Re: [HMM 01/16] mm/memory/hotplug: convert device bool to int to allow for more flags v3

[Mel Gorman]

On Thu, Mar 16, 2017 at 12:05:20PM -0400, J?r?me Glisse wrote:
> When hotpluging memory we want more informations on the type of memory and
> its properties. Replace the device boolean flag by an int and define a set
> of flags.
> 
> New property for device memory is an opt-in flag to allow page migration
> from and to a ZONE_DEVICE. Existing user of ZONE_DEVICE are not expecting
> page migration to work for their pages. New changes to page migration i
> changing that and we now need a flag to explicitly opt-in page migration.
> 
> Changes since v2:
>   - pr_err() in case of hotplug failure
> 
> Changes since v1:
>   - Improved commit message
>   - Improved define name
>   - Improved comments
>   - Typos
> 
> Signed-off-by: Jérôme Glisse <jglisse@xxxxxxxxxx>

Fairly minor but it's standard for flags to be unsigned due to
uncertainity about what happens when a signed type is bit shifted.
May not apply to your case but fairly trivial to address.