On Wed, Aug 21, 2013 at 12:07:13PM -0700, Andy Lutomirski wrote: > On Wed, Aug 21, 2013 at 12:03 PM, Cyrill Gorcunov <gorcu...@gmail.com> wrote: > > On Wed, Aug 21, 2013 at 08:50:26PM +0200, H. Peter Anvin wrote: > >> But is there a manifest bug or not? What is the deal with Xen? > >> > > > > I personally don't see bug here because > > > > - this swapped page soft dirty bit is set for non-present entries only, > > never for present ones, just at moment we form swap pte entry > > > > - i don't find any code which would test for this bit directly without > > is_swap_pte call > > > > but the use of paw bit itself is confusing, so I'm working on patch which > > won't use it. Again, if someone knows where exactly access to pse bit when > > pte keeps swap entry may happen (for any purpose other than dirty page > > tracking) please share. > > I doubt that there are cacheability issues here, since the swap type > already overlaps with PWT and PCD. > > What happens if the page being swapped is a THP page? (I have no idea > how, or even if, this works, but presumably PSE is important.)
add_to_swap -> split_huge_page_to_list, so thp will be splitted. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
