idle(2)

idle2

Make process 0 idle

Usage

#include <unistd.h>

[[deprecated]] int idle(void);

Overview

idle() is an internal system call used during bootstrap. It marks the process's pages as swappable, lowers its priority, and enters the main scheduling loop. idle() never returns.

Only process 0 may call idle(). Any user process, even a process with superuser permission, will receive EPERM.

Return value

idle() never returns for process 0, and always returns -1 for a user process.

Errors

EPERM

Always, for a user process.

Releases

19 releases since Debian 1.1 (Buzz); the text changed 15 times.

  1. 1.1–1.2
  2. 1.3–2.1
  3. 2.2
  4. 3.0
  5. 3.1
  6. 4.0
  7. 5.0
  8. 6.0
  9. 7
  10. 8
  11. 9
  12. 10
  13. 11
  14. 12
  15. 13
  16. Arch

Standards

Linux.

History

Removed in Linux 2.3.13.

From man-pages 6.19-1 in Arch Linux 2026-11-01. Parsed by carta from the page's man source.