11 ms·

GNU Hurd 0.7 has been released

208 points by vezzy-fnord 11y ago

scorpioxy 11y ago
From my understanding, the microkernel approach has been deemed impractical for real-world use. I wonder if there is anyone out there using it?
- Avshalom 11y ago
  To swipe a line from Chesterton: micro-kernels have not been tried and found wanting, they have been found different and wanted trying.
  - tomcam 11y ago
    More quotes for Chesterton are needed in this (literally) godforsaken place. Actually, more quotes from Chesterton are needed just about everywhere...
    - tomcam 11y ago
      Downvoted? I thought atheism was A Good Thing with the HN hive mind.
      - drdeca 11y ago
        I'm not totally sure what you mean. I would not expect an atheist to consider themselves "God forsaken", and I would not be surprised if one was kind of offended by being called that. (I myself am not an atheist, ftr) Given that,I am not sure why you would be surprised that people reacted negatively?
        tomcam 11y ago
        Because so many on HN are so proud of their atheism. I'm not a conventional believer either. But my description happened to be factual, not an insult.
        rodgerd 11y ago
        It can only be factual if you consider god real.
      - mindcrime 11y ago
        I imagine you got downvoted because this thread is neither about Chesterton nor about atheism. HN culture is generally not very tolerant of threads that deviate into things that aren't at least tangentially related to the main topic-at-hand.
  - nickpsecurity 11y ago
    It took decades to get UNIX's reliable enough to trust for day to day operation with labor estimates in hundreds of millions to billions of dollars. Three or so people got that done in a few years with MINIX 3 using micro-kernel architecture and self-healing services. QNX and INTEGRITY RTOS's have been doing that stuff for years in the field with less resources. And QNX-based Playbook was more reliable, responsive, and fast than iPad in its first incarnation. Before that, KeyKOS outperformed IBM's monolithic stuff on their mainframes with better security and full persistence of system state. So, they worked better and keep working better. People just use monolithic kernels for some reason. Just like they took forever to get off of C for reliable, business applications. "Worse is better."
- Rusky 11y ago
  Do you mean for GNU Hurd specifically, or just microkernels in general? Because there are several microkernels in production use if you look beyond desktop OSes.
- slacka 11y ago
  I doubt the engineers at Blackberry would agree with you when they chose the QNX microkernel as the basis of their next generation OS. Also I never heard any complaints about AmigaOS’s or Symbian's microkernel design as being impractical.
  - lobster_johnson 11y ago
    AmigaOS never implemented any memory protection, did it? So it hugely favours a microkernel design, since there's no expensive context switch to translate a call into kernel mode; everything is user mode.
    - ZenoArrow 11y ago
      Whilst you are correct in that AmigaOS didn't implement memory protection, it's possible to argue that wasn't by design. The original design for AmigaOS was known as CAOS. The CAOS design included resource tracking, which I believe is a useful feature when it comes to implementing memory protection. If I remember correctly what ended up happening was the microkernel for CAOS was developed in-house (Exec), but contractors were being paid to develop the rest of the OS, and they disagreed with the design decisions of CAOS and wanted to make it more Unix-like. Once the Amiga team realised the contractors had wasted time developing something different from what they intended, they sought out an alternative solution to replace the user-space side of the OS. As a result they contracted a different team to rework an OS called TripOS to use the Exec microkernel (that was originally intended for CAOS), which then became the AmigaOS that Amiga users know. You can read a bit more here: http://www.amigahistory.plus.com/caos.html http://www.amigahistory.plus.com/caos.html
      - nickpsecurity 11y ago
        Quark microkernel in MorphOS https://en.wikipedia.org/wiki/Quark_%28kernel%29 https://en.wikipedia.org/wiki/Quark_%28kernel%29 MorphOS - quite fast and usable :) http://www.morphos-team.net/intro http://www.morphos-team.net/intro So, out with the old and in with the new.
- jsmith0295 11y ago
  Not all microkernels. There are many newer ones which have much better performance characteristics of their predecessors. Mach, however, has rather slow IPC, which would be a problem for Hurd.
- lobster_johnson 11y ago
  QNX [1] is probably being the most successful and most mainstream example of a microkernel in real-world use. It's extremely popular for embedded use and/or apps with real-time demands, most famously in nuclear power plants. I've never used QNX myself, but I believe people also run full desktop environments on top of it. [1] https://en.wikipedia.org/wiki/QNX https://en.wikipedia.org/wiki/QNX
  - david-given 11y ago
