OSNews

No, it's because it's open source, cheap, and so can be customized by third parties.

Your second point doesn't actually make any sense at all, and it doesn't help you to bash NT or Windows, which is exactly what you did in your first message just for the sake of it. Sorry.

Edited 2008-12-25 21:58 UTC

Well, I'm a Linux guy. But I don't really see where this particular type of Linux kernel vs NT kernel stuff gets us. So let me throw this into the ring to see if maybe something constructive comes of it: MinWin is/was/will be about emulating some strengths of the Linux kernel philosophy.

Edited 2008-12-25 22:25 UTC

'Monolithic' refers to the memory model used by the kernel. The Linux kernel, like many other common kernels (eg BSD, BeOS, Syllable), is monolithic because all kernel code including modules runs in the same memory space; ie any kernel code, whether compiled into the kernel or in a module, can access any variables or data structures of any other part of the kernel. A consequence of this is that a crash or bug in a module can corrupt the whole kernel.
The usual example of a non-monolithic kernel is Minix, http://en.wikipedia.org/wiki/MINIX.

One might actually say that Windows Vista is less monolithic than Linux, since the new video driver system has video drivers running in userspace. This means that a buggy video driver won't crash the whole system - it just gets safely restarted and everything goes on as usual.

While Linux is not a microkernel it isn't as monolithic as earlier versions of Unix. A lot has been moved outside the kernel and it is extremely modular, much more so than Windows.



Vista's graphics driver model is actually similar to Linux because there are two parts to the driver, one in kernel space for things like memory management and another part resides in userspace to handle things like GL acceleration. Linux also has split graphics drivers and DRI2 introduces a kernel memory manager for graphics much like Vista has.

The linux kernel is Monolithic. You have no idea what you are talking about. Dynamic loadable modules are available in most modern kernels but they are still monolithic.

In kernel parlance, Monolithic refers to wether the kernel and all of its modules, including device drivers, execute in privileged mode.

You are confusing runtime/compile time binary level implementation with architecture.

The NT kernel is a hybrid kernel.

Your understanding is incorrect. The architecture of linux has nothing to do with its popularity or it being able to run on small memory foot print.

QNX is a microkernel and runs fine on small memory embedded systems.

Edited 2008-12-28 19:53 UTC

True. And that particular choice of architecture is nothing to be ashamed of. Microkernel was considered avante garde in the 90s. Nowadays, the word "microkernel" mainly evokes mental images of Andy Tannenbaum waiting for the Great Pumpkin to rise out of the pumpkin patch. I'm not a QNX expert. But from what I've heard, they do seem to have done a good job with a microkernel design in the RT space.


The NT kernel is a monolithic kernel in the ways that matter. Microsoft was happy to have buzz word compliance in the 90s, when NT was architected. But they were no more willing than was Linus to accept the overhead of message passing at that level. (Remember that QNX and real-time are about determinism, and not about speed.)


Probably not directly. But to the extent that Linux's design has allowed it to be performant, especially in the server space, it has no doubt contributed.


Yep.

Edited 2008-12-28 20:21 UTC

Thanks for pointing that out. I wasn't aware that according to the correct nomenclature he Linux kernel is indeed monolithic.