[Devel] Re: [PATCH 6/7] containers (V7): BeanCounters over generic process containers

[Paul Menage]

On 2/12/07, Srivatsa Vaddagiri <vatsa at in.ibm.com> wrote:
> On Mon, Feb 12, 2007 at 12:15:27AM -0800, menage at google.com wrote:
> > This patch implements the BeanCounter resource control abstraction
> > over generic process containers.
>
> Forgive my confusion, but do we really need two-levels of resource control
> abstraction here? Why can't resource controllers directly work with containers
> (just like cpu accounting does)?
>

The generic containers patch represents a pretty low-level view of
task grouping - it doesn't try to prescribe how to do accounting, nor
exactly what API to present to the user (beyond providing a
filesystem-based interface).

Resource controllers certainly can be written directly over it, but
equally having additional abstractions to provide a common user API
and kernel API for multiple resources is a reasonable goal.

I would imagine that each different resource being controlled would be
represented as a container subsystem, which is how I structured the
ResGroups example patch - ResGroups becomes a library that provides a
common set of file manipulations for different resource controllers,
each of which is a containers subsystem. The same could potentially be
done for BeanCounters if people wanted.

But the main point of the latter four patches in this series is to
illustrate to the various folks writing resource controller systems
(and other observers) that this patch provides sufficient features to
act as a base for their work. I don't presume to claim that one
higher-level resource control abstraction is better than another.

Paul