International Business Machines Corporation

Charles E Mari

Elpida Tzortzatos

Harris M Morgenstern

Robert Miller, Jr

Alfred F Foster

Thomas F Rankin

Scott B Tuttle

Peter Grimm Sutton

Steven M Partlow

Matthew J Mauriello

Mariama Ndoye

David Hom

Walter W Otto

Peter Jeremy Relson

Michael Gary Spiegel

Duane C Hughes

David Horn

Christopher G Brooker

Christopher Lee Wood

Chun Kwan K Yee

Peter Bergersen Yocom

Robert R Rogers

Danny R Sutherland

Roman Anthony Bobak

Chun-Kwan K Yee

Jim H Mulder

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.

A computer-implemented method includes pseudo-invalidating a first Dynamic Address Translation (DAT) table of a DAT structure associated with a workload. A page fault occurring during translation of a virtual memory address of data required by the workload is detected. Responsive to the page fault, the DAT structure is traversed. The DAT structure includes one or more DAT tables, and each DAT entry in each of the one or more DAT tables is associated with an in-use bit indicating whether the DAT entry is in use. Traversing the DAT structure includes pseudo-invalidating each of one or more DAT entries in the DAT structure that are involved in translating the virtual memory address for which the page fault occurred; and identifying a first page frame referenced by the virtual memory address for which the page fault occurred. The data in the first page frame is processed responsive to the page fault.

Pseudo-invalidating dynamic address translation (DAT) tables of a DAT structure associated with a workload

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

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

Embodiments of the disclosure include a method for reserving large pages in a large frame area (LFAREA) of a main memory. The method includes pre-scanning a plurality of storage increments and counting a number of available large pages that are online and issuing a message that indicates the number of available large pages. The method also includes receiving and parsing an LFAREA request including a target number of large pages to be reserved. The method further includes calculating an optimal number of large pages to be reserved, based upon the target number of available pages and a system limit. The method includes determining if the LFAREA request is valid and if the LFAREA request can be satisfied and scanning the plurality of the storage increments and reserving the optimal number of pages in the LFAREA.

Reserving fixed page areas in real storage increments

Embodiments of the disclosure include a method for optimizing large page processing. The method includes receiving an indication that a real memory includes a first page. The first page includes a plurality of smaller pages. The method also includes determining a page frame table entry associated with a first smaller page of the first page and storing data associated with the first page in the page frame table entry associated with the first smaller page. The page frame table entry associated with the first smaller page of the first page is a data repository for the plurality of smaller pages of the first page.

Optimizing large page processing

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

Dedicated large page memory pools are provided to, at least in part, facilitate access to large pages. The large page memory is managed by: establishing multiple large page memory pools, each large page memory pool of the multiple large page memory pools including a number of large pages; and dedicating each large page memory pool of the multiple large page memory pools to a respective processor of multiple processors of the computing environment, wherein processors of the multiple processors can concurrently access pages from the respective large page memory pools of the multiple large page memory pools.

Dedicated large page memory pools

Allocation of pages of memory is managed in computing environments that include multiple sized memory pools. Responsive to a request for a page of memory, one or more memory pools are searched for an available frame of memory to service the request. The search uses a predefined order of search, which includes multiple types of memory pools in a specific order based on the requested size of the page of memory.

Managing allocation of memory pages

Large page memory pools are managed. Thresholds are used to determine if the number of pages in a large page memory pool is to be adjusted. If the number of pages is to be increased, a particular technique is provided for adding additional pages to the pool. Further, if there are too many pages in the pool, one or more pages may be removed.

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Wappingers Falls, NY, United States of America

Charles E Mari