Re: [RFC] Demand faulting for large pages

[Andi Kleen <ak@suse.de>]

On Fri, Aug 05, 2005 at 12:00:00PM -0500, Adam Litke wrote:
> On Fri, 2005-08-05 at 11:47, Andi Kleen wrote:
> > On Fri, Aug 05, 2005 at 11:37:27AM -0500, Adam Litke wrote:
> > > On Fri, 2005-08-05 at 10:53, Andi Kleen wrote:
> > > > On Fri, Aug 05, 2005 at 10:21:38AM -0500, Adam Litke wrote:
> > > > > Below is a patch to implement demand faulting for huge pages.  The main
> > > > > motivation for changing from prefaulting to demand faulting is so that
> > > > > huge page allocations can follow the NUMA API.  Currently, huge pages
> > > > > are allocated round-robin from all NUMA nodes.   
> > > > 
> > > > I think matching DEFAULT is better than having a different default for
> > > > huge pages than for small pages.
> > > 
> > > I am not exactly sure what the above means.  Is 'DEFAULT' a system
> > > default numa allocation policy?
> > 
> > It's one of the four numa policies: DEFAULT, PREFERED, INTERLEAVE, BIND
> > 
> > It just means allocate on the local node if possible, otherwise fall back.
> > 
> > You said you wanted INTERLEAVE by default, which i think is a bad idea.
> > It should be only optional like in all other allocations.
> 
> I tried to say that allocations are _currently_ INTERLEAVE (aka
> round-robin) but that I want it to be configurable.  So I think we are
> in agreement here.

Ok, but the way to configure it should be the standard mempolicy
infrastructure (that is how it works in SLES9 too) 

-Andi