[PATCH] drivers/base, mm: move arch_numa.c to mm/

[PATCH] drivers/base, mm: move arch_numa.c to mm/

[Mike Rapoport (Microsoft)]

arch_numa.c implements boot time discovery and initialization of NUMA
topology on architectures that select GENERIC_ARCH_NUMA (currently arm64
and riscv).

Since this is step in the initialization of the memory management
subsystem, it's logical to have arch_numa.c in mm/ alongside numa.c,
numa_memblks.c and numa_emulation.c.

Move arch_numa.c to mm/ and add its F: entry to "MEMBLOCK AND MEMORY
MANAGEMENT INITIALIZATION" in MAINTAINERS.

Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
---
 MAINTAINERS                      | 1 +
 drivers/base/Kconfig             | 7 -------
 drivers/base/Makefile            | 1 -
 mm/Kconfig                       | 7 +++++++
 mm/Makefile                      | 1 +
 {drivers/base => mm}/arch_numa.c | 0
 6 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/MAINTAINERS b/MAINTAINERS
index 5114e6db7307..465b64f8e93c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16880,6 +16880,7 @@ T:	git git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock.git fixes
 F:	Documentation/core-api/boot-time-mm.rst
 F:	include/linux/kho/abi/memblock.h
 F:	include/linux/memblock.h
+F:	mm/arch_numa.c
 F:	mm/bootmem_info.c
 F:	mm/memblock.c
 F:	mm/memtest.c
diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index f7d385cbd3ba..1d93bfc34490 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -239,13 +239,6 @@ config GENERIC_ARCH_TOPOLOGY
 	  appropriate scaling, sysfs interface for reading capacity values at
 	  runtime.
 
-config GENERIC_ARCH_NUMA
-	bool
-	select NUMA_MEMBLKS
-	help
-	  Enable support for generic NUMA implementation. Currently, RISC-V
-	  and ARM64 use it.
-
 config FW_DEVLINK_SYNC_STATE_TIMEOUT
 	bool "sync_state() behavior defaults to timeout instead of strict"
 	help
diff --git a/drivers/base/Makefile b/drivers/base/Makefile
index 8074a10183dc..435710f643a5 100644
--- a/drivers/base/Makefile
+++ b/drivers/base/Makefile
@@ -25,7 +25,6 @@ obj-$(CONFIG_PINCTRL) += pinctrl.o
 obj-$(CONFIG_DEV_COREDUMP) += devcoredump.o
 obj-$(CONFIG_GENERIC_MSI_IRQ) += platform-msi.o
 obj-$(CONFIG_GENERIC_ARCH_TOPOLOGY) += arch_topology.o
-obj-$(CONFIG_GENERIC_ARCH_NUMA) += arch_numa.o
 obj-$(CONFIG_ACPI) += physical_location.o
 
 obj-y			+= test/
diff --git a/mm/Kconfig b/mm/Kconfig
index 9e0ca4824905..410b8a0a92b9 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -1469,6 +1469,13 @@ config NUMA_EMU
 	  into virtual nodes when booted with "numa=fake=N", where N is the
 	  number of nodes. This is only useful for debugging.
 
+config GENERIC_ARCH_NUMA
+	bool
+	select NUMA_MEMBLKS
+	help
+	  Enable support for generic NUMA implementation. Currently, RISC-V
+	  and ARM64 use it.
+
 config ARCH_HAS_USER_SHADOW_STACK
 	bool
 	help
diff --git a/mm/Makefile b/mm/Makefile
index eff9f9e7e061..fd29be716fa8 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -122,6 +122,7 @@ obj-$(CONFIG_CMA)	+= cma.o
 obj-$(CONFIG_NUMA) += numa.o
 obj-$(CONFIG_NUMA_MEMBLKS) += numa_memblks.o
 obj-$(CONFIG_NUMA_EMU) += numa_emulation.o
+obj-$(CONFIG_GENERIC_ARCH_NUMA) += arch_numa.o
 obj-$(CONFIG_BALLOON) += balloon.o
 obj-$(CONFIG_PAGE_EXTENSION) += page_ext.o
 obj-$(CONFIG_PAGE_TABLE_CHECK) += page_table_check.o
diff --git a/drivers/base/arch_numa.c b/mm/arch_numa.c
similarity index 100%
rename from drivers/base/arch_numa.c
rename to mm/arch_numa.c

---
base-commit: 075b74841bd0065a3bda3440873c747938e69b68
change-id: 20260806-arch-numa-444bb4806114

--
Sincerely yours,
Mike.

Re: [PATCH] drivers/base, mm: move arch_numa.c to mm/

[Greg Kroah-Hartman]

On Thu, Aug 06, 2026 at 09:58:38AM +0300, Mike Rapoport (Microsoft) wrote:
> arch_numa.c implements boot time discovery and initialization of NUMA
> topology on architectures that select GENERIC_ARCH_NUMA (currently arm64
> and riscv).
> 
> Since this is step in the initialization of the memory management
> subsystem, it's logical to have arch_numa.c in mm/ alongside numa.c,
> numa_memblks.c and numa_emulation.c.
> 
> Move arch_numa.c to mm/ and add its F: entry to "MEMBLOCK AND MEMORY
> MANAGEMENT INITIALIZATION" in MAINTAINERS.
> 
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>

No objection from me!

