Re: objrmap and vmtruncate

Benjamin LaHaise
2003-04-06T09:29:43Z

On Sat, Apr 05, 2003 at 06:30:03PM +0200, Andrea Arcangeli wrote:
>
> I'm not questioning during paging rmap is more efficient than objrmap,
> but your argument about rmap having lower complexity of objrmap and that
> rmap is needed is wrong. The fact is that with your 100 mappings per
> each of the 100 tasks case, both algorithms works in O(N) where N is
> the number of the pagetables mapping the page. No difference in

Small mistake on your part: there are two different parameters to that:
objrmap is O(N) where N is the number of vmas, and regular rmap is O(M)
where M is the number of currently mapped ptes. M <= N and is frequently
less for sparsely resident pages (ie in things like executables).

-ben