Hi Tim, > Some of the steps we have found to help include: > > 0. Employ large pages in Linux and in your java option.
Did that. We use 4 JVMs with ~3200M hugepages each, and each bound to 2 cores of one CPU. > 1. Employ a tickless kernel, probably a kernel close to 2.6.24. Yes, we are currently running 2.6.24-fc9 (while we are at it: can someone tell me if Rawhide packages are archived somewhere? When I installed that kernel I forgot to download the sources and the next time I checked the rawhide kernel was already at 2.6.25-rc1) > 2. Turn on the ondemand governor (set > /sys/devices/system/devices/system/cpu/cpu*/cpufreq/scaling_governor to > ondemand). Yes, it's running. It seems that it is switching back less aggressively than Windows, though. Our BIOS only defines to frequencies (highest, 2.83GHz and lowest, 2.00GHz). In the intermediate load levels (50%, say), the CPUs are about 70-80% in the high freq state. > 3. Trun on the menu idle governor (set > /sys/devices/system/cpu/cpuidle_governor_ro to menu) I am ~95% sure that it was running. Need to re-check though. > 4. Turning on the power aware scheduler (set > /sys/devices/system/cpu/sched_mc_power_savings to 1) In order to achieve high performance in SPECpower, the JVMs must be bound to CPU cores. AFAICS, this wouldn't work well with sched_mc_power_savings=1 (because the scheduler can't move the jobs away from a package). > 5. Use a larger sampling (like 1000000) versus the default value of 2000 > in /sys/devices/system/cpu/cpu*/cpufreq/ondemand/sampling_rate. For > SPECpower workload, the load level is very steady, so it does not pay to > shift gear to a high cpu frequency too quickly. I am not sure if that complies with the SPECPower rules. Anyway, it's worth a a try. > 6. Employ idle microstate accounting (not yet available in distribution > kernel) > > Also check the BIOS setting to make sure things like speedstep and fan > speed > accoustic is set properly. These things were already optimized to our best knowledge.The power consumption in the idle state is actually quite good Martin -- Martin Wilck PRIMERGY System Software Engineer FSC IP ESP DE6 Fujitsu Siemens Computers GmbH Heinz-Nixdorf-Ring 1 33106 Paderborn Germany Tel: ++49 5251 8 15113 Fax: ++49 5251 8 20209 Email: mailto:[EMAIL PROTECTED] Internet: http://www.fujitsu-siemens.com Company Details: http://www.fujitsu-siemens.com/imprint.html _______________________________________________ Discuss mailing list [email protected] http://mail.lesswatts.org/mailman/listinfo/discuss