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Re: [PATCH] drivers/base, mm: move arch_numa.c to mm/

[Lorenzo Stoakes (ARM)]

On Thu, Aug 06, 2026 at 09:58:38AM +0300, Mike Rapoport (Microsoft) wrote:
> arch_numa.c implements boot time discovery and initialization of NUMA
> topology on architectures that select GENERIC_ARCH_NUMA (currently arm64
> and riscv).
>
> Since this is step in the initialization of the memory management
> subsystem, it's logical to have arch_numa.c in mm/ alongside numa.c,
> numa_memblks.c and numa_emulation.c.
>
> Move arch_numa.c to mm/ and add its F: entry to "MEMBLOCK AND MEMORY
> MANAGEMENT INITIALIZATION" in MAINTAINERS.
>
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>

Everything is proceeding as I have foreseen... soon we shall have control
of all of the kernel! ;)

Acked-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>

> ---
>  MAINTAINERS                      | 1 +
>  drivers/base/Kconfig             | 7 -------
>  drivers/base/Makefile            | 1 -
>  mm/Kconfig                       | 7 +++++++
>  mm/Makefile                      | 1 +
>  {drivers/base => mm}/arch_numa.c | 0
>  6 files changed, 9 insertions(+), 8 deletions(-)
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 5114e6db7307..465b64f8e93c 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -16880,6 +16880,7 @@ T:	git git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock.git fixes
>  F:	Documentation/core-api/boot-time-mm.rst
>  F:	include/linux/kho/abi/memblock.h
>  F:	include/linux/memblock.h
> +F:	mm/arch_numa.c
>  F:	mm/bootmem_info.c
>  F:	mm/memblock.c
>  F:	mm/memtest.c
> diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
> index f7d385cbd3ba..1d93bfc34490 100644
> --- a/drivers/base/Kconfig
> +++ b/drivers/base/Kconfig
> @@ -239,13 +239,6 @@ config GENERIC_ARCH_TOPOLOGY
>  	  appropriate scaling, sysfs interface for reading capacity values at
>  	  runtime.
>
> -config GENERIC_ARCH_NUMA
> -	bool
> -	select NUMA_MEMBLKS
> -	help
> -	  Enable support for generic NUMA implementation. Currently, RISC-V
> -	  and ARM64 use it.
> -
>  config FW_DEVLINK_SYNC_STATE_TIMEOUT
>  	bool "sync_state() behavior defaults to timeout instead of strict"
>  	help
> diff --git a/drivers/base/Makefile b/drivers/base/Makefile
> index 8074a10183dc..435710f643a5 100644
> --- a/drivers/base/Makefile
> +++ b/drivers/base/Makefile
> @@ -25,7 +25,6 @@ obj-$(CONFIG_PINCTRL) += pinctrl.o
>  obj-$(CONFIG_DEV_COREDUMP) += devcoredump.o
>  obj-$(CONFIG_GENERIC_MSI_IRQ) += platform-msi.o
>  obj-$(CONFIG_GENERIC_ARCH_TOPOLOGY) += arch_topology.o
> -obj-$(CONFIG_GENERIC_ARCH_NUMA) += arch_numa.o
>  obj-$(CONFIG_ACPI) += physical_location.o
>
>  obj-y			+= test/
> diff --git a/mm/Kconfig b/mm/Kconfig
> index 9e0ca4824905..410b8a0a92b9 100644
> --- a/mm/Kconfig
> +++ b/mm/Kconfig
> @@ -1469,6 +1469,13 @@ config NUMA_EMU
>  	  into virtual nodes when booted with "numa=fake=N", where N is the
>  	  number of nodes. This is only useful for debugging.
>
> +config GENERIC_ARCH_NUMA
> +	bool
> +	select NUMA_MEMBLKS
> +	help
> +	  Enable support for generic NUMA implementation. Currently, RISC-V
> +	  and ARM64 use it.
> +
>  config ARCH_HAS_USER_SHADOW_STACK
>  	bool
>  	help
> diff --git a/mm/Makefile b/mm/Makefile
> index eff9f9e7e061..fd29be716fa8 100644
> --- a/mm/Makefile
> +++ b/mm/Makefile
> @@ -122,6 +122,7 @@ obj-$(CONFIG_CMA)	+= cma.o
>  obj-$(CONFIG_NUMA) += numa.o
>  obj-$(CONFIG_NUMA_MEMBLKS) += numa_memblks.o
>  obj-$(CONFIG_NUMA_EMU) += numa_emulation.o
> +obj-$(CONFIG_GENERIC_ARCH_NUMA) += arch_numa.o
>  obj-$(CONFIG_BALLOON) += balloon.o
>  obj-$(CONFIG_PAGE_EXTENSION) += page_ext.o
>  obj-$(CONFIG_PAGE_TABLE_CHECK) += page_table_check.o
> diff --git a/drivers/base/arch_numa.c b/mm/arch_numa.c
> similarity index 100%
> rename from drivers/base/arch_numa.c
> rename to mm/arch_numa.c
>
> ---
> base-commit: 075b74841bd0065a3bda3440873c747938e69b68
> change-id: 20260806-arch-numa-444bb4806114
>
> --
> Sincerely yours,
> Mike.
>

