Windows XP: PulseAudio consumes too much CPU when launched with high priority
Submitted by Michael DePaulo
Assigned to pul..@..op.org
Created attachment 102099 PulseAudio log while this bug is reproduced on XP SP3 32-bit
As reported in the X2Go bugtracker (bug #526 by "Nable 80"): http://bugs.x2go.org/cgi-bin/bugreport.cgi?bug=526
When I use sound forwarding and launch inside X2Go session some application with sound support, pulseaudio.exe at client side starts consuming ~100% CPU. By default, X2Go Client starts pulseaudio.exe with high priority (13). When I set priority to "Above Normal (10)" PA's CPU load drops to 10-20%. With "Normal (8)" it drops to almost 0%, although sound is still played stable, without any additional delays.
I'm using WinXP SP3 (32-bit) on my laptop with single core CPU. This issue seems to be "PulseAudio 5.0 && WinXP"-specific.
As I mentioned in a follow-up, I was able to reproduce this issue on a VM. ("setup #2") Therefore, I assume it affects all Windows XP machines. The VM was dual-core and only 1 CPU core was being maxed out by PulseAudio.
I also assume it affects windows server 2003 and server 2003 R2 due to their similarity with Windows XP. Those 2 server OS's are supported by Microsoft through July 2015.
For now, we on the X2Go project plan to work around this bug by lowering the priority of PulseAudio, but only when we are running on Windows XP or server 2003 (R2). We ship & use PulseAudio 5.0 on Windows.
Attachment 102099, "PulseAudio log while this bug is reproduced on XP SP3 32-bit":