Re: + memblock-fix-kernel-doc-for-memblock_rsrv_noinit.patch added to mm-unstable branch

[Mike Rapoport <rppt@kernel.org>]

Hi Andrew,

On Tue, Aug 26, 2025 at 08:25:07PM -0700, Andrew Morton wrote:
> 
> The patch titled
>      Subject: memblock: fix kernel-doc for MEMBLOCK_RSRV_NOINIT
> has been added to the -mm mm-unstable branch.  Its filename is
>      memblock-fix-kernel-doc-for-memblock_rsrv_noinit.patch

Can you drop it please?
I am meaning to take it via memblock tree.
 
> This patch will shortly appear at
>      https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/memblock-fix-kernel-doc-for-memblock_rsrv_noinit.patch
> 
> This patch will later appear in the mm-unstable branch at
>     git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
> 
> Before you just go and hit "reply", please:
>    a) Consider who else should be cc'ed
>    b) Prefer to cc a suitable mailing list as well
>    c) Ideally: find the original patch on the mailing list and do a
>       reply-to-all to that, adding suitable additional cc's
> 
> *** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
> 
> The -mm tree is included into linux-next via the mm-everything
> branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
> and is updated there every 2-3 working days
> 
> ------------------------------------------------------
> From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
> Subject: memblock: fix kernel-doc for MEMBLOCK_RSRV_NOINIT
> Date: Tue, 26 Aug 2025 10:19:46 +0300
> 
> The kernel-doc description of MEMBLOCK_RSRV_NOINIT and
> memblock_reserved_mark_noinit() do not accurately describe their
> functionality.
> 
> Expand their kernel doc to make it clear that the user of
> MEMBLOCK_RSRV_NOINIT is responsible to properly initialize the struct
> pages for such regions and add more details about effects of using this
> flag.
> 
> Link: https://lkml.kernel.org/r/20250826071947.1949725-1-rppt@kernel.org
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> Reviewed-by: David Hildenbrand <david@redhat.com>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> ---
> 
>  include/linux/memblock.h |    5 +++--
>  mm/memblock.c            |   15 +++++++++++----
>  2 files changed, 14 insertions(+), 6 deletions(-)
> 
> --- a/include/linux/memblock.h~memblock-fix-kernel-doc-for-memblock_rsrv_noinit
> +++ a/include/linux/memblock.h
> @@ -40,8 +40,9 @@ extern unsigned long long max_possible_p
>   * via a driver, and never indicated in the firmware-provided memory map as
>   * system RAM. This corresponds to IORESOURCE_SYSRAM_DRIVER_MANAGED in the
>   * kernel resource tree.
> - * @MEMBLOCK_RSRV_NOINIT: memory region for which struct pages are
> - * not initialized (only for reserved regions).
> + * @MEMBLOCK_RSRV_NOINIT: reserved memory region for which struct pages are not
> + * fully initialized. Users of this flag are responsible to properly initialize
> + * struct pages of this region
>   * @MEMBLOCK_RSRV_KERN: memory region that is reserved for kernel use,
>   * either explictitly with memblock_reserve_kern() or via memblock
>   * allocation APIs. All memblock allocations set this flag.
> --- a/mm/memblock.c~memblock-fix-kernel-doc-for-memblock_rsrv_noinit
> +++ a/mm/memblock.c
> @@ -1091,13 +1091,20 @@ int __init_memblock memblock_clear_nomap
>  
>  /**
>   * memblock_reserved_mark_noinit - Mark a reserved memory region with flag
> - * MEMBLOCK_RSRV_NOINIT which results in the struct pages not being initialized
> - * for this region.
> + * MEMBLOCK_RSRV_NOINIT
> + *
>   * @base: the base phys addr of the region
>   * @size: the size of the region
>   *
> - * struct pages will not be initialized for reserved memory regions marked with
> - * %MEMBLOCK_RSRV_NOINIT.
> + * The struct pages for the reserved regions marked %MEMBLOCK_RSRV_NOINIT will
> + * not be fully initialized to allow the caller optimize their initialization.
> + *
> + * When %CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled, setting this flag
> + * completely bypasses the initialization of struct pages for such region.
> + *
> + * When %CONFIG_DEFERRED_STRUCT_PAGE_INIT is disabled, struct pages in this
> + * region will be initialized with default values but won't be marked as
> + * reserved.
>   *
>   * Return: 0 on success, -errno on failure.
>   */
> _
> 
> Patches currently in -mm which might be from rppt@kernel.org are
> 
> init-mainc-fix-boot-time-tracing-crash.patch
> kho-allow-scratch-areas-with-zero-size.patch
> lib-test_kho-fixes-for-error-handling.patch
> selftest-kho-update-generation-of-initrd.patch
> memblock-fix-kernel-doc-for-memblock_rsrv_noinit.patch
> 

-- 
Sincerely yours,
Mike.