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Date:   Wed, 21 Apr 2021 09:37:44 +0200
From:   Oscar Salvador <osalvador@suse.de>
To:     Michal Hocko <mhocko@suse.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        David Hildenbrand <david@redhat.com>,
        Anshuman Khandual <anshuman.khandual@arm.com>,
        Pavel Tatashin <pasha.tatashin@soleen.com>,
        Vlastimil Babka <vbabka@suse.cz>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v9 2/8] mm,memory_hotplug: Relax fully spanned sections
 check
Message-ID: <20210421073744.GB22456@linux>
References: <20210416112411.9826-1-osalvador@suse.de>
 <20210416112411.9826-3-osalvador@suse.de>
 <YH6hoieSEFtSUfMQ@dhcp22.suse.cz>
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On Tue, Apr 20, 2021 at 11:40:50AM +0200, Michal Hocko wrote:
> On Fri 16-04-21 13:24:05, Oscar Salvador wrote:
> > When using self-hosted vmemmap pages, the number of pages passed to
> > {online,offline}_pages might not fully span sections, but they always
> > fully span pageblocks.
> > Relax the check account for that case.
> 
> It would be good to call those out explicitly.  It would be also
> great to explain why pageblock_nr_pages is an actual constrain. There
> shouldn't be any real reason for that except for "we want online_pages
> to operate on whole memblocks and memmap_on_memory will poke
> pageblock_nr_pages aligned holes in the beginning which is a special
> case we want to allow."

Sounds good.

> 
> > Signed-off-by: Oscar Salvador <osalvador@suse.de>
> > Reviewed-by: David Hildenbrand <david@redhat.com>
> 
> With the changelog extended and the comment clarification (se below)
> feel free to add

Ok, thanks for the suggestion Michal.

> Acked-by: Michal Hocko <mhocko@suse.com>

-- 
Oscar Salvador
SUSE L3