Re: [RFC PATCH 04/26] hugetlb: make huge_pte_lockptr take an explicit shift argument.

[James Houghton]

On Mon, Jun 27, 2022 at 1:52 PM Mike Kravetz <mike.kravetz@xxxxxxxxxx> wrote:
>
> On 06/24/22 17:36, James Houghton wrote:
> > This is needed to handle PTL locking with high-granularity mapping. We
> > won't always be using the PMD-level PTL even if we're using the 2M
> > hugepage hstate. It's possible that we're dealing with 4K PTEs, in which
> > case, we need to lock the PTL for the 4K PTE.
>
> I'm not really sure why this would be required.
> Why not use the PMD level lock for 4K PTEs?  Seems that would scale better
> with less contention than using the more coarse mm lock.

I should be using the PMD level lock for 4K PTEs, yeah. I'll work this
into the next version of the series. Thanks both.

>
> --
> Mike Kravetz