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Subject: Re: [PATCH] mm/isolation: Remove redundant pfn_valid_within() in
 __first_valid_page()
To:     Zi Yan <ziy@nvidia.com>
Cc:     linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        mike.kravetz@oracle.com, osalvador@suse.de, mhocko@suse.com,
        akpm@linux-foundation.org
References: <1553141595-26907-1-git-send-email-anshuman.khandual@arm.com>
 <8AB57711-48C0-4D95-BC5F-26B266DC3AE8@nvidia.com>
From:   Anshuman Khandual <anshuman.khandual@arm.com>
Message-ID: <cda4f247-4eea-decf-3f4a-3dc09364de27@arm.com>
Date:   Thu, 21 Mar 2019 11:03:18 +0530
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On 03/21/2019 10:31 AM, Zi Yan wrote:
> On 20 Mar 2019, at 21:13, Anshuman Khandual wrote:
> 
>> pfn_valid_within() calls pfn_valid() when CONFIG_HOLES_IN_ZONE making it
>> redundant for both definitions (w/wo CONFIG_MEMORY_HOTPLUG) of the helper
>> pfn_to_online_page() which either calls pfn_valid() or pfn_valid_within().
>> pfn_valid_within() being 1 when !CONFIG_HOLES_IN_ZONE is irrelevant either
>> way. This does not change functionality.
>>
>> Fixes: 2ce13640b3f4 ("mm: __first_valid_page skip over offline pages")
> 
> I would not say this patch fixes the commit 2ce13640b3f4 from 2017,
> because the pfn_valid_within() in pfn_to_online_page() was introduced by
> a recent commit b13bc35193d9e last month. :)

Right, will update the tag with this commit.