[PATCH hmm 15/15] mm/hmm: remove hmm_mirror and related

[Jason Gunthorpe]

On Mon, Oct 21, 2019 at 02:38:24PM -0400, Jerome Glisse wrote:
> On Tue, Oct 15, 2019 at 03:12:42PM -0300, Jason Gunthorpe wrote:
> > From: Jason Gunthorpe <jgg at mellanox.com>
> > 
> > The only two users of this are now converted to use mmu_range_notifier,
> > delete all the code and update hmm.rst.
> 
> I guess i should point out that the reasons for hmm_mirror and hmm
> was for:
>     1) Maybe define a common API for userspace to provide memory
>        placement hints (NUMA for GPU)

Do you think this needs special code in the notifiers?

>     2) multi-devices sharing same mirror page table

Oh neat, but I think this just means the GPU driver has to register a
single notifier for multiple GPUs??

> But support for multi-GPU in nouveau is way behind and i guess such
> optimization will have to re-materialize what is necessary once that
> happens.

Sure, it will be easier to understand what is needed with a bit of
code!

> Note this patch should also update kernel/fork.c and the mm_struct
> definition AFAICT. With those changes you can add my:

Can you please elaborate what updates you mean? I'm not sure. 

Maybe I already got the things you are thinking of with the get/put
changes?

Thanks,
Jason