Abstract: Embodiments include methods, systems and computer program products method for maintaining ordered memory access with parallel access data streams associated with a distributed shared memory system. The computer-implemented method includes performing, by a first cache, a key check, the key check being associated with a first ordered data store. A first memory node signals that the first memory node is ready to begin pipelining of a second ordered data store into the first memory node to an input/output (I/O) controller. A second cache returns a key response to the first cache indicating that the pipelining of the second ordered data store can proceed. The first memory node sends a ready signal indicating that the first memory node is ready to continue pipelining of the second ordered data store into the first memory node to the I/O controller, wherein the ready signal is triggered by receipt of the key response.

Abstract: A data processing apparatus is provided, which includes: a plurality of processor cores; a shared processor cache, the shared processor cache being connected to each of the processor cores and to a main memory; a bus controller, the bus controller being connected to the shared processor cache and performing, in response to receiving a descriptor sent by one of the processor cores, a transfer of requested data indicated by the descriptor from the shared processor cache to an input/output (I/O) device; a bus unit, the bus unit being connected to the bus controller and transferring data to/from the I/O device; wherein the shared processor cache includes means for prefetching the requested data from the shared processor cache or main memory by performing a direct memory access in response to receiving a descriptor from the one of the processor cores.

Abstract: A system and method to transfer an ordered partial store of data from a controller to a memory subsystem receives the ordered partial store of data into a buffer of the controller. The method also includes issuing a preinstall command to the memory subsystem, wherein the preinstall command indicates that data from a number of addresses of memory corresponding with a target memory location be obtained in local memory of the memory subsystem along with ownership of the data for subsequent use. A query command is issued to the memory subsystem. The query command requests an indication from the memory subsystem that the memory subsystem is ready to receive and correctly serialize the ordered partial store of data. The ordered partial store of data is transferred from the controller to the memory subsystem.

Abstract: A computing system includes a processor and a memory unit that stores program instructions. The system purges an entry from an address translation cache in response to the processor executing the program instructions to perform issuing, via an operating system running on the computing system, a command indicating a request to perform an I/O transaction requiring a translation entry. A host bridge monitors a total data length of the address translation entry to be transferred during the I/O transaction. An address translation entry is selected from an address translation table, loaded into the address translation cache, and data corresponding to the I/O transaction is transferred using the selected address translation entry. The host bridge automatically purges the selected address translation entry from the address translation cache in response to determining the transferred amount of data matches the total data length for the address translation entry.

Abstract: Embodiments include a technique for management of data transactions, where the technique includes receiving, at a link interface, a packet from an I/O device, wherein the packet includes address information, and performing, by a host bridge, an address translation for the address information included in the packet. The technique also includes responsive to performing the address translation, determining a target page associated with a translated address of the packet is for at least one of a payload target page or a signaling target page, and appending a flag to a command based at least in part on the target page being associated with the translated address of the packet. The technique includes transmitting the command to an ordering controller for ordering the packet.

Abstract: Embodiments include a technique for management of data transactions, where the technique includes receiving, at a link interface, a packet from an I/O device, wherein the packet includes address information, and performing, by a host bridge, an address translation for the address information included in the packet. The technique also includes responsive to performing the address translation, determining a target page associated with a translated address of the packet is for at least one of a payload target page or a signaling target page, and appending a flag to a command based at least in part on the target page being associated with the translated address of the packet. The technique includes transmitting the command to an ordering controller for ordering the packet.

Abstract: A synchronous input/output (I/O) computing system includes a processor and a memory unit that stores program instructions. The system purges one or more address translation entries in response to the processor executing the program instructions to issue, via an operating system running on the synchronous I/O computing system, a synchronous I/O command indicating a request to perform a transaction. The program instructions further command the operating system to select a device table entry from a device table, load the entry into the DTC, request required address translation entries, install the required address translation entries in the address translation cache, and transfer data packets corresponding to the transaction. The program instructions further command the operating system to automatically purge the address translation cache entries associated with a transaction in response to detect that the transaction is completed.

Abstract: A computer-implemented method for synchronous input/output (I/O) cache line padding is described. The cache line padding occurs between a server having a processor executing an operating system and a recipient control unit. The method can include receiving, via the processor at the recipient control unit, a partial line direct memory access (DMA) write request; fetching, via the processor, a device table entry (DTE) associated with the partial line DMA write request; determining, via the processor, a cache line size for a synchronous input/output (I/O) cache line; and writing a full cache line DMA write request by padding, via the processor, the partial line DMA write request with a padded portion, where the padded portion is based on the cache line size.

Abstract: A synchronous input/output (I/O) computing system includes a processor and a memory unit that stores program instructions. The system purges one or more address translation entries in response to the processor executing the program instructions to issue, via an operating system running on the synchronous I/O computing system, a synchronous I/O command indicating a request to perform a transaction. The program instructions further command the operating system to select a device table entry from a device table, load the entry into the DTC, request required address translation entries, install the required address translation entries in the address translation cache, and transfer data packets corresponding to the transaction. The program instructions further command the operating system to automatically purge the address translation cache entries associated with a transaction in response to detect that the transaction is completed.

Abstract: A method, computer program product, and system for maintaining a proper ordering of a data steam that includes two or more sequentially ordered stores, the data stream being moved to a destination memory device, the two or more sequentially ordered stores including at least a first store and a second store, wherein the first store is rejected by the destination memory device. A computer-implemented method includes sending the first store to the destination memory device. A conditional request is sent to the destination memory device for approval to send the second store to the destination memory device, the conditional request dependent upon successful completion of the first store. The second store is cancelled responsive to receiving a reject response corresponding to the first store.

