On 2015/10/17 1:01, Christopher Covington wrote: > On 10/16/2015 12:55 AM, Wei Huang wrote: >> > >> > >> > On 09/24/2015 05:31 PM, Shannon Zhao wrote: >>> >> This patchset adds guest PMU support for KVM on ARM64. It takes >>> >> trap-and-emulate approach. When guest wants to monitor one event, it >>> >> will be trapped by KVM and KVM will call perf_event API to create a perf >>> >> event and call relevant perf_event APIs to get the count value of event. >>> >> >>> >> Use perf to test this patchset in guest. When using "perf list", it >>> >> shows the list of the hardware events and hardware cache events perf >>> >> supports. Then use "perf stat -e EVENT" to monitor some event. For >>> >> example, use "perf stat -e cycles" to count cpu cycles and >>> >> "perf stat -e cache-misses" to count cache misses. >>> >> >>> >> Below are the outputs of "perf stat -r 5 sleep 5" when running in host >>> >> and guest. >>> >> >>> >> Host: >>> >> Performance counter stats for 'sleep 5' (5 runs): >>> >> >>> >> 0.551428 task-clock (msec) # 0.000 CPUs utilized ( +- 0.91% ) >>> >> 1 context-switches # 0.002 M/sec >>> >> 0 cpu-migrations # 0.000 K/sec >>> >> 48 page-faults # 0.088 M/sec ( +- 1.05% ) >>> >> 1150265 cycles # 2.086 GHz ( +- 0.92% ) >>> >> <not supported> stalled-cycles-frontend >>> >> <not supported> stalled-cycles-backend >>> >> 526398 instructions # 0.46 insns per cycle ( +- 0.89% ) >>> >> <not supported> branches >>> >> 9485 branch-misses # 17.201 M/sec ( +- 2.35% ) >>> >> >>> >> 5.000831616 seconds time elapsed ( +- 0.00% ) >>> >> >>> >> Guest: >>> >> Performance counter stats for 'sleep 5' (5 runs): >>> >> >>> >> 0.730868 task-clock (msec) # 0.000 CPUs utilized ( +- 1.13% ) >>> >> 1 context-switches # 0.001 M/sec >>> >> 0 cpu-migrations # 0.000 K/sec >>> >> 48 page-faults # 0.065 M/sec ( +- 0.42% ) >>> >> 1642982 cycles # 2.248 GHz ( +- 1.04% ) >>> >> <not supported> stalled-cycles-frontend >>> >> <not supported> stalled-cycles-backend >>> >> 637964 instructions # 0.39 insns per cycle ( +- 0.65% ) >>> >> <not supported> branches >>> >> 10377 branch-misses # 14.198 M/sec ( +- 1.09% ) >>> >> >>> >> 5.001289068 seconds time elapsed ( +- 0.00% ) >>> >> >> > >> > Thanks for V3. One suggestion is to run more perf stress tests, such as >> > "perf test". So we know the corner cases are covered as much as possible. > I'd also recommend Vince Weaver's perf_event_tests. It tests things like > signal-on-counter-overflow that I've never seen anywhere else (other than some > of my own code). > > https://github.com/deater/perf_event_tests Ok. Thanks for your suggestion. -- Shannon -- 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
