On Thu, Apr 30, 2015 at 4:22 PM, Kirill A. Shutemov <kirill@xxxxxxxxxxxxx> wrote: > On Thu, Apr 30, 2015 at 04:11:30PM +0300, Konstantin Khlebnikov wrote: >> On Thu, Apr 30, 2015 at 2:43 PM, Konstantin Khlebnikov <koct9i@xxxxxxxxx> wrote: >> > 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. >> >> Something like this (see patch in attachment) > > THP is not covered. Ok. Thanks. > > Any comments on kcmp() idea? Should work too. Supporing full equal-less-greater semantics seems safe -- it's obfuscation is strong enough for that. > > -- > Kirill A. Shutemov -- 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
