Talk:Operating Systems/Kernel Models

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I think there is more kernel models than just microkernel vs monolitic kernels. There are others options like exokernels. But unfortunately I don't know enough of it to complete this page. --Mildred 22:40, 13 March 2008 (UTC)[reply]

On µkernels[edit source]

L4 has proved that the speed problems of a µkernel is not inherited to the µkernel concept, but due to problems with specific implementations of the concept -- I think this should be noted.

On Hybrid kernels[edit source]

The image displaying how a hybrid kernel works looks to me like a µkernel with a single-server implementation which has been pulled back into kernelspace -- I suggest that this is either clarified or that hybrid kernel is purged from the article.

Also the introduction to hybrid kernels make no sense, since the design of a µkernel is mutually excluse to how a monolithic kernel is designed — having IPC into and out of a kernel, does not constitute µkernel design. µkernels are (most often) defined as having a minimality of features not in having certain features. This in itself makes a hybrid kernel (as defined as a combination of µ and monolithic kernel design) bogus. See [1] for a definition of µkernels.

On monolithic kernels[edit source]

I have never seen anyone claim that monolithic kernels are simpler in design than µkernels (there is no arguement against so-called hybrid kernels, which must be at least as complex as monolithic kernels and µkernels according to the definition in this article). The operating system at large may be simpler in design, but that is not what the article claims — I seriousely doubt that monolithic kernels can be simpler than µkernels in design. Of course, this depends on what you consider part of the kernel and what not (for example, are servers for a µkernel part of the kernel or external to the kernel?)