    I've used the desktop version. It's amazing: it looks, and feels, and operates, just like a Unix, except if you want it it's got this ultra-fast real-time core. When I say 'just like a Unix', I mean: you log in and start up some terminal windows and it's sh and you can compile and run X11 software with configure scripts and gcc and you can print stuff with lpr and it all just works. It even runs Java --- my copy was completely self-hosting via Eclipse! Years ago there was a single-floppy QNX demo disk: you booted from this and you got a basic desktop with dialup modem support and a web browser. SINGLE FLOPPY. Hey, look! I was all set to write a paragraph about how sad it was that you couldn't get the bootable QNX CD any more, but look what I found! http://www.qnx.com/download/feature.html?programid=19602 http://www.qnx.com/download/feature.html?programid=19602 It doesn't even need registration and a login any more! Holy crap, I have to see if this still works... Edit: looks like it won't install without a license key. I'll see if I can get one... Edit: apparently I have an account with QNX dating back from 2012, with three hobbyist license keys, one of which makes the installation CD happy. I don't know whether these are still available, though. Edit: so it installed into a VM in about two minutes flat, and I now have a very old copy of Firefox running. It can't see the network, but that's nothing to do with QNX and everything to do with my inability to set up kvm. I need to find a real machine to run this on. Edit: it will only install from CD, not from USB (unetbootin doesn't help). And I've lost the power cable for my CD burner. So until I find it, I won't be able to proceed here. Sorry. Still good to know this still exists, though...
    - tomcam 11y ago
      They have a license for evaluation & noncommercial use. http://www.qnx.com/legal/licensing/non_commercial.html http://www.qnx.com/legal/licensing/non_commercial.html
- _rook 11y ago
  Both Qualcomm and Apple are known to run variants of L4, a microkernel, on their mobile hardware: https://en.wikipedia.org/wiki/L4_microkernel_family#Commercial_deployment https://en.wikipedia.org/wiki/L4_microkernel_family#Commerci...
  - nickpsecurity 11y ago
    And Samsung uses INTEGRITY Multivisor in KNOX. http://www.ghs.com/products/rtos/integrity_virtualization.html http://www.ghs.com/products/rtos/integrity_virtualization.ht... Multivisor is kind of a combination of the INTEGRITY RTOS and virtualization stuff. The leader in this kind of stuff was OKL4 like in your reference, though. General Dynamics supplies their stuff now due to acquisition.
- agumonkey 11y ago
  As other said, QNX is used, in a lot of places. The microkernel issues raised in the 90s have been addressed partially at least (I'm just a noob) in the L4 mkernel family. Minix v3 too IIUC.
- vezzy-fnord 11y ago
  Your understanding is, I'm sorry if this comes across as hostile, absolute nonsense. You should actually consult the literature instead of reading Linus Torvalds rants. Back in 1990, the Amoeba system revealed 2x improvement in throughput and 5x improvement in latency for its RPC over the SunRPC of the time. [1] Relative measurements for the V-System and Sprite were similar. QNX, a microkernel-based system with high commercial success and a long history (used by over 40 automotive manufacturers) has highly fast IPC by integrating message passing with the CPU scheduler. After years of research, Jochann Liedtke introduced L4 in 1996 [2] using only seven generalized calls with a 20x improvement in speed over prior art such as Mach. Mach, by the way, is the glaring exception to microkernel performance because of complicated message packing and port rights checking. Yet the Hurd developers are doing well in optimizing it, and to this day Mach is used to malign microkernels by people with no background on the subject. OKL4, in turn, has shipped in ~1.5 billion devices by 2012, powering the baseband processor behind nearly every mobile phone. [3] MINIX 3 further only shows a ~5-10% performance drop relative to monolithic Unixes, this for 2006. [4] They never learn. [1] http://www.scs.stanford.edu/nyu/03sp/sched/amoeba.pdf http://www.scs.stanford.edu/nyu/03sp/sched/amoeba.pdf [2] https://homes.cs.washington.edu/~bershad/590s/papers/towards-ukernels.pdf https://homes.cs.washington.edu/~bershad/590s/papers/towards... [3] http://www.creativemac.com/article/OK-Labs-Software-Surpasses-Milestone-of-15-Billion-Mobile-Device-Shipments--1842548 http://www.creativemac.com/article/OK-Labs-Software-Surpasse... [4] http://www.minix3.org/doc/ACSAC-2006.pdf http://www.minix3.org/doc/ACSAC-2006.pdf
  - caycep 11y ago
    as an aside, how is Mach doing these days? I suppose the most visible use is OS X and I assume Apple's engineers have evolved it greatly to keep up with the times compared with the earlier versions of OS X?
    - vezzy-fnord 11y ago
      Apple's XNU is de facto monolithic in nature. It simply reuses OSF Mach primitives to build the BSD Unix layer next to it. Mach IPC is used primarily for service discovery these days, I think, what with launchd being responsible for being the bootstrap server, which maintains name-port bindings for Mach services to call into. This is a side effect of Mach port namespaces being internal to tasks, and hence not having an intrinsic arbiter. In contrast though, the Hurd decentralizes this activity by just assigning a bootstrap port for the client making the RPC call to rendezvous with the server or library in question. These days, OS X seldom uses Mach IPC directly, but rather via XPC. Mach had a surprising resurgence in interest over NextBSD implementing a ton of compatibility layers and mangling Apple sources in a weird, misguided attempt to make FreeBSD the new OS X. We'll see how it turns out.
- kryptiskt 11y ago
  Your phone likely has a L4 microkernel running the radio. There are millions and millions of microkernels out there running all kinds of things, going where Linux fear to tread.
  - technion 11y ago
    I'm surprised that something so incredibly prevalent is so rarely discussed.
