|
|
On multiprocessor systems, the scheduler looks for a CPU on which to run a process when that process becomes runnable, or when its time slice has expired. The scheduler first looks for an idle CPU. If it cannot find an idle CPU, it next considers preempting the process on the current CPU if it has a lower priority; it is quicker to preempt the current process as this does not require an interprocessor interrupt. With some application mixes, however, this can increase the number of context switches. For example, when a database server wakes a client, it may be more efficient, in terms of system resources, for the server to continue to run for a period of time after that wakeup.
To prevent the scheduler from preempting the current processor, change the value of preemptive to 0.