proc_pid_timerslack_ns(5)

proc_pid_timerslack_ns5

Timer slack in nanoseconds

Overview

/proc/pid/timerslack_ns (since Linux 4.6)

This file exposes the process's "current" timer slack value, expressed in nanoseconds. The file is writable, allowing the process's timer slack value to be changed. Writing 0 to this file resets the "current" timer slack to the "default" timer slack value. For further details, see the discussion of PR_SET_TIMERSLACK in prctl(2).

Initially, permission to access this file was governed by a ptrace access mode PTRACE_MODE_ATTACH_FSCREDS check (see ptrace(2)). However, this was subsequently deemed too strict a requirement (and had the side effect that requiring a process to have the CAP_SYS_PTRACE capability would also allow it to view and change any process's memory). Therefore, since Linux 4.9, only the (weaker) CAP_SYS_NICE capability is required to access this file.

Releases

2 releases since Debian 13 (Trixie); the text changed 1 time.

  1. 13
  2. Arch

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