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It's based on a microkernel (mach) but is hybrid, and the source is available https://github.com/apple-oss-distributions/xnu/tree/xnu-8020.140.41 https://github

It's based on a microkernel (mach) but is hybrid, and the source is available https://github.com/apple-oss-distributions/xnu/tree/xnu-8020.140.41 https://github.com/apple-oss-distributions/xnu/tree/xnu-8020...

pjmlp 4y ago
For the time being, after all kexts are forbidden, replaced by the respective userspace drivers, the real difference will only be arguing about semantics, as for all practical purposes from 3rd parties, it will be like a proper micro-kernel OS. https://support.apple.com/guide/security/kernel-extensions-sec8e454101b/1/web/1 https://support.apple.com/guide/security/kernel-extensions-s...
- snvzz 4y ago
  They'd need to replace Mach with something less inefficient first. Mach is a pre-Liedtke microkernel. It's slow at IPC. Which is bad when IPC is what it has to do the most in a proper multi-server system.
  - pjmlp 4y ago
    Regardless of what we think, Apple has been quite clear at WWDC what the end goal is, no more kexts allowed when there is a corresponding userspace framework for the respective driver class. This the the best thing in commercial software, decisions happen, and there are no forks botching the final outcome by disgruntled devs.
    - Pasta123 4y ago
      so ELI5 here, but aren't modern computers fast enough to overcome many of its original shortcomings? I'm not a software engineer, but out of curiosity.
      - pjmlp 4y ago
        Not only they are, many hardcode anti-microkernels folks kind of forget their beloved monolithic Linux kernel nowadays runs on top of type 1 hypervisors (which is basically a tiny micro-kernel), and then there is this whole thing with Docker and Kubernetes deployments for every executable.
        Pasta123 4y ago
        Ah. So there's no dire need for Apple to improve Mach's performance. I wonder if the computer industry in general tend to overlook at performance, that's how I feel about the hardware community, where a tiny differences in benchmarks always taking the crown.

pjmlp 4y ago

For the time being, after all kexts are forbidden, replaced by the respective userspace drivers, the real difference will only be arguing about semantics, as for all practical purposes from 3rd parties, it will be like a proper micro-kernel OS. https://support.apple.com/guide/security/kernel-extensions-sec8e454101b/1/web/1 https://support.apple.com/guide/security/kernel-extensions-s...

snvzz 4y ago
They'd need to replace Mach with something less inefficient first. Mach is a pre-Liedtke microkernel. It's slow at IPC. Which is bad when IPC is what it has to do the most in a proper multi-server system.
- pjmlp 4y ago
  Regardless of what we think, Apple has been quite clear at WWDC what the end goal is, no more kexts allowed when there is a corresponding userspace framework for the respective driver class. This the the best thing in commercial software, decisions happen, and there are no forks botching the final outcome by disgruntled devs.
  - Pasta123 4y ago
    so ELI5 here, but aren't modern computers fast enough to overcome many of its original shortcomings? I'm not a software engineer, but out of curiosity.
    - pjmlp 4y ago
      Not only they are, many hardcode anti-microkernels folks kind of forget their beloved monolithic Linux kernel nowadays runs on top of type 1 hypervisors (which is basically a tiny micro-kernel), and then there is this whole thing with Docker and Kubernetes deployments for every executable.
      - Pasta123 4y ago
        Ah. So there's no dire need for Apple to improve Mach's performance. I wonder if the computer industry in general tend to overlook at performance, that's how I feel about the hardware community, where a tiny differences in benchmarks always taking the crown.