Re: [PATCH v3 00/26] mm: introduce numa_memblks

Dan Williams
2024-08-05T19:41:22Z

Mike Rapoport wrote:
> From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
>
> Hi,
>
> Following the discussion about handling of CXL fixed memory windows on
> arm64 [1] I decided to bite the bullet and move numa_memblks from x86 to
> the generic code so they will be available on arm64/riscv and maybe on
> loongarch sometime later.
>
> While it could be possible to use memblock to describe CXL memory windows,
> it currently lacks notion of unpopulated memory ranges and numa_memblks
> does implement this.
>
> Another reason to make numa_memblks generic is that both arch_numa (arm64
> and riscv) and loongarch use trimmed copy of x86 code although there is no
> fundamental reason why the same code cannot be used on all these platforms.
> Having numa_memblks in mm/ will make it's interaction with ACPI and FDT
> more consistent and I believe will reduce maintenance burden.
>
> And with generic numa_memblks it is (almost) straightforward to enable NUMA
> emulation on arm64 and riscv.

Hey Mike,

So interesting to see this come full circle and instead of moving
numa_memblks to memblock, just uplevel numa_memblks. From the
perspective of having numa_memblks enhancements work for more
architectures this gets an enthusiastic thumbs up from me. Let me go
look at the details...