Bug 452689

SUMMARY

Original issue source:
https://www.reddit.com/r/kde/comments/u4rav6/kinfocenter_memory_module_replacement/

[This page from KInfoCenter](https://forum.manjaro.org/t/why-are-htop-and-system-monitor-showing-different-memory-usages/72984/19) appears to have been [dropped with Plasma 5.24](https://github.com/KDE/kinfocenter/commit/c529b9d4074bf4b545372ccd1d3ac9acdfdc10c8)?

The commit dropping it states System Monitor installs an "external module service" as a replacement for that view. All I see in System Monitor is a single "Memory" block in the "Overview" page, or the graph in "History" page.

It is unclear how to get access to such a view via System Monitor, beyond expecting the user to re-create the page or rely on a third-party solution via "Get New Pages".


STEPS TO REPRODUCE

1. Attempt to locate a view in System Monitor that provides the same information breakdown as KInfoCenter Memory Module once did pre-Plasma 5.24.
2. Fail to locate an equivalent view.


OBSERVED RESULT

No equivalent view is provided/available, despite the commit implying "external module service" in `plasma-systemmonitor` would cover the same functionality.

Unless the intention was "Tools => Launch Htop", but this does not provide the same focused breakdown/overview specific to memory usage.


EXPECTED RESULT

Some officially maintained view either by default or enabled to provide the same information.

Presently the "Shared Memory" and "Total Free Memory" (composite of two sensors) is missing. As is some functionality for a compact stacked bar chart (with text), or stacked horizontal bar.


SOFTWARE/OS VERSIONS
Linux/KDE Plasma:  X11 with Kernel 5.15.28
KDE Plasma Version: 5.24.3
KDE Frameworks Version: 5.91.0
Qt Version: 5.15.3


ADDITIONAL INFORMATION

Attempting to DIY the Memory Module as a new page, I could not produce a similar view.

- Text portion was truncating labels depending on width. Only supported ordering, but not layout (eg single column), which further restricted label width for "Text" widget/components.
- Stacked bar chart does not support inlining/embedding the labels+data.
- No composite sensor ("Total Free Memory" in KInfoCenter was a composite of Total Physical and Total Swap available). Not available from sensor selection, or any apparent way to composite multiple sensors into a single one.
- At this point I stopped trying to reproduce the view, presumably the rest is possible with nested items.

Using "Horizontal Bars" display style with Text-Only sensors provides a close-enough equivalent of the text section, but still truncates the full labels of a certain length, despite ample room..? This is not an issue if using regular sensors, which add actual bars, but these don't seem helpful.

With the horizontal bars drawn, the value shown for each sensor is the current value, but the bar is drawn as a portion of that value to some range that is specific to the sensor (or largest value of all sensors in the group rather?), so it's not communicating much to a user (eg 100% full for "Total Physical Memory" with a variable width beneath it for "Free Physical Memory", (no "Shared Memory" sensor), and Disk Buffer/Cache likewise that could all be stacked together as a single bar which is doable with Pie/Bar charts only, but requires identifying a matching label by colour (no hover/interaction hinting).