Re: [PATCH 00/17] mm: introduce numa_memblks

Jonathan Cameron
2024-07-19T13:33:52Z

On Tue, 16 Jul 2024 14:13:29 +0300
Mike Rapoport <rppt@kernel.org> 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.
>
> The first 5 commits in this series are cleanups that are not strictly
> related to numa_memblks.
>
> Commits 6-11 slightly reorder code in x86 to allow extracting numa_memblks
> and NUMA emulation to the generic code.
>
> Commits 12-14 actually move the code from arch/x86/ to mm/ and commit 15
> does some aftermath cleanups.
>
> Commit 16 switches arch_numa to numa_memblks.
>
> Commit 17 enables usage of phys_to_target_node() and
> memory_add_physaddr_to_nid() with numa_memblks.

Hi Mike,

I've lightly tested with emulated CXL + Generic Ports and Generic
Initiators as well as more normal cpus and memory via qemu on arm64 and it's
looking good.

From my earlier series, patch 4 is probably still needed to avoid
presenting nodes with nothing in them at boot (but not if we hotplug
memory then remove it again in which case they disappear)
https://lore.kernel.org/all/20240529171236.32002-5-Jonathan.Cameron@huawei.com/
However that was broken/inconsistent before your rework so I can send that
patch separately.

Thanks for getting this sorted! I should get time to do more extensive
testing and review in next week or so.

Jonathan

>
> [1] https://lore.kernel.org/all/20240529171236.32002-1-Jonathan.Cameron@huawei.com/
>
> Mike Rapoport (Microsoft) (17):
> mm: move kernel/numa.c to mm/
> MIPS: sgi-ip27: make NODE_DATA() the same as on all other
> architectures
> MIPS: loongson64: rename __node_data to node_data
> arch, mm: move definition of node_data to generic code
> arch, mm: pull out allocation of NODE_DATA to generic code
> x86/numa: simplify numa_distance allocation
> x86/numa: move FAKE_NODE_* defines to numa_emu
> x86/numa_emu: simplify allocation of phys_dist
> x86/numa_emu: split __apicid_to_node update to a helper function
> x86/numa_emu: use a helper function to get MAX_DMA32_PFN
> x86/numa: numa_{add,remove}_cpu: make cpu parameter unsigned
> mm: introduce numa_memblks
> mm: move numa_distance and related code from x86 to numa_memblks
> mm: introduce numa_emulation
> mm: make numa_memblks more self-contained
> arch_numa: switch over to numa_memblks
> mm: make range-to-target_node lookup facility a part of numa_memblks
>
> arch/arm64/include/asm/Kbuild | 1 +
> arch/arm64/include/asm/mmzone.h | 13 -
> arch/arm64/include/asm/topology.h | 1 +
> arch/loongarch/include/asm/Kbuild | 1 +
> arch/loongarch/include/asm/mmzone.h | 16 -
> arch/loongarch/include/asm/topology.h | 1 +
> arch/loongarch/kernel/numa.c | 21 -
> arch/mips/include/asm/mach-ip27/mmzone.h | 1 -
> .../mips/include/asm/mach-loongson64/mmzone.h | 4 -
> arch/mips/loongson64/numa.c | 20 +-
> arch/mips/sgi-ip27/ip27-memory.c | 2 +-
> arch/powerpc/include/asm/mmzone.h | 6 -
> arch/powerpc/mm/numa.c | 26 +-
> arch/riscv/include/asm/Kbuild | 1 +
> arch/riscv/include/asm/mmzone.h | 13 -
> arch/riscv/include/asm/topology.h | 4 +
> arch/s390/include/asm/Kbuild | 1 +
> arch/s390/include/asm/mmzone.h | 17 -
> arch/s390/kernel/numa.c | 3 -
> arch/sh/include/asm/mmzone.h | 3 -
> arch/sh/mm/init.c | 7 +-
> arch/sh/mm/numa.c | 3 -
> arch/sparc/include/asm/mmzone.h | 4 -
> arch/sparc/mm/init_64.c | 11 +-
> arch/x86/Kconfig | 9 +-
> arch/x86/include/asm/Kbuild | 1 +
> arch/x86/include/asm/mmzone.h | 6 -
> arch/x86/include/asm/mmzone_32.h | 17 -
> arch/x86/include/asm/mmzone_64.h | 18 -
> arch/x86/include/asm/numa.h | 24 +-
> arch/x86/include/asm/sparsemem.h | 9 -
> arch/x86/mm/Makefile | 1 -
> arch/x86/mm/amdtopology.c | 1 +
> arch/x86/mm/numa.c | 618 +-----------------
> arch/x86/mm/numa_internal.h | 24 -
> drivers/acpi/numa/srat.c | 1 +
> drivers/base/Kconfig | 1 +
> drivers/base/arch_numa.c | 223 ++-----
> drivers/cxl/Kconfig | 2 +-
> drivers/dax/Kconfig | 2 +-
> drivers/of/of_numa.c | 1 +
> include/asm-generic/mmzone.h | 5 +
> include/asm-generic/numa.h | 6 +-
> include/linux/numa.h | 5 +
> include/linux/numa_memblks.h | 58 ++
> kernel/Makefile | 1 -
> kernel/numa.c | 26 -
> mm/Kconfig | 11 +
> mm/Makefile | 3 +
> mm/numa.c | 57 ++
> {arch/x86/mm => mm}/numa_emulation.c | 42 +-
> mm/numa_memblks.c | 565 ++++++++++++++++
> 52 files changed, 847 insertions(+), 1070 deletions(-)
> delete mode 100644 arch/arm64/include/asm/mmzone.h
> delete mode 100644 arch/loongarch/include/asm/mmzone.h
> delete mode 100644 arch/riscv/include/asm/mmzone.h
> delete mode 100644 arch/s390/include/asm/mmzone.h
> delete mode 100644 arch/x86/include/asm/mmzone.h
> delete mode 100644 arch/x86/include/asm/mmzone_32.h
> delete mode 100644 arch/x86/include/asm/mmzone_64.h
> create mode 100644 include/asm-generic/mmzone.h
> create mode 100644 include/linux/numa_memblks.h
> delete mode 100644 kernel/numa.c
> create mode 100644 mm/numa.c
> rename {arch/x86/mm => mm}/numa_emulation.c (94%)
> create mode 100644 mm/numa_memblks.c
>
>
> base-commit: 22a40d14b572deb80c0648557f4bd502d7e83826