Re: [PATCH 21/46] hugetlb: use struct hugetlb_pte for walk_hugetlb_range

[Mike Kravetz]

On 01/19/23 18:07, Peter Xu wrote:
> 
> Actually when revisiting the locks I'm getting a bit confused on whether
> the vma lock is needed if pmd sharing is anyway forbidden for HGM.  I
> raised a question in the other patch of MADV_COLLAPSE, maybe they're
> related questions so we can keep it there.

I can quickly answer that.  Yes.  The vma lock is also being used for
fault/truncation synchronization.  Commit e700898fa075 make sure it is
even used on architectures that do not support PMD sharing.

I had come up with a rather ugly method of using the fault mutex for
fault/truncation synchronization, but using the vma lock was more
elegant.
-- 
Mike Kravetz