Monolithic Kernel: Difference between revisions
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{{Template:Kernel designs}}
==Design==
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|[[Image:Monolithic.png|frame|right|Basic overview of a monolithic kernel.]]
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A monolithic kernel includes all (or at least, most) of its services in the kernel proper.
This reduces the amount of context switches and messaging involved, making the concept faster than a [[Microkernel]]. On the downside, the amount of code running in kernel space makes the kernel more prone to fatal bugs.
The word "monolithic" by itself means a single piece (mono) that is of or like stone (lithic), however when applied to kernels the exact meaning is more general. Most people{{who}} consider that a kernel where device drivers and services run as part of the kernel is a monolithic kernel, regardless of whether parts are dynamically loaded "kernel modules" or if everything is a true single unchangeable binary. For this reason
Modern versions of Linux are a well-known example of a monolithic kernel - while drivers are shipped as dynamically loaded "kernel modules" they are still loaded into and running in kernel space. Monolithic kernels are common for the 80x86/PC architecture.
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In general most OS's aren't "pure monolithic" or "pure micro-kernel", but fall somewhere between these extremes in order to make use of the advantages of both methods.
==Examples==
*Linux
*MSDOS, including Windows 9x (95, 98, Me)
*Mac OS <= 8.6
*Most BSDs
*[[Xv6]]
[[Category:Kernel]]
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Latest revision as of 19:09, 5 October 2021
| Kernel Designs |
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| Models |
| Other Concepts |
Design
 |
A monolithic kernel includes all (or at least, most) of its services in the kernel proper.
This reduces the amount of context switches and messaging involved, making the concept faster than a Microkernel. On the downside, the amount of code running in kernel space makes the kernel more prone to fatal bugs.
The word "monolithic" by itself means a single piece (mono) that is of or like stone (lithic), however when applied to kernels the exact meaning is more general. Most people[who?] consider that a kernel where device drivers and services run as part of the kernel is a monolithic kernel, regardless of whether parts are dynamically loaded "kernel modules" or if everything is a true single unchangeable binary. For this reason, a distinction can be drawn between "monolithic" and "pure monolithic".
Modern versions of Linux are a well-known example of a monolithic kernel - while drivers are shipped as dynamically loaded "kernel modules" they are still loaded into and running in kernel space. Monolithic kernels are common for the 80x86/PC architecture.
Examples of "pure monolithic" kernels are rare for the 80x86/PC architecture (but more common in embedded systems). This is because of the wide variety of devices, hardware and CPU features that may be present within a modern PC - a pure monolithic kernel would need to be far too large or compiled specifically for the computer before use.
In general most OS's aren't "pure monolithic" or "pure micro-kernel", but fall somewhere between these extremes in order to make use of the advantages of both methods.
Examples
- Linux
- MSDOS, including Windows 9x (95, 98, Me)
- Mac OS <= 8.6
- Most BSDs
- Xv6