libpipewire-module-rt - Man Page

The rt modules can give real-time priorities to processing threads​.

It uses the operating system's scheduler to enable realtime scheduling for certain threads to assist with low latency audio processing​. This requires RLIMIT_RTPRIO to be set to a value that's equal to this module's rt​.prio parameter or higher​. Most distros will come with some package that configures this for certain groups or users​. If this is not set up and DBus is available, then this module will fall back to using the Portal Realtime DBus API or RTKit​.

libpipewire-module-rt

• nice​.level: The nice value set for the application thread​. It improves performance of the communication with the pipewire daemon​.
• rt​.prio: The realtime priority of the data thread​. Higher values are higher priority​.
• rt​.time​.soft, rt​.time​.hard: The amount of CPU time an RT thread can consume without doing any blocking calls before the kernel kills the thread​. This is a safety measure to avoid lockups of the complete system when some thread consumes 100%​.
• rlimits​.enabled: enable the use of rtlimits, default true​.
• rtportal​.enabled: enable the use of realtime portal, default true
• rtkit​.enabled: enable the use of rtkit, default true
• uclamp​.min: the minimum utilisation value the scheduler should consider
• uclamp​.max: the maximum utilisation value the scheduler should consider

The nice level is by default set to an invalid value so that clients don't automatically have the nice level raised​.

The PipeWire server processes are explicitly configured with a valid nice level​.

A module​.rt​.args config section can be added to override the module arguments​.

# ~/​.config/pipewire/pipewire​.conf​.d/my-rt-args​.conf

module​.rt​.args = {
    #nice​.level = 22
}

context​.modules = [
{   name = libpipewire-module-rt
    args = {
        #nice​.level   = 20
        #rt​.prio      = 88
        #rt​.time​.soft = -1
        #rt​.time​.hard = -1
        #rlimits​.enabled = true
        #rtportal​.enabled = true
        #rtkit​.enabled = true
        #uclamp​.min = 0
        #uclamp​.max = 1024
    }
    flags = [ ifexists nofail ]
}
]