Re: [PATCH V2] mm: Some arch may want to use HPAGE_PMD related values as variables

From: Kirill A. Shutemov
Date: Tue Feb 09 2016 - 18:15:13 EST


On Tue, Feb 09, 2016 at 01:26:08PM -0800, Andrew Morton wrote:
> On Tue, 9 Feb 2016 21:41:44 +0530 "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx> wrote:
> > @@ -660,6 +660,18 @@ static int __init hugepage_init(void)
> > return -EINVAL;
> > }
> >
> > + khugepaged_pages_to_scan = HPAGE_PMD_NR * 8;
> > + khugepaged_max_ptes_none = HPAGE_PMD_NR - 1;
>
> I don't understand this change. We change the initialization from
> at-compile-time to at-run-time, but nothing useful appears to have been
> done.

It's preparation patch. HPAGE_PMD_NR is going to be based on variable on
Power soon. Compile-time is not an option.

--
Kirill A. Shutemov