International Business Machines Corporation

Harris M Morgenstern

Elpida Tzortzatos

Steven M Partlow

Robert Miller, Jr

Charles E Mari

Thomas F Rankin

Alfred F Foster

Scott B Tuttle

David Hom

Dieter Wellerdiek

Christopher Lee Wood

James H Mulder

Danny R Sutherland

Walter W Otto

Peter Jeremy Relson

Duane C Hughes

Peter Grimm Sutton

Scott Brady Compton

Greg A Dyck

Christopher G Brooker

Peter Bergersen Yocom

Gary Stuart Puchkoff

Robert R Rogers

Donald Fred Ault

Michael Page Kasper

Roman Anthony Bobak

Michael Gary Spiegel

Karl David Schmitz

Horst Sinram

Wendy L Wang

James M Hertzig

Peter A Fatzinger

Susan Z Demkowicz

Jim H Mulder

Joseph Danieli

Tracy Christie

Providing a service to obtain attributes of memory frames includes receiving a query indicating a range of memory locations from a program. The method also includes identifying, in response to the query, page frame table data for one or more real memory frames corresponding to the range of memory locations. The method also includes generating, based on the page frame table data, defined output data describing attributes of the one or more real memory frames.

Providing a service to obtain attributes of memory frames

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.

An aspect includes determining, via a processor, context attributes of a storage. Data address translation (DAT) tables are created, via the processor, to map virtual addresses to real addresses within the storage. When detecting, via the processor, that a context attribute of the storage has changed, and the DAT tables are updated based at least in part on the changed context attributes of the storage.

Dynamically joining and splitting dynamic address translation (DAT) tables based on operational context

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

Memory management is provided which includes a page replacement process managed by a storage manager and a workload manager. The page replacement process swaps out the content associated with a frame of physical memory to an auxiliary storage in order to provide a free frame. The memory management process includes: determining that the physical memory runs out of free frames; providing priority information from the workload manager to the storage manager, the priority information indicating the priority or business relevance of a certain process; selecting one or more pages to be swapped to the auxiliary storage based on the priority information; and swapping out the contents of the one or more selected pages to the auxiliary storage.

Importance based page replacement

Embodiments are provided for implementing a transparent conversion of common virtual storage requests to storage with limited access. Embodiments include providing a storage manager configured to perform address translation for requests, providing a data address translation (DAT) structure configured to connect a higher-level DAT table to a lower-level DAT table, and creating the DAT structure based on a request from a process. Embodiments also include responsive to receiving a storage request, performing a DAT fault process based on validating user credentials associated with an entry of the higher-level DAT table corresponding to the storage request, and responsive to the validation, updating the higher-level DAT table entry to allow access to the restricted-use portion of the common virtual storage, and otherwise, returning a DAT fault for the higher-level DAT table entry.

Transparent conversion of common virtual storage

Provided herein is a computer-implemented method. The computer-implemented method includes updating, by a processor, a value of a delta field of an entry of a data structure indexed for the processor. The computer-implemented method also includes comparing, by the processor, a predefined threshold for a global field corresponding to the delta field and the value of the delta field. The computer-implemented method also includes rolling, by the processor, the value of the delta field into the global field when an absolute value of the value of the delta field meets or exceeds the predefined threshold for the global field. Note that the data structure is stored in a first area of a memory in communication with the processor that is separate from a second area of the memory storing the global field.

Reducing cache thrashing for counts in hot cache lines

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

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

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Wappingers Falls, NY, United States of America

Harris M Morgenstern