GNOME Bugzilla – Bug 703328
Divide CPU usage by CPU count does not work
Last modified: 2018-05-22 12:10:39 UTC
Created attachment 248066 [details] Divide CPU usage by CPU count off Divide CPU usage by CPU count does not work. It only changes scale on CPU usage graphs, but graphs stay the same.
Created attachment 248067 [details] Divide CPU usage by CPU count on
Please explain in more detail how do you expect this to work: as I see it, the graphs should not change, as full processor usage is number of cores x100% or 100%, that meaning the lines go at the top of the graph, half CPU usage is no of cores x 50% or 50% with divide by cpu usage on, meaning that the line goes at the middle of the graph. So in my opinion, the graph should not change, only the scale, but I might be missing something.
My logic is this: With Divide CPU usage by CPU count off I have scale up to 800%. If one core does a lot of work its graph will go up to 800%, but that core can't do 800% by itself, it can only do 100%. So, Divide CPU usage by CPU count off is wrong. If there is 800% on the scale, there should be only one, summary CPU graph. Then it makes sense. Or, in Divide CPU usage by CPU count off mode, CPU lines should be scaled to go to only 100%, and additional summary line can be introduced)
Yes, you are right. However there's some problem with the whole thing: the divide by CPU chart is on the Processes preferences tab, so it is meant for the process list. You're also right that by toggling it, the CPU scale on the Resources tab changes... in fact I feel like the solution would be to add another checkbox to the Resources tab for "Show CPU usage separately for each core" or something like that, and with that option on we would have a scale 0-100% showing n graphs (n=number of cores), and if that's turned off, just like you are saying, we would have a single one with the sum of all per-core usages, meaning the total CPU usage.
For the stacked area chart, it makes sense to switch the scale from 100% to n*100%, depending on the divide option. The standart separate lines chart should always go to max. 100% as long there is no extra option for a summarized graph.
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