Re: [PATCH v2] mm/huge_memory.c: reorder operations in __split_huge_page_tail()

[Kirill A. Shutemov]

On Sun, Feb 11, 2018 at 05:29:37PM +0300, Konstantin Khlebnikov wrote:
> And replace page_ref_inc()/page_ref_add() with page_ref_unfreeze() which
> is made especially for that and has semantic of smp_store_release().

Nak on this part.

page_ref_unfreeze() uses atomic_set() which neglects the situation in the
comment you're removing.

You need at least explain why it's safe now.

I would rather leave page_ref_inc()/page_ref_add() + explcit
smp_mb__before_atomic().

-- 
 Kirill A. Shutemov