On Thu, Aug 22, 2019 at 09:58:42AM -0700, Ira Weiny wrote: > Add to your list "how does destruction of a MR in 1 process get communicated to > the other?" Does the 2nd process just get failed WR's? IHMO a object that has been shared can no longer be asynchronously destroyed. That is the whole point. A lkey/rkey # alone is inherently unsafe without also holding a refcount on the MR. > I have some of the same concerns as Doug WRT memory sharing. FWIW I'm not sure > that what SCM_RIGHTS is doing is safe or correct. > > For that work I'm really starting to think SCM_RIGHTS transfers should be > blocked. That isn't possible, SCM_RIGHTS is just some special case, fork(), exec(), etc all cause the same situation. Any solution that blocks those is a total non-starter. > It just seems wrong that Process B gets references to Process A's > mm_struct and holds the memory Process A allocated. Except for ODP, a MR doesn't reference the mm_struct. It references the pages. It is not unlike a memfd. Jason
