> On Jun 3, 2021, at 12:14 PM, Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > > On Thu, Jun 3, 2021 at 12:07 PM Hugh Dickins <hughd@xxxxxxxxxx> wrote: >> >> But the point that we've arrived at, that I'm actually now fairly >> happy with, is do *not* permit MAP_NOSIGBUS on MAP_SHARED mappings. > > Yeah, if that's sufficient, then that original patch should just work as-is. > > But there was some reason why people didn't like that patch > originally, and I think it was literally about how it only worked on > private mappings (the "we don't have a flag for it in the vm_flags" > part was just a small detail. > > I guess that objection ended up changing over time. > > I don’t understand the use case well enough to comment on whether MAP_PRIVATE is sufficient, but I’m with Hugh: if this feature is implemented for MAP_SHARED, it should be fully coherent.