Re: [PATCH 0/33] KVM: MMU: Cache shadow page tables

Ingo Molnar
2007-01-04T18:05:57Z

* Avi Kivity <avi@qumranet.com> wrote:

> Andrew Morton wrote:
> >Is this intended for 2.6.20, or would you prefer that we release what we
> >have now and hold this off for 2.6.21?
> >
>
> Even though these patches are potentially destabilazing, I'd like them
> (and a few other patches) to go into 2.6.20:
>
> - kvm did not exist in 2.6.19, hence we cannot regress from that
> - this patchset is the difference between a working proof of concept and
> a generally usable system
> - from my testing, it's quite stable

seconded - i have tested the new MMU changes quite extensively and they
are converging nicely. It brings down context-switch costs by a factor
of 10 and more, even for microbenchmarks: instead of throwing away the
full shadow pagetable hiearchy we have worked so hard to construct this
patchset allows the intelligent caching of shadow pagetables. The effect
is human-visible as well - the system got visibly snappier.

(I'd increase the shadow cache pool from the current 256 pages to at
least 1024 pages, but that's a detail.)

Acked-by: Ingo Molnar <mingo@elte.hu>

Ingo