Unisys Corporation

Uniys Corporation

James F Merten

Michael J Rieschl

James W Willen

Steven Bernardy

Brian Garrett

James R McBreen

Matthew E Trautman

Warren N Stockton

John Loberg

Systems and methods for obtaining access to database files in a computing system. A method may include receiving a first call from a database management system requesting access to a database file. The method may further include transmitting a second call to an operating system interface requesting that a memory-mapped data expanse file be created. The method may also include receiving a first address representing the database file in response to successful mapping of the database file to the memory-mapped data expanse file located at the operating system interface.

Data expanse using memory-mapped files on a system architecture interface layer-based mainframe operating system

Systems and methods for managing memory in a dynamic translation computer system are provided. Embodiments may include receiving an instruction packet and processing the instruction packet. The instruction packet may include one or more instructions for obtaining a block of virtual memory for use in an emulated operating environment from a slab of virtual memory in a host environment, maintaining a mapping between the block of virtual memory and physical memory when the block is returned to the host environment, and for filling the block of virtual memory with zeros and a pattern based, at least in part, on a detected fill type.

Systems and methods for memory management in a dynamic translation computer system

Systems and methods for obtaining access to a database file managed by an operating system in a computing system are disclosed. One method includes transmitting a call to an operating system from a database management system, the call requesting access to a database file. The method also includes receiving an address from the operating system at the database management system. The address represents a general address of the database file managed by the operating system. The method further includes transmitting a call to the operating system from the database management system, which includes an address and a size of a view of the database file to be created. The method also includes receiving an address of the view of the database file from the operating system.

Data expanse viewer for database systems

This invention provides to large-scale operating systems supporting multiple classes of tasks a method to allocate processor resources to the classes according to a probability model. It is useful in preventing a class from being denied resources by giving it positive measure in the model. A first stage probability algorithm assigns classes of tasks to an IP resource available to a given scheduler queue. Each class is allocated a probability level in a lottery-type draw in this first stage. In preferred embodiments, a second stage probability algorithm is used to assign tasks within a class to an available processor resource. This second stage algorithm is biased in a feedback manner by task resource usage history. Tasks of extreme high or low priority may avoid the probabilistic mechanisms in preferred embodiments.

Operating system scheduler/dispatcher with randomized resource allocation and user manipulable weightings

An Operating System (OS) function maps affinity to processors for each new task and except for certain circumstances where other processors are permitted to steal tasks, this affinity remains unchanged. Hierarchical load balancing is mapped through an affinity matrix (that can be expressed as a table) which is accessed by executable code available through a dispatcher to the multiplicity of instruction processors (IPs) in a multiprocessor computer system. Since the computer system has multiple layers of cache memories, connected by busses, and crossbars to the main memory, the hierarchy mapping matches the cache memories to assign tasks first to IPs most likely to share the same cache memory residue from related tasks, or at least less likely to incur a large access time cost. Each IP has its own switching queue (SQ) for primary task assignments through which the OS makes the initial affinity assignment. When an IP's SQ becomes task free, the dispatcher code has the free IP look to the SQ of other IPs in accord with the mapped hierarchy, if a threshold of idleness is reached.

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Roseville, MN, United States of America

James F Merten