lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Date:   Thu, 5 Apr 2018 10:27:08 +0200
From:   Michal Hocko <mhocko@...nel.org>
To:     Joonsoo Kim <iamjoonsoo.kim@....com>
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        "Kirill A . Shutemov" <kirill.shutemov@...ux.intel.com>,
        Mel Gorman <mgorman@...e.de>, Vlastimil Babka <vbabka@...e.cz>,
        linux-mm@...ck.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] mm/thp: don't count ZONE_MOVABLE as the target for
 freepage reserving

On Thu 05-04-18 17:05:39, Joonsoo Kim wrote:
> On Thu, Apr 05, 2018 at 09:57:53AM +0200, Michal Hocko wrote:
> > On Thu 05-04-18 16:27:16, Joonsoo Kim wrote:
> > > From: Joonsoo Kim <iamjoonsoo.kim@....com>
> > > 
> > > ZONE_MOVABLE only has movable pages so we don't need to keep enough
> > > freepages to avoid or deal with fragmentation. So, don't count it.
> > > 
> > > This changes min_free_kbytes and thus min_watermark greatly
> > > if ZONE_MOVABLE is used. It will make the user uses more memory.
> > 
> > OK, but why does it matter. Has anybody seen this as an issue?
> 
> There was a regression report for CMA patchset and I think that it is
> related to this problem. CMA patchset makes the system uses one more
> zone (ZONE_MOVABLE) and then increase min_free_kbytes. It reduces
> usable memory and it could cause regression.
> 
> http://lkml.kernel.org/r/20180102063528.GG30397@yexl-desktop

Then this should be a part of the changelog along with some reproducible
results, please.
-- 
Michal Hocko
SUSE Labs

Powered by blists - more mailing lists