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

From: Stephen Rothwell <[email-masked]>
Date: Fri, 1 Dec 2023 09:04:39 +1100

Hi all,

On Mon, 27 Nov 2023 14:48:52 +1100 Stephen Rothwell <[email-masked]> wrote:
> 
> Just cc'ing the PowerPC guys to see if my fix is sensible.
> 
> On Mon, 27 Nov 2023 13:28:09 +1100 Stephen Rothwell <[email-masked]> wrote:
> >
> > After merging the mm tree, today's linux-next build (powerpc64
> > allnoconfig) failed like this:
> > 
> > arch/powerpc/mm/book3s64/pgtable.c:557:5: error: no previous prototype for 'pmd_move_must_withdraw' [-Werror=missing-prototypes]
> >   557 | int pmd_move_must_withdraw(struct spinlock *new_pmd_ptl,
> >       |     ^~~~~~~~~~~~~~~~~~~~~~
> > cc1: all warnings being treated as errors
> > 
> > Caused by commit
> > 
> >   c6345dfa6e3e ("Makefile.extrawarn: turn on missing-prototypes globally")
> > 
> > I have added the following patch for today (which could be applied to
> > the mm or powerpc trees):
> > 
> > From 194805b44c11b4c0aa28bdcdc0bb0d82acef394c Mon Sep 17 00:00:00 2001
> > From: Stephen Rothwell <[email-masked]>
> > Date: Mon, 27 Nov 2023 13:08:57 +1100
> > Subject: [PATCH] powerpc: pmd_move_must_withdraw() is only needed for
> >  CONFIG_TRANSPARENT_HUGEPAGE
> > 
> > Signed-off-by: Stephen Rothwell <[email-masked]>
> > ---
> >  arch/powerpc/mm/book3s64/pgtable.c | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
> > index be229290a6a7..3438ab72c346 100644
> > --- a/arch/powerpc/mm/book3s64/pgtable.c
> > +++ b/arch/powerpc/mm/book3s64/pgtable.c
> > @@ -542,6 +542,7 @@ void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr,
> >  	set_pte_at(vma->vm_mm, addr, ptep, pte);
> >  }
> >  
> > +#ifdef CONFIG_TRANSPARENT_HUGEPAGE
> >  /*
> >   * For hash translation mode, we use the deposited table to store hash slot
> >   * information and they are stored at PTRS_PER_PMD offset from related pmd
> > @@ -563,6 +564,7 @@ int pmd_move_must_withdraw(struct spinlock *new_pmd_ptl,
> >  
> >  	return true;
> >  }
> > +#endif
> >  
> >  /*
> >   * Does the CPU support tlbie?
> > -- 
> > 2.40.1  

I am still carrying this patch (it should probably go into the mm
tree).  Is someone going to pick it up (assuming it is correct)?

-- 
Cheers,
Stephen Rothwell