Re: [HMM 12/15] mm/migrate: new memory migration helper for use with device memory v4

[Reza Arbab]

On Mon, May 22, 2017 at 12:52:03PM -0400, Jérôme Glisse wrote:
> This patch add a new memory migration helpers, which migrate memory
> backing a range of virtual address of a process to different memory
> (which can be allocated through special allocator). It differs from
> numa migration by working on a range of virtual address and thus by
> doing migration in chunk that can be large enough to use DMA engine
> or special copy offloading engine.
>
> Expected users are any one with heterogeneous memory where different
> memory have different characteristics (latency, bandwidth, ...). As
> an example IBM platform with CAPI bus can make use of this feature
> to migrate between regular memory and CAPI device memory. New CPU
> architecture with a pool of high performance memory not manage as
> cache but presented as regular memory (while being faster and with
> lower latency than DDR) will also be prime user of this patch.
>
> Migration to private device memory will be useful for device that
> have large pool of such like GPU, NVidia plans to use HMM for that.

Acked-by: Reza Arbab <arbab@xxxxxxxxxxxxxxxxxx>

--
Reza Arbab