Re: [Powertop] powertop putting far too much blame on wifi

On Monday 06 January 2014 at 11:53:15, Andreas wrote:
> Hi,
> 
> On Sun, Jan 05, 2014 at 12:00:02PM -0800, powertop-request(a)lists.01.org 
wrote:
> > From: Marc MERLIN <marc_powertop(a)merlins.org>
> > 
> > Unfortunately, it's not just you. I've reported the same problem
> > multiple times over the last year, but not heard back from anyone yet
> > (except you saying you see the same).
> > 
> > I had this on a T530, and now it's even worse on a T540:
> > The battery reports a discharge rate of 28.5 W
> > The estimated remaining time is 1 hours, 53 minutes
> > 
> > Summary: 689.5 wakeups/second,  214.0 GPU ops/seconds, 0.0 VFS ops/sec and
> > 10.4% CPU use
> > 
> > Power est.              Usage       Events/s    Category       Description
> > 
> >   15.3 W     95.8%                      Device         Display backlight
> >   2.07 W     36.0 ms/s     642.4        Process       
> >   /usr/bin/enlightenment
> >   115 mW      4.5 ms/s      62.3        Interrupt      PS/2 Touchpad /
> >   Keyboard / Mouse>  
> >  86.8 mW      0.9 ms/s      37.0        Process        xfce4-terminal -T
> >  window11 --role=window11 --tab 71.3 mW     35.4 ms/s      36.2       
> >  Process        /usr/bin/X :0 vt7 -br -nolisten tcp -auth /var/r 51.2 mW 
> >      0.8 ms/s      27.9        Timer          hrtimer_wakeup> 
> > 15W for my backlight at mid brightness? I don't think so.
> 
> 600+ wakeups/second sounds like the usual intermediate activity
> due to touchpad/mouse movement (that figure is exactly what I usually got
> on my machine), and if that is the case
> (what happens if the human part gets its dirty fingers off the machine? :)
> then it's strange to see this otherwise *very high* value (642.4)
> attributed to /usr/bin/enlightenment (a very seasoned/stable WM, for
> crying out loud) rather than mouse as in the *directly following*
>     PS/2 Touchpad / Keyboard / Mouse
> line.
> 
> Or, in other words, this example hints at a rather mischievous mixup of
> data, e.g. an off-by-1 or a post-insert of certain items without accounting
> for other columns (within the data model, of course), or perhaps (the
> column data values might even support such a suspicion) even completely
> wrong (re-sorted) display of data.
> 
> Perhaps I should actually test/investigate a recent powertop version... ;)
> 
> Andreas Mohr

IMHO, the usage and event counters seem to be valid. What's wrong is energy 
estimation: it is done entirely in software, using some strange semi-heuristic 
guesswork.

-- 
Ivan Shapovalov / intelfx /

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