>
>
>Right now, registering the fib notifier walks all namespaces. That is
>not a scalable solution. Are you changing that to replay only a given
>netns? Are you changing the notifiers to be per-namespace?
Eventually, that seems like good idea. Currently I want to do
if (net==nsim_dev->mynet)
done
check at the beginning of the notifier.
>
>Also, you are still allowing devlink instances to be created within a
>namespace?
Yes, netdevsim is planned to be created directly in namespace.
