Subject: Re: linux-next: build failure after merge of the mm-hotfixes tree

From: Stephen Rothwell <[email-masked]>
Date: Wed, 3 Jul 2024 08:44:40 +1000

Hi Andrew,

On Mon, 1 Jul 2024 11:15:17 -0700 Yang Shi <[email-masked]> wrote:
>
> On 6/30/24 6:01 PM, Stephen Rothwell wrote:
> >
> > On Mon, 1 Jul 2024 10:16:41 +1000 Stephen Rothwell <[email-masked]> wrote:  
> >> After merging the mm-hotfixes tree, today's linux-next build (powerpc
> >> ppc64_defconfig) failed like this:
> >>
> >> mm/gup.c: In function 'gup_hugepte':
> >> mm/gup.c:474:25: error: implicit declaration of function 'try_grab_folio_fast'; did you mean 'try_grab_folio'? [-Werror=implicit-function-declaration]
> >>    474 |                 folio = try_grab_folio_fast(page, refs, flags);
> >>        |                         ^~~~~~~~~~~~~~~~~~~
> >>        |                         try_grab_folio
> >> mm/gup.c:474:23: warning: assignment to 'struct folio *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
> >>    474 |                 folio = try_grab_folio_fast(page, refs, flags);
> >>        |                       ^
> >> mm/gup.c: At top level:
> >> mm/gup.c:2747:22: error: conflicting types for 'try_grab_folio_fast'; have 'struct folio *(struct page *, int,  unsigned int)'
> >>   2747 | static struct folio *try_grab_folio_fast(struct page *page, int refs,
> >>        |                      ^~~~~~~~~~~~~~~~~~~
> >> mm/gup.c:474:25: note: previous implicit declaration of 'try_grab_folio_fast' with type 'int()'
> >>    474 |                 folio = try_grab_folio_fast(page, refs, flags);
> >>        |                         ^~~~~~~~~~~~~~~~~~~
> >> cc1: some warnings being treated as errors
> >>
> >> Caused by commit
> >>
> >>    5f408bfe0d13 ("mm: gup: stop abusing try_grab_folio")
> >>
> >> I have reverted that commit for today.  
> > And I also had to revert commit
> >
> >    52cca85b0ebf ("mm-gup-introduce-memfd_pin_folios-for-pinning-memfd-folios-fix")
> >
> > from the mm-unstable branch of the mm tree.  
> 
> The patch attached in this mail should fix the compile error.
> 
> https://lore.kernel.org/linux-mm/[email-masked]/

It looks like that patch has been applied to the mm tree instead of the
mm-hotfixes tree - as a fix for commit

  50ceb37037f3 ("mm: gup: stop abusing try_grab_folio")

-- 
Cheers,
Stephen Rothwell