Re: [RFC] mm/hmm: pass mmu_notifier_range to sync_cpu_device_pagetables

[Christoph Hellwig <hch@lst.de>]

On Tue, Jul 02, 2019 at 10:59:16PM +0000, Jason Gunthorpe wrote:
> > As this creates a somewhat hairy conflict for amdgpu, wouldn't it be
> > a better idea to wait a bit and apply it first thing for next merge
> > window?
> 
> My thinking is that AMD GPU already has a monster conflict from this:
> 
>  int hmm_range_register(struct hmm_range *range,
> -                      struct mm_struct *mm,
> +                      struct hmm_mirror *mirror,
>                        unsigned long start,
>                        unsigned long end,
>                        unsigned page_shift);

Well, that seems like a relatively easy to fix conflict, at least as
long as you have the mirror easily available.  The notifier change
on the other hand basically requires rewriting about two dozen lines
of code entirely.