Fundamentals · Medium · Free
What is a Process Control Block (PCB)? What does the OS store in it?
FresherFundamentalsOperating Systems
Process Control Block
The PCB is the OS kernel's record for a process—everything needed to suspend and resume execution.
- Process ID, state (running/ready/blocked)
- CPU registers, program counter, stack pointer
- Memory map / page tables pointer
- Open files, signal handlers, scheduling priority
Context switch = swap PCB info—why switching threads in-process is cheaper than processes.