Re: [PATCH 2/2] mm: move alloc tag to mm

[Lorenzo Stoakes <ljs@kernel.org>]

On Thu, Jun 25, 2026 at 11:48:57AM -0700, Suren Baghdasaryan wrote:
> From: Lorenzo Stoakes <ljs@kernel.org>
>
> The alloc tagging work is really mm-specific, so move alloc_tag.c to mm/
> and additionally update the MAINTAINERS entry to place it within memory
> management and port over the Kconfig and Makefile code to mm.
>
> Signed-off-by: Lorenzo Stoakes <ljs@kernel.org>
> Signed-off-by: Suren Baghdasaryan <surenb@google.com>

LGTM (obviously :P) so:

Reviewed-by: Lorenzo Stoakes <ljs@kernel.org>

> ---
>  MAINTAINERS             | 20 ++++++++++----------
>  lib/Kconfig.debug       | 28 ----------------------------
>  lib/Makefile            |  1 -
>  mm/Kconfig.debug        | 28 ++++++++++++++++++++++++++++
>  mm/Makefile             |  1 +
>  {lib => mm}/alloc_tag.c |  0
>  6 files changed, 39 insertions(+), 39 deletions(-)
>  rename {lib => mm}/alloc_tag.c (100%)
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 0948dc573744..3cf3cf2311e2 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -16704,16 +16704,6 @@ F:	mm/mm_init.c
>  F:	mm/rodata_test.c
>  F:	tools/testing/memblock/
>
> -MEMORY ALLOCATION PROFILING
> -M:	Suren Baghdasaryan <surenb@google.com>
> -R:	Hao Ge <hao.ge@linux.dev>
> -L:	linux-mm@kvack.org
> -S:	Maintained
> -F:	Documentation/mm/allocation-profiling.rst
> -F:	include/linux/alloc_tag.h
> -F:	include/linux/pgalloc_tag.h
> -F:	lib/alloc_tag.c
> -
>  MEMORY CONTROLLER DRIVERS
>  M:	Krzysztof Kozlowski <krzk@kernel.org>
>  L:	linux-kernel@vger.kernel.org
> @@ -16758,6 +16748,16 @@ T:	quilt git://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new
>  F:	mm/
>  F:	tools/mm/
>
> +MEMORY MANAGEMENT - ALLOCATION PROFILING (ALLOC TAG)
> +M:	Suren Baghdasaryan <surenb@google.com>
> +R:	Hao Ge <hao.ge@linux.dev>
> +L:	linux-mm@kvack.org
> +S:	Maintained
> +F:	Documentation/mm/allocation-profiling.rst
> +F:	include/linux/alloc_tag.h
> +F:	include/linux/pgalloc_tag.h
> +F:	mm/alloc_tag.c
> +
>  MEMORY MANAGEMENT - BALLOON
>  M:	Andrew Morton <akpm@linux-foundation.org>
>  M:	David Hildenbrand <david@kernel.org>
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index 8ff5adcfe1e0..3762015522c3 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -1048,34 +1048,6 @@ config CODE_TAGGING
>  	bool
>  	select KALLSYMS
>
> -config MEM_ALLOC_PROFILING
> -	bool "Enable memory allocation profiling"
> -	default n
> -	depends on MMU
> -	depends on PROC_FS
> -	depends on !DEBUG_FORCE_WEAK_PER_CPU
> -	select CODE_TAGGING
> -	select PAGE_EXTENSION
> -	select SLAB_OBJ_EXT
> -	help
> -	  Track allocation source code and record total allocation size
> -	  initiated at that code location. The mechanism can be used to track
> -	  memory leaks with a low performance and memory impact.
> -
> -config MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT
> -	bool "Enable memory allocation profiling by default"
> -	default y
> -	depends on MEM_ALLOC_PROFILING
> -
> -config MEM_ALLOC_PROFILING_DEBUG
> -	bool "Memory allocation profiler debugging"
> -	default n
> -	depends on MEM_ALLOC_PROFILING
> -	select MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT
> -	help
> -	  Adds warnings with helpful error messages for memory allocation
> -	  profiling.
> -
>  source "lib/Kconfig.kasan"
>  source "lib/Kconfig.kfence"
>  source "lib/Kconfig.kmsan"
> diff --git a/lib/Makefile b/lib/Makefile
> index f33a24bf1c19..44f6538533a9 100644
> --- a/lib/Makefile
> +++ b/lib/Makefile
> @@ -197,7 +197,6 @@ obj-$(CONFIG_OF_RECONFIG_NOTIFIER_ERROR_INJECT) += \
>  obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
>
>  obj-$(CONFIG_CODE_TAGGING) += codetag.o
> -obj-$(CONFIG_MEM_ALLOC_PROFILING) += alloc_tag.o
>
>  lib-$(CONFIG_GENERIC_BUG) += bug.o
>
> diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug
> index 91b3e027b753..5737a504efbb 100644
> --- a/mm/Kconfig.debug
> +++ b/mm/Kconfig.debug
> @@ -320,3 +320,31 @@ config PER_VMA_LOCK_STATS
>  	  overhead in the page fault path.
>
>  	  If in doubt, say N.
> +
> +config MEM_ALLOC_PROFILING
> +	bool "Enable memory allocation profiling"
> +	default n
> +	depends on MMU
> +	depends on PROC_FS
> +	depends on !DEBUG_FORCE_WEAK_PER_CPU
> +	select CODE_TAGGING
> +	select PAGE_EXTENSION
> +	select SLAB_OBJ_EXT
> +	help
> +	  Track allocation source code and record total allocation size
> +	  initiated at that code location. The mechanism can be used to track
> +	  memory leaks with a low performance and memory impact.
> +
> +config MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT
> +	bool "Enable memory allocation profiling by default"
> +	default y
> +	depends on MEM_ALLOC_PROFILING
> +
> +config MEM_ALLOC_PROFILING_DEBUG
> +	bool "Memory allocation profiler debugging"
> +	default n
> +	depends on MEM_ALLOC_PROFILING
> +	select MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT
> +	help
> +	  Adds warnings with helpful error messages for memory allocation
> +	  profiling.
> diff --git a/mm/Makefile b/mm/Makefile
> index eff9f9e7e061..4fc713867b9b 100644
> --- a/mm/Makefile
> +++ b/mm/Makefile
> @@ -147,3 +147,4 @@ obj-$(CONFIG_SHRINKER_DEBUG) += shrinker_debug.o
>  obj-$(CONFIG_EXECMEM) += execmem.o
>  obj-$(CONFIG_TMPFS_QUOTA) += shmem_quota.o
>  obj-$(CONFIG_LAZY_MMU_MODE_KUNIT_TEST) += tests/lazy_mmu_mode_kunit.o
> +obj-$(CONFIG_MEM_ALLOC_PROFILING) += alloc_tag.o
> diff --git a/lib/alloc_tag.c b/mm/alloc_tag.c
> similarity index 100%
> rename from lib/alloc_tag.c
> rename to mm/alloc_tag.c
> --
> 2.55.0.rc0.799.gd6f94ed593-goog
>

Thanks, Lorenzo