On Wed, Aug 02, 2017 at 06:40:01PM +0200, Andrea Arcangeli wrote: > On Wed, Aug 02, 2017 at 06:22:49PM +0200, Michal Hocko wrote: > > ESRCH refers to "no such process". Strictly speaking userfaultfd code is > > about a mm which is gone but that is a mere detail. In fact the owner of > > Well this whole issue about which retval, is about a mere detail in > the first place, so I don't think you can discount all other mere > details as irrelevant in the evaluation of a change to solve a mere > detail. > > > But as I've said, this might be really risky to change. My impression > > was that userfaultfd is not widely used yet and those can be fixed > > easily but if that is not the case then we have to live with the current > > ENOSPC. > > The only change would be for userfaultfd non cooperative mode, and > CRIU is the main user of that. So I think it is up to Mike to decide, > I'm fine either ways. I certainly agree ESRCH could be a slightly > better fit, I only wanted to clarify it's not a 100% match either. I'm Ok with updating the code and the man page as long as Michal takes the blame if anything but CRIU breaks :) Now, seriously, I believe there are not many users of non-cooperative uffd if at all and it is very unlikely anybody has it in production. I'll send a patch with s/ENOSPC/ESRCH in the next few days. -- Sincerely yours, Mike.