Re: [PATCH] mm/huge_memory.c: Remove unused variable unmap_success

[Yang Shi]

On Tue, May 18, 2021 at 1:09 PM Souptick Joarder <jrdr.linux@xxxxxxxxx> wrote:
>
> Kernel test robot throws below warning ->
>
>    mm/huge_memory.c: In function 'unmap_page':
> >> mm/huge_memory.c:2345:7: warning: variable 'unmap_success' set but not used [-Wunused-but-set-variable]
>     2345 |  bool unmap_success;
>          |       ^~~~~~~~~~~~~
>
> Remove the unused variable unmap_success.
>
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Signed-off-by: Souptick Joarder <jrdr.linux@xxxxxxxxx>

Thanks for catching this. Reviewed-by: Yang Shi <shy828301@xxxxxxxxx>

Just like https://lore.kernel.org/linux-mm/CAHbLzkonsd9f=48+cxKOJamNb9e8qpvWJCYDGFB_wNTdET2zmQ@xxxxxxxxxxxxxx/T/#t,
not sure why my compiler didn't catch such warning.
> ---
>  mm/huge_memory.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index 52ca04b905cf..ff79a12993c9 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -2342,14 +2342,13 @@ static void unmap_page(struct page *page)
>  {
>         enum ttu_flags ttu_flags = TTU_IGNORE_MLOCK |
>                 TTU_RMAP_LOCKED | TTU_SPLIT_HUGE_PMD;
> -       bool unmap_success;
>
>         VM_BUG_ON_PAGE(!PageHead(page), page);
>
>         if (PageAnon(page))
>                 ttu_flags |= TTU_SPLIT_FREEZE;
>
> -       unmap_success = try_to_unmap(page, ttu_flags);
> +       try_to_unmap(page, ttu_flags);
>  }
>
>  static void remap_page(struct page *page, unsigned int nr)
> --
> 2.25.1
>
>