Generic IOMMU pooled allocator

[David Miller]

From: Sowmini Varadhan <sowmini.varadhan at oracle.com>
Date: Mon, 23 Mar 2015 12:54:06 -0400

> If it was only an optimization (i.e., removing it would not break
> any functionality), and if this was done for older hardware,
> and *if* we believe that the direction of most architectures is to 
> follow the sun4v/HV model, then, given that the sun4u code only uses 1 
> arena pool anyway, one thought that I have for refactoring this
> is the following:

Why add performance regressions to old machines who already are
suffering too much from all the bloat we are constantly adding to the
kernel?