International Business Machines Corporation

Robert Miller, Jr

Elpida Tzortzatos

Harris M Morgenstern

Charles E Mari

Alfred F Foster

Thomas F Rankin

Scott B Tuttle

Steven M Partlow

Peter Grimm Sutton

David Hom

Matthew J Mauriello

Mariama Ndoye

James H Mulder

Dieter Wellerdiek

Walter W Otto

Michael Gary Spiegel

Duane C Hughes

David Horn

Christopher Lee Wood

Christopher G Brooker

Chun Kwan K Yee

Douglas Michael Zobre

Andrew M Sica

Nicholas R Jones

Joseph Griesemer

Chun-Kwan K Yee

Tracy Christie

Joseph Danieli

Tarun Chopra

Dynamic memory area configuration includes designating a portion of memory as a specialized memory unit, and reserving a first portion of specialized memory unit for a plurality of page frame table entries (PFTEs) representing a plurality of frames in the specialized memory. One or more of the PFTEs are stored in respective queue entries within a queue in a reserved area of the specialized memory unit. A particular queue entry indicates that a particular PFTE associated with a particular frame is available for use. An offline request to take a second portion of the specialized memory unit offline is received. Whether to fulfill the offline request is determined based on whether the second portion of the specialized memory unit has an associated queue entry within the queue indicating that the associated frame is not in use back a portion of a page frame table (PFT) or the specialized memory unit.

Dynamic memory area configuration for building page frame table entries

A transient input/output in progress state is established during processing of a testcase by a test infrastructure in a computing environment. The method includes obtaining the testcase for an object having one or more pages, and processing the testcase by the test infrastructure. Processing the testcase by the test infrastructure includes, for a page of the object, generating a delay in the processing of the testcase for the page of the object. The delay opens a transient input/output in progress state during which one or more test operations reference the page of the object.

Controlled input/output in progress state during testcase processing

A transient input/output in progress state is established during processing of an input/output testcase by a test infrastructure in a computing environment. The method includes obtaining the input/output testcase for an object having one or more pages, and processing the input/output testcase by the test infrastructure. Processing the input/output testcase by the test infrastructure includes, for a page of the object, generating a delay in the processing of the input/output testcase for the page of the object. The delay opens a transient input/output in progress state during which one or more concurrent test operations are to reference the page of the object.

Examples of techniques for environment modification for software application testing are described herein. An aspect includes, based on starting testing of an application under test using a test case in a testing environment and determining that modification of the testing environment is enabled, modifying the testing environment. Another aspect includes running the testing of the application under test using the test case in the modified testing environment. Another aspect includes, based on detection of an error during the testing of the application under test, determining whether the error was caused by the modified testing environment. Another aspect includes, based on determining that the error was caused by the modified testing environment, suppressing the error and continuing the testing of the application under test in the modified testing environment. Another aspect includes, based on determining that the error was not caused by the modified testing environment, percolating the error.

Environment modification for software application testing

A computing system includes a processor in signal communication with a memory unit. A test case and recovery (TCR) system is configured to operate in a first mode to perform recovery and repair operations on the memory unit in response to detecting an error event and a second mode to perform test case analysis and verification of an operating system stored in the memory unit in response to being called by a test case.

Self-verification of operating system memory 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

Technical solutions for reducing page invalidation broadcasts in virtual storage management are described. One general aspect includes a method including allocating, by a storage manager, a virtual memory page to a memory buffer that is used by an application being executed by a multiprocessor system, the virtual memory page being allocated from an address space of the application. The method also includes recording, by a memory management unit, a mapping between the virtual memory page and a physical location in a memory. The method also includes in response to a request, from the application, to deallocate the memory buffer, delaying invalidation of the mapping between the virtual memory page and the physical location in a memory, based on a count of free frames in the address space of the application.

Reducing page invalidation broadcasts in virtual storage management

A method, a computer program product, and a system for performing a batch processing are provided. The batch processing includes initializing a set of elements corresponding to a set of resources to produce an initialized group and chaining the initialized group to previously initialized elements to produce an element batch, when the previously initialized elements are available. The batch processing further includes setting a system lock on the set of resources after the element batch is produced; executing a service routine to move the element batch to a queue by referencing first and last elements of the element batch; and releasing the system lock on the set of resources once the service routine is complete.

Optimizing the initialization of a queue via a batch operation

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

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Poughkeepsie, NY, United States of America

Robert Miller, Jr