Definition
User Process
A user process is a process executing an application program, typically initiated by a user or interactive session. Distinguished from system processes (daemons) performing background OS maintenance.
Composition
Process Image
A user process is represented by its process image, spanning two memory regions:
- User Space: Program code, application data, user stack
- Kernel Space: PCB and kernel stack
Execution
Definition
Link to originalOS Execution within User Processes
OS execution within user processes is an architecture where the kernel is mapped into the address space of every process. The OS exists as a privileged part of the process itself, not as a separate entity.
When a process requires an OS service (e.g., a system call), it performs a mode switch to kernel mode but remains within its own process context.