Re: [PATCH] General purpose zeroed page slab

Andi Kleen
2004-10-15T01:18:38Z

On Thu, Oct 14, 2004 at 06:36:47PM -0500, Adam Heath wrote:
> On Thu, 14 Oct 2004, Andi Kleen wrote:
>
> > Also that's pretty dumb. How about keeping track how much of the
> > page got non zeroed (e.g. by using a few free words in struct page
> > for a coarse grained dirty bitmap)
> >
> > Then you could memset on free only the parts that got actually
> > changed, and never waste cache lines for anything else.
>
> That will fail when a struct is placed in the page, and only the beginning and
> end of the struct was changed.

Hmm? I think you're misunderstanding me. The dirty bitmap would cover
all areas that are potentially not zero. If someone changes a byte
without setting the bitmap they're buggy.

-Andi
>