Hi, David, On Wed, Feb 17, 2021 at 04:48:44PM +0100, David Hildenbrand wrote: > When we manage sparse memory mappings dynamically in user space - also > sometimes involving MADV_NORESERVE - we want to dynamically populate/ > discard memory inside such a sparse memory region. Example users are > hypervisors (especially implementing memory ballooning or similar > technologies like virtio-mem) and memory allocators. In addition, we want > to fail in a nice way if populating does not succeed because we are out of > backend memory (which can happen easily with file-based mappings, > especially tmpfs and hugetlbfs). Could you explain a bit more on how do you plan to use this new interface for the virtio-balloon scenario? Meanwhile, here you seemed to be talking about file-backed mem, however later it sounds more like for anonymous, so I'm slightly confused. Thanks, -- Peter Xu
