On 1/17/20 3:48 PM, Wei Yang wrote: > This is another point I think current code is not working well. And actually, > the behavior is not well defined or our kernel is broken for a while. > > When you look at the man page, it says: > > RETURN VALUE > On success move_pages() returns zero. On error, it returns -1, and sets errno to indicate the error > Is this from your migrate_pages(2) man page? The latest version of the migrate_pages(2) man page in the git repo has this for RETURN VALUE. RETURN VALUE On success migrate_pages() returns the number of pages that could not be moved (i.e., a return of zero means that all pages were successfully moved). On error, it returns -1, and sets errno to indicate the error. -- Mike Kravetz