On Tue, 2013-06-25 at 18:01 +0200, Mike Galbraith wrote: > On Thu, 2013-06-20 at 14:46 -0500, Dave Chiluk wrote: > > Running the below testcase shows each process consuming 41-43% of it's > > respective cpu while per core idle numbers show 63-65%, a disparity of > > roughly 4-8%. Is this a bug, known behaviour, or consequence of the > > process being io bound? > > All three I suppose.
P.S. perf top --sort=comm -C 3 -d 5 -F 250 (my tick freq) 56.65% netserver 43.35% pert perf top --sort=comm -C 3 -d 5 67.16% netserver 32.84% pert If you sample a high freq signal (netperf TCP_RR) at low freq (tick), then try to reproduce the original signal, (very familiar) distortion results. Perf doesn't even care about softirq yada yada, so seems it's a pure sample rate thing. -Mike -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
