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Date:   Thu, 17 Oct 2019 14:44:58 +0300
From:   "Kirill A. Shutemov" <kirill@shutemov.name>
To:     Dave Hansen <dave.hansen@linux.intel.com>
Cc:     linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        dan.j.williams@intel.com, keith.busch@intel.com
Subject: Re: [PATCH 1/4] node: Define and export memory migration path
Message-ID: <20191017114458.x4atu3vy7ogddvbm@box>
References: <20191016221148.F9CCD155@viggo.jf.intel.com>
 <20191016221149.74AE222C@viggo.jf.intel.com>
 <20191017111205.krurdatuv7d4brs4@box>
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On Thu, Oct 17, 2019 at 02:12:05PM +0300, Kirill A. Shutemov wrote:
> > +		spin_lock(&node_migration_lock);
> > +		WRITE_ONCE(node_migration[nid], TERMINAL_NODE);
> > +		spin_unlock(&node_migration_lock);
> > +		return count;
> > +	}
> > +	if (next >= MAX_NUMNODES || !node_online(next))
> > +		return -EINVAL;
> 
> What prevents offlining after the check?

And what is story with memory hotplug interaction? I don't see any hooks
into memory hotplug to adjust migration path on offlining. Hm?

-- 
 Kirill A. Shutemov