Re: Regression: x86/mm: new _PTE_SWP_SOFT_DIRTY bit conflicts withexisting use

[Linus Torvalds]

On Wed, Aug 21, 2013 at 12:03 PM, Cyrill Gorcunov <gorcunov@xxxxxxxxx> wrote:
>
> 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

Ok, having gone through the places that use swp_*soft_dirty(), I have
to agree. Afaik, it's only ever used on a swap-entry that has (by
definition) the P bit clear. So with or without Xen, I don't see how
it can make any difference.

David/Konrad - did you actually see any issues, or was this just from
(mis)reading the code?

                Linus
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/