Re: [RFC] implicit per-namespace devlink instance to set kernel resource limitations

[David Ahern <dsahern@gmail.com>]

On 8/7/19 12:49 PM, Jakub Kicinski wrote:
> Perhaps I'm misinterpreting your point there.

yes, this thread is getting out of hand.

I am not pushing for an in-kernel, fib resource controller. Jiri wants
to remove the existing devlink resource code from netdevsim into a
standalone driver, code that was added for testing and as the commit log
shows as a demonstration of how one could create a controller using the
devlink API. I added some color commentary as to why a devlink
controller makes sense for the use case and how it should work, but I am
not asking for such a controller to be added to the kernel.

The netdevsim resource controller is counter based; the absolute
simplest form of limits. If I wanted basic counting for a fib resource
controller, I would add an option to limit the number of fib rules and
routes using sysctl similar to what exists for neighbors. Consistency. I
don't need the overhead and unrelated messiness of cgroups. I don't need
the overhead of handling fib notifiers. fib (rule) add -- check counter,
increment counter; fib (rule) delete -- decrement counter. Simple, per
namespace, done.