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

From	"Kirill A. Shutemov" <kirill@shutemov.name>
Newsgroups	linux.kernel
Subject	Re: [PATCH -mm -v10 3/3] mm, THP, swap: Enable THP swap optimization only if has compound map
Date	2017-04-28 15:20 +0200
Message-ID	<tBdYu-7Nk-17@gated-at.bofh.it> (permalink)
References	<tA8et-4Pu-17@gated-at.bofh.it> <tA8eu-4Pu-29@gated-at.bofh.it> <tAgvn-1HU-13@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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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@intel.com>
> > 
> > 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@cmpxchg.org>
> > Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
> 
> Acked-by: Johannes Weiner <hannes@cmpxchg.org>
> 
> CC Kirill to double check the reasoning here

Looks good to me:

Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>

-- 
 Kirill A. Shutemov

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[PATCH -mm -v10 3/3] mm, THP, swap: Enable THP swap optimization only if has compound map "Huang, Ying" <ying.huang@intel.com> - 2017-04-25 15:00 +0200
  Re: [PATCH -mm -v10 3/3] mm, THP, swap: Enable THP swap optimization  only if has compound map Johannes Weiner <hannes@cmpxchg.org> - 2017-04-25 23:50 +0200
    Re: [PATCH -mm -v10 3/3] mm, THP, swap: Enable THP swap optimization  only if has compound map "Kirill A. Shutemov" <kirill@shutemov.name> - 2017-04-28 15:20 +0200

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