Messages in this thread | | | Date | Fri, 28 May 1999 18:05:33 -0700 | From | Oscar Levi <> | Subject | Re: is Linux obsolete? |
| |
On Tue, May 25, 1999 at 05:28:41PM -0700, doctor@fruitbat.org wrote: > Stefan Monnier said ... > > > > >>>>> "David" == David Leal <lorien@esoterica.pt> trolled: > > > developed today are microkernel based, e. g. Windows NT, GNU HURD, BeOS... > > > > Nitpick: WinNT is *not* based on a microkernel. > > Just out of curiosity, what makes you say that?
The quintessential microkernel operating system is Mach. It is based on passing messages between independent services. The memory allocator is a services as is the process scheduler and the disk IO subsystem. Windows NT is based on VMS. They made some gestures toward a layered kernel design, but it fails when you examine it closely. Their interfaces are overloaded with special-purpose parameters. All kernel services, except for graphics drivers in 4.0, share the same process space and can therefore stomp on each other. In spite of moving display drivers out of the normal kernel space, they can still crash the OS. Whoops.
The NT kernel API *looks* like it could be for a microkernel, but their execution is sloppy. Mach did a good job of designing an appealing microkernel, but the service transitions sap kernel performance. The NT designers foundered between a clean microkernel design and striving for performance. AFAICT, they lost on both fronts.
-O
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/
| |