Hi Dhaval, On Mon, 29 Oct 2012 12:45:53 -0400, Dhaval Giani wrote: > On Mon, Oct 29, 2012 at 12:01 PM, Dhaval Giani <dhaval.gi...@gmail.com> wrote: >> 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
You meant $WAITPID, right? >> kill $KILLPID Doesn't it kill the last load generator only? >> mv perf.data results/perf.data.$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. > > I just updated to 6b0cb4eef7bdaa27b8021ea81813fba330a2d94d and I still > see this happen. > > 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/