On 26.01.22 14:38, 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. > I might be missing something important, because KVM can deal with file-back memory just fine and uffd is used heavily outside of hypervisors. I'd love to learn how to handle what ordinary uffd (handle missing/unpopulated pages) and uffd-wp (handle write access to pages) can do with files instead. Because if something like that already exists, it would be precisely what I am talking about. Maybe mentioning uffd was a bad choice ;) -- Thanks, David / dhildenb
