schedule_timeout (process_timeout)

[aldebaran]

Hi all!
Do you know what do all those "schedule_timeout (process_timeout)" mean?
Are they related to   "29.2% ( 67.2)  <kernel IPI> : Rescheduling 
interrupts"?
If so how could I get rid of all those schedule related wakeups?
Now I'm using  2.6.24-8-generic SMP (2.6.24.2) on Ubuntu Hardy beta 5, 
when I was using 2.6.23 I had far less wakeups (around 25)!!
I just cannot understand what an improvement had the new scheduler 
actually brought.
Thanks!!

Cn                Avg residency       P-states (frequencies)
C0 (cpu running)        ( 2.1%)         2.01 Ghz     0.0%
C1                0.0ms ( 0.0%)         2.00 Ghz     0.0%
C2                0.4ms ( 0.0%)         1.60 Ghz     1.4%
C3                4.7ms (97.8%)          800 Mhz    98.6%


Wakeups-from-idle per second : 209.8    interval: 15.0s
Power usage (5 minute ACPI estimate) :  21.2 W (0.6 hours left)

Top causes for wakeups:
  36.9% ( 84.8)       <interrupt> : PS/2 keyboard/mouse/touchpad
  29.2% ( 67.2)      <kernel IPI> : Rescheduling interrupts
   9.0% ( 20.6)       compiz.real : schedule_timeout (process_timeout)
   6.3% ( 14.5)       <interrupt> : extra timer interrupt
   4.4% ( 10.0)     <kernel core> : ehci_work (ehci_watchdog)
   2.6% (  6.0)          trackerd : schedule_timeout (process_timeout)
   1.8% (  4.1)   <kernel module> : usb_hcd_poll_rh_status (rh_timer_func)
   1.6% (  3.7)    scim-panel-gtk : schedule_timeout (process_timeout)
   1.0% (  2.3)              Xorg : schedule_timeout (process_timeout)
   0.8% (  1.7)    gnome-terminal : schedule_timeout (process_timeout)
   0.5% (  1.1)    cpufreq-applet : schedule_timeout (process_timeout)
   0.5% (  1.1)         nm-applet : schedule_timeout (process_timeout)
   0.5% (  1.1)   gnome-screensav : schedule_timeout (process_timeout)
   0.4% (  1.0)       <interrupt> : uhci_hcd:usb1, nvidia
   0.4% (  1.0)              Xorg : nv_start_rc_timer (nv_kern_rc_timer)
   0.4% (  1.0)            dhcdbd : schedule_timeout (process_timeout)
   0.4% (  0.9)    NetworkManager : schedule_timeout (process_timeout)
   0.4% (  0.9)    sensors-applet : schedule_timeout (process_timeout)
   0.3% (  0.8)       gnome-panel : schedule_timeout (process_timeout)
   0.3% (  0.7)     <kernel core> : neigh_table_init_no_netlink 
(neigh_periodic_timer)
   0.2% (  0.5)   <kernel module> : neigh_table_init_no_netlink 
(neigh_periodic_timer)
   0.2% (  0.5)        pulseaudio : schedule_timeout (process_timeout)