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Date: Fri, 7 Aug 2015 17:50:56 +0300
From: "Kirill A. Shutemov" <kirill@shutemov.name>
Subject: Re: page-flags behavior on compound pages: a worry
Message-ID: <20150807145056.GB12177@node.dhcp.inet.fi>
References: <1426784902-125149-1-git-send-email-kirill.shutemov@linux.intel.com>
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To: Christoph Lameter <cl@linux.com>
Cc: Hugh Dickins <hughd@google.com>, "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>, Andrew Morton <akpm@linux-foundation.org>, Andrea Arcangeli <aarcange@redhat.com>, David Rientjes <rientjes@google.com>, Dave Hansen <dave.hansen@intel.com>, Mel Gorman <mgorman@suse.de>, Rik van Riel <riel@redhat.com>, Vlastimil Babka <vbabka@suse.cz>, Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>, Steve Capper <steve.capper@linaro.org>, "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>, Johannes Weiner <hannes@cmpxchg.org>, Michal Hocko <mhocko@suse.cz>, Jerome Marchand <jmarchan@redhat.com>, linux-kernel@vger.kernel.org, linux-mm@kvack.org

On Thu, Aug 06, 2015 at 03:45:31PM -0500, Christoph Lameter wrote:
> On Thu, 6 Aug 2015, Hugh Dickins wrote:
> 
> > > I know a patchset which solves this! ;)
> >
> > Oh, and I know a patchset which avoids these problems completely,
> > by not using compound pages at all ;)
> 
> Another dumb idea: Stop the insanity of splitting pages on the fly?
> Splitting pages should work like page migration: Lock everything down and
> ensure no one is using the page and then do it. That way the compound pages
> and its metadata are as stable as a regular page.
 
That's what I do in refcounting patchset.

-- 
 Kirill A. Shutemov

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