Hybrid (micro)kernels

By: Linus Torvalds (torvalds.delete@this.osdl.org), May 15, 2006 10:56 am
Room: Moderated Discussions
Linus Torvalds (torvalds@osdl.org) on 5/15/06 wrote:
>
>I'd worry about some really smart kid in some random country
>that I've never heard of, who just doesn't know how hard
>things are, and who is hungry for the challenge, and decides
>to "just do it". And does things differently (in some
>respect - maybe he decides that the real problem is the
>language, and writes a much better model for handling all
>the complex issues).

Btw, I'm not just saying that. I think the success of Unix
and the fact that it is intertwined with C and implemented
in C-like languages (where C++ very much counts as C-like),
is not just a random historical oddity.

If you want to change the OS model, I don't think that
microkernels is where it is at. A really different model
for how you state the problems and solutions might be it,
though. In that sense, Java (and that whole virtual
machine model, and yes, I realize it wasn't new to java
per se) is much more likely to make more of a difference.

The whole protection model (and thus largely security
model) of UNIX/C depends on mutual distrust of independent
entities, and that involves some real costs in the form
of hardware protection domains. The microkernel issue takes
that notion of protection domains further, and makes it
much worse.

But that's not actually the only model. You can certainly
have your protection model defined by the language, and
be able to "securely" call across protection domains without
any run-time costs if you can show the accesses to be
statically safe through the language interfaces used.

Of course, that has its own set of downsides, and for a
really secure system you probably want both - true security
is often a set of layers, with "if the bad guys get through
one layer, they'll be stopped by the next one or the one
after that", where you end up hoping that any security
issues at different layers are not related.

