I would like to implement a new I/O disk scheduler for Ubuntu in addition to the existing Deadline, Noop and CFQ schedulers. My scheduler would be a real time scheduler considering the deadline of incoming I/O requests, before granting disk access. From my research, i found that the schedulers are defined in the sched.c file. But i am unable to find these files in my Ubuntu 12.04. Kindly let me know the procedure to approach my problem and the set of files to be modified to implement my new I/O scheduling algorithm.