International Business Machines Corporation

Globalfoundries Inc.

Thomas F Rankin

Elpida Tzortzatos

Robert Miller, Jr

Steven M Partlow

Harris M Morgenstern

Charles E Mari

Alfred F Foster

Scott B Tuttle

Walter W Otto

Peter Jeremy Relson

Duane C Hughes

Peter Grimm Sutton

Christopher G Brooker

Douglas Michael Zobre

Andrew M Sica

Nicholas R Jones

Joseph Griesemer

Tarun Chopra

Frank Hemsing

Examples of techniques for function modification for software application testing are described herein. An aspect includes, based on a function call to a function by an application under test that is being tested using a test case in a testing environment, determining whether modification of the function is enabled. Another aspect includes, based on determining that modification of the function is enabled, running the function in a modified mode.

Function modification for software application testing

A memory system is configured for access by a plurality of computer processing units. An address lock bit is configured in a translation table of the memory system. The address lock supports both address lock shared and address lock exclusive functions. A storage manager of an operating system configured to obtain exclusive access to an entry in a DAT table either by obtaining an address space lock exclusive or obtaining an address space lock shared, and setting a lock bit in a DAT entry.

Concurrent virtual storage management

In one embodiment, a computer-implemented method includes producing one or more clean frames by clearing a batch of one or more frames for use in backing virtual memory pages. The producing the one or more clean frames may be performed asynchronously from a unit of work being performed by a processor. The one or more clean frames may be added to a clean frame queue, where the clean frame queue includes a plurality of clean frames that have been cleared. A first request may be received, from the processor, for a frame for use in backing a virtual memory page of the unit of work. A clean frame, of the one or more clean frames, may be removed from the clean frame queue, responsive to the first request. The clean frame may be delivered to the processor, responsive to the first request.

Asynchronously clearing page frames

A method, system, and computer program product to verify serialization of storage frames within an address space via multi-threaded programs is described. The method includes dynamically scaling a number of units of work based on a number of available processors, each of the units of work configured to execute actions, and dynamically scaling an amount and page size of virtual storage accessed by each of the units of work based on a total available memory. The method also includes obtaining, at each of the units of work, different types of storage pages and accessing storage pages corresponding with the respective different types of virtual storage pages associated with the different frame sizes and attributes and performing a respective action, and verifying, for each of the units of work performing the respective action, a state and data content of the storage pages.

Verification of serialization of storage frames within an address space via multi-threaded programs

A method, system, and computer program product to verify management of real storage via multi-threaded thrashers in multiple address spaces are described. The method includes dynamically scaling a number of units of work and a number of address spaces based on a number of available processors and dynamically scaling an amount and page size of storage pages representing virtual storage accessed by each of the number of units of work based on a total available memory. The method also includes obtaining, at each of the units of work, different types of storage frame sizes and attributes, accessing the storage pages corresponding with the respective different types of storage frame sizes and attributes and performing a respective function, and verifying, for each of the units of work performing the respective function, a location of the storage pages and content of the storage pages based on the respective function.

Verification of management of real storage via multi-threaded thrashers in multiple address spaces

Embodiments relate to methods, computer systems and computer program products for improving software performance by identifying and preloading data pages. Embodiments include executing an instruction that requests a data page from the one or more auxiliary storage devices. Based on determining that the instruction is present in the long-running instruction list, embodiments include examining one or more characteristics of a plurality of data pages that will be requested by the instruction. Based on determining that the plurality of data pages are located on a single auxiliary storage device and that the plurality of data pages can be efficiently retrieved by the single auxiliary storage device, embodiments include initiating a pre-load operation to move the plurality of data pages to the main memory.

Software performance by identifying and pre-loading data pages

Embodiments relate to methods, systems and computer program products for defragmenting storage class memory by comparing a utilization rate of the storage class memory to a threshold value. If the utilization rate of the storage class memory is greater than the threshold value, the potentially wasted storage space is then compared to the combined storage capacity of the unclaimed extents of the storage class memory. If the potentially wasted storage space is greater than the combined storage capacity of the unclaimed extents of the storage class memory, a determination is made whether a defragmentation was recently performed. Based on determining that the defragmentation was not recently performed, or that it was recently performed and was productive, performing a defragmentation of the storage class memory.

Defragmentation of storage class memory managed in extents

An auxiliary storage medium is selected for writing data of a set of one or more pages being paged-out from real memory. The auxiliary storage medium is selected from among a plurality of auxiliary storage media, including differing types of storage media, based on characteristics of the plurality of storage media and/or the attributes of the data being written to the auxiliary storage media.

Growing community of inventors

Wallkill, NY, United States of America

Thomas F Rankin