On 08/21/2013 11:07 PM, 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.)
Huge-page is splitted into small ones, then the smaller ones get swapped out. > --Andy > -- 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/
