Definition
User Process
A user process is a process executing an application program, typically initiated by a user or an interactive session. It is distinguished from system processes (daemons) which perform background OS maintenance.
Composition
A user process is represented by its Process Image, which typically spans two distinct regions of memory:
- User Space: Contains the program code, application data, and the user stack.
- Kernel Space: Contains the PCB and the Kernel Stack.
OS Execution within User Processes
Definition
Link to originalOS Execution within User Processes
OS execution within user processes is a modern operating system architecture where the kernel code and data are mapped into the address space of every user process. In this model, the OS does not exist as a separate entity but as a privileged part of the process itself.
When a process requires an OS service (e.g., via a system call), it performs a mode switch to kernel mode but remains within its own process context.