Re: [RFC] Re: Costless huge virtual memory? /dev/same, /dev/null?

From: Matthew Wilcox
Date: Thu Apr 13 2017 - 12:34:24 EST


On Thu, Apr 13, 2017 at 06:29:46PM +0200, Samuel Thibault wrote:
> (Ideally we'd be able to take the MAP_HUGETLB mmap flag into account to
> map a single huge page repeatedly, even lowering the populating cost,
> but AIUI of the current hugepage support it would be far from easy)

You could implement ->map_pages instead of (or as well as) ->fault, which
would lower your costs if that is a concern. I think the eventual intent
is that map_pages would be able to populate a PMD or even a PUD.