Abstract: Address-based thresholds for freemained frames are used to determine retention actions. Based, at least in part, on a comparison of a number of freemained frames for an address space against a threshold of freemained frames for the address space, freemained frames can be retained or rejected and/or the threshold can be adjusted.

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: More robust testing of computer module responses to processing errors using a flexible, lightweight solution that does not alter the computer module. Through modification of processing pointers, a wide variety of processing errors and delays are injected into a computer module without modifying the computer module.

Abstract: Embodiments of the present invention provide methods, computer program products, and systems for performing bind breaks. Embodiments of the present invention can be used to reduce bind breaks by saving a save sequence number that reflects a count associated with updates made to a data structure responsive to performing an update to a data structure, retrieving a done sequence number that reflects a count associated with completed bind breaks, and determining whether the save sequence number is less than the done sequence number. Responsive to determining that the save sequence number is less than the done sequence number, embodiments of the invention can reuse the data structure without performing a bind break for the update of the data structure. Embodiments of the invention can be used to reduce bind breaks using sequence numbers to identify when a bind break occurred and updating other processors to avoid duplicating work.

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: 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: Address-based thresholds for freemained frames are used to determine retention actions. Based, at least in part, on a comparison of a number of freemained frames for an address space against a threshold of freemained frames for the address space, freemained frames can be retained or rejected and/or the threshold can be adjusted.

Abstract: Embodiments of the disclosure serializing wrapping of a circularly wrapping trace buffer via a compare-and-swap (CS) instruction by a method including executing a CS loop to advance to a location in the buffer indicated by a next free pointer. The method also includes incrementing a master wrap sequence number each time the next free pointer returns to a top of the buffer and executing another CS loop to increment a wrap number stored in a trace block corresponding to the location indicated by the next free pointer. Based upon determining that the wrap number stored in the trace block is one less than or equal to the master wrap sequence number, the method includes reserving space in a buffer associated with the trace block and storing the wrap number stored in the trace block as an old wrap number and incrementing a use-count of the trace block.

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: 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: 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: 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: 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: 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: 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: 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: 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.