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Date:   Mon, 25 Nov 2019 09:40:58 +0100
From:   Michal Hocko <mhocko@kernel.org>
To:     Pengfei Li <fly@kernel.page>
Cc:     akpm@linux-foundation.org, mgorman@techsingularity.net,
        vbabka@suse.cz, cl@linux.com, iamjoonsoo.kim@lge.com, guro@fb.com,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [RFC v1 00/19] Modify zonelist to nodelist v1
Message-ID: <20191125084058.GD31714@dhcp22.suse.cz>
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 <20191121180401.GL23213@dhcp22.suse.cz>
 <20191122230543.2f106c80.fly@kernel.page>
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On Fri 22-11-19 23:05:43, Pengfei Li wrote:
> On Thu, 21 Nov 2019 19:04:01 +0100
> Michal Hocko <mhocko@kernel.org> wrote:
> 
> > On Thu 21-11-19 23:17:52, Pengfei Li wrote:
> > [...]
> > > Since I don't currently have multiple node NUMA systems, I would be
> > > grateful if anyone would like to test this series of patches.
> > 
> > I didn't really get to think about the actual patchset. From a very
> > quick glance I am wondering whether we need to optimize as there are
> > usually only small amount of numa nodes. But I am quite busy so I
> > cannot really do any claims.
> 
> Thanks for your comments.
> 
> I think it's time to modify the zonelist to nodelist because the
> zonelist is always in node order and the page reclamation is based on
> node.
> 
> I will do more performance testing to show that multi-node systems will
> benefit from this series of patches.

Sensible performance numbers on multiple workloads (ideally some real
world ones rather than artificial microbenchmarks) is essential for a
performance optimization that is this large.
-- 
Michal Hocko
SUSE Labs