@Haw Loeung: In addition to what I wrote earlier: > With the new Ubuntu archive servers, we saw constantly high load > and after some tinkering, we found that it was mostly CPUs > being woken up to see if they should enter idle states. > Changing the CPU frequency scaling governor to "performance" saw a > considerable drop.
What do you mean by "high load"? And when you say "saw a considerable drop", does that mean in wakeups per second or load? Note that you should observe a significant difference in load average on a server between powersave and performance mode, and that actually indicates things are working as they should be. For the SpecPower simulator test I posted above, I'll add some more data for the 0.5X and X lines: 0.5X, where Performance used 31.7% more package power: Powersave: Busy%: 12.58% (load average = 1.01) Bzy MHz: 1651 Performance: Busy%: 5.04% (load average = 0.40) Bzy MHz: 3686 X, where Performance used 42.1% more package power: Powersave: Busy%: 23.66% (load average = 1.89) Bzy MHz: 1798 Performance: Busy%: 10.56% (load average = 0.84) Bzy MHz: 3681 Isn't energy consumption what really matters, as long as performance doesn't suffer too much? What I would like to see for your servers is the results from: sudo turbostat -J -S --debug sleep 300 For the intel_pstate CPU frequency scaling driver and the powersave and performance scaling governors with your work flow. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1579278 Title: Keep powersave CPU frequency scaling governor for CPUs that support intel_pstate To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1579278/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
