Article · Wikipedia archive · Last revised Jul 3, 2026

Tickless kernel

A tickless kernel is an operating system kernel in which timer interrupts do not occur at regular intervals, but are only delivered as required.

Last revised
Jul 3, 2026
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A tickless kernel is an operating system kernel in which timer interrupts do not occur at regular intervals, but are only delivered as required.1

The Linux kernel on s390 from 2.6.62 and on i386 from release 2.6.213 can be configured to turn the timer tick off (tickless or dynamic tick) for idle CPUs using CONFIG_NO_HZ, and from 3.10 with CONFIG_NO_HZ_IDLE extended for non-idle processors with CONFIG_NO_HZ_FULL.4 The XNU kernel from Mac OS X 10.4 on, and the NT kernel from Windows 8 on, are also tickless.1 The Solaris 8 kernel introduced the cyclic subsystem which allows arbitrary resolution timers and tickless operation.5 FreeBSD 9 introduced a "dynamic tick mode" (a.k.a. tickless).67

As of 2020, there is a plan to add this to MINIX 38 in the medium term.9

References

References

  1. Bright, Peter (October 28, 2012). "Better on the inside: under the hood of Windows 8". Ars Technica. section "Tick tock".
  2. "Linux 2.6.6-rc3". Lwn.net. Retrieved 2015-04-09.
  3. "Clockevents and dyntick". Lwn.net. 2007-02-21. Retrieved 2015-04-09.
  4. "(Nearly) full tickless operation in 3.10". Lwn.net. Retrieved 2015-04-09.
  5. "Bryan Cantrill (former Solaris kernel engineer) comment". Retrieved 2017-01-07..
  6. "What's cooking for FreeBSD 9?".
  7. mav (2010-09-13). "[base] Revision 212541". Retrieved 2026-01-23.
  8. "Tickless Kernel". Retrieved 25 February 2020.
  9. "The MINIX 3 Road Map". Retrieved 25 February 2020.