Comment 46 for bug 413135

On Thu, Oct 22, 2009 at 04:49:09PM -0000, Kees Cook wrote:
> (As a tangent, it might be easier to just install the PAE kernels if the
> "pae" flag exists in /proc/cpuinfo. Without that flag, the amount of
> memory isn't interesting. With that flag, they should get a kernel that
> supports future memory upgrades.)

I've stated my position on this before in an e-mail thread, although it
doesn't look as though it made it into this bug.

PAE is slow. I realise that it has some security benefits, but it is
SLOW. Linus has some fairly excoriating comments on it here (HIGHMEM64G
== PAE) - I don't fancy the idea of making forks significantly more
expensive, especially considering the focus on boot speed:

  http://article.gmane.org/gmane.linux.kernel/845637

As such, I strongly feel that we have to make its use conditional on
having enough memory to require it. The memory upgrade issue is
unfortunate, but with creativity we could address it in other ways.