Kumar Gala writes:

On Jun 17, 2009, at 6:50 AM, Paul Mackerras wrote:

quoted

+config PPC_HAVE_PMU_SUPPORT
+       bool

what does this mean?

At the moment it means that arch/powerpc/kernel/perf_counters.c works
for at least some processors in the selected processor family.

quoted

+
+config PPC_PERF_CTRS
+       def_bool y
+       depends on PERF_COUNTERS && PPC_HAVE_PMU_SUPPORT
+       help
+         This enables the powerpc-specific perf_counter back-end.

Can we distinguish between the two different architected perf counters  
programming models to start with.  Maybe something like:

PPC_BOOK3S_PERF_CTRS and PPC_BOOK3E_PERF_CTRS (or  
PPC_SERVER_PERF_CTRS / PPC_EMB_PERF_CTRS)

We can do that once we have code to support the Freescale embedded PMU
and we know how much of arch/powerpc/kernel/perf_counters.c is or
isn't useful there.  We don't have to get to the final state in one
patch.  I'd rather put this patch in as-is and then see a patch series
that adds the Freescale embedded PMU support and makes whatever
Kconfig changes are necessary later.

Paul.