Re: [PATCH 0/3] powerpc: Instrument Hypervisor Calls

linuxppc-dev-bounces+lukebrowning=us.ibm.com@ozlabs.org wrote on 
07/16/2006 12:53:54 AM:

On Sat, Jul 15, 2006 at 02:00:02AM +0200, Arnd Bergmann wrote:

quoted

What happened to the question whether to use PURR values for also 

measuring

quoted

cycles spent executing the hcall as opposed to cycles that passed 

before

quoted

the hcall returns. Did that turn out not giving extra information 

after all

quoted

or was there a different reason to drop that idea?

Just so people don't forget: this can't be done on all processors. For
example, PPC970 and POWER4 don't implement the PURR SPR. And it doesn't
make sense to use H_PURR to get the software emulated ones there. Not
really an issue on POWER4 since they don't do shared processor LPAR, but
on JS21 I think they might do?

Isn't there someway to do a platform specific processor overlay, where you 

get PURR if it exists and TB otherwise.

Luke