HP 3000 Manuals HP 3000 Manuals
Chapter 2 SYSTEM INFORMATION MPE XL Supports Multiprocessors by Kimberly Rogers Commercial Systems Division Hewlett-Packard is pleased to introduce a new enhancement to the MPE XL Operating System to support multiple processors (MP). The HP 3000 Series 980/200 is the first HP 3000 platform to support 2-way MP. The MP system features include: * Symmetric Multiprocessor Operation. * Automatic Processor Configuration. * User Transparency. SYMMETRIC MULTIPROCESSOR OPERATION This release of MPE XL supports a symmetric tightly-coupled, shared memory multiprocessor configuration. This means that there are no restrictions placed upon the tasks or user processes that a processor may execute. The system will exploit parallelism at the process level (i.e., processes will be scheduled concurrently across both processors) and will dynamically balance the load among the processors. Thus, the system performance will be dependent on the degree of multiprogramming (opportunity for concurrent execution of processes) exhibited by the workload. AUTOMATIC PROCESSOR CONFIGURATION Each time that the system is booted, MPE XL will automatically determine the actual number of processors physically present on the system and will start all of them. By simply adding an additional processor and then booting the system, the system will be transformed into a multiprocessor system. If, during the boot sequence, any of the processors fail their self-test, they will not be available for initialization. MPE XL will note the failure (via console message and system logging) and then continue to boot the system with the remaining processor. As a result, it will not be necessary to have all of the processors functioning in order to successfully boot and use the system. USER TRANSPARENCY The MP enhancements to the operating system are fully compatible with existing application code. There are no source code changes necessary for an application to execute in an MP configuration nor is there any need for an application to be aware of the existence of multiple processors. MPE XL already provides the basic services that will allow application developers the ability, if they choose, to divide applications into smaller components. These smaller components may execute as separate processes while still having the ability to share data and synchronize activities (RINS, Message File IPC, Mapped Files, etc.). SYSTEM LOG RECORD CHANGES A new log record, identified by log event 139 (also known as log event MP), has been defined. This event will record all processors MPE XL has attempted to initiate and will indicate success/failure of the initialization.