Bug#894801: wmmon CPU graph gets unreadable at high loads

[Doug Torrance]

Control: tags -1 fixed-upstream pending

On 04/04/2018 07:23 AM, Pedro Gimeno wrote:
> During compilation of a program, the CPU graph of wmmon kept adding horizontal green lines (the ones that serve as a hint for the range of the value) until the whole graph was just made of horizontal lines, i.e. it was completely green.
> 
> I've composed a series of snapshots into a single image to show the progression, and then the cooldown:
> 
> http://www.formauri.es/personal/pgimeno/temp/wmmon-cpugraph-progression.png
> 
> The program whose compilation caused that CPU load was the latest version of Löve, an OpenGL 2D framework. An older version is included as a Debian package, simply called love. The problem is also reproducible in this older version, by issuing 'make clean ; make -j' directly in the source; I couldn't get dpkg-buildpackage -j to work on Löve.
> 
> The compile was restarted after finished (make clean ; make -j); the first compilation didn't completely fill wmmon's graph with green.
> 
> Load average reported by /proc/loadavg peaked at 107.69 74.17 37.30 104/1136 9178 during the compilation.
> 
> Maybe a colour change could be used as an indicator of higher ranges, past a certain threshold? For example, when there are going to be more than 15 horizontal green lines, switch to purple (or some other colour) lines, where each purple line is equivalent to 16 green lines. Not sure if more colours would be needed.

Thanks for your report!

I've released a new upstream version (1.4) of wmmon which I believe 
fixes the issue based on your suggestion. [1]

In particular, once we reach a load average of 10, it switches to yellow 
hint lines for each multiple of 10.  Once it reaches 100, it switches to 
red hint lines for each multiple of 100.

We would need to reach a load average of 4000 for everything to get 
filled with red.

I should get an updated package uploaded to Debian soon.

[1] http://www.dockapps.net/wmmon