Hi, As part of a class assignment I have to collect some performance statistics. In order to do so I run
perf record -g <the program I have to profile> And in another window, I start 200 threads of the load generator (which is not recorded by perf) This generates me statistics that I expect to see, and I am happy. As this is academia and a class assignment, I need to collect information and analyze it across different setups. Which of course meant I script this whole thing, which basically is for i in all possibilities do perf record -g <the program I have to profile> & WAITPID=$! for j in NR_THREADS do <start load generator> & KILLPID=$! done wait $PID kill $KILLPID mv perf.data results/perf.data.$i done (This is basic pseudo script of what I am doing), which results me having my profile being topped by _vscanf() and the function which I was seeing dominating in the older report dropping down to something like 5% (as opposed to 16-17%) Have I misunderstood how perf works? Something deeper? I am currently on 3.6.3. I can update to the latest upstream and report back. Any debug code is very welcome. I can also make my toy program and the scripts available for you to try out. Thanks! Dhaval -- 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/
