Re: [RFC PATCH 1/2] mm,drm/ttm: Block fast GUP to TTM huge pages

From: Jason Gunthorpe
Date: Thu Mar 25 2021 - 08:02:15 EST


On Thu, Mar 25, 2021 at 12:53:15PM +0100, Thomas Hellström (Intel) wrote:

> Nope. The point here was that in this case, to make sure mmap uses the
> correct VA to give us a reasonable chance of alignement, the driver might
> need to be aware of and do trickery with the huge page-table-entry sizes
> anyway, although I think in most cases a standard helper for this can be
> supplied.

Of course the driver needs some way to influence the VA mmap uses,
gernally it should align to the natural page size of the device

Jason