On Thu, 2008-09-25 at 17:32 +0800, Liu Yu-B13201 wrote: > > > > On Wed, 2008-09-24 at 11:24 +0200, Christian Ehrhardt wrote: > > > count min max > > > sum avg stddev time% > > > EMULINST 6,423,699 12 247,582 > > 91,732,705 > > > 14.2804 241.200 45.36 > > > ITLBVIRT 1,777,242 21 264,257 > > 47,116,557 > > > 26.5111 286.040 23.30 > > > DTLBVIRT 1,544,241 22 263,947 > > 41,765,447 > > > 27.0459 218.997 20.65 > > > > (The max here is of course when the guest was de-scheduled in favor of > > another host process.) > > > > I think it's interesting that the min instruction emulation time is 12 > > usecs. In fact, our "null" exits where we do almost no > > processing (ISI, > > DSI, syscall) are 11 usecs, which suggests we have a problem with > > interrupt handler overhead (for all exit types). > > > > Will you consider about moving tlb manipulation out of entering path? > Examining the modify array may cost some time. Yes, definitely. That's about the only thing I can see in the 440 interrupt path that might take significant time. Unfortunately we can't profile that code because we have no performance counters, so finding the problem will require some experimentation. -- Hollis Blanchard IBM Linux Technology Center -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
