Re: [patch -mm] cpusets: add memory_slab_hardwall flag

[Matt Mackall <mpm@selenic.com>]

On Thu, 2009-03-12 at 12:08 -0400, Christoph Lameter wrote:
> On Tue, 10 Mar 2009, Matt Mackall wrote:
> 
> > > > Yes, and that's why we require the cpuset hardwall on a configurable
> > > > per-cpuset basis.  If a cpuset has set this option for its workload, then
> > > > it is demanding object allocations from local memory.  Other cpusets that
> > > > do not have memory_slab_hardwall set can still allocate from any cpu slab
> > > > or partial slab, including those allocated for the hardwall cpuset.
> > >
> > > You cannot hardwall something that is used in a shared way by processes in
> > > multiple cpusets.
> >
> > He can enforce that every allocation made when a given task is current
> > conforms. His patch demonstrates that.
> 
> Of course. But that may just be a subset of the data used by a task. If an
> inode, dentry and so on was already allocated in the context of another
> process then the locality of that allocation will not be changed. The
> hardwall will have no effect.

It will if he's also using a namespace. This is part of a larger puzzle.

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