Re: [PATCH v2] mm/huge_memory: prevent THP_ZERO_PAGE_ALLOC increased twice

[Kirill A. Shutemov]

On Thu, Sep 08, 2022 at 09:07:04PM +0800, Liu Shixin wrote:
> 
> 
> On 2022/9/8 20:31, Kirill A. Shutemov wrote:
> > On Thu, Sep 08, 2022 at 11:55:33AM +0800, Liu Shixin wrote:
> >> If two or more threads call get_huge_zero_page concurrently,
> >> THP_ZERO_PAGE_ALLOC may increased two or more times. But actually,
> >> this should only count as once since the extra zero pages has been
> >> freed. Redefine its meaning to indicate the times a huge zero page
> >> used for thp is successfully allocated.
> > I don't particularly care, but it is not obvoius why the new behaviour is
> > better.
> The user who read the value may be more concerned about the huge zero
> pages that are really allocated using for thp and can indicated the
> times of calling huge_zero_page_shrinker.
> I misunderstood when I first saw it.

Please, explain the motivation in the commit message.

-- 
  Kiryl Shutsemau / Kirill A. Shutemov