Re: 4level page tables for Linux

[Andrea Arcangeli <andrea@novell.com>]

On Mon, Oct 18, 2004 at 10:02:20AM -0700, Christoph Lameter wrote:
> Would it not be best to give up hardcoding these page mapping levels into
> the kernel? Linux should support N levels. pml4,pgd,pmd,pte needs to
> disappear and be replaced by
> 
> pte_path[N]

those aren't the same thing. they may have different
format and different size, plus as Ingo pointed out we use type checking
even when they're the same size. Plus they're already an array. It's not
that simple to remove those duplicate loops, and pte[N] wouldn't mean
the level but the entry offset in the pagetable. Peraphs it's possible
to remove the loops but you'd need at least more runtime branches to
execute in each loop to understand which methods you need to execute
depending on the level you're running on. I certainly don't like the
loops myself so I see your point ;).