201 results about "Multiprocessing" patented technology

A mechanism for exception and interrupt handling in multithreaded multiprocessors is provided. The mechanism allows the handling of exceptions and interruptions in a multithreaded multiprocessor computer, while hiding the multiprocessor nature of the computer from the operating system. Generally, when an operating system is cognizant of the multiprocessor nature of a computer, additional overhead may be required when handling exceptions and interruptions. Due to the overhead involved in saving and restoring processing states, the performance of a processor may be significantly impacted. Additional circuitry is provided which allows the multiprocessor nature of the computer to be hidden from the operating system, while minimizing the overhead necessary for proper handling.

An infrastructure and a set of steps are disclosed for evaluating performance of computer systems. The infrastructure and method provide a flexible platform for carrying out analysis of various computer systems under various workload conditions. The flexible platform is achieved by allowing / supporting independent designation / incorporation of a workload specification and a system upon which the workload is executed. The analytical framework disclosed and claimed herein facilitates flexible / dynamic integration of various hardware models and workload specifications into a system performance analysis, and potentially streamlines development of customized computer software / system specific analyses.The disclosed performance technology infrastructure includes a workload specification interface facilitating designation of a particular computing instruction workload. The workload comprises a list of resource usage requests. The performance technology infrastructure also includes a hardware model interface facilitating designation of a particular computing environment (e.g., hardware configuration and / or network / multiprocessing load). A disclosed hardware model comprises a specification of delays associated with particular resource uses. A disclosed hardware specification further specifies a hardware configuration describing actual resource elements (e.g., hardware devices) and their interconnections in the system of interest. The performance technology infrastructure further comprises an evaluation engine for performing a system performance analysis in accordance with a specified workload and hardware model incorporated via the workload specification and hardware model interfaces.

In a multiprocessing system, hierarchically superior configuration managers maintain profiles of operating characteristics to which subordinate managed units selectively subscribe. If the profiles or operating characteristics change, the configuration managers propagate the changes to all managed units. Each configuration manager stores a record of operating characteristics and multiple server profiles, each profile specifying one or more operating characteristics. A subscription list identifies one or more managed units, each associated with one or more server profiles. Each managed unit acts according to its current operating characteristics, stored locally at the managed unit. If the managed unit receives a profile subscription request from a system administrator, the managed unit sends a subscription message to the configuration manager to subscribe to that input profile. Receiving the subscription, the configuration manager enters the subscribing managed unit and the associated profile into the subscription list, and returns the profiled operating characteristics to the subscribing managed unit. The subscribing managed unit stores these operating characteristics in its record of current operating characteristics. If there is a change to the operating characteristics (or to the profiles), the configuration manager transmits the changed matter to all managed units with affected subscriptions. Upon receipt of this data, each subscribing managed units stores the changed operating characteristics in its record of current operating characteristics.

A system, method and computer program product for processing overflow transactions in a transactional memory system. The transactional memory system is provided in a multiprocessing system having one or more processor devices and a shared memory storage system, and implements a best effort hardware transactional memory system. The method includes acquiring, by a requesting processor, lockbits associated with a memory structure of the shared memory storage system to be reserved for an overflowing transaction. The lockbits determine the granularity at which memory reservations for an overflow transaction are recorded. The method includes implementation of control mechanism for controlling concurrency between overflowing and non-overflowing transactions requested by processor devices in the multiprocessing system, the method enabling only one overflowing transaction to execute at a time in the multiprocessing system.

Lock-free circular queues relying only on atomic aligned read / write accesses in multiprocessing systems are disclosed. In one embodiment, when comparison between a queue tail index and each queue head index indicates that there is sufficient room available in a circular queue for at least one more queue entry, a single producer thread is permitted to perform an atomic aligned write operation to the circular queue and then to update the queue tail index. Otherwise an enqueue access for the single producer thread would be denied. When a comparison between the queue tail index and a particular queue head index indicates that the circular queue contains at least one valid queue entry, a corresponding consumer thread may be permitted to perform an atomic aligned read operation from the circular queue and then to update that particular queue head index. Otherwise a dequeue access for the corresponding consumer thread would be denied.