Thu, Aug 29, 2019 at 02:54:39PM CEST, dsah...@gmail.com wrote: >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.
Fair enough. Will include this now. Thanks!
