---
name: "priclass.d"
section: "1m"
platform: "macos"
package: "dtrace"
version: "413"
release: "macOS 26.5"
platforms: ["macos"]
url: "https://new.carta.tech/priclass.d"
---

# priclass.d(1m)

priority distribution by scheduling class. Uses DTrace.

## NAME

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

## SYNOPSIS

**priclass.d**

## DESCRIPTION

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.

## EXAMPLES

- This samples until Ctrl-C is hit.

  \#  **priclass.d**

## FIELDS

- value

  process priority

- count

  number of samples of at least this priority

## SCHEDULING CLASSES

- TS

  time sharing

- IA

  interactive

- RT

  real time

- SYS

  system

- FSS

  fair share scheduler

## BASED ON

/usr/demo/dtrace/pri.d

## DOCUMENTATION

DTrace Guide "profile Provider" chapter (docs.sun.com)

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

## EXIT

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

## SEE ALSO

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