Re: [PATCH V2 2/2] mm/highmem: Lift memcpy_[to|from]_page to core

[Matthew Wilcox]

On Mon, Dec 07, 2020 at 02:57:03PM -0800, ira.weiny@xxxxxxxxx wrote:
> Placing these functions in 'highmem.h' is suboptimal especially with the
> changes being proposed in the functionality of kmap.  From a caller
> perspective including/using 'highmem.h' implies that the functions
> defined in that header are only required when highmem is in use which is
> increasingly not the case with modern processors.  Some headers like
> mm.h or string.h seem ok but don't really portray the functionality
> well.  'pagemap.h', on the other hand, makes sense and is already
> included in many of the places we want to convert.

pagemap.h is for the page cache.  It's not for "random page
functionality".  Yes, I know it's badly named.  No, I don't want to
rename it.  These helpers should go in highmem.h along with zero_user().