On Apr 13, 2007, at 12:49 AM, Richard Earnshaw wrote:

> No, its more to do with the memory mappings for a kernel.  It's far
> easier if your operating system pages live at the top of the Virtual
> memory range to have the vectors at a high address than to have them  
> at
> a lower one (where the vectors are pretty much in the user pages
> (particularly, part of the user level1 look up).

I think the original reason was driven by the address space identifier  
feature, yes?

-- thorpej