Re: [RFC PATCH 0/6] Add support for shared PTEs across processes

[Mike Rapoport]

On Wed, Jan 26, 2022 at 01:38:49PM +0000, Matthew Wilcox wrote:
> On Wed, Jan 26, 2022 at 11:16:42AM +0100, David Hildenbrand wrote:
> > A while ago I talked with Peter about an extended uffd (here: WP)
> > mechanism that would work on fds instead of the process address space.
> 
> As far as I can tell, uffd is a grotesque hack that exists to work around
> the poor choice to use anonymous memory instead of file-backed memory
> in kvm.  Every time I see somebody mention it, I feel pain.

How file-backed memory would have helped for the major use-case of uffd
which is post-copy migration?

-- 
Sincerely yours,
Mike.