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In more recent interviews Cutler has been firm that the NT kernel was designed pragmatically, a view that Tevanian also evidently later adopted, as evident with

In more recent interviews Cutler has been firm that the NT kernel was designed pragmatically, a view that Tevanian also evidently later adopted, as evident with the great wheel of incarnation that Darwin went through on the road to XNU, although I'm not sure Tevanian ever stated his perspectives on this matter publicly. Neither of these systems were ever true monolithic kernels in the Linux or Unix sense—at all times they both had some measure of sandboxing between e.g. driver code and the scheduler—rather sitting somewhere between. True microkernels are, alas, more of an ideology than a practical reality, as the long-suffering GNU/HURD team discovered; Tanenbaum has been clear that the MINIX/NetBSD experiment was more about principles than performance. That said, certainly many hypervisors have attained success with configurations that coincidentally happen to be the same footprint as a microkernel.

vacuity 2y ago
The hypervisor/microkernel boundary has blurred, and commercial success for microkernels is more or less as hypervisors, e.g. OKL4 is widely used in mobile devices[0]. And Tanenbaum's Minix is used for the Intel Management Engine. I don't know the details with HURD, but I don't think it is mainly suffering from "inherent" or "nearly-inherent" (strongly associated) problems of microkernels. The main cost of microkernels is developer effort and likely performance overhead. [0] https://vita.militaryembedded.com/5159-open-virtualization-arm-cortex-a15-processor/ https://vita.militaryembedded.com/5159-open-virtualization-a...
snvzz 2y ago
>the long-suffering GNU/HURD team discovered; HURD is Mach-based; it is stuck in a pre-L4 world and thus irrelevant to this conversation. Very 40 years ago technology. Still better than ~60yr ago UNIX, although they're trying to ultimately be UNIX-like. It is sad Mach and HURD still keep coming up in microkernel discussion.
- naasking 2y ago
  Maybe not that irrelevant, since another desktop and mobile operating system used around the world is also based on Mach.
  - snvzz 2y ago
    There's some hope now that Apple is a seL4 foundation member.
  - indolering 2y ago
    A Mach that is neutered WRT it's microkernel architecture.
p_l 2y ago
From talking with some people who were witnesses to earliest days of Hurd (but not involved in the project), the real problems of Hurd were social not technical - if anything, OSF/1 & NeXTSTEP succeeding from similar code base (for some value of) points that it was possible to do it. The story goes that the early days were dominated by some ridiculously bad project management that makes Cathedral and the Bazaar era "Cathedral" a nice and well maintained project. Most importantly, GNU Hurd lacked the "ecological niche" to drive work towards it because it couldn't deliver enough, just like lack of information about 386BSD led to Linux (Linus explicitly said that if he had known about 386BSD, he would have worked on it and maybe forked it)

vacuity 2y ago

The hypervisor/microkernel boundary has blurred, and commercial success for microkernels is more or less as hypervisors, e.g. OKL4 is widely used in mobile devices[0]. And Tanenbaum's Minix is used for the Intel Management Engine. I don't know the details with HURD, but I don't think it is mainly suffering from "inherent" or "nearly-inherent" (strongly associated) problems of microkernels. The main cost of microkernels is developer effort and likely performance overhead. [0] https://vita.militaryembedded.com/5159-open-virtualization-arm-cortex-a15-processor/ https://vita.militaryembedded.com/5159-open-virtualization-a...

snvzz 2y ago

>the long-suffering GNU/HURD team discovered; HURD is Mach-based; it is stuck in a pre-L4 world and thus irrelevant to this conversation. Very 40 years ago technology. Still better than ~60yr ago UNIX, although they're trying to ultimately be UNIX-like. It is sad Mach and HURD still keep coming up in microkernel discussion.

naasking 2y ago
Maybe not that irrelevant, since another desktop and mobile operating system used around the world is also based on Mach.
- snvzz 2y ago
  There's some hope now that Apple is a seL4 foundation member.
- indolering 2y ago
  A Mach that is neutered WRT it's microkernel architecture.

p_l 2y ago

From talking with some people who were witnesses to earliest days of Hurd (but not involved in the project), the real problems of Hurd were social not technical - if anything, OSF/1 & NeXTSTEP succeeding from similar code base (for some value of) points that it was possible to do it. The story goes that the early days were dominated by some ridiculously bad project management that makes Cathedral and the Bazaar era "Cathedral" a nice and well maintained project. Most importantly, GNU Hurd lacked the "ecological niche" to drive work towards it because it couldn't deliver enough, just like lack of information about 386BSD led to Linux (Linus explicitly said that if he had known about 386BSD, he would have worked on it and maybe forked it)