Hi Michael, > Thanks for this patch. I've applied it, and done quite a > bit of editing. Could you please take a look at the > version in Git, and let me know if I made any bad changes > to your text. Your changes look good. > You write "move", but would it not be more correcrt to say something > like "duplicate"? It's a little of both, it duplicates the VMA but moves the page table entries. So the behavior feels more like a move followed by a new mapping created that had the same properties as the previous. Does that make sense? > > +Possible applications for this behavior might be garbage collection or > > Can you elaborate the garbage collection use case a little, please? Lokesh, who is CCed, can probably expand better than I can, Lokesh would you mind elaborating on how the JVM plans to use this. > > +non-cooperative > > +.BR userfaultfd (2) . > > What is noncooperative userfaultfd(2)? No cooperative userfaultfd is the term that people tend to use when the threads accessing the memory are not cooperating with the fault handling, MREMAP_DONTUNMAP is interesting for this as you can yank out the page tables from a running process and immediately start handling faults for the registered range without having to stop the process. I hope that answers your questions, feel free to ask if you need more clarification. Brian
