Re: [PATCH v5 00/11] Introduce huge zero page

Andrew Morton
2012-11-14T23:32:46Z

On Wed, 14 Nov 2012 23:20:13 +0000
Alan Cox <alan@lxorguk.ukuu.org.uk> wrote:

> > I'm still a bit concerned over the possibility that some workloads will
> > cause a high-frequency free/alloc/memset cycle on that huge zero page.
> > We'll see how it goes...
>
> That is easy enough to fix - we can delay the freeing by a random time or
> until memory pressure is applied.
>

The current code does the latter, by freeing the page via a
"slab"-shrinker callback.

But I do suspect that with the right combination of use/unuse and
memory pressure, we could still get into the high-frequency scenario.