On Thu, Apr 30, 2015 at 12:02 AM, Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > On Wed, Apr 29, 2015 at 1:44 PM, Konstantin Khlebnikov <koct9i@xxxxxxxxx> wrote: >> >> This's no longer true. After recent fixes for "anon_vma endless growing" new vma >> might reuse old anon_vma from grandparent vma. > > Oh well. I guess that was too simple. > > If Mark is ok with the rule that "it's not reliably if you have two > nested forks" (ie it only works if you exec for every fork you do), it > should still work, right? It sounds like Mark doesn't necessarily need > to handle the *generic* case. What about exposing shared/exclusive bit in pagemap == 1 if page_mapcount() > 1, otherwise 0 (or vise versa). Seems like this should work for detecting CoWed pages in child mm. -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