    - techdragon 11y ago
      Much of the tech community views this as "settled" thanks to the Linux versus Tannenbaum debate. Microkernels aren't going away any time soon. :-)
      - technion 11y ago
        Oh I know - I meant more "running L4 kernels", with the seL4 currently looking quite interesting. At what point do you conclude that you're: * running everything in hypervisor X, thus hardware support doesn't matter * running only servers, thus desktops don't matter * and thusly, may stand more to gain from an environment that never catered to the above two?
- skykooler 11y ago
  Mac OS X is based on the Mach microkernel. I would think that counts as real-world use.
  - lobster_johnson 11y ago
    XNU (OS X's kernel) doesn't really use Mach as a microkernel. It supports user-mode device drivers, so you might call it a hybrid microkernel, but practically speaking, it's a monolith just like Linux; everything of practical relevance (file system, graphics, most disk and networking I/O) runs in kernel mode. Some parts (high-level USB, Bluetooth, power management, etc.) run as user-space processes, but they talk to kernel-mode device drivers. (XNU was inherited from NeXT, which was based on Mach 2.5, which was actually not a microkernel at all.)
- artlogic 11y ago
  I think a lot of the common idioms passed around about microkernels stem from the old Torvalds v. Tannenbaum argument [1]. It wasn't that Torvalds was right and Tannebaum was wrong. It was simply that Tannenbaum had reliability and theoretical correctness in mind, while Torvalds was concerned with performance. The less context switching you do, the more performant your computer will be. We can take this to the extreme and look at OSes like TempleOS [2] where EVERYTHING runs in kernel mode. Most people prefer a bit more reliability, and so modern desktop kernels are generally hybrid kernels (with the notable exception of Linux which is, of course monolithic). I don't think there's any real technical reason a microkernel couldn't work on today's hardware which is many orders of magnitude faster than what we had in 1992, but a hybrid kernel is always going to be faster. [1] https://en.wikipedia.org/wiki/Tanenbaum%E2%80%93Torvalds_debate https://en.wikipedia.org/wiki/Tanenbaum%E2%80%93Torvalds_deb... [2] http://www.templeos.org/ http://www.templeos.org/
  - lobster_johnson 11y ago
    I always found it interesting how much Intel's protection ring architecture dictated the direction of operating systems back in the 1980s. (I'm sure Intel didn't even invent it; similar concepts were probably already in place in mainframes?) x86 has highly specific support for protection rings and switching between them, as well as things like page faulting and interrupt management, leading to the classic kernel/user split with a kernel as a privileged actor underneath a user mode. But having just one exclusive, reserved "kernel mode" is starting to look old, which is why there's now so much talk about virtualization and exokernels and so on. The microkernel design certainly seems very elegant, but it looks to me like Intel's architecture was always a stumbling block. You have to wonder about what hardware support you could invent that would make microkernels a better fit.
    - marcosdumay 11y ago
      Take a look at the Mill's security presentation. It's an architecture where there is no real border between a monolithical kernel and a microkernel. It's just differences on access control policies, to the point that those names lose their meaning. As always, it's a very interesting architecture. I hope they produce it someday.
- nickpsecurity 11y ago
  In his defence of them, Tannenbaum mentions a lot of companies using microkernels for high-reliability applications: https://www.cs.vu.nl/~ast/reliable-os/ https://www.cs.vu.nl/~ast/reliable-os/ For consumer devices, the Blackberry Playbook was one of the better examples given it was built on QNX microkernel for reliability and nobody was complaining about its performance (i.e. doing two games at once). Lots of phones have microkernels in them to isolate baseband from problems in main OS. Did you know you were using a virtualized OS message passing to other components? I didn't either until I saw the vendor's press release. They might be efficient after all. ;) Here's one used a lot in safety-critical and security-critical apps with nice security architecture: http://www.ghs.com/products/rtos/integrity.html http://www.ghs.com/products/rtos/integrity.html The beautiful and efficient MorphOS uses a microkernel: http://www.morphos-team.net/intro http://www.morphos-team.net/intro One that was made for capability-security model with FOSS code: https://web.archive.org/web/20070428020436/http://www.eros-os.org/eros.html https://web.archive.org/web/20070428020436/http://www.eros-o... Note: See their papers and KeyKOS especially, as it was first successful one on IBM mainframes of old. GenodeOS and MINIX 3 are the best efforts to look at in FOSS today as they're actively maintained. Not at Linux feature set or stability yet given almost no staff haha. Already on bare metal and hosting apps/desktops, though. Just don't think stuff like Hurd is representative of microkernels in general. It's just a failed GNU project. ;)
kriro 11y ago
Good to see steady progress :) I hope the L4 port picks up a new round of steam eventually [1] but they squeeze quite a bit out of the Mach design (from my lay person's understanding of microkernels) and having GNU/Guix since this year is also nice. [1] https://www.gnu.org/software/hurd/history/port_to_another_microkernel.html#index2h2 https://www.gnu.org/software/hurd/history/port_to_another_mi...
