Re: [PATCH V5 4/6] mm: reclaim MADV_FREE pages

From	Michal Hocko <mhocko@kernel.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH V5 4/6] mm: reclaim MADV_FREE pages
Date	2017-02-27 17:40 +0100
Message-ID	<tfwv7-8at-7@gated-at.bofh.it> (permalink)
References	<tevKN-693-3@gated-at.bofh.it> <tevKN-693-15@gated-at.bofh.it> <tfni9-1BB-5@gated-at.bofh.it> <tfwv8-8at-9@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On Mon 27-02-17 08:19:08, Shaohua Li wrote:
> On Mon, Feb 27, 2017 at 03:33:15PM +0900, Minchan Kim wrote:
[...]
> > > --- a/include/linux/rmap.h
> > > +++ b/include/linux/rmap.h
> > > @@ -298,6 +298,6 @@ static inline int page_mkclean(struct page *page)
> > >  #define SWAP_AGAIN	1
> > >  #define SWAP_FAIL	2
> > >  #define SWAP_MLOCK	3
> > > -#define SWAP_LZFREE	4
> > > +#define SWAP_DIRTY	4
> > 
> > I still don't convinced why we should introduce SWAP_DIRTY in try_to_unmap.
> > https://marc.info/?l=linux-mm&m=148797879123238&w=2
> > 
> > We have been SetPageMlocked in there but why cannot we SetPageSwapBacked
> > in there? It's not a thing to change LRU type but it's just indication
> > we found the page's status changed in late.
> 
> This one I don't have strong preference. Personally I agree with Johannes,
> handling failure in vmscan sounds better. But since the failure handling is
> just one statement, this probably doesn't make too much difference. If Johannes
> and you made an agreement, I'll follow.

FWIW I like your current SWAP_DIRTY and the later handling at the vmscan
level more.
-- 
Michal Hocko
SUSE Labs

Thread

[PATCH V5 0/6] mm: fix some MADV_FREE issues Shaohua Li <shli@fb.com> - 2017-02-24 22:40 +0100
  [PATCH V5 6/6] proc: show MADV_FREE pages info in smaps Shaohua Li <shli@fb.com> - 2017-02-24 22:40 +0100
    Re: [PATCH V5 6/6] proc: show MADV_FREE pages info in smaps Michal Hocko <mhocko@kernel.org> - 2017-02-27 16:10 +0100
    Re: [PATCH V5 6/6] proc: show MADV_FREE pages info in smaps "Hillf Danton" <hillf.zj@alibaba-inc.com> - 2017-02-28 04:30 +0100
  [PATCH V5 4/6] mm: reclaim MADV_FREE pages Shaohua Li <shli@fb.com> - 2017-02-24 22:40 +0100
    Re: [PATCH V5 4/6] mm: reclaim MADV_FREE pages Minchan Kim <minchan@kernel.org> - 2017-02-27 07:50 +0100
      Re: [PATCH V5 4/6] mm: reclaim MADV_FREE pages Michal Hocko <mhocko@kernel.org> - 2017-02-27 17:40 +0100
      Re: [PATCH V5 4/6] mm: reclaim MADV_FREE pages Minchan Kim <minchan@kernel.org> - 2017-02-28 06:50 +0100
    Re: [PATCH V5 4/6] mm: reclaim MADV_FREE pages Michal Hocko <mhocko@kernel.org> - 2017-02-27 16:30 +0100
    Re: [PATCH V5 4/6] mm: reclaim MADV_FREE pages Johannes Weiner <hannes@cmpxchg.org> - 2017-02-27 18:30 +0100
    Re: [PATCH V5 4/6] mm: reclaim MADV_FREE pages "Hillf Danton" <hillf.zj@alibaba-inc.com> - 2017-02-28 04:30 +0100
  [PATCH V5 1/6] mm: delete unnecessary TTU_* flags Shaohua Li <shli@fb.com> - 2017-02-24 22:40 +0100
    Re: [PATCH V5 1/6] mm: delete unnecessary TTU_* flags Michal Hocko <mhocko@kernel.org> - 2017-02-27 16:10 +0100
  [PATCH V5 2/6] mm: don't assume anonymous pages have SwapBacked flag Shaohua Li <shli@fb.com> - 2017-02-24 22:40 +0100
    Re: [PATCH V5 2/6] mm: don't assume anonymous pages have SwapBacked flag "Hillf Danton" <hillf.zj@alibaba-inc.com> - 2017-02-27 08:00 +0100
    Re: [PATCH V5 2/6] mm: don't assume anonymous pages have SwapBacked  flag Michal Hocko <mhocko@kernel.org> - 2017-02-27 16:00 +0100
      Re: [PATCH V5 2/6] mm: don't assume anonymous pages have SwapBacked  flag Michal Hocko <mhocko@kernel.org> - 2017-02-27 17:50 +0100

csiph-web