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Date: Fri, 21 Sep 2012 13:07:33 -0700
From: Tejun Heo <tj@kernel.org>
To: Pekka Enberg <penberg@kernel.org>
Cc: Glauber Costa <glommer@parallels.com>, Christoph Lameter <cl@linux.com>,
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        Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [PATCH v3 09/16] sl[au]b: always get the cache from its page
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Hello,

On Fri, Sep 21, 2012 at 12:41:52PM +0300, Pekka Enberg wrote:
> > I am already using static keys extensively in this patchset, and that is
> > how I intend to handle this particular case.
> 
> Cool.
> 
> The key point here is that !CONFIG_MEMCG_KMEM should have exactly *zero* 
> performance impact and CONFIG_MEMCG_KMEM disabled at runtime should have 
> absolute minimal impact.

Not necessarily disagreeing, but I don't think it's helpful to set the
bar impossibly high.  Even static_key doesn't have "exactly *zero*"
impact.  Let's stick to as minimal as possible when not in use and
reasonable in use.

And, yeah, this one can be easily solved by using static_key.

Thanks.

-- 
tejun