- vezzy-fnord 11y ago
  Strongly doubt it. The developers have adamantly focused on improving the standard Hurd/Mach over pursuing other microkernels or even compatibility layers on monolithic Unixes. Given how ridiculously little manpower they have, it's only the most practical. Not to mention the fact that rump kernel integration is very slowly but steadily picking up: https://lists.gnu.org/archive/html/bug-hurd/2015-10/index.html https://lists.gnu.org/archive/html/bug-hurd/2015-10/index.ht... Of course, if all else fails, you can just go with the "write a Mach kernel module for Linux" route and make Linux cannibalize itself. The Darling (OS X compatibility layer for Linux) developer has done some work on this for his project, and it's one I might try to pick up for the Hurd if things advance too slowly, or simply as a research curiosity after I'm done with other projects.
  - techdragon 11y ago
    the desperate need for a decent "can run as a desktop" userland suite of services for the L4 family of microkernels might actually help get them more manpower working on the project. Other than that yeah sticking to what they know does make sense.
  - nickpsecurity 11y ago
    "Given how ridiculously little manpower they have, it's only the most practical." I disagree given how many microkernel projects by tiny teams have been started or finished before they got to even 0.7. Especially the 2-3 person project that was MINIX 3. I think GenodeOS started as a few people's L4 work, too. Maybe what they're doing is fundamentally wrong and they should do it different while leveraging existing work. Just a thought.
iamsohungry 11y ago
Does anyone have practical experience running GNU Hurd as a personal computing environment? I see they have Debian running on GNU Hurd... if I were to install that on my X200 running with LibreBoot (currently running Trisquel Linux) what would my user experience be like?
- vezzy-fnord 11y ago
  You probably couldn't get it to run on bare metal, what with I don't think Mach handling message-signaled interrupts for PCI, on top of the lack of USB and sound for desktop functionality. It's strictly developed and used in virtualization currently, and the motivation for rump kernel integration is to finally escape the hellish circle of that and relying on old NetDDE drivers, perhaps finally making it an everyday OS. On the other hand, it is stable enough to serve the Hurd wiki. In addition, it has ~81% of Debian building, it can run Xfce and Firefox... not bad. It's much more than MINIX 3, which is solid but lacking in packages.
  - auvrw 11y ago
    yea, i tried to run it on real hardware a couple of years ago, and the response from the community was "no one does that, use virtualization." i got the sense that it was a friendly group. expressing interest, even as someone who just wanted to play around and see what it was all about, was well-received.
- ymse 11y ago
  Since you have the luxury of a FSF-blessed laptop, I would recommend trying GuixSD[0]. Transactional package managers are the best thing since sliced bread. 0: https://www.gnu.org/software/guix/ https://www.gnu.org/software/guix/
  - davexunit 11y ago
    Note that while Guix, the package manager, has been successfully ported to the Hurd, GuixSD has not. Still some work to do there, but I invite anyone interested to join in and help it make it happen.
746F7475 11y ago
Why should I be excited?
- omegaham 11y ago
  "Excited" is the wrong word for this sort of development. "Interested" is probably a better word. Right now, I see this sort of thing as a project for its own sake, and that can still be interesting. More importantly, projects like this frequently spread their ideas elsewhere, even if the project itself isn't very useful. Another possibility is that someone gets a bunch of skills from developing in the much more open territory of Hurd and uses that knowledge to contribute in a more limited fashion in the Linux kernel. Of course, I'm sure that Richard Stallman & Friends would be unhappy with my characterization of Hurd as an academic toy project, but them's the breaks. It's on them to show that this is dompetitive on any level with Linux, and right now that's not the case.
  - vezzy-fnord 11y ago
    RMS isn't really involved in the Hurd, in fact he's mostly given up on it. It's being developed by a few enthusiasts, and academic interest in it has been dwindling. Being competitive with Linux isn't even a project goal.
  - quadrangle 11y ago
    Richard Stallman thinks work on HURD is unimportant and nothing more than an academic toy project. He is interested in the ethics and philosophy of software freedom, and the Linux kernel provides that when combined with adequate other completely free software. RMS has repeatedly said that he sees no real value in continuing the HURD project particularly and is much more interested in high priority things like free software replacements for Skype, free firmware, etc.
pmoriarty 11y ago
I just hope it's not infected by systemd.
- suprjami 11y ago
  Fantastic comment, because the kernel is the init process. You should get a medal.
BogusIKnow 11y ago
Since the Linus discussion years ago there is this myth that microkernels are slow. And it's the first post - here again - whenever someone mentions Hurd. Nevertheless we read stories here again and again about how to achieve faster server speed - cloudflare stories come to mind - with userspace tcp stacks etc.
fithisux 11y ago
It is a pitty iokit is not ported with other userland stuff.

