On 01/03/13 15:06, Paul Robert Marino wrote:
> Have you run a ps -ax on a Linux box lately? You call that monolithic?
> The linux kernel has been migrating to a micro kernel slowly for the
> last decade now. In some ways its benefited from its older cousin GNU
> Hurd because the Linux Kernel developers had the benefit of knowing what
> went wrong and what worked well in Hurd. By the way from my
> understanding one of the things they really got wrong was using Mach as
> a base because it was the root cause of a majority of the issues they've
> had, and last I herd they were stripping Mach out of the Hurd kernel.

I'm sorry, but the Linux kernel is far far far from a microkernel.  It
does indeed have loadable modules support, kernel threads running as
separate tasks (including IRQ threads) and such things.  But those
threads have full access to global variables in the kernel and the
general design of the Linux kernel is monolithic.

The traditional microkernel design have separate processes which lives
in their own memory spaces, only communicating through a message bus.
This is far from what the Linux kernel is today.

And to be honest, I honestly doubt Linus want to make the Linux kernel a
microkernel; if you've read about what Linus' opinions is about the
microkernel design.

   "Personally, I'm not interested in making device drivers look like
    user-level. They aren't, they shouldn't be, and microkernels are
    just stupid. "  (2002-05-25, Linus Torvalds)

<https://groups.google.com/forum/?fromgroups=#!msg/mlist.linux.kernel/avl2ZFiVRw8/etxgrob6j5MJ>

   "<odd>.x.x: Linus went crazy, broke absolutely everything, and
    rewrote the kernel to be a microkernel using a special message-
    passing version of Visual Basic. (timeframe: "we expect that he
    will be released from the mental institution in a decade or two")."
    (2005-03-02, Linus Torvalds)
    <https://lkml.org/lkml/2005/3/2/247>

   "... even if the Hurd didn't depend on Linux code (and as far as I
    know, it does, but since I think they have their design heads
    firmly up their *sses anyway with that whole microkernel thing,
    I've never felt it was worth my time even looking at their code)..."
    (2006-09-27, Linus Torvalds)

<https://groups.google.com/forum/?fromgroups=#!msg/fa.linux.kernel/V5Njq8zcZt4/8dDRu5RyYeQJ>

   "We're not masturbating around with some research project. We never
    were. Even when Linux was young, the whole and only point was to
    make a *usable* system. It's why it's not some crazy drug-induced
    microkernel or other random crazy thing. "
    (2012-03-08, Linus Torvalds)
    <https://lkml.org/lkml/2012/3/8/495>

And of course, you have the classic Tanenbaum-Torvalds debate as well.
<http://en.wikipedia.org/wiki/Tanenbaum-Torvalds_debate>


--
kind regards,

David Sommerseth


> ------------------------------------------------------------------------
> On Mar 1, 2013 12:13 AM, zxq9 <[log in to unmask]> wrote:
> 
> On 03/01/2013 01:03 PM, Yasha Karant wrote:
>> Modern BSD is a micro-kernel ("MACH") design, whereas Linux still is a
>> monolithic kernel design...
> 
> implying...
> 
> That monolithic kernel design is demonstrably primitive in every respect
> to micro-kernel design and that there is a universal evolutionary path
> predicted by some law we have yet to discover.
> 
> That kernel design trumps driver availability in every respect.
> 
> That any of this matters since nobody is fronting the development time
> to implement $astronaut_arch_X.
> 
> That this is the place to discuss this.