Re: [PATCH] mm/shmem: Fix a build error due to shmem_unuse() under !CONFIG_SHMEM

[Randy Dunlap <rdunlap@infradead.org>]

On 12/30/21 02:38, SeongJae Park wrote:
> A patch[1] in -mm tree that titled mm-simplify-try_to_unuse.patch[2]
> didn't properly change the type of 'shmem_unuse()' definition under
> !CONFIG_SHMEM, and therefore causing below build error when CONFIG_SHMEM
> is not set.
> 
>     linux/mm/shmem.c:3992:5: error: conflicting types for 'shmem_unuse'
>      3992 | int shmem_unuse(unsigned int type, unsigned long *fs_pages_to_unuse)
>           |     ^~~~~~~~~~~
>     In file included from linux/include/linux/khugepaged.h:6,
>                      from linux/mm/shmem.c:37:
>     linux/include/linux/shmem_fs.h:86:5: note: previous declaration of 'shmem_unuse' was here
>        86 | int shmem_unuse(unsigned int type);
>           |     ^~~~~~~~~~~
>     linux/scripts/Makefile.build:289: recipe for target 'mm/shmem.o' failed
> 
> This commit fixes the issue by fixing the type of the definition under
> the config.
> 
> [1] https://lore.kernel.org/linux-mm/20211224062246.1258487-9-hch@lst.de/
> [2] https://www.ozlabs.org/~akpm/mmotm/broken-out/mm-simplify-try_to_unuse.patch
> 
> Signed-off-by: SeongJae Park <sj@kernel.org>

Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested

Thanks.

> ---
>  mm/shmem.c              | 2 +-
>  scripts/rust-version.sh | 0
>  2 files changed, 1 insertion(+), 1 deletion(-)
>  mode change 100644 => 100755 scripts/rust-version.sh
> 
> diff --git a/mm/shmem.c b/mm/shmem.c
> index 421b2459929a..a83c91282c1f 100644
> --- a/mm/shmem.c
> +++ b/mm/shmem.c
> @@ -3989,7 +3989,7 @@ int __init shmem_init(void)
>  	return 0;
>  }
>  
> -int shmem_unuse(unsigned int type, unsigned long *fs_pages_to_unuse)
> +int shmem_unuse(unsigned int type)
>  {
>  	return 0;
>  }
> diff --git a/scripts/rust-version.sh b/scripts/rust-version.sh
> old mode 100644
> new mode 100755

-- 
~Randy