Re: [PATCH v2 1/1] mm: numa_memblks: Identify the accurate NUMA ID of CFMW

[Andrew Morton]

On Thu, 15 Jan 2026 17:43:02 +0800 Cui Chao <cuichao1753@xxxxxxxxxxxxxx> wrote:

> When a CXL RAM region is created in userspace, the memory capacity of 
> the newly created region is not added to the CFMW-dedicated NUMA node. 
> Instead, it is accumulated into an existing NUMA node (e.g., NUMA0 
> containing RAM). This makes it impossible to clearly distinguish between 
> the two types of memory, which may affect memory-tiering applications.
> 

OK, thanks, I added this to the changelog.  Please retain it when
sending v3.

What I'm actually looking for here are answers to the questions

  Should we backport this into -stable kernels and if so, why?
  And if not, why not?

So a very complete description of the runtime effects really helps
myself and others to decide which kernels to patch.  And it helps
people to understand *why* we made that decision.

And sorry, but "may affect memory-tiering applications" isn't very
complete!

So please, tell us how much our users are hurting from this and please
make a recommendation on the backporting decision.