Re: [PATCH 4/5] mm, hmm: replace hmm_devmem_pages_create() with devm_memremap_pages()

[Christoph Hellwig]

On Mon, May 21, 2018 at 03:35:34PM -0700, Dan Williams wrote:
> Commit e8d513483300 "memremap: change devm_memremap_pages interface to
> use struct dev_pagemap" refactored devm_memremap_pages() to allow a
> dev_pagemap instance to be supplied. Passing in a dev_pagemap interface
> simplifies the design of pgmap type drivers in that they can rely on
> container_of() to lookup any private data associated with the given
> dev_pagemap instance.
> 
> In addition to the cleanups this also gives hmm users multi-order-radix
> improvements that arrived with commit ab1b597ee0e4 "mm,
> devm_memremap_pages: use multi-order radix for ZONE_DEVICE lookups"

None of them has any caller despite being in the tree for 9 month.
I think it's time to simply drop the whole hmm code instead instead of
carrying this dead weight around.