Created attachment 176536 [details] screenshot SUMMARY Individual Core Usage shows wrong data sometimes, incorrectly marking applications as 100% CPU usage when they are idle. Please audit its logic to make sure it matches System Monitor and htop. This was brought up here and incorrectly dismissed: https://discuss.kde.org/t/individual-core-usage-doesnt-match-top-by-a-lot/9232 STEPS TO REPRODUCE and OBSERVED RESULT 1. Wait for the public release of Ghostty, scheduled for December 31, 2024, or ask Mitchell Hashimoto for a private beta invitation. 2. Follow the steps in the README of that project to build from source. 3. Run the ghostty binary and observe 2 apparently pegged CPU cores per open window. 4. Run htop and notice ghostty actually is idle. 5. Run System Monitor and notice ghostty is actually idle. EXPECTED RESULT No bars shown in the Individual Core Usage widget when the app is idling. SOFTWARE/OS VERSIONS Operating System: NixOS 24.11 KDE Plasma Version: 6.2.4 KDE Frameworks Version: 6.8.0 Qt Version: 6.8.0 Kernel Version: 6.12.3 (64-bit) Graphics Platform: Wayland Processors: 32 × AMD Ryzen 9 7950X 16-Core Processor Memory: 62.0 GiB of RAM Graphics Processor: AMD Radeon RX 7900 XTX ADDITIONAL INFORMATION I observed this also in Plasma 5, before upgrading to Plasma 6.2.
The widget doesn't measure apps but rather than whole system. Apps can still be consuming CPU even when they're idle, too. Can you attach a new screenshot that shows the output of htop and System Monitor disagreeing with what the widget is saying?
Created attachment 176567 [details] screenshot with htop and system monitor Here is the requested screenshot.
To be clear when I use the word "idle" here, I mean "using 0% CPU".
Updated steps to reproduce now that ghostty is released as free and open source software: First, ensure x11 or wayland, libadwaita, pkg-config, and gtk4 development system libraries are installed. Build from source: ``` wget https://ziglang.org/download/0.13.0/zig-linux-x86_64-0.13.0.tar.xz tar xf zig-linux-x86_64-0.13.0.tar.xz git clone https://github.com/ghostty-org/ghostty/ cd ghostty git checkout v1.0.0 ../zig-linux-x86_64-0.13.0/zig build ./zig-out/bin/ghostty ``` Observe 2 apparently pegged CPU cores per open window. Run htop and notice ghostty actually is idle. Run System Monitor and notice ghostty is actually idle.
For what it's worth I can confirm this happening on my system too: Operating System: openSUSE Tumbleweed 20241224 KDE Plasma Version: 6.2.4 KDE Frameworks Version: 6.9.0 Qt Version: 6.8.1 Kernel Version: 6.12.6-1-default (64-bit) Graphics Platform: Wayland Processors: 12 × AMD Ryzen 5 5600X 6-Core Processor Memory: 15.5 GiB of RAM Graphics Processor: AMD Radeon RX 6600 XT Manufacturer: Micro-Star International Co., Ltd. Product Name: MS-7C56 System Version: 6.0 Another screenshot that illustrates the problem: https://ibb.co/bzdkbvS On the dashboard the CPU usage is constantly at around 17 percent while Ghostty is running (and that is mirrored when using the applet "Individual Core Usage" which shows 2 of 12 cores constantly busy with Ghostty). But the actual list of processes (or htop) show that Ghostty is basically idle at zero percent cpu usage. This is the first time I've seen this happen though. No other software than Ghostty leads to this false reporting of cpu usage.