For an actual fork bomb, nothing ends up in the PID graveyard. No process ever dies. The fork bomb by itself is a problem, even without a PID graveyard. Process

For an actual fork bomb, nothing ends up in the PID graveyard. No process ever dies. The fork bomb by itself is a problem, even without a PID graveyard. Process limits are required to stop a fork bomb. For other situations, just keep the direct parents. Worst case, that doubles the PID usage.