I have been experimenting with different command-files with the sample solution and have a few questions regarding the wait system call. I understand that if wait is called when there are no child processes left, the process will be put back on the ready queue. In the sample solution, if there are no processes in the ready queue, the process that called wait is still put back into the ready queue and then back into running consuming a total of 15 usecs. Is this what is meant to happen? I had assumed that if there were no processes in the ready queue, the process that called wait would just keep running until the time quantum is reached. (It seemed terribly inefficient to move the process off the running state just to put it back in again).