AIX Tip of the Week

AIX Tip of the Week: AIX bindprocessor Command

Audience: AIX Administrators

Date: October 22, 1999

The AIX "bindprocessor" command can be used to bind a process to a specific processor in a SMP system. In some cases, binding a process to a CPU can improve its performance. For example, binding can be useful for CPU intensive programs that experience few interrupts. Binding eliminates the overhead of setting up the cache when AIX scheduler moves the process between processors**.

However, you need to be careful with the "bindprocessor" command because it can degrade performance. A bound process still shares it's CPU with other processes (binding does not dedicate a CPU to a process, rather it binds a process to a CPU). The bound process must wait for its CPU to become available even though other CPU's in the system are available. I generally recommend letting AIX scheduler (kernel) or the new AIX 4.3.3 Workload Manager manage the workload.

** AIX 4.3.3 scheduler has cache affinity which diminishes the need to bind processes.