Bug 398774

Summary:	Hanging program impacts plasma
Product:	[Plasma] plasmashell	Reporter:	lesto <lestofante88>
Component:	general	Assignee:	David Edmundson <kde>
Status:	RESOLVED BACKTRACE
Severity:	normal	CC:	nate, plasma-bugs-null
Priority:	NOR
Version First Reported In:	master
Target Milestone:	1.0
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description lesto 2018-09-17 20:15:54 UTC

The program "hterm", DerHammer Terminal, has a bug in witch when opening a usb serial port, the cpu usare FOR ONE CORE jump to 100%.
Now, there is a sode effect; the Task Manager widget basically hangs, the alt-tab work but severly delayed. Nothe this pc is an i8 and all the other core are basically free.
Since alt-tab work, and even the hanging program GUI is responsive, although obviusly with some lag, i can disconnect the serial port and all goes back to normal. But if i don-t disconnect and let it run for a long time (30min-1h), plasmashell will crash.

reproducible 100%

Comment 1 Nate Graham 2021-03-10 03:46:54 UTC

Plasma can't prevent misbehaving apps from consuming excessive CPU resources. You would need to report this to the developers of that program. Thanks!

Comment 2 lesto 2021-03-10 10:34:37 UTC

hi nate not that only ONE virtual core is at 100% while the other 3 are free (so there is 1 full HW core free) and yet Plasma would CRASH.

Again Plasma has 3 core it could fully use and yet it crash

Comment 3 lesto 2021-03-10 10:43:02 UTC

ah sorry, forgot to add, hterm/linux has been recently updated and the issue fixed (i tried with the older version of hterm and could not reproduce, so maybe it was some driver issue), i need to test if this can be replicated with one bash script running 100% single core, or it need to be a gui app, in particular hterm is a GTK app so it may be also something there

Comment 4 David Edmundson 2021-03-10 10:51:57 UTC

>i need to test if this can be replicated with one bash script running 100% single core,

Please do.

Please also include a gdb trace of plasmashell when it is in this frozen state, or of the crash, otherwise we can't do a lot.