-- On Fri, 2 Nov 2007, Gernot Hillier wrote: > On Thu, 25 Oct 2007, Steven Rostedt wrote: > > The latest 2.6.23-rt3 (as well as -rt2) has new RT balancing code. Could > > you try that to see if it solves you issues. > > Sorry - being a bit late here. > > I now tried my testcase with the current 2.6.23.1-rt5 patch (please tell > if you're still interested in test results for the old 2.6.23-rt3!) and No need for 2.6.23-rt3 > it didn't get better. I still see only 2 CPUs being occupied by our test > program. > > Interestingly enough, it seems I now can't use CPU2 and CPU3 at all - Is this also the case without PREEMPT_RT configured? > even if I start several test processes in parallel. IIRC, this was > better with 2.6.22.1-rt9 - there CPU2 and CPU3 got used if I started two > test programs in parallel. > > I can now even reproduce the problem with a simple kernel make. Here's a > snapshot of /proc/stat after compiling the kernel with "make -j 4": > > MRBOX:~/linux-2.6.23.1 # cat /proc/stat > cpu 249482 0 46304 683034 9592 90 358 0 1 28 > cpu0 124240 0 20690 99283 2767 50 214 0 0 8 > cpu1 125242 0 25586 89781 6431 33 136 0 0 10 > cpu2 0 0 8 246867 333 0 0 0 0 0 > cpu3 0 0 18 247103 60 6 7 0 0 8 > intr 115025 > ctxt 8498063 > btime 1193997310 > processes 82614 > procs_running 1 > procs_blocked 0 > > As with 2.6.23-rt1, behaviour only breaks for me as soon as I enable > PREEMPT_RT. But otherwise it runs fine (you can use CPU2 and CPU3)? > > To narrow it down a bit, I now played a bit with the configure options > of 2.6.23.1-rt5 (leaving PREEMPT_RT disabled and enabling the other RT > features one after another). The culprit for me is > CONFIG_PREEMPT_SOFTIRQS. As soon as I enable it, only CPU0 and 1 are > used. Disabling it again makes the kernel use all CPUs. > > Any hint how to continue with this matter is greatly appreciated... Could you send me the contents of /proc/cpuinfo your dmesg on bootup as well as the .config that you are using. Thanks, -- Steve - To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
