On Mon, Jul 02, 2018 at 02:49:28PM +0200, Michal Hocko wrote: > On Mon 02-07-18 15:33:50, Kirill A. Shutemov wrote: > [...] > > I probably miss the explanation somewhere, but what's wrong with allowing > > other thread to re-populate the VMA? > > We have discussed that earlier and it boils down to how is racy access > to munmap supposed to behave. Right now we have either the original > content or SEGV. If we allow to simply madvise_dontneed before real > unmap we could get a new page as well. There might be (quite broken I > would say) user space code that would simply corrupt data silently that > way.
Okay, so we add a lot of complexity to accommodate broken userspace that may or may not exist. Is it right? :) -- Kirill A. Shutemov