Abstract: A computing system includes a processor and a memory unit that stores program instructions. The system purges an entry from an address translation cache in response to the processor executing the program instructions to perform issuing, via an operating system running on the computing system, a command indicating a request to perform an I/O transaction requiring a translation entry. A host bridge monitors a total data length of the address translation entry to be transferred during the I/O transaction. An address translation entry is selected from an address translation table, loaded into the address translation cache, and data corresponding to the I/O transaction is transferred using the selected address translation entry. The host bridge automatically purges the selected address translation entry from the address translation cache in response to determining the transferred amount of data matches the total data length for the address translation entry.

Abstract: According to embodiments of the invention, methods, computer system, and apparatus for virtual channel management and bus multiplexing are disclosed. The method may include establishing a virtual channel from a first device to a second device via a bus, the bus having a first bus capacity and a second bus capacity, the second bus capacity having greater capacity than the first bus capacity, determining whether a store command is issued for the first bus capacity, determining whether the first bus capacity is available, and allocating the second bus capacity and marking the second bus capacity as unavailable in response to the store command if the first bus capacity is unavailable.

Abstract: A method of maintaining a device table cache (DTC) included in a Synchronous input/output (I/O) computing system includes issuing, with a processor executing an operating system running on the Synchronous I/O computing system, a Synchronous I/O command indicating a request to perform a device table entry transaction including a plurality of device table entries. The method also includes determining, with a host bridge processor, based on device table information, whether the device table entry transaction is associated with a cyclic redundancy check (CRC) transaction, and pinning, with the host bridge processor, a device table entry from a device table based on the determination.

Abstract: A method of maintaining a device table cache (DTC) included in a Synchronous input/output (I/O) computing system includes issuing, with a processor executing an operating system running on the Synchronous I/O computing system, a Synchronous I/O command indicating a request to perform a device table entry transaction including a plurality of device table entries. The method also includes determining, with a host bridge processor, based on device table information, whether the device table entry transaction is associated with a cyclic redundancy check (CRC) transaction, and pinning, with the host bridge processor, a device table entry from a device table based on the determination.

Abstract: In an approach for determining a physical address for object access in an object-based storage device (OSD) system, a processor divides a first data object into one or more partitions, including at least a first partition, and providing each partition for storage as individual stored objects in an OSD system. A processor adds a first entry in a page table, the first entry representing the first partition without an indication of a physical address. A memory management unit (MMU) of the OSD system receives a first request of the first partition. Responsive to receiving the first request of the first partition, a MMU identifies that the first entry of the page table represents the first partition. A MMU obtains a physical address of the first partition from one of a hardware component and a firmware component.

Abstract: A data processing apparatus includes a number of processor cores, a shared processor cache, a bus unit and a bus controller. The shared processor cache is connected to each of the processor cores and to a main memory. The bus unit is connected to the shared processor cache by a bus controller for transferring data to/from an I/O device. In order to achieve further improvements to the data transfer rate between the processor cache and I/O devices, the bus controller is configured, in response to receiving a descriptor from a processor core, to perform a direct memory access to the shared processor cache for transferring data according to the descriptor from the shared processor cache to the I/O device via the bus unit.

Abstract: Creating hash values based on bit values of an input vector. An apparatus includes a first and a second hash table, a first and second hash function generator adapted to configure a respective hash function for a creation of a first and second hash value based on the bit values of the input vector. The hash values are stored in the respective hash tables. An evaluation unit includes a comparison unit to compare a respective effectiveness of the first hash function and the second hash function, and an exchanging unit responsive to the comparison unit adapted to replace the first hash function by the second hash function.

Abstract: Embodiments include methods, systems, and computer program products for performing synchronous data I/O. Aspects include a processor of computer system sending a store block to request data from a device through a PCIe connection, requested data having a predetermined number of data blocks, and the processor executing a data transaction loop to retrieve requested data. Executing the data transaction loop may include writing to a table prefetch trigger register on host bridge to queue up speculative prefetches in ETU for each data block. The host bridge may perform a first speculative prefetch to install a device table entry in a device table cache. The processor may further perform a second speculative prefetch to install an address translation in an address translation cache. The host bridge processes the data block received through direct memory access over the PCIe connection using the prefetched device table entry and address translation.

Abstract: In an approach for determining a physical address for object access in an object-based storage device (OSD) system, a processor divides a first data object into one or more partitions, including at least a first partition, and providing each partition for storage as individual stored objects in an OSD system. A processor adds a first entry in a page table, the first entry representing the first partition without an indication of a physical address. A memory management unit (MMU) of the OSD system receives a first request of the first partition. Responsive to receiving the first request of the first partition, a MMU identifies that the first entry of the page table represents the first partition. A MMU obtains a physical address of the first partition from one of a hardware component and a firmware component.

Abstract: Creating hash values based on bit values of an input vector. An apparatus includes a first and a second hash table, a first and second hash function generator adapted to configure a respective hash function for a creation of a first and second hash value based on the bit values of the input vector. The hash values are stored in the respective hash tables. An evaluation unit includes a comparison unit to compare a respective effectiveness of the first hash function and the second hash function, and an exchanging unit responsive to the comparison unit adapted to replace the first hash function by the second hash function.