Collecting hypervisor call stats

[Mike Kravetz]

On Thu, Jun 01, 2006 at 08:40:50AM +1000, Paul Mackerras wrote:
> I think that gathering those statistics would be useful.  I suggest
> you use a per-cpu array for them, to reduce the performance impact.

Yes, that is a must do.

We need to get a timestamp before and after the call.  mftb should do
the trick.  Also, I'd prefer to have the code that stuffs the values
into the array be C.  So, the decision is to have the assembly code
call out to the C routine -OR- create wrappers for the assembly routines.
I much prefer C wrappers to touching the assembly.

-- 
Mike