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Date:   Wed, 12 Aug 2020 11:31:01 +0530
From:   Srikar Dronamraju <srikar@linux.vnet.ibm.com>
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     Michal Hocko <mhocko@kernel.org>,
        Michal Such?nek <msuchanek@suse.de>,
        David Hildenbrand <david@redhat.com>,
        Gautham R Shenoy <ego@linux.vnet.ibm.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>,
        Mel Gorman <mgorman@suse.de>,
        "Kirill A. Shutemov" <kirill@shutemov.name>,
        linuxppc-dev@lists.ozlabs.org, Christopher Lameter <cl@linux.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        Andi Kleen <ak@linux.intel.com>
Subject: Re: [PATCH v5 3/3] mm/page_alloc: Keep memoryless cpuless node 0
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Hi Andrew, Michal, David

* Andrew Morton <akpm@linux-foundation.org> [2020-08-06 21:32:11]:

> On Fri, 3 Jul 2020 18:28:23 +0530 Srikar Dronamraju <srikar@linux.vnet.ibm.com> wrote:
> 
> > > The memory hotplug changes that somehow because you can hotremove numa
> > > nodes and therefore make the nodemask sparse but that is not a common
> > > case. I am not sure what would happen if a completely new node was added
> > > and its corresponding node was already used by the renumbered one
> > > though. It would likely conflate the two I am afraid. But I am not sure
> > > this is really possible with x86 and a lack of a bug report would
> > > suggest that nobody is doing that at least.
> > > 
> > 
> > JFYI,
> > Satheesh copied in this mailchain had opened a bug a year on crash with vcpu
> > hotplug on memoryless node. 
> > 
> > https://bugzilla.kernel.org/show_bug.cgi?id=202187
> 
> So...  do we merge this patch or not?  Seems that the overall view is
> "risky but nobody is likely to do anything better any time soon"?

Can we decide on this one way or the other?

-- 
Thanks and Regards
Srikar Dronamraju