Tickless kernel

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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 2.6.6 [2] and on i386 from release 2.6.21 [3] 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 in Mac OS X 10.4 on, and the NT kernel in 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" (aka tickless). [6]

There is a plan to add this to MINIX 3 [7] in the medium term. [8]

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  1. 1 2 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. "Tickless Kernel" . Retrieved 25 February 2020.
  8. "The MINIX 3 Road Map" . Retrieved 25 February 2020.