catflap.org Online Dictionary Query

  priority scheduling
       
           Processes scheduling in which the
          scheduler selects tasks to run based on their priority as
          opposed to, say, a simple round-robin.
       
          Priorities may be static or dynamic.  Static priorities are
          assigned at the time of creation, while dynamic priorities are
          based on the processes' behaviour while in the system.  For
          example, the scheduler may favour I/O-intensive tasks so
          that expensive requests can be issued as early as possible.
       
          A danger of priority scheduling is starvation, in which
          processes with lower priorities are not given the opportunity
          to run.  In order to avoid starvation, in preemptive
          scheduling, the priority of a process is gradually reduced
          while it is running.  Eventually, the priority of the running
          process will no longer be the highest, and the next process
          will start running.  This method is called aging.