208 points by vezzy-fnord 11y ago

From my understanding, the microkernel approach has been deemed impractical for real-world use. I wonder if there is anyone out there using it?

Avshalom 11y ago
To swipe a line from Chesterton: micro-kernels have not been tried and found wanting, they have been found different and wanted trying.
- tomcam 11y ago
  More quotes for Chesterton are needed in this (literally) godforsaken place. Actually, more quotes from Chesterton are needed just about everywhere...
  - tomcam 11y ago
    Downvoted? I thought atheism was A Good Thing with the HN hive mind.
    - drdeca 11y ago
      I'm not totally sure what you mean. I would not expect an atheist to consider themselves "God forsaken", and I would not be surprised if one was kind of offended by being called that. (I myself am not an atheist, ftr) Given that,I am not sure why you would be surprised that people reacted negatively?
      - tomcam 11y ago
        Because so many on HN are so proud of their atheism. I'm not a conventional believer either. But my description happened to be factual, not an insult.
        rodgerd 11y ago
        It can only be factual if you consider god real.
    - mindcrime 11y ago
      I imagine you got downvoted because this thread is neither about Chesterton nor about atheism. HN culture is generally not very tolerant of threads that deviate into things that aren't at least tangentially related to the main topic-at-hand.
- nickpsecurity 11y ago
  It took decades to get UNIX's reliable enough to trust for day to day operation with labor estimates in hundreds of millions to billions of dollars. Three or so people got that done in a few years with MINIX 3 using micro-kernel architecture and self-healing services. QNX and INTEGRITY RTOS's have been doing that stuff for years in the field with less resources. And QNX-based Playbook was more reliable, responsive, and fast than iPad in its first incarnation. Before that, KeyKOS outperformed IBM's monolithic stuff on their mainframes with better security and full persistence of system state. So, they worked better and keep working better. People just use monolithic kernels for some reason. Just like they took forever to get off of C for reliable, business applications. "Worse is better."
Rusky 11y ago
Do you mean for GNU Hurd specifically, or just microkernels in general? Because there are several microkernels in production use if you look beyond desktop OSes.
slacka 11y ago
I doubt the engineers at Blackberry would agree with you when they chose the QNX microkernel as the basis of their next generation OS. Also I never heard any complaints about AmigaOS’s or Symbian's microkernel design as being impractical.
- lobster_johnson 11y ago
  AmigaOS never implemented any memory protection, did it? So it hugely favours a microkernel design, since there's no expensive context switch to translate a call into kernel mode; everything is user mode.
  - ZenoArrow 11y ago
    Whilst you are correct in that AmigaOS didn't implement memory protection, it's possible to argue that wasn't by design. The original design for AmigaOS was known as CAOS. The CAOS design included resource tracking, which I believe is a useful feature when it comes to implementing memory protection. If I remember correctly what ended up happening was the microkernel for CAOS was developed in-house (Exec), but contractors were being paid to develop the rest of the OS, and they disagreed with the design decisions of CAOS and wanted to make it more Unix-like. Once the Amiga team realised the contractors had wasted time developing something different from what they intended, they sought out an alternative solution to replace the user-space side of the OS. As a result they contracted a different team to rework an OS called TripOS to use the Exec microkernel (that was originally intended for CAOS), which then became the AmigaOS that Amiga users know. You can read a bit more here: http://www.amigahistory.plus.com/caos.html http://www.amigahistory.plus.com/caos.html
    - nickpsecurity 11y ago
      Quark microkernel in MorphOS https://en.wikipedia.org/wiki/Quark_%28kernel%29 https://en.wikipedia.org/wiki/Quark_%28kernel%29 MorphOS - quite fast and usable :) http://www.morphos-team.net/intro http://www.morphos-team.net/intro So, out with the old and in with the new.
jsmith0295 11y ago
Not all microkernels. There are many newer ones which have much better performance characteristics of their predecessors. Mach, however, has rather slow IPC, which would be a problem for Hurd.
lobster_johnson 11y ago
QNX [1] is probably being the most successful and most mainstream example of a microkernel in real-world use. It's extremely popular for embedded use and/or apps with real-time demands, most famously in nuclear power plants. I've never used QNX myself, but I believe people also run full desktop environments on top of it. [1] https://en.wikipedia.org/wiki/QNX https://en.wikipedia.org/wiki/QNX
- david-given 11y ago
