On 8/29/19 12:28 AM, Jiri Pirko wrote: > 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. >
The per-namespace replay should be done as part of this re-work. It should not be that big of a change. Add 'struct net' arg to register_fib_notifier. If set, call fib_net_dump only for that namespace. The seq check should be made per-namespace. You mentioned mlxsw works fine with moving ports to a new network namespace, so that will be a 'real' example with a known scalability problem that should be addressed now.