--
Cheers, Lorenzo

Re: [PATCH] drivers/base, mm: move arch_numa.c to mm/

[Mike Rapoport]

On Thu, Aug 06, 2026 at 08:06:12AM +0100, Lorenzo Stoakes (ARM) wrote:
> On Thu, Aug 06, 2026 at 09:58:38AM +0300, Mike Rapoport (Microsoft) wrote:
> > arch_numa.c implements boot time discovery and initialization of NUMA
> > topology on architectures that select GENERIC_ARCH_NUMA (currently arm64
> > and riscv).
> >
> > Since this is step in the initialization of the memory management
> > subsystem, it's logical to have arch_numa.c in mm/ alongside numa.c,
> > numa_memblks.c and numa_emulation.c.
> >
> > Move arch_numa.c to mm/ and add its F: entry to "MEMBLOCK AND MEMORY
> > MANAGEMENT INITIALIZATION" in MAINTAINERS.
> >
> > Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> 
> Everything is proceeding as I have foreseen... soon we shall have control
> of all of the kernel! ;)

I'm also eyeing drivers/base/memory.c, but that one is more involved :)
 
> Acked-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
 
Thanks!

-- 
Sincerely yours,
Mike.

Re: [PATCH] drivers/base, mm: move arch_numa.c to mm/

[David Hildenbrand (Arm)]

On 8/6/26 08:58, Mike Rapoport (Microsoft) wrote:
> arch_numa.c implements boot time discovery and initialization of NUMA
> topology on architectures that select GENERIC_ARCH_NUMA (currently arm64
> and riscv).
> 
> Since this is step in the initialization of the memory management
> subsystem, it's logical to have arch_numa.c in mm/ alongside numa.c,
> numa_memblks.c and numa_emulation.c.
> 
> Move arch_numa.c to mm/ and add its F: entry to "MEMBLOCK AND MEMORY
> MANAGEMENT INITIALIZATION" in MAINTAINERS.
> 
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> ---

Acked-by: David Hildenbrand (Arm) <david@kernel.org>

-- 
Cheers,

David

Re: [PATCH] drivers/base, mm: move arch_numa.c to mm/

[Danilo Krummrich]

On Thu Aug 6, 2026 at 8:58 AM CEST, Mike Rapoport (Microsoft) wrote:
> arch_numa.c implements boot time discovery and initialization of NUMA
> topology on architectures that select GENERIC_ARCH_NUMA (currently arm64
> and riscv).
>
> Since this is step in the initialization of the memory management
> subsystem, it's logical to have arch_numa.c in mm/ alongside numa.c,
> numa_memblks.c and numa_emulation.c.
>
> Move arch_numa.c to mm/ and add its F: entry to "MEMBLOCK AND MEMORY
> MANAGEMENT INITIALIZATION" in MAINTAINERS.
>
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>

Acked-by: Danilo Krummrich <dakr@kernel.org>

Re: [PATCH] drivers/base, mm: move arch_numa.c to mm/

[Andrew Morton]

On Thu, 06 Aug 2026 09:58:38 +0300 "Mike Rapoport (Microsoft)" <rppt@kernel.org> wrote:

> arch_numa.c implements boot time discovery and initialization of NUMA
> topology on architectures that select GENERIC_ARCH_NUMA (currently arm64
> and riscv).
> 
> Since this is step in the initialization of the memory management
> subsystem, it's logical to have arch_numa.c in mm/ alongside numa.c,
> numa_memblks.c and numa_emulation.c.
> 
> Move arch_numa.c to mm/ and add its F: entry to "MEMBLOCK AND MEMORY
> MANAGEMENT INITIALIZATION" in MAINTAINERS.

Unclear what tree this is targeted at.  I grabbed it.


mm-stable does have this change:

--- linux-7.2-rc5/drivers/base/arch_numa.c	2026-07-27 04:44:55.000000000 -0700
+++ 25/drivers/base/arch_numa.c	2026-08-06 15:47:59.019918702 -0700
@@ -231,10 +231,6 @@ static int __init numa_init(int (*init_f
 {
 	int ret;
 
-	nodes_clear(numa_nodes_parsed);
-	nodes_clear(node_possible_map);
-	nodes_clear(node_online_map);
-
 	ret = numa_memblks_init(init_func, /* memblock_force_top_down */ false);
 	if (ret < 0)
 		goto out_free_distance;


which is easily handled either way.