c-treeACE CPU Configuration Options

c-treeACE can now be configured to run on specified CPUs on Windows and Solaris operating systems with multi-CPU configurations. For some applications and environments with a large number of CPUs available, this may improve performance.

The CPU_AFFINITY keyword allows an administrator to set the processor affinity mask for the c-treeACE process. By default, the c-treeACE process will use all available processors.

CPU_AFFINITY <cpu list>

On Windows CPU_AFFINITY can be used to set the processor affinity mask for the c-treeACE process. The option accepts a comma-delimited list of processor numbers. For example: CPU_AFFINITY 0,1,2,3,8,9,10,11 indicates that c-treeACE is to be run on the eight specified CPUs.

If c-treeACE successfully sets the CPU affinity to the specified CPUs, the following message is logged to CTSTATUS.FCS, where <cpulist> is the list of CPUs specified for the CPU_AFFINITY option:

Successfully set CPU affinity to: <cpulist>

The following error situations can occur when using the CPU_AFFINITY option:

If the list of CPUs specifies a CPU number that is out of range on the system, a message is logged to CTSTATUS.FCS:

Configuration error: <config_file_name>, line <line_number>: The CPU_AFFINITY option specifies an invalid CPU number for this system.

On Solaris, CPU_AFFINITY accepts a single numeric value, which is interpreted as a processor set number. For example, CPU_AFFINITY 2 configures c-treeACE to run on processor set 2.

If the process does not have permission to assign itself to the specified processor set (or if an invalid processor set is specified), c-treeACE logs the following message to CTSTATUS.FCS, where <configuration_file_name> is the name of the c-treeACE configuration file, <line_number> is the line number on which the CPU_AFFINITY option was specified, and <error_code> is the system error code returned by the OS.

Configuration error: <configuration_file_name>, line <line_number>: Failed to set CPU affinity: system error code <error_code>.

Refer to the c-treeACE Administrator's Guide for complete details about this new configuration option.

Note: A default c-treeACE installation is restricted to 2 CPUs. This limit can be increased with an appropriate activation key available from your nearest FairCom office. You will receive a notification on startup if you attempt to run a default installation on a hardware platform with more than 4 CPUs (counting all cores). To take advantage of more than 2 CPUs, you can either purchase the necessary activation key, bind your c-treeACE process to 2 CPUs, or specify the CPU_AFFINITY keyword to allow the c-treeACE process to bind itself to 2 CPUs.