priclass.d(1m) USER COMMANDS priclass.d(1m)

priclass.d - priority distribution by scheduling class. Uses DTrace.


This is a simple DTrace script that samples at 1000 Hz the current thread's scheduling class and priority. A distribution plot is printed.

With priorities, the higher the priority the better chance the thread has of being scheduled.

This idea came from the script /usr/demo/dtrace/pri.d, which produces similar output for priority changes, not samples.

Since this uses DTrace, only users with root privileges can run this command.

# priclass.d

process priority
number of samples of at least this priority

time sharing
real time
fair share scheduler


DTrace Guide "profile Provider" chapter (

See the DTraceToolkit for further documentation under the Docs directory. The DTraceToolkit docs may include full worked examples with verbose descriptions explaining the output.

priclass.d will sample until Ctrl-C is hit.

pridist.d(1M), dispadmin(1M), dtrace(1M)

April 22, 2006 version 1.00