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

[Alistair Popple]

On Wednesday, 19 May 2021 10:21:08 PM AEST Peter Xu wrote:
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> 
> 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?

Sure.

 - Alistair

> --
> Peter Xu