Date: Wed, 27 Mar 2013 23:55:59 +0100
From: Michal Hocko <mhocko@suse.cz>
To: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
        Mel Gorman <mel@csn.ul.ie>, Hugh Dickins <hughd@google.com>,
        KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
        Andi Kleen <andi@firstfloor.org>, Hillf Danton <dhillf@gmail.com>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 09/10] memory-hotplug: enable memory hotplug to handle
 hugepage
Message-ID: <20130327225548.GA401@dhcp22.suse.cz>
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On Wed 27-03-13 17:29:19, Naoya Horiguchi wrote:
> On Wed, Mar 27, 2013 at 03:19:21PM +0100, Michal Hocko wrote:
[...]
> > If we made sure that all page on the hugepage_freelists have reference
> > 0 (which is now not the case and it is yet another source of confusion)
> > then the whole loop could be replaced by page_count check.
> 
> I think that free hugepages have refcount 0,

You are right. For some reason I totally missed that we drop
the reference from page allocator (put_page_testzero in
gather_surplus_pages).

Sorry about the stupit question.
-- 
Michal Hocko
SUSE Labs
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