Re: [RFC PATCH] page_cgroup: Reduce allocation overhead forpage_cgroup array for CONFIG_SPARSEMEM

From: Michal Hocko
Date: Thu Feb 24 2011 - 04:33:14 EST

On Wed 23-02-11 10:19:22, Dave Hansen wrote:
> On Wed, 2011-02-23 at 16:10 +0100, Michal Hocko wrote:
> > We can reduce this internal fragmentation by splitting the single
> > page_cgroup array into more arrays where each one is well kmalloc
> > aligned. This patch implements this idea.
> How about using alloc_pages_exact()? These things aren't allocated
> often enough to really get most of the benefits of being in a slab.

Yes, you are right. alloc_pages_exact (which I wasn't aware of) is much
simpler solution and it gets comparable results. I will prepare the
patch for review.

Thanks for pointing this out.
Michal Hocko
Lihovarska 1060/12
190 00 Praha 9
Czech Republic
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