Stephen Rothwell [off-list ref] writes:

On Mon, 27 Nov 2023 14:48:52 +1100 Stephen Rothwell [off-list ref] wrote:

quoted

Just cc'ing the PowerPC guys to see if my fix is sensible.

On Mon, 27 Nov 2023 13:28:09 +1100 Stephen Rothwell [off-list ref] wrote:

quoted

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 <redacted>
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 <redacted>
---
 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)?

I applied it to my next a few days ago, but I must have forgotten to
push. It's in there now.

cheers