Linus
< Previous Post in ThreadNext Post in Thread >
TopicPosted ByDate
Hybrid (micro)kernelsTzvetan Mikov2006/05/08 03:41 PM
  Hybrid (micro)kernelsS. Rao2006/05/08 05:14 PM
  Hybrid (micro)kernelsBill Todd2006/05/08 05:16 PM
    Hybrid (micro)kernelsTzvetan Mikov2006/05/08 06:21 PM
      Hybrid (micro)kernelsnick2006/05/08 06:50 PM
      Hybrid (micro)kernelsBill Todd2006/05/09 12:26 AM
        There aren't enough words...Rob Thorpe2006/05/09 01:39 AM
          There aren't enough words...Tzvetan Mikov2006/05/09 02:10 PM
            There aren't enough words...Rob Thorpe2006/05/14 11:25 PM
        Hybrid (micro)kernelsTzvetan Mikov2006/05/09 10:17 AM
          Hybrid (micro)kernelsBill Todd2006/05/09 03:05 PM
  Hybrid (micro)kernelsrwessel2006/05/08 10:23 PM
    Hybrid kernel, not NTRichard Urich2006/05/09 05:03 AM
      Hybrid kernel, not NT_Arthur2006/05/09 06:06 AM
        Hybrid kernel, not NTRob Thorpe2006/05/09 06:40 AM
          Hybrid kernel, not NT_Arthur2006/05/09 07:30 AM
            Hybrid kernel, not NTRob Thorpe2006/05/09 08:07 AM
              Hybrid kernel, not NT_Arthur2006/05/09 08:36 AM
                Linux vs MacOSX peformance, debunked_Arthur2006/05/18 06:30 AM
                  Linux vs MacOSX peformance, debunkedRob Thorpe2006/05/18 07:19 AM
                    Linux vs MacOSX peformance, debunkedAnonymous2006/05/18 11:31 AM
        Hybrid kernel, not NTLinus Torvalds2006/05/09 07:16 AM
          Hybrid kernel, not NTAndi Kleen2006/05/09 01:32 PM
            Hybrid kernel, not NTmyself2006/05/09 02:24 PM
              Hybrid kernel, not NTmyself2006/05/09 02:41 PM
              Hybrid kernel, not NTBrendan2006/05/09 04:26 PM
                Hybrid kernel, not NTLinus Torvalds2006/05/09 07:06 PM
                  Hybrid kernel, not NTBrendan2006/05/13 12:35 AM
                    Hybrid kernel, not NTnick2006/05/13 03:40 AM
                      Hybrid kernel, not NTBrendan2006/05/13 08:48 AM
                        Hybrid kernel, not NTnick2006/05/13 06:41 PM
                          Hybrid kernel, not NTBrendan2006/05/13 08:51 PM
                            Hybrid kernel, not NTnick2006/05/14 04:57 PM
                              Hybrid kernel, not NTBrendan2006/05/14 09:40 PM
                                Hybrid kernel, not NTnick2006/05/14 10:46 PM
                                  Hybrid kernel, not NTBrendan2006/05/15 03:00 AM
                                    Hybrid kernel, not NTrwessel2006/05/15 06:21 AM
                                      Hybrid kernel, not NTBrendan2006/05/15 07:55 AM
                                        Hybrid kernel, not NTLinus Torvalds2006/05/15 08:49 AM
                                          Hybrid kernel, not NTnick2006/05/15 03:41 PM
                                          Hybrid kernel, not NTtony roth2008/01/31 01:20 PM
                                    Hybrid kernel, not NTnick2006/05/15 05:33 PM
                                      Hybrid kernel, not NTBrendan2006/05/16 12:39 AM
                                        Hybrid kernel, not NTnick2006/05/16 01:53 AM
                                          Hybrid kernel, not NTBrendan2006/05/16 04:37 AM
                  Hybrid kernel, not NTAnonymous2008/05/01 09:31 PM
                    Following the structure of the treeMichael S2008/05/02 03:19 AM
                      Following the structure of the treeDean Kent2008/05/02 04:31 AM
                        Following the structure of the treeMichael S2008/05/02 05:02 AM
                        Following the structure of the treeDavid W. Hess2008/05/02 05:48 AM
                          Following the structure of the treeDean Kent2008/05/02 08:14 AM
                            Following the structure of the treeDavid W. Hess2008/05/02 09:05 AM
                              LOL!Dean Kent2008/05/02 09:33 AM
                              Following the structure of the treeanonymous2008/05/02 02:04 PM
                                Following the structure of the treeDean Kent2008/05/02 06:52 PM
                                Following the structure of the treeFoo_2008/05/03 01:01 AM
                                  Following the structure of the treeDavid W. Hess2008/05/03 05:54 AM
                                    Following the structure of the treeDean Kent2008/05/03 09:06 AM
                                      Following the structure of the treeFoo_2008/05/04 12:06 AM
                                        Following the structure of the treeMichael S2008/05/04 12:22 AM
            Hybrid kernel, not NTLinus Torvalds2006/05/09 04:19 PM
              Microkernel Vs Monolithic KernelKernel_Protector2006/05/09 08:41 PM
                Microkernel Vs Monolithic KernelDavid Kanter2006/05/09 09:30 PM
                  Sigh, Stand back, its slashdotting time. (NT)Anonymous2006/05/09 09:44 PM
                  Microkernel Vs Monolithic Kernelblah2006/05/12 07:58 PM
                  Microkernel Vs Monolithic KernelRob Thorpe2006/05/15 12:41 AM
          Hybrid kernel, not NTAnalGuy2006/05/16 02:10 AM
            Theory versus practiceDavid Kanter2006/05/16 11:55 AM
              Distributed algorithmsRob Thorpe2006/05/16 11:53 PM
              Theory versus practiceHoward Chu2006/05/17 01:54 AM
                Theory versus practiceJS2006/05/17 03:29 AM
          Play online poker, blackjack !!! Gamezonex2007/08/16 12:49 PM
  Hybrid (micro)kernelsphilt2006/05/14 08:15 PM
    Hybrid (micro)kernelsLinus Torvalds2006/05/15 07:20 AM
      Hybrid (micro)kernelsLinus Torvalds2006/05/15 10:56 AM
        Hybrid (micro)kernelsRob Thorpe2006/05/16 12:22 AM
          Hybrid (micro)kernelsrwessel2006/05/16 10:23 AM
            Hybrid (micro)kernelsRob Thorpe2006/05/16 11:43 PM
              Hybrid (micro)kernelsrwessel2006/05/17 12:33 AM
                Hybrid (micro)kernelsRob Thorpe2006/05/19 06:51 AM
                  Hybrid (micro)kernelsrwessel2006/05/19 11:27 AM
      Hybrid (micro)kernelstechIperson2006/05/15 12:25 PM
      Hybrid (micro)kernelsmas2006/05/15 04:17 PM
        Hybrid (micro)kernelsLinus Torvalds2006/05/15 04:39 PM
          Hybrid (micro)kernelsColonel Kernel2006/05/15 08:17 PM
            Hybrid (micro)kernelsWink Saville2006/05/15 09:31 PM
              Hybrid (micro)kernelsLinus Torvalds2006/05/16 09:08 AM
                Hybrid (micro)kernelsWink Saville2006/05/16 08:55 PM
          Hybrid (micro)kernelsrwessel2006/05/16 10:31 AM
            Hybrid (micro)kernelsLinus Torvalds2006/05/16 11:00 AM
        Hybrid (micro)kernelsBrendan2006/05/16 12:36 AM
        Hybrid (micro)kernelsPaul Elliott2006/09/03 07:44 AM
          Hybrid (micro)kernelsRob Thorpe2006/09/04 08:25 AM
      Hybrid (micro)kernelsphilt2006/05/15 11:55 PM
        Hybrid (micro)kernelspgerassi2007/08/16 06:41 PM
  Another questionable entry on Wikipedia?Chung Leong2006/05/18 09:33 AM
  Hybrid (micro)kernelsisrael2006/05/20 03:25 AM
    Hybrid (micro)kernelsRob Thorpe2006/05/22 07:35 AM
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