Re: quicklists confuse meminfo

From: Ingo Molnar
Date: Sun Mar 09 2008 - 15:26:02 EST



* Arjan van de Ven <arjan@xxxxxxxxxxxxx> wrote:

> > > ouch! Could you try the patch below? How large is the quicklist
> > > cache with this applied?
> >
> > hm, Thomas pointed it out that this wont solve all the problems as
> > quicklists have a built-in "preserve me" throttle (which is rather
> > stupid).
> >
> > the right solution is to get rid of quicklists altogether (Thomas
> > expects to have patches for that later today).
>
> careful with this; the quicklists aren't JUST for speed they are also
> there to make sure a page we free that is a pagetable, is not reused
> until we have finished flushing the tlbs on all the cpus that saw it.
> This is a really hard correctness requirement, and while I can see
> that quicklists are probably not the best way to achieve this, we
> can't just throw away the behavior ;(

no, that's not true anymore - and the current quicklists code doesnt do
anything like that AFAICS. It used to be a lot more complex, but now
it's just a thin wrapper around the page allocator.

Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/