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

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

What happened to the question whether to use PURR values for also measuring
cycles spent executing the hcall as opposed to cycles that passed before
the hcall returns. Did that turn out not giving extra information after all
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?


-Olof