On Tue, Aug 9, 2022 at 1:30 PM Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > > And here we are, 30 years later, and it still does that, but it leaves > the VM_MAYSHARE flag so that /proc/<pid>/maps can show that it's a > shared mapping. .. thinking about it, we end up still having some things that this helps. For example, because we clear the VM_SHARED flags for read-only shared mappings, they don't end up going through mapping_{un}map_writable(), and don't update i_mmap_writable, and don't cause issues with mapping_deny_writable() or mapping_writably_mapped(). So it ends up actually having random small semantic details due to those almost three decades of history. I'm sure there are other odd pieces like that. Linus