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Date: Tue, 14 Jan 2014 14:17:06 -0800
From: Dave Hansen <dave@sr71.net>
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To: Christoph Lameter <cl@linux.com>
CC: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        akpm@linux-foundation.org, penberg@kernel.org
Subject: Re: [RFC][PATCH 3/9] mm: page->pfmemalloc only used by slab/skb
References: <20140114180042.C1C33F78@viggo.jf.intel.com> <20140114180051.0181E467@viggo.jf.intel.com> <alpine.DEB.2.10.1401141348130.19618@nuc>
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On 01/14/2014 11:49 AM, Christoph Lameter wrote:
> On Tue, 14 Jan 2014, Dave Hansen wrote:
>> page->pfmemalloc does not deserve a spot in 'struct page'.  It is
>> only used transiently _just_ after a page leaves the buddy
>> allocator.
> 
> Why would we need to do this if we are removing the cmpxchg_double?

Why do we need the patch?

'struct page' is a mess.  It's really hard to follow, and the space in
the definition is a limited resource.  We should not waste that space on
such a transient and unimportant value as pfmemalloc.