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Date:   Thu, 15 Jul 2021 20:54:15 -0700
From:   Andrew Morton <akpm@linux-foundation.org>
To:     "Huang, Ying" <ying.huang@intel.com>
Cc:     linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        Dave Hansen <dave.hansen@linux.intel.com>,
        yang.shi@linux.alibaba.com, rientjes@google.com,
        dan.j.williams@intel.com, david@redhat.com, osalvador@suse.de,
        weixugc@google.com, Michal Hocko <mhocko@suse.com>,
        Yang Shi <shy828301@gmail.com>, Zi Yan <ziy@nvidia.com>
Subject: Re: [PATCH -V10 0/9] Migrate Pages in lieu of discard
Message-Id: <20210715205415.2d6842be57032fbdb2cd2a82@linux-foundation.org>
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References: <20210715055145.195411-1-ying.huang@intel.com>
        <20210715123836.ad76b0a2e29c0bbd3cd67767@linux-foundation.org>
        <87k0lrndc6.fsf@yhuang6-desk2.ccr.corp.intel.com>
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On Fri, 16 Jul 2021 11:32:09 +0800 "Huang, Ying" <ying.huang@intel.com> wrote:

> Andrew Morton <akpm@linux-foundation.org> writes:
> 
> > On Thu, 15 Jul 2021 13:51:36 +0800 Huang Ying <ying.huang@intel.com> wrote:
> >
> > The [0/n] description talks a lot about PMEM, but the patches
> > themselves are all about NUMA nodes.  I assume that what ties this
> > together is that the PMEM tends to be organized as a NUMA node on its
> > own, and that by enabling migrate-to-remote-node-during-reclaim, we get
> > this PMEM behaviour as a desired side-effect?
> >
> > IOW, perhaps this [0/n] description could explain the linkage between
> > PMEM and NUMA nodes more explicitly.
> 
> Hi, Andrew,
> 
> I have added some words in the [0/9] description to link PMEM and NUMA
> nodes.  The updated description is as below.  Can you take a look at it?
> 
> ...
>
> With that, the DRAM and PMEM in each socket will be represented as 2
> separate NUMA nodes, with the CPUs sit in the DRAM node.  So the
> general inter-NUMA demotion mechanism introduced in the patchset can
> migrate the cold DRAM pages to the PMEM node.
> 

Bingo, thanks.