Re: Page allocator: Single Zone optimizations

Christoph Lameter
2006-11-03T21:53:55Z

On Fri, 3 Nov 2006, Andrew Morton wrote:

> > Kernel pages are buffered already in the slab
> > allocator
>
> But why? I've been intermittently campaigning to stop doing that for about
> five years now. Having private lists of free pages in the slab allocator
> is duplicative of the page allocator's lists and worsens performance.

This has to do with the constructors and the destructors. They are only
applied during the first allocation or the final deallocation of the slab.
The slab (with the pages) stays on the freelist with all objects having
proper values as set by the constructors.