Created attachment 480677 [details] Powertop console output Description of problem: According to bug https://bugzilla.redhat.com/show_bug.cgi?id=635813 I'm creating new bug report to resolve problem with Load Balancing Tick. Version-Release number of selected component (if applicable): kernel-2.6.35.11-83.fc14.x86_64 How reproducible: Always Steps to Reproduce: 1. Boot machine 2. Watch the powertop 3. Actual results: 35W power consumption on idle'ing Core2Duo T5250 (2*1,5GHz) with integrated graphics! Expected results: ~13-15W when idle'ing (easy to acheive on fedora 8-9-10-11-12-13-early 14) with a perspective to acheive low 10W (My personal record is 10,2W with 7h@battery) Additional info: Lenovo Thinkpad R61i 8943-DKG with Core2Duo T5250, i965, 3GiB RAM and 640gb/5200RPM HDD and 1024x768 15" LCD/cold cathode backlight http://www.smolts.org/client/show/pub_155ba98d-3576-4e0a-8940-e209a5675506
Created attachment 480678 [details] /boot/grub/menu.lst
Please repeat using an idle system. You've got ~300 wakeups a second from your web browser and java, which is going to be responsible for a lot of the rebalancing.
*** Bug 664027 has been marked as a duplicate of this bug. ***
Also, please make sure that there are no wakeups from i8042 (ie, don't touch the keyboard or touchpad)
Created attachment 481465 [details] Powertop on idle Laptop 23:54 [ root @ samhain ] /opt ROOTMODE> uname -a Linux samhain 2.6.35.11-83.fc14.x86_64 #1 SMP Mon Feb 7 07:06:44 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux Completely idle
Created attachment 481467 [details] Archive screenshot from powertop - Dec 5, 2009 I can't remember Kernel version and Fedora version, but this screenshot was taken on December 5th 2009 with up-do-date system and packages. Unbeaten power consumption score.
You've got activity from evince, nautilus, something's hitting the disk and X is asking for interrupts. Otherwise you'd have pretty identical results, so I don't see any sign of a kernel bug here. You may want to file bugs against evince, nautilus, knotify and psi.
Regardless of that activity, Load Balancing Tick causes most CPU wakeups. It's job is causing more job for itself. Starting boinc-client with milestone RSA bruteforcing and WorldCommunityGrid - Fight AIDS@Home causes: 86,7% (1721,6) [kernel scheduler] Load balancing tick 2,2% ( 43,0) chromium-browse 1,8% ( 35,8) Xorg 1,0% ( 20,1) wcg_faah_autodo 1,0% ( 20,0) knotify4 0,9% ( 18,2) milestone_1.02_ Isn't it illogical to wake up CPU 1700 times/sec (with 2000/sec is a max value achieved on my CPU) to try to balance load caused by two threads, when both are designed to eat 100% of core running on? In my opinion load balancer should be disabled od throttled way down when cores load is above specified treshold.
No, the timeslice is 1ms. You'll enter the scheduler 1000 times a second per CPU assuming a fully loaded system. If your CPU is busy then wakeups cost you nothing.
Maybe costs me nothing, naybe not- a fact is that due to additional CPU work CPU is warmer and I can't pass through 5h on battery barrier whatever I do or I don't. When kernel hadn't mentioned bug/feature this score was easy to achieve.
You're seeing far more userspace wakeups than you were before, which would explain a lot of that.