Recovery from Deadlock?

Process Termination:

·         Abort all deadlocked processes.

·         Abort one process at a time until the deadlock cycle is eliminated.

·         In which order should we choose to abort?

   1) Priority of the process.

   2) How long process has computed, and how much longer to completion.

   3) Resources the process has used. 

   4) Resources process needs to complete.

   5) How many processes will need to be terminated? 

   6) Is process interactive or batch?

 Resource Preemption:

§  Selecting a victim – minimize cost.

§  Rollback – return to some safe state, restart process for that state.

§  Starvation – same process may always be picked as victim, include number of rollback in cost factor.