Re: [RFC] cgroup TODOs

[Glauber Costa <glommer-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>]

On 09/14/2012 07:14 PM, Vivek Goyal wrote:
> Those who really need to implement % model, they will have to do heavy
> lifting in user space. I am skeptical that will take off but kernel
> does not prohibit from somebody creating a group, moving all tasks
> there and making sure tasks and groups are not at same level hence
> % becomes more predictable. Just that, that's not the default from
> kernel.
I subscribe to that.

I use a % model for memory / kernel memory (Give kernel 20 % of
userspace memory), but the kernel never knows about it. It only
understand megabytes. Of course this is simpler, because it is all
inside the same cgroup.

But if you want global %'s you need to calculate it from everybody
*anyway*, be it in the kernel or in userspace.