Re: [PATCH 05/13] mm: prefer mm->def_vma_flags in mm logic

[Lance Yang <lance.yang@linux.dev>]

On Mon, Jun 29, 2026 at 08:25:28PM +0100, Lorenzo Stoakes wrote:
>Currently mm->def_flags (of type vm_flags_t) is union'd with
>mm->def_vma_flags (of type vma_flags_t).
>
>As part of the effort to convert vm_flags_t usage to vma_flags_t (in order
>to no longer be arbitrarily limited to a system word size for VMA flags),
>prefer mm->def_vma_flags to mm->def_flags throughout the mm logic.
>
>No functional change intended.
>
>Signed-off-by: Lorenzo Stoakes <ljs@kernel.org>
>---
> mm/debug.c |  2 +-
> mm/mlock.c | 13 +++++++------
> mm/mmap.c  | 11 ++++++-----
> mm/vma.c   |  4 ++--
> 4 files changed, 16 insertions(+), 14 deletions(-)
>
>diff --git a/mm/debug.c b/mm/debug.c
>index 497654b36f1a..f0a354a9496a 100644
>--- a/mm/debug.c
>+++ b/mm/debug.c
>@@ -226,7 +226,7 @@ void dump_mm(const struct mm_struct *mm)
> 		mm->numa_next_scan, mm->numa_scan_offset, mm->numa_scan_seq,
> #endif
> 		atomic_read(&mm->tlb_flush_pending),
>-		mm->def_flags, &mm->def_flags
>+		vma_flags_to_legacy(mm->def_vma_flags), &mm->def_vma_flags
> 	);

While at it, one thing for later: dump_mm() still assumes one-world VMA
flags. That works today since vma_flags_t is one word. Maybe worth a
BUILD_BUG_ON() here, before that stops being true?

Not a big deal though. Feel free to add:

Reviewed-by: Lance Yang <lance.yang@linux.dev>

> }
> EXPORT_SYMBOL(dump_mm);
[...]