Re: [PATCH 2/2] page table iterators

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Thu, 2005-02-17 at 20:43 +0100, Andi Kleen wrote:
> On Fri, Feb 18, 2005 at 01:03:35AM +1100, Nick Piggin wrote:
> > I am pretty surprised myself that I was able to consolidate
> > all "page table range" functions into a single type of iterator
> > (well, there are a couple of variations, but it's not too bad).
> 
> I started a similar project - but it uses the existing loops,
> just using {pte,pmd,pud,pgd}_next. The idea is to optimize
> page table walking by keeping some state in the struct page
> of the page table page that says whether an entry is set 
> or not. To make this work I switched everything to indexes
> instead of pointers.
> 
> Main problem are some nasty include loops. 

I though about both ways yesterday, and in the end, I prefer Nick stuff,
at least for now. It gives us also more flexibility to change gory
implementation details in the future. I still have to run it through a
bit of torture testing though.

Ben.