  I've used the desktop version. It's amazing: it looks, and feels, and operates, just like a Unix, except if you want it it's got this ultra-fast real-time core. When I say 'just like a Unix', I mean: you log in and start up some terminal windows and it's sh and you can compile and run X11 software with configure scripts and gcc and you can print stuff with lpr and it all just works. It even runs Java --- my copy was completely self-hosting via Eclipse! Years ago there was a single-floppy QNX demo disk: you booted from this and you got a basic desktop with dialup modem support and a web browser. SINGLE FLOPPY. Hey, look! I was all set to write a paragraph about how sad it was that you couldn't get the bootable QNX CD any more, but look what I found! http://www.qnx.com/download/feature.html?programid=19602 http://www.qnx.com/download/feature.html?programid=19602 It doesn't even need registration and a login any more! Holy crap, I have to see if this still works... Edit: looks like it won't install without a license key. I'll see if I can get one... Edit: apparently I have an account with QNX dating back from 2012, with three hobbyist license keys, one of which makes the installation CD happy. I don't know whether these are still available, though. Edit: so it installed into a VM in about two minutes flat, and I now have a very old copy of Firefox running. It can't see the network, but that's nothing to do with QNX and everything to do with my inability to set up kvm. I need to find a real machine to run this on. Edit: it will only install from CD, not from USB (unetbootin doesn't help). And I've lost the power cable for my CD burner. So until I find it, I won't be able to proceed here. Sorry. Still good to know this still exists, though...
  - tomcam 11y ago
    They have a license for evaluation & noncommercial use. http://www.qnx.com/legal/licensing/non_commercial.html http://www.qnx.com/legal/licensing/non_commercial.html
_rook 11y ago
Both Qualcomm and Apple are known to run variants of L4, a microkernel, on their mobile hardware: https://en.wikipedia.org/wiki/L4_microkernel_family#Commercial_deployment https://en.wikipedia.org/wiki/L4_microkernel_family#Commerci...
- nickpsecurity 11y ago
  And Samsung uses INTEGRITY Multivisor in KNOX. http://www.ghs.com/products/rtos/integrity_virtualization.html http://www.ghs.com/products/rtos/integrity_virtualization.ht... Multivisor is kind of a combination of the INTEGRITY RTOS and virtualization stuff. The leader in this kind of stuff was OKL4 like in your reference, though. General Dynamics supplies their stuff now due to acquisition.
agumonkey 11y ago
As other said, QNX is used, in a lot of places. The microkernel issues raised in the 90s have been addressed partially at least (I'm just a noob) in the L4 mkernel family. Minix v3 too IIUC.
vezzy-fnord 11y ago
Your understanding is, I'm sorry if this comes across as hostile, absolute nonsense. You should actually consult the literature instead of reading Linus Torvalds rants. Back in 1990, the Amoeba system revealed 2x improvement in throughput and 5x improvement in latency for its RPC over the SunRPC of the time. [1] Relative measurements for the V-System and Sprite were similar. QNX, a microkernel-based system with high commercial success and a long history (used by over 40 automotive manufacturers) has highly fast IPC by integrating message passing with the CPU scheduler. After years of research, Jochann Liedtke introduced L4 in 1996 [2] using only seven generalized calls with a 20x improvement in speed over prior art such as Mach. Mach, by the way, is the glaring exception to microkernel performance because of complicated message packing and port rights checking. Yet the Hurd developers are doing well in optimizing it, and to this day Mach is used to malign microkernels by people with no background on the subject. OKL4, in turn, has shipped in ~1.5 billion devices by 2012, powering the baseband processor behind nearly every mobile phone. [3] MINIX 3 further only shows a ~5-10% performance drop relative to monolithic Unixes, this for 2006. [4] They never learn. [1] http://www.scs.stanford.edu/nyu/03sp/sched/amoeba.pdf http://www.scs.stanford.edu/nyu/03sp/sched/amoeba.pdf [2] https://homes.cs.washington.edu/~bershad/590s/papers/towards-ukernels.pdf https://homes.cs.washington.edu/~bershad/590s/papers/towards... [3] http://www.creativemac.com/article/OK-Labs-Software-Surpasses-Milestone-of-15-Billion-Mobile-Device-Shipments--1842548 http://www.creativemac.com/article/OK-Labs-Software-Surpasse... [4] http://www.minix3.org/doc/ACSAC-2006.pdf http://www.minix3.org/doc/ACSAC-2006.pdf
- caycep 11y ago
  as an aside, how is Mach doing these days? I suppose the most visible use is OS X and I assume Apple's engineers have evolved it greatly to keep up with the times compared with the earlier versions of OS X?
  - vezzy-fnord 11y ago
    Apple's XNU is de facto monolithic in nature. It simply reuses OSF Mach primitives to build the BSD Unix layer next to it. Mach IPC is used primarily for service discovery these days, I think, what with launchd being responsible for being the bootstrap server, which maintains name-port bindings for Mach services to call into. This is a side effect of Mach port namespaces being internal to tasks, and hence not having an intrinsic arbiter. In contrast though, the Hurd decentralizes this activity by just assigning a bootstrap port for the client making the RPC call to rendezvous with the server or library in question. These days, OS X seldom uses Mach IPC directly, but rather via XPC. Mach had a surprising resurgence in interest over NextBSD implementing a ton of compatibility layers and mangling Apple sources in a weird, misguided attempt to make FreeBSD the new OS X. We'll see how it turns out.
kryptiskt 11y ago
