Microkernel - Revision history

Jnc: /* See also */ +MERT

2023-12-14T21:15:23Z

‎See also: +MERT

Jnc: move pros/cons text here

2022-01-29T12:14:00Z

move pros/cons text here

Jnc: +cat

2018-12-16T21:18:32Z

+cat

Jnc: An OK start

2018-10-30T17:59:35Z

An OK start

New page

A '''microkernel''' is a way of [[architecture|structuring]] an [[operating system]]; the [[kernel]] contains as little as possible, and many functions performed in the kernel in a 'monolithic' kernel (e.g. the [[file system]]) are moved out to 'privileged' [[process]]es, which perform those functions for [[user]]s.

Microkernels can, unless implemented cleverly, be slower than a normal operating system; the extra [[context switch]]es required to activate the processes providing 'system' functions can be a source of overhead. The advantages of a microkernel are that the amount of code in the kernel is minimized, reducing the chance of a bug that can crash the entire system; and that the functions moved out to processes can be upgraded while the system is running.

Functions typically left in the kernel are the provision of processes (and their [[address space]]s), including scheduling, and some sort of [[inter-process communication]].

==See also==

* [[Hypervisor]]
* [[Exokernel]]

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← Older revision		Revision as of 12:14, 29 January 2022
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	A '''microkernel''' is a way of [[architecture\|structuring]] an [[operating system]]; the [[kernel]] contains as little as possible, and many functions performed in the kernel in a 'monolithic' kernel (e.g. the [[file system]]) are moved out to 'privileged' [[process]]es, which perform those functions for [[user]]s.		A '''microkernel''' is a way of [[architecture\|structuring]] an [[operating system]]; the [[kernel]] contains as little as possible, and many functions performed in the kernel in a 'monolithic' kernel (e.g. the [[file system]]) are moved out to 'privileged' [[process]]es, which perform those functions for [[user]]s.
		+
		+	There is still no general agreement on the use of microkernels; although they are generally more robust, and have capabilities that the 'classic' '''monolithic kernels''' do not have (e.g. the ability to switch to a new version of the file system code while the system is running), the division usually imposes some overhead, which is un-acceptable to some.

	Microkernels can, unless implemented cleverly, be slower than a normal operating system; the extra [[context switch]]es required to activate the processes providing 'system' functions can be a source of overhead. The advantages of a microkernel are that the amount of code in the kernel is minimized, reducing the chance of a bug that can crash the entire system; and that the functions moved out to processes can be upgraded while the system is running.		Microkernels can, unless implemented cleverly, be slower than a normal operating system; the extra [[context switch]]es required to activate the processes providing 'system' functions can be a source of overhead. The advantages of a microkernel are that the amount of code in the kernel is minimized, reducing the chance of a bug that can crash the entire system; and that the functions moved out to processes can be upgraded while the system is running.

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		+	[[Category: OS Concepts]]

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 Functions typically left in the kernel are the provision of processes (and their [[address space]]s), including scheduling, and some sort of [[inter-process communication]].
 ==See also==
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 * [[Hypervisor]]
 * [[Exokernel]]
+* [[MERT]] - perhaps the earliest microkernel
 [[Category: OS Concepts]]