The audio indicator now checks whether the parent process is in the same cgroup to avoid showing the indicator e.g. on a Dolphin window that spawned a VLC player. However, that KSysguard stuff is super slow STEPS TO REPRODUCEv 1. Receive a Telegram notification or start playing a video in your browser OBSERVED RESULT Plasma freezes for a few seconds EXPECTED RESULT Plasma does not freeze SOFTWARE/OS VERSIONS Linux/KDE Plasma: git master as of 2021-05-17 ADDITIONAL INFORMATION Also causes a noticeable freeze on startup when taskbar widget appears. Or just starting VLC player. It does not happen with VLC player when pause/unpause becuase the Audio stream stays. It's only when a new Audio stream is created, e.g. starting a video in the browser. Offending code https://invent.kde.org/plasma/plasma-desktop/-/blob/master/applets/taskmanager/plugin/backend.cpp#L558
Can reproduce. So this is what's been causing those slowdowns I've been experiencing lately! Reverting c59edc9826a64c51f9ed41f7ccaf2cc5ade86d4b (in plasma-desktop) fixes the issue immediately. I guess we need to figure out a less-performance-heavy way to fix Bug 417457.
Marking as VHI; we need to fix this or revert c59edc9826a64c51f9ed41f7ccaf2cc5ade86d4b before the final release of Plasma 5.22.
bug 436947 seems related.
Yep, definitely the same issue.
*** Bug 436947 has been marked as a duplicate of this bug. ***
A possibly relevant merge request was started @ https://invent.kde.org/plasma/plasma-desktop/-/merge_requests/479
Git commit 7bfb5570eb0f3434eceb6641cb796573bf93b9f7 by Kai Uwe Broulik. Committed on 17/05/2021 at 17:03. Pushed by broulik into branch 'master'. [Task Manager] Optimize parent process CGroup check There's no need to update all processes when we can just explicitly add info about the parent process. FIXED-IN: 5.22.0 M +2 -5 applets/taskmanager/plugin/backend.cpp https://invent.kde.org/plasma/plasma-desktop/commit/7bfb5570eb0f3434eceb6641cb796573bf93b9f7
Git commit 4cd6ae59ca3949a6d96c4730ffefb60b8c76e9af by Nate Graham, on behalf of Kai Uwe Broulik. Committed on 17/05/2021 at 18:24. Pushed by ngraham into branch 'Plasma/5.22'. [Task Manager] Optimize parent process CGroup check There's no need to update all processes when we can just explicitly add info about the parent process. FIXED-IN: 5.22.0 (cherry picked from commit 7bfb5570eb0f3434eceb6641cb796573bf93b9f7) M +2 -5 applets/taskmanager/plugin/backend.cpp https://invent.kde.org/plasma/plasma-desktop/commit/4cd6ae59ca3949a6d96c4730ffefb60b8c76e9af