Linked by Kroc Camen on Thu 25th Dec 2008 07:50 UTC, submitted by diegocg
Linux Heise Open Source provides an extensive breakdown of the innovations present in the latest release of the Linux kernel, announced by Linus Torvalds. This version adds the first version of Ext4 as a stable filesystem, the much-anticipated GPU memory manager which will be the foundation of a renewed graphic stack, support for Ultra Wide Band (Wireless USB, UWB-IP), memory management scalability and performance improvements, a boot tracer, disk shock protection, the phonet network protocol, support of SSD discard requests, transparent proxy support, high-resolution poll()/select()... full Changelog here
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RE[4]: the list is impressive
by akrosdbay on Sun 28th Dec 2008 19:51 UTC in reply to "RE[3]: the list is impressive"
akrosdbay
Member since:
2008-06-09

Your argument misses the point. I'll tell you why. 1.) The Linux Kernel is modular and not monolithic and it comes in a variety of flavours because companies with actual developers use it to fit their needs. This is why today you have a multitude of devices running Linux - probably your also router/cable modem.


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

Reply Parent Score: 2

sbergman27 Member since:
2005-07-24

The linux kernel is Monolithic.

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 hybrid kernel.

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.)

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.

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.

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

Yep.

Edited 2008-12-28 20:21 UTC

Reply Parent Score: 2

RE[6]: the list is impressive
by akrosdbay on Mon 29th Dec 2008 06:18 in reply to "RE[5]: the list is impressive"
akrosdbay Member since:
2008-06-09


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.


Oh please spare me the Linus vs Tannenbaum argument.

Each kernel architecture when implemented properly works just fine. QNX is an great example of that.



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.)


The OP didn't mention anything about speed. QNX offers much better latencies than linux so obviously the message passing doesn't cause that much overhead.

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.


Nothing in my response or the person I was responding to mentioned performance.

You are mistaken if you think the standard Linux kernel offers anything close to real time performance and microsecond latencies that QNX offers. Even with RTAI and other extensions.

QNX also scales down to smaller systems than Linux. I don't see where the overhead from message passing comes in.

So It doesn't matter one bit if the kernel is monolithic or microkernel or a mish mash of both.

The architecture doesn't matter the implementation does. No one OS or architecture can deal with all the niches.

Reply Parent Score: 1

RE[5]: the list is impressive
by dwave on Tue 30th Dec 2008 15:37 in reply to "RE[4]: the list is impressive"
dwave Member since:
2006-09-19

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

Reply Parent Score: 1