Re: [PATCH v8 5/8] mm: Device exclusive memory access

Peter Xu
2021-05-19T12:21:16Z

On Wed, May 19, 2021 at 09:35:10PM +1000, Alistair Popple wrote:
> I think the approach you are describing is similar to what
> migrate_vma_collect()/migrate_vma_unamp() does now and I think it could be
> made to work. I ended up going with the GUP+unmap approach in part because
> Christoph suggested it but primarily because it required less code especially
> given we needed to call something to fault the page in/break COW anyway (or
> extend what was there to call handle_mm_fault(), etc.).

I see, thank. Would you mind add a short paragraph in the commit message
talking about these two solutions and why we choose the GUP way?

--
Peter Xu