Scheduling engines to CPUs

In a system with multiple CPUs, multiple processes can run concurrently. Figure 3-5 represents Adaptive Server engines as the nonshaded ovals waiting in the operating - system run queue for processing time on one of three CPUs. It shows two Adaptive Server engines, proc 3 and proc 8, being processed simultaneously.

Figure 3-5: Processes queued in the OS run queue for multiple CPUs

The symmetric aspect of SMP is a lack of affinity between processes and CPUs—processes are not attached to a specific CPU. Without CPU affinity, the operating - system schedules engines to CPUs in the same way as it schedules non-Adaptive Server processes to CPUs. If an Adaptive Server engine does not find any runnable tasks, it can either relinquish the CPU to the operating - system or continue to look for a task to run by looping for the number of times set in the runnable process search count configuration parameter.