Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: In one embodiment, a computer-implemented method includes receiving a large frame area (LFAREA) request, including a request for a plurality of page frame table entries (PFTEs) to back a plurality of frames in an LFAREA of main memory. Each of the plurality of frames has one of a first size and a second size, where the second size is larger than the first size. The method further includes counting how many frames in the main memory have yet to be initialized and have one of the first size and the second size. A size needed for the plurality of PFTEs is calculated, based at least in part on the counting. A storage area is reserved for the plurality of PFTEs, by a computer processor, where a size of the storage area is the size calculated based at least in part on the counting.

Abstract: In one embodiment, a computer-implemented method includes building an available frame header queue (AFHQ). The AFHQ includes one or more headers, each header including one or more frame references being no more than a maximum count of frame references. Each of the one or more frame references of each of the one or more headers refers to an available frame. A frame request is received for one or more requested frames. One or more frame references are extracted, by a computer processor, from the AFHQ in response to the frame request. The extracting includes extracting from the AFHQ one or more requested headers including the one or more frame references referring to at least a portion of the one or more requested frames.

Abstract: In one embodiment, a computer-implemented method includes receiving a large frame area (LFAREA) request, including a request for a plurality of page frame table entries (PFTEs) to back a plurality of frames in an LFAREA of main memory. Each of the plurality of frames has one of a first size and a second size, where the second size is larger than the first size. The method further includes counting how many frames in the main memory have yet to be initialized and have one of the first size and the second size. A size needed for the plurality of PFTEs is calculated, based at least in part on the counting. A storage area is reserved for the plurality of PFTEs, by a computer processor, where a size of the storage area is the size calculated based at least in part on the counting.

Abstract: In one embodiment, a computer-implemented method includes receiving a large frame area (LFAREA) request, including a request for a plurality of page frame table entries (PFTEs) to back a plurality of frames in an LFAREA of main memory. Each of the plurality of frames has one of a first size and a second size, where the second size is larger than the first size. The method further includes counting how many frames in the main memory have yet to be initialized and have one of the first size and the second size. A size needed for the plurality of PFTEs is calculated, based at least in part on the counting. A storage area is reserved for the plurality of PFTEs, by a computer processor, where a size of the storage area is the size calculated based at least in part on the counting.

Abstract: Embodiments of the present invention provide systems and methods for clearing specified blocks of main storage. In one embodiment, an EADM start subchannel is executed. The instructions of the execution of the EADM start subchannel may include a SAP receiving an ADM request block, which specifies a main-storage-clearing operation command. The address and size of a block of main memory to be cleared by the SAP is specified in an MSB designated by the ADM request block.

Abstract: Embodiments of the present invention provide systems and methods for clearing specified blocks of main storage. In one embodiment, an EADM start subchannel is executed. The instructions of the execution of the EADM start subchannel may include a SAP receiving an ADM request block, which specifies a main-storage-clearing operation command. The address and size of a block of main memory to be cleared by the SAP is specified in an MSB designated by the ADM request block.

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 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: 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: 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: 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.

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: 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: 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.