Comment by dundarious
3 days ago
If you include all the drivers too (which surely makes the comparison more accurate), is that still the case?
3 days ago
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.
This is outdated since Windows Vista, and even more so in Windows 11.
Windows Vista isn't Windows NT 3.x. In the internal versioning, it's not even 4.0.
3 replies →
What do you meant by them sidestepping the HAL?
I think the biggest one is that the whole GDI library was moved into the Kernel in 3.5x because the performance was terrible at the time.
I don't think they ever intended to keep all drivers strictly userland, though. Just the service side.
Mind you I don't have access to Microsoft code, so this is all indirect, and a lot of this knowledge was when I was fledgling developer.
The Windows NT code was engineered to be portable across many different architectures--not just X86--so it has a hardware abstraction layer. The kernel only ever communicated to the device-driver implementation through this abstraction layer; so the kernel code itself was isolated.
That doesn't mean the device drivers were running in user-land privilege, but it does mean that the kernel code is quite stable and easy to reason about.
When Microsoft decided to compromise on this design, I remember senior engineers--when I first started my career--being abuzz about it for Windows NT 4.0 (or apparently earlier?).