On Wed, Aug 21, 2013 at 02:48:20PM +0100, David Vrabel wrote: > All, > > 179ef71c (mm: save soft-dirty bits on swapped pages) introduces a new > PTE bit on x86 _PTE_SWP_SOFT_DIRTY which has the same value as _PTE_PSE > and _PTE_PAT. > > With a Xen PV guest, the use of the _PTE_PAT will result in the page > having unexpected cachability which will introduce a range of subtle > performance and correctness issues. Xen programs the entry 4 in the PAT > table with WC so a page that was previously WB will end up as WC. >
David, could you please explain, Xen keeps and analyze _PTE_PAT bit for ptes which are not present? -- 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/
