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Date: Thu, 24 Feb 2011 14:40:45 +0100
From: Michal Hocko <mhocko@suse.cz>
Subject: Re: [RFC PATCH] page_cgroup: Reduce allocation overhead for
 page_cgroup array for CONFIG_SPARSEMEM v2
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References: <20110223151047.GA7275@tiehlicka.suse.cz>
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To: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: linux-mm@kvack.org, KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>, linux-kernel@vger.kernel.org

Here is the second version of the patch. I have used alloc_pages_exact
instead of the complex double array approach.

I still fallback to kmalloc/vmalloc because hotplug can happen quite
some time after boot and we can end up not having enough continuous
pages at that time. 

I am also thinking whether it would make sense to introduce
alloc_pages_exact_node function which would allocate pages from the
given node.

Any thoughts?
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