Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Sat, 2 May 2020 23:05:28 +0000 (UTC)
From:   Christopher Lameter <cl@linux.com>
To:     Srikar Dronamraju <srikar@linux.vnet.ibm.com>
cc:     Andrew Morton <akpm@linux-foundation.org>,
        linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, Michal Hocko <mhocko@suse.com>,
        Mel Gorman <mgorman@suse.de>, Vlastimil Babka <vbabka@suse.cz>,
        "Kirill A. Shutemov" <kirill@shutemov.name>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Gautham R Shenoy <ego@linux.vnet.ibm.com>
Subject: Re: [PATCH v3 3/3] mm/page_alloc: Keep memoryless cpuless node 0
 offline
In-Reply-To: <20200501031128.19584-4-srikar@linux.vnet.ibm.com>
Message-ID: <alpine.DEB.2.21.2005022304190.28355@www.lameter.com>
References: <20200501031128.19584-1-srikar@linux.vnet.ibm.com> <20200501031128.19584-4-srikar@linux.vnet.ibm.com>
User-Agent: Alpine 2.21 (DEB 202 2017-01-01)
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Fri, 1 May 2020, Srikar Dronamraju wrote:

> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -116,8 +116,10 @@ EXPORT_SYMBOL(latent_entropy);
>   */
>  nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
>  	[N_POSSIBLE] = NODE_MASK_ALL,
> +#ifdef CONFIG_NUMA
> +	[N_ONLINE] = NODE_MASK_NONE,

Hmmm.... I would have expected that you would have added something early
in boot that would mark the current node (whatever is is) online instead?