Re: [PATCH 0/6] RFC v2: mm: gup/dma tracking

From: Christoph Hellwig
Date: Mon Feb 04 2019 - 11:12:22 EST

On Mon, Feb 04, 2019 at 04:08:02PM +0000, Christopher Lameter wrote:
> It may be worth noting a couple of times in this text that this was
> designed for anonymous memory and that such use is/was ok. We are talking
> about a use case here using mmapped access with a regular filesystem that
> was not initially intended. The mmapping of from the hugepages filesystem
> is special in that it is not a device that is actually writing things
> back.
> Any use with a filesystem that actually writes data back to a medium
> is something that is broken.

Saying it was not intended seems rather odd, as it was supported
since day 0 and people made use of it.