Re: [RFC PATCH v2 0/8] mm: Hot page tracking and promotion infrastructure

[Jonathan Cameron]

On Wed, 22 Oct 2025 11:05:16 -0400
Gregory Price <gourry@xxxxxxxxxx> wrote:

> On Wed, Oct 22, 2025 at 10:09:50AM +0100, Jonathan Cameron wrote:
> > 
> > My gut feeling is the need to do dynamic NUMA nodes will not be driven
> > but this but more by large scale fabrics (if that ever happens)
> > and trade offs of host PA space vs QoS in the hardware.  Those
> > trade offs might put memory with very different performance
> > characteristics behind one window.
> >   
> 
> I can't believe we live in a world where "We have to think about the
> scenario where we actually need all 256 TB of 48-bit phys-addressing"
> is not a tongue in cheek joke o_o

You think everyone wires all the 48 bits?  Certainly not everyone does.

> 
> That's a paltry 2048 128GB DIMMs... and whatever monstrosity you have to
> build to host it all but that's at least a fun engineering problem :V
> 
> Bring on the 128-bit CPUs!
> 
> What do we name those x86 registers though? Slap the E back on for ERAX?
> 
> > Meh. Let's suggest people burn host PA space for now.  If anyone hits
> > that limit they can solve it (crosses fingers it's not my lot :)
> >   
> 
> +1
> 
> ~Gregory