Why the process priority of Pulseaudio is -11?

Question

Why it so low? Sometime when cpu is high load sound through Pulseaudio becomes choppy. I think this happens because process priority of Pulseaudio has so low value. So why it so low by default if it can cause problems.

Solution

High nice values correspond to low priorities for a process. So a nice value of -11 actually means that Pulse Audio is running with higher priority than most processes on the system.

Comments

[Vineet Menon]

nice specifies how much a program is nicer to others, so a -11 nice value mean you are not at all nicer to other program and hence you will get a higher priority.

[Dmitry Misharov]

Ok, I got it. But why nice value different from another processes in the system? And why sound becomes choppy when cpu is high load?

[James Henstridge]

Pulse Audio contains code to set its priority (-11 is the default, but it can be changed in the configuration file), which explains why it doesn't have the standard setting of zero. While the boosted priority helps it function correctly, Linux doesn't offer hard real time latency guarantees so it doesn't completely remove the possibility of audio drop outs.