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? -- Kirill A. Shutemov -- 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>