On Mon, Apr 11, 2022 at 11:51:46AM -0700, Dave Hansen wrote: > On 4/11/22 10:37, Matthew Wilcox wrote: > > Another argument that MM developers find compelling is that we can reduce > > some of the complexity in hugetlbfs where it has the ability to share > > page tables between processes. > > When could this complexity reduction actually happen in practice? Can > this mshare thingy be somehow dropped in underneath the existing > hugetlbfs implementation? Or would userspace need to change? Userspace needs to opt in to mshare, so there's going to be a transition period where we still need hugetlbfs to still support it, but I have the impression that the users that need page table sharing are pretty specialised and we'll be able to find them all before disabling it. I don't think we can make it transparent to userspace, but I'll noodle on that a bit.