Re: [PATCH 42/46] mm/huge_memory: split huge PUDs when adjusting VMA boundaries

[Kiryl Shutsemau]

On Thu, Oct 29, 2026 at 04:35:46PM +0100, David Hildenbrand (Arm) wrote:
> On 10/29/26 15:40, David Hildenbrand (Arm) wrote:
> > On 10/29/26 15:31, Kiryl Shutsemau wrote:
> >> On Thu, Oct 29, 2026 at 03:24:29PM +0100, David Hildenbrand (Arm) wrote:
> >>>
> >>> __split_huge_pud() must split a leave. Either by zapping it (what we do right
> >>> now) or by populating page tables (as in Usama's PoC).
> >>
> >> No, meant the situation when pud_leaf() is true, but split_pud is false,
> >> so __split_huge_pud() is never hit. pud_present() is true so we proceed
> >> to pmd_offset()
> > 
> > Oh, yeah, I can add a WARN_ON_ONCE() for that, it would be a bug in the software.
> 
> Ah, or I can just drop the split_pud check. Let me do that.

Yeah, looks good.

-- 
  Kiryl Shutsemau / Kirill A. Shutemov