On Thu, May 22, 2014 at 01:47:48PM -0400, Naoya Horiguchi wrote: ... > > BTW, does everybody happy with mincore() interface? We report 1 there if > > pte is present, but it doesn't really say much about the page for cases > > like zero page... > > According to manpage of mincore(2), > mincore() returns a vector that indicates whether pages of the calling process's vir‐ > tual memory are resident in core (RAM), and so will not cause a disk access (page > fault) if referenced. ... > > so we can assume that the callers want to predict whether they will have > page faults. But it depends on whether the access is read or write. > So I think current mincore() is not enough to do this prediction precisely > for privately shared pages (including zero page and ksm page). > Maybe we need a new syscall to solving this problem. Sorry, this is not correct, we can use upper bits of each vector to show protection info of page table entry. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href