Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An abstraction for storage class memory is provided that hides the details of the implementation of storage class memory from a program, and provides a standard channel programming interface for performing certain actions, such as controlling movement of data between main storage and storage class memory or managing storage class memory.

Abstract: 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.

Abstract: 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.

Abstract: A method for obtaining a measurement of storage usage includes sending a request, by a processor, for the measurement of storage usage during execution of an application by the processor; counting blocks of storage to generate the measurement of storage usage by the application; and providing the measurement of storage usage to the application.

Abstract: 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.

Abstract: Embodiments relate to methods, systems and computer program products for evacuating a portion of a storage class memory. Upon receiving a request to evacuate the portion of the storage class memory a determination is made if the requested evacuation will result in a storage shortage. Based upon determining that the requested evacuation will not result in a storage shortage, the portion of the storage class memory is initialized for evacuation. After initialization is complete, evacuation of the plurality of address spaces of the portion of the storage class memory is preformed, wherein one or more of the plurality of address spaces are evacuated in parallel.

Abstract: A computer system includes memory and a processor configured to manage memory allocation. The processor is configured to execute a memory allocation request to allocate a portion of the memory to an application by determining whether a size of the memory allocation request is less than a first pre-defined size. The processor searches virtual memory for a free allocated memory area corresponding at least to the size of the memory allocation request based on determining that the size of the memory allocation request is less than the first pre-defined size.

Abstract: Auxiliary storage is segmented into different types of extents (i.e., ranges of storage), including extents with 4K blocks of storage, extents with 1M blocks of storage, empty extents, and mixed extents that include blocks of storage of various sizes (e.g., 4K blocks and 1M blocks). The auxiliary storage, and in particular, the extents and blocks of storage therein, are managed to reduce storage fragmentation and optimize system performance.

Abstract: A fault occurs in a virtual environment that includes a base space, a first subspace, and a second subspace, each with a virtual address associated with content in auxiliary storage memory. The fault is resolved by copying the content from auxiliary storage to central storage memory and updating one or more base space dynamic address translation (DAT) tables, and not updating DAT tables of the first and second subspace. A subsequent fault at the first subspace virtual address is resolved by copying the base space DAT table information to the first subspace DAT tables and not updating the second subspace DAT tables. A fault occurring with association to the virtual address of the first subspace is resolved for the base space and the base space DAT table information is copied to the first subspace DAT tables, and the second subspace DAT tables are not updated.

Abstract: A computer system includes a translation look-aside (TLB) buffer and a processing unit. The TLB is configured to store an entry that comprises virtual address information, real address information associated with the virtual address information, and additional information corresponding to at least one of the virtual address information and the real address information. The processing unit is configured to control the TLB to modify the additional information while maintaining the entry in a valid state accessible by the processing unit for a translation look-aside operation corresponding to the virtual address information and the real address information.

Abstract: Embodiments relate to optimizing write performance of a flash device. Aspects include receiving a request to evict a plurality of pages from a main memory and determining a block size for the flash device. Aspects also include grouping the plurality of pages from the main memory into a move specification block, wherein a size of the move specification block is the block size and writing the move specification block to the flash device. The block size being determined based on one or more operational characteristics of the flash device.

Abstract: A method for obtaining a measurement of storage usage includes sending a request, by a processor, for the measurement of storage usage during execution of an application by the processor; counting blocks of storage to generate the measurement of storage usage by the application; and providing the measurement of storage usage to the application.

Abstract: 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.

Abstract: A method includes making in a real storage, a copy of a first page content stored in a first page data structure by creating a second page content in a second data structure, the second page content pointing to actual data pointed to by the first page content, storing the second page content in the second data structure, marking the first page content in the first page data structure with a page protection bit, wherein the page protection bit prevents a modification of the virtual page, in response to an attempt to modify the virtual page, copying the virtual page in the event the first page content in the first page data structure is marked with the page protection bit, storing the copied virtual page in a second virtual storage, and altering the second page content in the second data structure to point to the stored virtual page.

Abstract: A method includes copying a first virtual storage by making, a point-in-time copy of a first page content stored in a first structure by creating a second page content in a second structure, the second page content pointing to actual data pointed to by the first page content, storing the second page content in the second data structure, marking the first page content in the first structure with a bit, copying the virtual page in the event the first page content in the first structure is marked with the bit, storing the copied virtual page in a second virtual storage, altering the second page content to point to the stored virtual page, and using the second virtual storage to perform the core dump process, wherein the second virtual storage is referenced via the second page content stored in the real storage.

Abstract: An abstraction for storage class memory is provided that hides the details of the implementation of storage class memory from a program, and provides a standard channel programming interface for performing certain actions, such as controlling movement of data between main storage and storage class memory or managing storage class memory.

Abstract: An abstraction for storage class memory is provided that hides the details of the implementation of storage class memory from a program, and provides a standard channel programming interface for performing certain actions, such as controlling movement of data between main storage and storage class memory or managing storage class memory.