On 06/16/2011 07:53 AM, Avi Kivity wrote: > On 06/15/2011 07:51 PM, David Ahern wrote: >> The qemu-kvm change is setting the pmu version to 1, and your patchset >> introduces v1 event constraints. So based on intel_pmu_init model=0 is >> an appropriate model - and a required parameter (-cpu host,model=0). >> With that option I get the<not supported> label as expected. >> >> Guest side: >> Performance counter stats for 'openssl speed aes': >> >> 45160.015949 task-clock # 0.998 CPUs utilized >> >> 192 context-switches # 0.000 M/sec >> >> 0 CPU-migrations # 0.000 M/sec >> >> 650 page-faults # 0.000 M/sec >> >> 57,064,592,321 cycles # 1.264 GHz >> [49.96%] >> 138,608,368,094 instructions # 2.43 insns per cycle >> [50.04%] >> 3,003,337,751 branches # 66.504 M/sec >> [50.04%] >> 21,890,537 branch-misses # 0.73% of all branches >> [49.96%] >> >> 45.242117218 seconds time elapsed >> >> (<not supported> events removed). And comparable events from running the >> same command host side: >> Performance counter stats for 'openssl speed aes': >> >> 44947.093539 task-clock # 0.998 CPUs utilized >> >> 4,800 context-switches # 0.000 M/sec >> >> 5 CPU-migrations # 0.000 M/sec >> >> 481 page-faults # 0.000 M/sec >> >> 124,610,137,228 cycles # 2.772 GHz >> [27.77%] >> 338,982,292,106 instructions # 2.72 insns per cycle >> >> 6,061,899,079 branches # 134.867 M/sec >> [33.33%] >> 2,236,965 branch-misses # 0.04% of all branches >> [33.33%] >> 45.043442068 seconds time elapsed >> >> So cycles are off by roughly 2, instructions are off by roughly a factor >> of 2.5, branches by a factor of 2. Those 3 events are fairly close from >> one run to the next in the host. > > Oh, there's the scaling issue that Peter pointed out. > > Can you try the tests again, but now measuring just one counter per run > (perf stat -e xxx command). > > Command: perf stat -e instructions openssl speed aes Guest: 135,522,189,056 instructions # 0.00 insns per cycle Host: 346,082,922,185 instructions # 0.00 insns per cycle Adding '--no-scale' to the perf-stat had no effect on the relative difference. David -- 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
