Re: [PATCH -mm -v10 3/3] mm, THP, swap: Enable THP swap optimization only if has compound map

[Kirill A. Shutemov]

On Tue, Apr 25, 2017 at 05:46:18PM -0400, Johannes Weiner wrote:
> On Tue, Apr 25, 2017 at 08:56:58PM +0800, Huang, Ying wrote:
> > From: Huang Ying <ying.huang@xxxxxxxxx>
> > 
> > If there is no compound map for a THP (Transparent Huge Page), it is
> > possible that the map count of some sub-pages of the THP is 0.  So it
> > is better to split the THP before swapping out. In this way, the
> > sub-pages not mapped will be freed, and we can avoid the unnecessary
> > swap out operations for these sub-pages.
> > 
> > Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
> > Signed-off-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
> 
> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
> 
> CC Kirill to double check the reasoning here

Looks good to me:

Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>

-- 
 Kirill A. Shutemov