Re: [ckrm-tech] [patch00/05]: Containers(V2)- Introduction

[Chandra Seetharaman <sekharan@us.ibm.com>]

On Wed, 2006-09-20 at 18:52 -0700, Paul Menage wrote:
> On 9/20/06, Chandra Seetharaman <sekharan@us.ibm.com> wrote:
> >
> > Interesting. So you could set up the fake node with "guarantee" and let
> > it grow till "limit" ?
> 
> Sure - that works great. (Theoretically you could do this all in
> userspace - start by assigning  "guarantee" nodes to a
> container/cpuset and when it gets close to its memory limit assign
> more nodes to it. But in practice userspace can't keep up with rapid
> memory allocators.
> 
I agree, especially when one of your main object is resource
utilization. Think about the magnitude of this when you have to deal
with 100s of containers.

> >
> > BTW, can you do these with fake nodes:
> >  - dynamic creation
> >  - dynamic removal
> >  - dynamic change of size
> 
> The current fake numa support requires you to choose your node layout
> at boot time - I've been working with 64 fake nodes of 128M each,
> which gives a reasonable granularity for dividing a machine between
> multiple different sized jobs.

It still will not satisfy what OpenVZ/Container folks are looking for:
100s of containers.

> 
> >
> > Also, How could we account when a process moves from one node to
> > another ?
> 
> If you want to do that (the systems I'm working on don't really) you
> could probably do it with the migrate_pages() syscall. It might not be
> that efficient though.

Totally agree, that will be very costly.
> 
> Paul
-- 

----------------------------------------------------------------------
    Chandra Seetharaman               | Be careful what you choose....
              - sekharan@us.ibm.com   |      .......you may get it.
----------------------------------------------------------------------