Abstract: Embodiments are provided for deferring allocation of storage for segments. The method includes receiving, at a first moment in time, a request to allocate a first segment within a memory. Information corresponding to the first segment is stored in a first entry in a hash table, and memory is allocated for the first segment. Information about the first segment is returned to an entity that requested the allocation of the first segment, where the first segment is not allocated auxiliary storage until predefined criteria are satisfied. At a second moment in time, upon receiving an indication to deallocate the first segment, memory corresponding to the first segment is deallocated, where the first segment is never allocated auxiliary storage and the first entry in the hash table is deleted.

Abstract: Embodiments are provided for deferring allocation of storage for segments. The method includes receiving, at a first moment in time, a request to allocate a first segment within a memory. Information corresponding to the first segment is stored in a first entry in a hash table, and memory is allocated for the first segment. Information about the first segment is returned to an entity that requested the allocation of the first segment, where the first segment is not allocated auxiliary storage until predefined criteria are satisfied. At a second moment in time, upon receiving an indication to deallocate the first segment, memory corresponding to the first segment is deallocated, where the first segment is never allocated auxiliary storage and the first entry in the hash table is deleted.

Abstract: An apparatus, method, and program product for optimizing a multiprocessor computing system by sampling memory reference latencies and adjusting components of the system in response thereto. During execution of processes the computing system, memory reference sampling of memory locations from shared memory of the computing system referenced in the executing processes is performed. Each sampled memory reference collected from sampling is associated with a latency and a physical memory location in the shared memory.

Abstract: An apparatus, method, and program product for optimizing a multiprocessor computing system by sampling memory reference latencies and adjusting components of the system in response thereto. During execution of processes the computing system, memory reference sampling of memory locations from shared memory of the computing system referenced in the executing processes is performed. Each sampled memory reference collected from sampling is associated with a latency and a physical memory location in the shared memory.

Abstract: A method, apparatus and computer program product are provided for implementing feedback directed deferral on nonessential direct access storage device (DASD) operations. A kernel DASD I/O manager maintains a queue depth count value for a DASD unit and maintains a busy flag that indicates when the queue depth count value is greater than a predefined threshold. The kernel DASD I/O manager defers optional operations responsive to the busy flag being set for the DASD unit.

Abstract: A method backs up computer data by organizing update requests into groups. All update requests in one group complete concurrently before requests of a subsequent group complete.

Abstract: A method, apparatus and computer program product are provided for implementing feedback directed deferral on nonessential direct access storage device (DASD) operations. A kernel DASD I/O manager maintains a queue depth count value for a DASD unit and maintains a busy flag that indicates when the queue depth count value is greater than a predefined threshold. The kernel DASD I/O manager defers optional operations responsive to the busy flag being set for the DASD unit.

Abstract: A method, apparatus and computer program product are provided for implementing feedback directed deferral on nonessential direct access storage device (DASD) operations. A kernel DASD I/O manager maintains a queue depth count value for a DASD unit and maintains a busy flag that indicates when the queue depth count value is greater than a predefined threshold. The kernel DASD I/O manager defers optional operations responsive to the busy flag being set for the DASD unit.