Re: linux-next: build warning after merge of the mm tree

Mike Kravetz
2022-06-22T16:40:18Z

On 06/22/22 17:11, Stephen Rothwell wrote:
> Hi all,
>
> On Wed, 22 Jun 2022 15:54:08 +1000 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
> >
> > After merging the mm tree, today's linux-next build (powerpc
> > ppc64_defconfig) produced this warning:
> >
> > mm/hugetlb.c: In function 'hugetlb_mask_last_page':
> > mm/hugetlb.c:6908:23: warning: unused variable 'hp_size' [-Wunused-variable]
> > 6908 | unsigned long hp_size = huge_page_size(h);
> > | ^~~~~~~
> >
> > Introduced by commit
> >
> > 76005bedbc32 ("hugetlb: do not update address in huge_pmd_unshare")
>
> This became a build failure in my powerpc allyesconfig build, so I
> applied this patch:
>
> From: Stephen Rothwell <sfr@canb.auug.org.au>
> Date: Wed, 22 Jun 2022 17:04:46 +1000
> Subject: [PATCH] hugetlb: fix an unused variable warning/error
>
> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
> ---
> mm/hugetlb.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index 2e4a92cebd9c..f338640fbe4a 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -6905,10 +6905,8 @@ unsigned long hugetlb_mask_last_page(struct hstate *h)
> /* See description above. Architectures can provide their own version. */
> __weak unsigned long hugetlb_mask_last_page(struct hstate *h)
> {
> - unsigned long hp_size = huge_page_size(h);
> -
> #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE
> - if (hp_size == PMD_SIZE)
> + if (huge_page_size(h) == PMD_SIZE)
> return PUD_SIZE - PMD_SIZE;
> #endif
> return 0UL;
> --

Thanks Stephen, my bad for not building !CONFIG_ARCH_WANT_HUGE_PMD_SHARE and,
the error is pretty obvious. :(

Andrew, do you want me to send an updated version of the patch? Or,
would you prefer to include Stephen's fix?
--
Mike Kravetz