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Subject: Re: [PATCH 1/1] mm: compaction: avoid fast_isolate_around() to set
 pageblock_skip on reserved pages
To:     Andrea Arcangeli <aarcange@redhat.com>,
        Mel Gorman <mgorman@suse.de>,
        Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org,
        Qian Cai <cai@lca.pw>
Cc:     Vlastimil Babka <vbabka@suse.cz>, Michal Hocko <mhocko@kernel.org>,
        linux-kernel@vger.kernel.org, Mike Rapoport <rppt@linux.ibm.com>,
        Baoquan He <bhe@redhat.com>
References: <8C537EB7-85EE-4DCF-943E-3CC0ED0DF56D@lca.pw>
 <20201121194506.13464-1-aarcange@redhat.com>
 <20201121194506.13464-2-aarcange@redhat.com> <X7lwT2+uSVGKRApQ@redhat.com>
From:   David Hildenbrand <david@redhat.com>
Organization: Red Hat GmbH
Message-ID: <4e551b29-9bc6-3c4b-4b40-cf68ecb7b6f1@redhat.com>
Date:   Mon, 23 Nov 2020 12:26:28 +0100
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On 21.11.20 20:53, Andrea Arcangeli wrote:
> On Sat, Nov 21, 2020 at 02:45:06PM -0500, Andrea Arcangeli wrote:
>> +					if (likely(!PageReserved(page)))
> 
> NOTE: this line will have to become "likely(page &&
> !PageReserved(page))" to handle the case of non contiguous zones,
> since pageblock_pfn_to_page might return NULL in that case.. I noticed
> right after sending, but I'll wait some feedback before resending the
> correction in case it gets fixed in another way.

With that fixed, this looks sane to me.


-- 
Thanks,

David / dhildenb