2.6.33 & 2.6.34-rc6: Huge number of Load Balancing tick wakeups.

[Nigel Cunningham]

Hi all.

I'm seeing a huge number of load balancing tick wakeups, with both 
2.6.33 and current git (f1c448e0a9e99c76f4ece368714fb35a40a8daba).

This has been reported as a bug in some distros:

http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=521944
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/524281

Regards,

Nigel

PowerTOP 1.12   (C) 2007, 2008 Intel Corporation

Collecting data for 15 seconds


Your CPU supports the following C-states : C1 C2 C3 C4
Your BIOS reports the following C-states : C1 C2 C4
Cn                Avg residency
C0 (cpu running)        (40.8%)
polling           0.7ms ( 0.1%)
C1 mwait          0.0ms ( 0.0%)
C2 mwait          0.1ms ( 3.2%)
C4 mwait          0.4ms (56.0%)
P-states (frequencies)
Turbo Mode     7.3%
  2.21 Ghz     0.7%
  1.60 Ghz     0.8%
  1200 Mhz     0.9%
   800 Mhz    90.3%
Wakeups-from-idle per second : 1727.3   interval: 15.0s
no ACPI power usage estimate available
Top causes for wakeups:
  53.0% (1983.1)   [kernel scheduler] Load balancing tick
  27.7% (1035.1)   vmware-vmx
   8.8% (330.6)   [extra timer interrupt]
   2.3% ( 85.5)   [TLB shootdowns] <kernel IPI>
   1.6% ( 61.3)   totem
   1.2% ( 45.9)   [Rescheduling interrupts] <kernel IPI>
   1.1% ( 41.1)   [iwl3945] <interrupt>
   1.0% ( 36.2)   firefox-bin
   0.4% ( 16.2)   [ata_piix] <interrupt>
   0.3% ( 11.6)   vmware
   0.3% ( 11.3)   pulseaudio
   0.3% ( 11.1)   vmware-unity-he
   0.3% ( 10.7)   skype
   0.2% (  8.0)   [kernel core] usb_hcd_poll_rh_status (rh_timer_func)
   0.1% (  5.4)   [hda_intel] <interrupt>
   0.1% (  5.3)   gnome-do
   0.1% (  5.1)   compiz
   0.1% (  4.1)   python
   0.1% (  4.0)   avant-window-na
   0.1% (  2.3)   liferea
   0.1% (  2.1)   vmware-tray
   0.1% (  2.1)   thunderbird-bin
   0.1% (  2.0)   mysqld
   0.1% (  2.0)   emerald
   0.1% (  1.9)   gnome-terminal
   0.0% (  1.3)   [kernel core] sk_reset_timer (tcp_delack_timer)
   0.0% (  1.3)   [ahci] <interrupt>
   0.0% (  1.2)   cc1
   0.0% (  1.0)   [nvidia] <interrupt>
   0.0% (  1.0)   vmware-usbarbit
   0.0% (  1.0)   vmnet-natd
   0.0% (  1.0)   gvfs-afc-volume
   0.0% (  1.0)   [kernel core] enqueue_task_rt (sched_rt_period_timer)
   0.0% (  1.0)   [kernel module] HostIF_InitUptime 
(HostIFUptimeResyncMono)
   0.0% (  0.8)   cli
   0.0% (  0.5)   events/1
   0.0% (  0.5)   events/0
   0.0% (  1.0)   vmware-usbarbit
   0.0% (  1.0)   vmnet-natd
   0.0% (  1.0)   gvfs-afc-volume
   0.0% (  1.0)   [kernel core] enqueue_task_rt (sched_rt_period_timer)
   0.0% (  1.0)   [kernel module] HostIF_InitUptime 
(HostIFUptimeResyncMono)
   0.0% (  0.8)   cli
   0.0% (  0.5)   events/1
   0.0% (  0.5)   events/0
   0.0% (  0.5)   hald-addon-stor
   0.0% (  0.5)   udisks-daemon
   0.0% (  0.3)   tomboy
   0.0% (  0.3)   awn-applet
   0.0% (  0.2)   rtkit-daemon
   0.0% (  0.2)   Thunar
   0.0% (  0.2)   padevchooser
   0.0% (  0.2)   xfdesktop
   0.0% (  0.1)   gnome-power-man
   0.0% (  0.1)   ssh-agent
   0.0% (  0.1)   mono
   0.0% (  0.1)   NetworkManager
   0.0% (  0.1)   hald

An audio device is active 100.0% of the time:
hwC0D2 SigmaTel STAC9228

A USB device is active  0.0% of the time:
USB device  2-2 : Biometric Coprocessor (STMicroelectronics)

Suggestion: Enable SATA ALPM link power management via:
  echo min_power > /sys/class/scsi_host/host0/link_power_management_policy
or press the S key.

Suggestion: Enable wireless power saving mode by executing the following 
command:
  iwconfig wlan0 power timeout 500ms
This will sacrifice network performance slightly to save power.

Suggestion: Enable the CONFIG_USB_SUSPEND kernel configuration option.
This option will automatically disable UHCI USB when not in use, and may
save approximately 1 Watt of power.

Recent USB suspend statistics
Active  Device name
  0.0%  USB device  5-2 : Generic RNDIS (HTC)
  0.0%  USB device  2-2 : Biometric Coprocessor (STMicroelectronics)
  0.0%  USB device  1-1 : Laptop Integrated Webcam (OmniVision 
Technologies, Inc. -2640-07.07.20.3)
  0.0%  USB device usb7 : UHCI Host Controller (Linux 2.6.34-rc6 uhci_hcd)
  0.0%  USB device usb6 : UHCI Host Controller (Linux 2.6.34-rc6 uhci_hcd)
  0.0%  USB device usb5 : UHCI Host Controller (Linux 2.6.34-rc6 uhci_hcd)
  0.0%  USB device usb4 : EHCI Host Controller (Linux 2.6.34-rc6 ehci_hcd)
  0.0%  USB device usb3 : UHCI Host Controller (Linux 2.6.34-rc6 uhci_hcd)
  0.0%  USB device usb2 : UHCI Host Controller (Linux 2.6.34-rc6 uhci_hcd)
  0.0%  USB device usb1 : EHCI Host Controller (Linux 2.6.34-rc6 ehci_hcd)

Recent audio activity statistics
Active  Device name
100.0%  hwC0D2 SigmaTel STAC9228

Recent SATA AHCI link activity statistics
Active  Partial Slumber Device name
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