Application: knotify4 (4.0) KDE Platform Version: 4.8.5 (4.8.5) Qt Version: 4.8.2 Operating System: Linux 3.5.3-1.fc17.x86_64 x86_64 Distribution (Platform): Fedora RPMs Reproducible: Always Steps to Reproduce: 1. I set up a sound to be played whenever a global keyboard shortcut gets pressed; please see the first attachment. 2. I kept Ctrl+F1 (goto vDesktop 1) shortcut pressed for a few seconds; as a cosequence of this, the process of knotify ate aprox 360% of the CPU; please see the second attachment. 3. After a few seconds of this abuse, knotify simply seg-faulted... Attached you find the Backtrace, as it was longer that 65000 characters and couldn't be directly posted here.
Created attachment 73733 [details] empty
Created attachment 73734 [details] global shortcut plays a sound
Created attachment 73735 [details] knotify eating 360% CPU
These bugs seem related to the current report: Bug 197315 - knotify4 slows down when flooding with messages Bug 195691 - Knotify can easily get flooded up to 800MB and more by remote.... Bug 142438 - should have flood prevention
Created attachment 73736 [details] The big Backtrace - contains over 500 Threads
A possible solution: Knotify should STOP collecting and start dropping notifications requests from PID xyz, if that PID has too many (eg 100) not settled notification requests. That should be a simple anti flooding mechanism...
The crash is a phonon/gstreamer issue. Please try newest phonon with different backends (e.g. phonon-vlc backend).
<rocks> phonon --> phonon-backend-vlc v0.6.0 --> ALSA ~ excellent audio quality ~ low CPU <works> phonon --> phonon-backend-gstreamer v4.6.2 --> pulseaudio v1.1 --> ALSA ~ good audio quality ~ high CPU <sucks> phonon --> phonon-backend-gstreamer v4.6.2 --> ALSA ~ poor audio quality ~ crashes knotify ~ extremely high CPU Now I have a millon dollars question: why "phonon-backend-vlc" (the best phonon backend) is not in the __official__ Fedora Repos ?! I had tu use rpmfusion to install it...
Because of software patents.
Hum, only 4.6.2 without PA causes the crash? Because then the backtrace seems wrong... unless something in gstreamer's alsa output is memleaking/corrupting as clearly something went astray with malloc there.
@Christoph: Ok, I understand that VLC includes some patents and cannot be included in the official Fedora repos, but I wasn't talking about VLC, I was talking about phonon-backend-vlc wich is merely a middleware and is free of patents. Isn't it ?
I switched to phonon-backend-vlc, btw :)