Operating System Models

Operating System Models
Name
Institution
Operating System Models
UNIX is a natively parallel operating system. The classic design of the UNIX OS assumes the use of a uniprocessor architecture, made up of a single CPU, memory, and peripherals. Although, the UNIX OS uses master and slave processors, and semaphores to protect the integrity of the kernel data structures on multiprocessing systems. DOS, on the other hand, was a single-tasking operating system that supported terminate and stay resident (TSR) programs when triggered by a hardware interrupt. Windows 2000 Server supports the symmetric multiprocessing environments with some versions supporting two processors up to 16 processors. Red Hat Linux 9.0 supports multiprocessing by allowing symmetric multiprocessing (Silberschatz, Galvin, & Gagne, 2014). In my opinion, the Windows 2000 servers manage multiprocessing most efficiently.
A thread approach is a better model for an OS than a process approach since it is less costly (Ritter, 2014). A process is made up of too many things: address space, OS descriptions of resources allocated, and execution state. Creating a new process may be costly since it has many data structures that have to be both allocated and initialized. Also, the communication between processes is costly since it has to utilize Inter-Process Communication (IPC) which creates takes up space for system calls and copied data (Ritter, 2014). Multithreading, on the other hand, improves responsiveness to the user since the program can proceed running when sections of it are waiting.

Also, multithreading allows the sharing of resources since threads run on the same address space, shared memory and resources of their process. Threads allow communication via mutual data thus avoiding the cost of system calls. Finally, multithreading enables performance of a parallel processor on a multiprocessor (Ritter, 2014).

References
Ritter, E. (2014). Operating Systems.
Silberschatz, A., Galvin, P. B., & Gagne, G. (2014). Operating system concepts essentials. John Wiley & Sons, Inc.