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

[Rohit Seth]

On Wed, 2006-09-20 at 15:58 -0700, Paul Jackson wrote:
> Seth wrote:
> > So now we depend on getting memory hot-plug to work for faking up these
> > nodes ...for the memory that is already present in the system. It just
> > does not sound logical.
> 
> It's logical to me.  Part of memory hotplug is adding physial memory,
> which is not an issue here.  Part of it is adding another logical
> memory node (turning on another bit in node_online_map) and fixing up
> any code that thought a systems memory nodes were baked in at boottime.
> Perhaps the hardest part is the memory hot-un-plug, which would become
> more urgently needed with such use of fake numa nodes.  The assumption
> that memory doesn't just up and vanish is non-trivial to remove from
> the kernel.  A useful memory containerization should (IMHO) allow for
> both adding and removing such containers.
> 

Absolutely.  Since these containers are not (hard) partitioning the
memory in any way so it is easy to change the limits (effectively
reducing and increasing the memory limits for tasks belonging to
containers).  As you said, memory hot-un-plug is important and it is
non-trivial amount of work.

-rohit