Re: [RFC] VMX CR3 cache

Ingo Molnar
2008-01-28T17:17:34Z

* Marcelo Tosatti <marcelo-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org> wrote:

> lat_ctx numbers (output is "nr-procs overhead-in-us"):
>
> cr3-cache:
> "size=0k ovr=1.30
> 2 6.63
> "size=0k ovr=1.31
> 4 7.43
> "size=0k ovr=1.32
> 8 11.02

when i did the testing then i was able to get zero VM exits in the
lat_ctx hotpath and get the same performance as on native. The above
numbers you got suggest that this is not the case. (your lat_ctx numbers
on native are probably around 1 usec, right?) If that is the case, could
you check via profile=kvm (or whatever other method you use to profile
KVM) where the VM exits come from?

Ingo