Subject: Re: [PATCH 3/9] mm: drop page_initialized check from get_nid_for_pfn
To: Michal Hocko <mhocko@kernel.org>, linux-mm@kvack.org
References: <20170410110351.12215-1-mhocko@kernel.org>
 <20170410110351.12215-4-mhocko@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
        Mel Gorman <mgorman@suse.de>, Andrea Arcangeli <aarcange@redhat.com>,
        Jerome Glisse <jglisse@redhat.com>,
        Reza Arbab <arbab@linux.vnet.ibm.com>,
        Yasuaki Ishimatsu <yasu.isimatu@gmail.com>, qiuxishi@huawei.com,
        Kani Toshimitsu <toshi.kani@hpe.com>, slaoub@gmail.com,
        Joonsoo Kim <js1304@gmail.com>, Andi Kleen <ak@linux.intel.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>, Michal Hocko <mhocko@suse.com>
From: Vlastimil Babka <vbabka@suse.cz>
Message-ID: <1157048b-512d-277b-b005-3703ffec4907@suse.cz>
Date: Thu, 13 Apr 2017 14:59:00 +0200
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On 04/10/2017 01:03 PM, Michal Hocko wrote:
> From: Michal Hocko <mhocko@suse.com>
> 
> c04fc586c1a4 ("mm: show node to memory section relationship with
> symlinks in sysfs") has added means to export memblock<->node
> association into the sysfs. It has also introduced get_nid_for_pfn
> which is a rather confusing counterpart of pfn_to_nid which checks also
> whether the pfn page is already initialized (page_initialized).  This
> is done by checking page::lru != NULL which doesn't make any sense at
> all. Nothing in this path really relies on the lru list being used or
> initialized. Just remove it because this will become a problem with
> later patches.
> 
> Thanks to Reza Arbab for testing which revealed this to be a problem
> (http://lkml.kernel.org/r/20170403202337.GA12482@dhcp22.suse.cz)
> 
> Signed-off-by: Michal Hocko <mhocko@suse.com>

Acked-by: Vlastimil Babka <vbabka@suse.cz>