On 05/13/10 16:57, Avi Kivity wrote: > On 05/13/2010 05:35 PM, Stefan Hajnoczi wrote: >> How to count and trace KVM perf events: >> >> http://www.linux-kvm.org/page/Perf_events >> >> I want to draw attention to this because traditional kvm_stat and >> kvm_trace use has been moving over to the debugfs based tracing >> mechanisms. Perhaps we can flesh out documentation and examples of >> common perf event usage. >> >> > > Two things are missing to make this really useful: > > - a continuously updating difference mode like kvm_stat > - subevents; for example kvm:kvm_exit is an aggregate of all exit types > that can be split using filters to show individual exit reason statistics Third missing item, which I find really useful: - run once spit out raw counters For some operations, like file system benchmarking, it is useful to sample the counters before and after and then divide the raw number of events by the number of IOPS performed by the benchmark. If perf spits out events/sec it's kinda hard to get this. Cheers, Jes -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
