A tickless kernel is an
operating system kernel
A kernel is a computer program at the core of a computer's operating system that always has complete control over everything in the system. The kernel is also responsible for preventing and mitigating conflicts between different processes. It is ...
in which timer
interrupt
In digital computers, an interrupt (sometimes referred to as a trap) is a request for the processor to ''interrupt'' currently executing code (when permitted), so that the event can be processed in a timely manner. If the request is accepted ...
s do not occur at regular intervals, but are only delivered as required.
The
Linux kernel
The Linux kernel is a Free and open-source software, free and open source Unix-like kernel (operating system), kernel that is used in many computer systems worldwide. The kernel was created by Linus Torvalds in 1991 and was soon adopted as the k ...
on
s390 from 2.6.6
and on i386 from release 2.6.21
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.
The
XNU
XNU ("X is Not Unix") is the computer operating system (OS) kernel developed at Apple Inc. since December 1996 for use in the Mac OS X (now macOS) operating system and released as free and open-source software as part of the Darwin OS, which, ...
kernel from
Mac OS X 10.4
Mac OS X Tiger (version 10.4) is the 5th major release of macOS, Apple's desktop and server operating system for Mac computers. Tiger was released to the public on April 29, 2005, for US$129.95 as the successor to Mac OS X 10.3 Panther. Incl ...
on, and the
NT kernel from
Windows 8
Windows 8 is a major release of the Windows NT operating system developed by Microsoft. It was Software release life cycle#Release to manufacturing (RTM), released to manufacturing on August 1, 2012, made available for download via Microsoft ...
on, are also tickless.
The
Solaris
Solaris is the Latin word for sun.
It may refer to:
Arts and entertainment Literature, television and film
* ''Solaris'' (novel), a 1961 science fiction novel by Stanisław Lem
** ''Solaris'' (1968 film), directed by Boris Nirenburg
** ''Sol ...
8 kernel introduced the cyclic subsystem which allows arbitrary resolution timers and tickless operation.
[.] FreeBSD
FreeBSD is a free-software Unix-like operating system descended from the Berkeley Software Distribution (BSD). The first version was released in 1993 developed from 386BSD, one of the first fully functional and free Unix clones on affordable ...
9 introduced a "dynamic tick mode" (aka tickless).
As of 2020, there is a plan to add this to
MINIX 3 in the medium term.
References
Operating system kernels
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