Date: Tue, 4 Apr 2017 11:02:39 -0500
From: Reza Arbab <arbab@linux.vnet.ibm.com>
To: Michal Hocko <mhocko@kernel.org>
Cc: Mel Gorman <mgorman@suse.de>, linux-mm@kvack.org,
        Andrew Morton <akpm@linux-foundation.org>,
        Vlastimil Babka <vbabka@suse.cz>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Yasuaki Ishimatsu <yasu.isimatu@gmail.com>,
        Tang Chen <tangchen@cn.fujitsu.com>, qiuxishi@huawei.com,
        Kani Toshimitsu <toshi.kani@hpe.com>, slaoub@gmail.com,
        Joonsoo Kim <js1304@gmail.com>, Andi Kleen <ak@linux.intel.com>,
        Zhang Zhen <zhenzhang.zhang@huawei.com>,
        David Rientjes <rientjes@google.com>,
        Daniel Kiper <daniel.kiper@oracle.com>,
        Igor Mammedov <imammedo@redhat.com>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Chris Metcalf <cmetcalf@mellanox.com>,
        Dan Williams <dan.j.williams@gmail.com>,
        Heiko Carstens <heiko.carstens@de.ibm.com>,
        Lai Jiangshan <laijs@cn.fujitsu.com>,
        Martin Schwidefsky <schwidefsky@de.ibm.com>
Subject: Re: [PATCH 0/6] mm: make movable onlining suck less
References: <20170330115454.32154-1-mhocko@kernel.org>
 <20170403115545.GK24661@dhcp22.suse.cz>
 <20170403195830.64libncet5l6vuvb@arbab-laptop>
 <20170403202337.GA12482@dhcp22.suse.cz>
 <20170403204213.rs7k2cvsnconel2z@arbab-laptop>
 <20170404072329.GA15132@dhcp22.suse.cz>
 <20170404073412.GC15132@dhcp22.suse.cz>
 <20170404082302.GE15132@dhcp22.suse.cz>
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On Tue, Apr 04, 2017 at 10:23:02AM +0200, Michal Hocko wrote:
>diff --git a/drivers/base/node.c b/drivers/base/node.c
>index 5548f9686016..ee080a35e869 100644
>--- a/drivers/base/node.c
>+++ b/drivers/base/node.c
>@@ -368,8 +368,6 @@ int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
> }
>
> #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
>-#define page_initialized(page)  (page->lru.next)
>-
> static int __ref get_nid_for_pfn(unsigned long pfn)
> {
> 	struct page *page;
>@@ -380,9 +378,6 @@ static int __ref get_nid_for_pfn(unsigned long pfn)
> 	if (system_state == SYSTEM_BOOTING)
> 		return early_pfn_to_nid(pfn);
> #endif
>-	page = pfn_to_page(pfn);
>-	if (!page_initialized(page))
>-		return -1;
> 	return pfn_to_nid(pfn);
> }
>

You can get rid of 'page' altogether.

drivers/base/node.c: In function ‘get_nid_for_pfn’:
drivers/base/node.c:373:15: warning: unused variable ‘page’ [-Wunused-variable]

-- 
Reza Arbab