Re: [PATCH] mm: remove unnecessary WARN_ONCE in page_vma_mapped_walk().

[Kirill A. Shutemov]

On Tue, Oct 03, 2017 at 10:26:06AM -0400, Zi Yan wrote:
> From: Zi Yan <zi.yan@xxxxxxxxxxxxxx>
> 
> A non present pmd entry can appear after pmd_lock is taken in
> page_vma_mapped_walk(), even if THP migration is not enabled.
> The WARN_ONCE is unnecessary.
> 
> Fixes: 616b8371539a ("mm: thp: enable thp migration in generic path")
> Reported-and-tested-by: Abdul Haleem <abdhalee@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Zi Yan <zi.yan@xxxxxxxxxxxxxx>
> Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
> Cc: Anshuman Khandual <khandual@xxxxxxxxxxxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>

Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>

-- 
 Kirill A. Shutemov