Re: [PATCH v2 03/11] mm/gup: Applies counting method to monitor gup_pgd_range

On Mon, 2019-09-23 at 13:27 -0700, John Hubbard wrote: > I'd also like a second opinion from the "core" -mm maintainers, but it seems > like > there is now too much code around the gup_pgd_range() call. Especially since > there > are two places where it's called--did you forget the other one in

[PATCH v2 03/11] mm/gup: Applies counting method to monitor gup_pgd_range

As decribed, gup_pgd_range is a lockless pagetable walk. So, in order to monitor against THP split/collapse with the couting method, it's necessary to bound it with {start,end}_lockless_pgtbl_walk. There are dummy functions, so it is not going to add any overhead on archs that don't use this