Re: [HMM 03/16] mm/ZONE_DEVICE/free-page: callback when page is freed v3

[Mel Gorman]

On Thu, Mar 16, 2017 at 12:05:22PM -0400, J?r?me Glisse wrote:
> When a ZONE_DEVICE page refcount reach 1 it means it is free and nobody
> is holding a reference on it (only device to which the memory belong do).
> Add a callback and call it when that happen so device driver can implement
> their own free page management.
> 

If it does not implement it's own management then it still needs to be
freed to the main allocator.