Re: [HMM 02/15] mm/hmm: heterogeneous memory management (HMM for short) v4

From: Balbir Singh
Date: Tue May 30 2017 - 22:10:45 EST


On Wed, 24 May 2017 13:20:11 -0400
JÃrÃme Glisse <jglisse@xxxxxxxxxx> wrote:

> HMM provides 3 separate types of functionality:
> - Mirroring: synchronize CPU page table and device page table
> - Device memory: allocating struct page for device memory
> - Migration: migrating regular memory to device memory
>
> This patch introduces some common helpers and definitions to all of
> those 3 functionality.
>
> Changed since v3:
> - Unconditionaly build hmm.c for static keys
> Changed since v2:
> - s/device unaddressable/device private
> Changed since v1:
> - Kconfig logic (depend on x86-64 and use ARCH_HAS pattern)
>
> Signed-off-by: JÃrÃme Glisse <jglisse@xxxxxxxxxx>
> Signed-off-by: Evgeny Baskakov <ebaskakov@xxxxxxxxxx>
> Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx>
> Signed-off-by: Mark Hairgrove <mhairgrove@xxxxxxxxxx>
> Signed-off-by: Sherry Cheung <SCheung@xxxxxxxxxx>
> Signed-off-by: Subhash Gutti <sgutti@xxxxxxxxxx>
> ---

It would be nice to explain a bit of how hmm_pfn_t bits work with pfn
and find out what we need from an arch to support HMM.


Balbir Singh.