Your phone likely has a L4 microkernel running the radio. There are millions and millions of microkernels out there running all kinds of things, going where Linux fear to tread.
- technion 11y ago
  I'm surprised that something so incredibly prevalent is so rarely discussed.
  - techdragon 11y ago
    Much of the tech community views this as "settled" thanks to the Linux versus Tannenbaum debate. Microkernels aren't going away any time soon. :-)
    - technion 11y ago
      Oh I know - I meant more "running L4 kernels", with the seL4 currently looking quite interesting. At what point do you conclude that you're: * running everything in hypervisor X, thus hardware support doesn't matter * running only servers, thus desktops don't matter * and thusly, may stand more to gain from an environment that never catered to the above two?
skykooler 11y ago
Mac OS X is based on the Mach microkernel. I would think that counts as real-world use.
- lobster_johnson 11y ago
  XNU (OS X's kernel) doesn't really use Mach as a microkernel. It supports user-mode device drivers, so you might call it a hybrid microkernel, but practically speaking, it's a monolith just like Linux; everything of practical relevance (file system, graphics, most disk and networking I/O) runs in kernel mode. Some parts (high-level USB, Bluetooth, power management, etc.) run as user-space processes, but they talk to kernel-mode device drivers. (XNU was inherited from NeXT, which was based on Mach 2.5, which was actually not a microkernel at all.)
artlogic 11y ago
I think a lot of the common idioms passed around about microkernels stem from the old Torvalds v. Tannenbaum argument [1]. It wasn't that Torvalds was right and Tannebaum was wrong. It was simply that Tannenbaum had reliability and theoretical correctness in mind, while Torvalds was concerned with performance. The less context switching you do, the more performant your computer will be. We can take this to the extreme and look at OSes like TempleOS [2] where EVERYTHING runs in kernel mode. Most people prefer a bit more reliability, and so modern desktop kernels are generally hybrid kernels (with the notable exception of Linux which is, of course monolithic). I don't think there's any real technical reason a microkernel couldn't work on today's hardware which is many orders of magnitude faster than what we had in 1992, but a hybrid kernel is always going to be faster. [1] https://en.wikipedia.org/wiki/Tanenbaum%E2%80%93Torvalds_debate https://en.wikipedia.org/wiki/Tanenbaum%E2%80%93Torvalds_deb... [2] http://www.templeos.org/ http://www.templeos.org/
- lobster_johnson 11y ago
  I always found it interesting how much Intel's protection ring architecture dictated the direction of operating systems back in the 1980s. (I'm sure Intel didn't even invent it; similar concepts were probably already in place in mainframes?) x86 has highly specific support for protection rings and switching between them, as well as things like page faulting and interrupt management, leading to the classic kernel/user split with a kernel as a privileged actor underneath a user mode. But having just one exclusive, reserved "kernel mode" is starting to look old, which is why there's now so much talk about virtualization and exokernels and so on. The microkernel design certainly seems very elegant, but it looks to me like Intel's architecture was always a stumbling block. You have to wonder about what hardware support you could invent that would make microkernels a better fit.
  - marcosdumay 11y ago
    Take a look at the Mill's security presentation. It's an architecture where there is no real border between a monolithical kernel and a microkernel. It's just differences on access control policies, to the point that those names lose their meaning. As always, it's a very interesting architecture. I hope they produce it someday.
nickpsecurity 11y ago
In his defence of them, Tannenbaum mentions a lot of companies using microkernels for high-reliability applications: https://www.cs.vu.nl/~ast/reliable-os/ https://www.cs.vu.nl/~ast/reliable-os/ For consumer devices, the Blackberry Playbook was one of the better examples given it was built on QNX microkernel for reliability and nobody was complaining about its performance (i.e. doing two games at once). Lots of phones have microkernels in them to isolate baseband from problems in main OS. Did you know you were using a virtualized OS message passing to other components? I didn't either until I saw the vendor's press release. They might be efficient after all. ;) Here's one used a lot in safety-critical and security-critical apps with nice security architecture: http://www.ghs.com/products/rtos/integrity.html http://www.ghs.com/products/rtos/integrity.html The beautiful and efficient MorphOS uses a microkernel: http://www.morphos-team.net/intro http://www.morphos-team.net/intro One that was made for capability-security model with FOSS code: https://web.archive.org/web/20070428020436/http://www.eros-os.org/eros.html https://web.archive.org/web/20070428020436/http://www.eros-o... Note: See their papers and KeyKOS especially, as it was first successful one on IBM mainframes of old. GenodeOS and MINIX 3 are the best efforts to look at in FOSS today as they're actively maintained. Not at Linux feature set or stability yet given almost no staff haha. Already on bare metal and hosting apps/desktops, though. Just don't think stuff like Hurd is representative of microkernels in general. It's just a failed GNU project. ;)

