CODEWITHSUNDEEP
processoperating-system
user2130898
user2130898

Reputation: 899

is the OS a process itself?

I am recently develop a big interest to learn about operating systems and I have been studying about this topic, I have a question that I am not pretty sure if is a valid one.

I am aware that the OS is the one who controls the process but,

is the OS a process itself? If so, who controls the OS?

Sorry for my ignorance I am learning about operating system and I am trying to have a solid idea about how it works.

Thanks in advance.

Upvotes: 6

Views: 5288

Answers (3)

Nguyễn Tiến Đạt
Nguyễn Tiến Đạt

Reputation: 1

It depends on design approaches. According to 3.5 section of "Operating Systems Internal and Design Principles - 7th edition" textbook (written by William Stalling), there are 3 approaches:

  1. non-process kernel.

In this approach, user process and kernel are separate.

process image = address space + PCB = (code + data + stack + heap) + PCB

  1. Execution within User Process

In this approach, some common functions of Operation Systems (run in kernel mode) belong to User processes.

process image = PCB + user address space + kernel address space = PCB + (user code + user data + user stack + user heap) + (kernel code + kernel data + kernel stack + kernel heap).

  1. Process-Based Operating System.

In this approach Operating System is a collection of system processes, each system process executes in kernel mode, and is in charge of specific function.

In addition, these system processes separate with user processes.

Best Regards

Viet Nam.

Upvotes: 0

Dougvj
Dougvj

Reputation: 6575

The term OS comes with some ambiguities... Does the user interface count as the OS? What about software that reads file systems?

The Kernel is generally the most important aspect of an Operating System. The Kernel is responsible for scheduling threads and processes, as well as abstracting the hardware from the software. The kernel itself is NOT a process, but it is a program. It's a program that always exists in every process space. When a process needs to access hardware, the kernel takes over and returns a response to the process. When the process's allotted time on the CPU is over, the kernel takes over and gives the CPU to a new process.

Other aspects of an Operating System, however, are their own processes. For example, on Windows, the user interface and many background services are their own processes. On Linux and other UNIX-like operating systems, the User Interfaces are also in their own respective processes, and in some cases things like filesystem drivers are in their own process as well, sometimes this is considered a hardware abstraction and is therefore placed in the kernel.

There are many possible design choices, however when it comes down to it there will always be a part of the operating system (the Kernel) that will never be it's own process.

Upvotes: 8

Victor Engel
Victor Engel

Reputation: 2133

The OS is a bunch of processes. It is started up during the boot process. How the boot process works depends on the system. But generally, the boot process is also a process whose sole job is to start up the OS.

The OS is generally specific to the hardware it runs on. A main function of the OS is to be a layer between the hardware and application programs. Which processes in the OS are used depend on what functions the application programs need to do.

Upvotes: 0

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