Nathan Lynch wrote: > Kumar Gala wrote: > >> On Jul 3, 2008, at 6:20 PM, Nathan Lynch wrote: >> >> >>> Beginning with Power6, there is a set of 32 PMU events which is >>> compatible across POWER processor lines. PPC_FEATURE_PMU_COMPAT >>> indicates support for this subset. >>> >>> Signed-off-by: Nathan Lynch <[EMAIL PROTECTED]> >>> --- >>> arch/powerpc/kernel/cputable.c | 4 ++-- >>> include/asm-powerpc/cputable.h | 1 + >>> 2 files changed, 3 insertions(+), 2 deletions(-) >>> >> Can you explain what these PMU events are a bit further? >> > > Maynard, can you help out here...? :) > As of POWER6, a set of 32 common events were defined that must be supported on all future POWER processors -- aka "PMU compat set". The main impetus for this compat set is the need to support partition migration, especially from processor P(n) to processor P(n+1), where performance software that's running in the new partition may not be knowledgeable about processor P(n+1). If a performance tool determines it does not support the physical processor, but is told (via the PPC_FEATURE_PMU_COMPAT bit) that the processor supports the notion of the PMU compat set, then the performance tool can surface just those events to the user of the tool.
Hope that helps. -Maynard _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
