On Tue, Aug 26, 2014 at 06:43:55PM +0300, Kirill A. Shutemov wrote: > On Tue, Aug 26, 2014 at 07:18:13PM +0400, Cyrill Gorcunov wrote: > > > Basically, it's safe if only soft-dirty is allowed to modify vm_flags > > > without down_write(). But why is soft-dirty so special? > > > > because how we use this bit, i mean in normal workload this bit won't > > be used intensively i think so it's not widespread in kernel code > > Weak argument to me. > > What about walk through vmas twice: first with down_write() to modify > vm_flags and vm_page_prot, then downgrade_write() and do > walk_page_range() on every vma? I still it's undeeded, but for sure using write-lock/downgrade won't hurt, so no argues from my side. -- 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=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>