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From: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Date: Tue, 31 Mar 2015 14:06:42 -0400

> Having bravely said that..
> 
> the IB team informs me that they see a 10% degradation using 
> the spin_lock as opposed to the trylock.
> 
> one path going forward is to continue processing this patch-set 
> as is. I can investigate this further, and later revise the spin_lock
> to the trylock, after we are certain that it is good/necessary.
> 
> thoughts?

Let's address the trylock vs. spin_lock thing later and use plain
spin_lock for now.