You can configure the process scheduling policy to suit a particular application mix by adjusting the values of a few kernel variables as described in the following sections.
The variables dopricalc, primove, and cache_affinity control the behavior of priority calculations and the scheduler on both single processor and multiprocessor machines; they are found in the file /etc/conf/pack.d/kernel/space.c.
The variables preemptive and loadbalance only apply to SMP and can be found in /etc/conf/pack.d/crllry/space.c. To change the values of these variables, edit the files, then relink and reboot the kernel.
It is not possible to predict the effect of the settings on a particular system. It is likely that you will have to try alternative values to determine whether there is a gain.
For database servers on systems with an SCO SMP License, you may find that setting preemptive, loadbalance and dopricalc to zero gives a performance improvement.
The following sections describe the effect of adjusting these variables: