Re: [PATCH 0/4] mm/mempolicy: introduce package-aware weighted interleave

On Sun, 16 Aug 2026 20:46:16 -0400 Gregory Price <[email protected]> wrote:

> On Thu, Aug 13, 2026 at 03:23:48PM +0900, Rakie Kim wrote:
> > On Wed, 12 Aug 2026 22:37:06 -0400 Gregory Price <[email protected]> wrote:
> > 
> > The cpuset.mems = 0,2 you describe is the node set of package 0, so
> > the tasks in that cgroup use node0 and node2 wherever they run.
> > 
> 
> I think you are over-complicating the explanation and that's making it
> hard for folks to reason about this.
> 
> My best understanding here is for multi-socket systems, weighted
> interleave as-designed is inherently sub-optimal for scaled workloads
> that utilize multi-socket ("package") memory resources (DRAM, CXL...)

I was thinking about this and I think Gregory is right here.

I wonder how much of the framing around this series can be preserved /
simplified if we just say "prevent tasks from allocating memory
cross-socket".

I also wonder if instead of limiting this to weighted interleave,
this can sit on top of other mpols and just nodemasks against
cross-socket nodes.

> I think there is also an assumption that total memory utilization is
> less than the total capacity - otherwise some of the assumptions here
> break, but that comes with the general weighted interleave story.
> 
> I'm getting back from vacation, I will take a closer look this week.

I am also out on vacation this week : -)
I'll take a closer look along with the code next week as well.

Thanks, Rakie and Gregory!
Joshua