Mach is not a very good microkernel at all, because the overhead is much higher than necessary. The L4 family’s IPC design is substantially more efficient, and that’s why they’re used in actual systems. Fuchsia/Zircon have improved on the model further.
Someone will of course bring up XNU, but the microkernel aspect of it died when they smashed the FreeBSD kernel into the codebase. DriverKit has brought some userspace drivers back, but they use shared memory for all the heavy lifting.
> Mach is not a very good microkernel at all, because the overhead is much higher than necessary. The L4 family’s IPC design is substantially more efficient, and that’s why they’re used in actual systems.
As opposed to Mach, which is not used in any actual systems
Windows NT 3.x was a true microkernel. Microsoft ruined it but the design was quite good and the driver question was irrelevant, until they sidestepped HAL.
I think NTFS get a bit of crap from the OS above it adding limitations. If you read up on what NTFS allows, it is far better than what Windows and the explorer allows you to do with it.
NTFS is a beast of a filesystem and has been nothing but solid for 25+ years. The performance grievances ignore the warranties that NTFS offers vs many antiquated POSIX filesystems.
Yes. As far as kernels go, NT was pretty damn good.
So is Mach, by the way, if you can afford the microkernel performance overhead.
Mach is not a very good microkernel at all, because the overhead is much higher than necessary. The L4 family’s IPC design is substantially more efficient, and that’s why they’re used in actual systems. Fuchsia/Zircon have improved on the model further.
Someone will of course bring up XNU, but the microkernel aspect of it died when they smashed the FreeBSD kernel into the codebase. DriverKit has brought some userspace drivers back, but they use shared memory for all the heavy lifting.
> Mach is not a very good microkernel at all, because the overhead is much higher than necessary. The L4 family’s IPC design is substantially more efficient, and that’s why they’re used in actual systems.
As opposed to Mach, which is not used in any actual systems
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XNU monolith-ized itself over time, even over some microkernel-esque boundaries.
If you include all the drivers too (which surely makes the comparison more accurate), is that still the case?
Windows NT 3.x was a true microkernel. Microsoft ruined it but the design was quite good and the driver question was irrelevant, until they sidestepped HAL.
The Linux kernel was and is a monstrosity.
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Apple at least has been making a concerted effort to kick more macOS/iOS functionality out into userland in the past several years.
Just like Windows since Vista.
NT is actually a pretty good kernel. NTFS and the userland is what is shit.
I think NTFS get a bit of crap from the OS above it adding limitations. If you read up on what NTFS allows, it is far better than what Windows and the explorer allows you to do with it.
NTFS is a beast of a filesystem and has been nothing but solid for 25+ years. The performance grievances ignore the warranties that NTFS offers vs many antiquated POSIX filesystems.
What warranties? I assume you’re comparing it to ext4 and not e.g. ZFS?
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Userland peaked in Windows 2000