GATE CS 2012 Q8 — System Calls

When a process executes a fork() system call, it creates a duplicate child process. Both the parent and the child processes continue execution from the next instruction.

If we start with $1$ parent process, the number of processes doubles with each fork() call:

• Initially: $1$ process (the parent)
• After the $1^{\text{st}}$ fork(): $2^1 = 2$ processes
• After the $2^{\text{nd}}$ fork(): $2^2 = 4$ processes
• After the $3^{\text{rd}}$ fork(): $2^3 = 8$ processes

In general, after $n$ consecutive fork() calls, the total number of processes is $2^n$.

The question asks for the total number of child processes created:

Hence, the correct option is C.