Hello I have a new AMD A8 system and perf multiplexing support is acting weird.
If I run the perf_event_tests check_multiplexing test it fails like this: Event TotalCount RawCount Scale ScaledCount Error 0 500282143 150403975 -2.00 (c8050b5 fffffffff9c224ef) -300807950 160.13% So the problem is that the TOTAL_TIME_RUNNING value is negative, which as far as I know shouldn't be possible. I can't seem to track down why this would happen, and the same kernel (4.2-rc3) running on a Haswell machine doesn't have this problem. I tried to replicate the problem using perf, but for some reason I can't get perf to multiplex on any of my machines. That used to transparently work didn't it? here's the result on the haswell machine perf stat -e cycles,instructions,cycles,instructions,cycles,instructions,cycles,instructions sleep 5 Performance counter stats for 'sleep 5': 1,354,527 cycles 1,934,694 instructions # 1.76 insns per cycle 1,521,148 cycles 1,934,694 instructions # 1.76 insns per cycle 1,521,148 cycles 1,223,321 instructions # 1.11 insns per cycle [13.61%] <not counted> cycles <not counted> instructions 5.003651781 seconds time elapsed Vince -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/