On Fri, Jul 26, 2013 at 2:18 PM, Cyrill Gorcunov <gorcu...@gmail.com> wrote: > On Fri, Jul 26, 2013 at 01:55:04PM -0700, Andy Lutomirski wrote: >> On Fri, Jul 26, 2013 at 1:18 PM, Cyrill Gorcunov <gorcu...@gmail.com> wrote: >> > Andy reported that if file page get reclaimed we loose soft-dirty bit >> > if it was there, so save _PAGE_BIT_SOFT_DIRTY bit when page address >> > get encoded into pte entry. Thus when #pf happens on such non-present >> > pte we can restore it back. >> > >> >> Unless I'm misunderstanding this, it's saving the bit in the >> non-present PTE. This sounds wrong -- what happens if the entire pmd > > It's the same as encoding pgoff in pte entry (pte is not present), > but together with pgoff we save soft-bit status, later on #pf we decode > pgoff and restore softbit back if it was there, pte itself can't disappear > since it holds pgoff information.
Isn't that only the case for nonlinear mappings? --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/
