Re: [PATCH RFC net-next 7/7] netdevsim: Add simple FIB resource controller via devlink

Sun, Mar 25, 2018 at 04:24:11PM CEST, dsa@cumulusnetworks.com wrote:

On 3/24/18 10:02 AM, Jiri Pirko wrote:

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Wait a second. What do you mean by "per-network namespace"? Devlink
instance is always associated with one physical device. Like an ASIC.

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has a net entry, the simplest design is to put it into the namespace of
the controller. Without it, controlling resource sizes in namespace
'foobar' has to be done from init_net, which is just wrong.

you need to look at how netdevsim creates a device per netdevice.

That means one devlink instance for each netdevsim device, doesn't it?

yes.

Still not sure how to handle namespaces in devlink. Originally, I
thought it would be okay to leave all devlink instances in init_ns.
Because what happens if you move netdev to another namespace? Should the
devlink move as well? What if you have multiple ports, each in different
namespace. Can user move devlink instance to another namespace? Etc.

The devlink instance is associated with a 'struct device' and those do
not change namespaces AFAIK.

Yeah. But you put devlink instance into namespace according to struct
net_device. That is mismatch.

New netdevsim netdevice creates a new 'struct device' which creates a
new devlink instance. The namespace the netdev is created in is then
passed to the devlink instance. Yes, the netdev could change namespaces,
but that is something we can easily prevent if it has a devlink instance.

But really, we are way down a tangent with respect to the intent of this
patch set. I am fine with limiting the example resource controller to

I know. That is just something that I spotted :)