panel plugins that cause too many wakeups/s

[Tino Keitel]

Hi,

I noticed at some point that the Xfce panel produces a fair number of
wakeups/s. So I always kill it when running on battery, and I can see
that this gains some battery runtime.

I tried to find out what specific panel component is responsible for
this. Conclusion: the most wakeups/s are caused by the system load
plugin. Here are some numbers:

system load plugin: 11
wlan monitor plugin: 6
battery monitor plugin: 3

Without the above plugins, an idle desktop causes less than 7
wakeups/s. This is with a running panel with the weather, clock, and
sensors plugin running (and a few other plugins with static content,
like the pager, task list, menu, dict, quit button and some launchers).
The sensors plugin update interval is 60 seconds.

I think that the affected plugins should be optimized, so that running
them on battery power doesn't cause noticable decreasement in battery
runtime.

I'm aware of the current 4.6 development status, so I'd like to know if
some of the issues are already fixed.

Below are the numbers I collected:

wlan and system load load plugins:

keups-from-idle per second : 22.8     interval: 15.0s
Power usage (ACPI estimate): 10.2W (6.9 hours) (long term: 10.2W,/6.9h)

Top causes for wakeups:
  51.6% ( 16.5)       <interrupt> : i915 at pci:0000:00:02.0 
  12.3% (  3.9)   xfce4-wavelan-p : schedule_timeout (process_timeout)
  12.3% (  3.9)   xfce4-systemloa : schedule_timeout (process_timeout)
   9.6% (  3.1)      <kernel IPI> : Rescheduling interrupts
   3.1% (  1.0)              Xorg : schedule_timeout (process_timeout)
   3.1% (  1.0)          noflushd : do_nanosleep (hrtimer_wakeup)

system load plugin:

Wakeups-from-idle per second : 17.0     interval: 20.0s
Power usage (ACPI estimate): 9.8W (7.2 hours) (long term: 10.2W,/6.9h)

Top causes for wakeups:
  29.3% (  4.0)   xfce4-systemloa : schedule_timeout (process_timeout)
  23.0% (  3.1)      <kernel IPI> : Rescheduling interrupts
  12.2% (  1.6)       <interrupt> : acpi
   7.4% (  1.0)          noflushd : do_nanosleep (hrtimer_wakeup)

battery monitor plugin:

Wakeups-from-idle per second :  9.6     interval: 30.0s
Power usage (ACPI estimate): 9.8W (7.2 hours) (long term: 10.1W,/6.9h)

Top causes for wakeups:
  45.1% (  4.6)       <interrupt> : acpi
   9.8% (  1.0)          noflushd : do_nanosleep (hrtimer_wakeup)
   9.8% (  1.0)              Xorg : schedule_timeout (process_timeout)

none of the above:

Wakeups-from-idle per second :  6.3     interval: 30.0s
Power usage (ACPI estimate): 9.6W (7.3 hours) (long term: 10.0W,/7.0h)

Top causes for wakeups:
  19.9% (  1.3)       <interrupt> : acpi
  15.3% (  1.0)          noflushd : do_nanosleep (hrtimer_wakeup)
  15.3% (  1.0)              Xorg : schedule_timeout (process_timeout)

Regards,
Tino