kriro 11y ago

Good to see steady progress :) I hope the L4 port picks up a new round of steam eventually [1] but they squeeze quite a bit out of the Mach design (from my lay person's understanding of microkernels) and having GNU/Guix since this year is also nice. [1] https://www.gnu.org/software/hurd/history/port_to_another_microkernel.html#index2h2 https://www.gnu.org/software/hurd/history/port_to_another_mi...

vezzy-fnord 11y ago
Strongly doubt it. The developers have adamantly focused on improving the standard Hurd/Mach over pursuing other microkernels or even compatibility layers on monolithic Unixes. Given how ridiculously little manpower they have, it's only the most practical. Not to mention the fact that rump kernel integration is very slowly but steadily picking up: https://lists.gnu.org/archive/html/bug-hurd/2015-10/index.html https://lists.gnu.org/archive/html/bug-hurd/2015-10/index.ht... Of course, if all else fails, you can just go with the "write a Mach kernel module for Linux" route and make Linux cannibalize itself. The Darling (OS X compatibility layer for Linux) developer has done some work on this for his project, and it's one I might try to pick up for the Hurd if things advance too slowly, or simply as a research curiosity after I'm done with other projects.
- techdragon 11y ago
  the desperate need for a decent "can run as a desktop" userland suite of services for the L4 family of microkernels might actually help get them more manpower working on the project. Other than that yeah sticking to what they know does make sense.
- nickpsecurity 11y ago
  "Given how ridiculously little manpower they have, it's only the most practical." I disagree given how many microkernel projects by tiny teams have been started or finished before they got to even 0.7. Especially the 2-3 person project that was MINIX 3. I think GenodeOS started as a few people's L4 work, too. Maybe what they're doing is fundamentally wrong and they should do it different while leveraging existing work. Just a thought.

iamsohungry 11y ago

Does anyone have practical experience running GNU Hurd as a personal computing environment? I see they have Debian running on GNU Hurd... if I were to install that on my X200 running with LibreBoot (currently running Trisquel Linux) what would my user experience be like?

vezzy-fnord 11y ago
You probably couldn't get it to run on bare metal, what with I don't think Mach handling message-signaled interrupts for PCI, on top of the lack of USB and sound for desktop functionality. It's strictly developed and used in virtualization currently, and the motivation for rump kernel integration is to finally escape the hellish circle of that and relying on old NetDDE drivers, perhaps finally making it an everyday OS. On the other hand, it is stable enough to serve the Hurd wiki. In addition, it has ~81% of Debian building, it can run Xfce and Firefox... not bad. It's much more than MINIX 3, which is solid but lacking in packages.
- auvrw 11y ago
  yea, i tried to run it on real hardware a couple of years ago, and the response from the community was "no one does that, use virtualization." i got the sense that it was a friendly group. expressing interest, even as someone who just wanted to play around and see what it was all about, was well-received.
ymse 11y ago
Since you have the luxury of a FSF-blessed laptop, I would recommend trying GuixSD[0]. Transactional package managers are the best thing since sliced bread. 0: https://www.gnu.org/software/guix/ https://www.gnu.org/software/guix/
- davexunit 11y ago
  Note that while Guix, the package manager, has been successfully ported to the Hurd, GuixSD has not. Still some work to do there, but I invite anyone interested to join in and help it make it happen.

746F7475 11y ago

Why should I be excited?

omegaham 11y ago
"Excited" is the wrong word for this sort of development. "Interested" is probably a better word. Right now, I see this sort of thing as a project for its own sake, and that can still be interesting. More importantly, projects like this frequently spread their ideas elsewhere, even if the project itself isn't very useful. Another possibility is that someone gets a bunch of skills from developing in the much more open territory of Hurd and uses that knowledge to contribute in a more limited fashion in the Linux kernel. Of course, I'm sure that Richard Stallman & Friends would be unhappy with my characterization of Hurd as an academic toy project, but them's the breaks. It's on them to show that this is dompetitive on any level with Linux, and right now that's not the case.
- vezzy-fnord 11y ago
  RMS isn't really involved in the Hurd, in fact he's mostly given up on it. It's being developed by a few enthusiasts, and academic interest in it has been dwindling. Being competitive with Linux isn't even a project goal.
- quadrangle 11y ago
  Richard Stallman thinks work on HURD is unimportant and nothing more than an academic toy project. He is interested in the ethics and philosophy of software freedom, and the Linux kernel provides that when combined with adequate other completely free software. RMS has repeatedly said that he sees no real value in continuing the HURD project particularly and is much more interested in high priority things like free software replacements for Skype, free firmware, etc.

pmoriarty 11y ago

I just hope it's not infected by systemd.

suprjami 11y ago
Fantastic comment, because the kernel is the init process. You should get a medal.

BogusIKnow 11y ago

Since the Linus discussion years ago there is this myth that microkernels are slow. And it's the first post - here again - whenever someone mentions Hurd. Nevertheless we read stories here again and again about how to achieve faster server speed - cloudflare stories come to mind - with userspace tcp stacks etc.

fithisux 11y ago

It is a pitty iokit is not ported with other userland stuff.