Re: [PATCH] mm/thp: Make ARCH_ENABLE_SPLIT_PMD_PTLOCK dependent on PGTABLE_LEVELS > 2

From: Oscar Salvador
Date: Mon May 10 2021 - 06:10:13 EST


On Mon, May 10, 2021 at 03:36:29PM +0530, Anshuman Khandual wrote:
>
>
> On 5/10/21 2:23 PM, Peter Zijlstra wrote:
> > On Mon, May 10, 2021 at 10:05:45AM +0530, Anshuman Khandual wrote:
> >> - select ARCH_ENABLE_SPLIT_PMD_PTLOCK if X86_64 || X86_PAE
> >> + select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE)
> >
> > It's still very early on a Monday, but IIRC this new condition is
> > identical to the pre-existing one.
>
> Did not get it, could you please elaborate ?

When using x86_PAE, you must have more than two pgtable levels, right?
And not speaking of x86_64.

--
Oscar Salvador
SUSE L3