Abstract: A computer-implemented method, apparatus, and computer program product are disclosed for bus/device/function (BDF) translation and routing of communications packets through a fabric that utilizes PCI switches. Identifiers are included in communications packets that are routed between a host and an I/O adapter using a PCI fabric to which the host and the I/O adapter are coupled. Destination identifiers that are included in first communications packets that are received by edge switches, which are connected directly to said host or directly connected to said I/O adapter, are translated before routing the communications packets out of the edge switches. Second communications packets that are received by internal switches, which are not directly connected to the host or directly connected to the I/O adapter, are routed without translating destination identifiers that are included in the second communications packets.

Abstract: System and method for managing routing of data in a distributed computing system, such as a distributed computing system that uses PCI Express protocol to communicate over an I/O fabric. A physical tree that is indicative of a physical configuration of the distributed computing system is determined, and a virtual tree is created from the physical tree. The virtual tree is then modified to change an association between at least one source device and at least one target device in the virtual tree. A validation mechanism validates the changed association between the at least one source device and the at least one target device to enable routing of data from the at least one source device to the at least one target device.

Abstract: A computer-implemented method, apparatus, and computer program product are disclosed in a data processing environment that includes host computer systems that are coupled to adapters utilizing a switched fabric for routing packets between the host computer systems and the adapters. A unique destination identifier is assigned to one of the host computer systems. A portion of a standard format packet destination address is selected. Within a particular packet, the portion is set equal to the unique identifier that is assigned to the host computer system. The particular packet is then routed through the fabric to the host computer system using the unique destination identifier.

Abstract: System and method for managing routing of data in a distributed computing system, such as a distributed computing system that uses PCI Express protocol to communicate over an I/O fabric. A physical tree that is indicative of a physical configuration of the distributed computing system is determined, and a virtual tree is created from the physical tree. The virtual tree is then modified to change an association between at least one source device and at least one target device in the virtual tree. A validation mechanism validates the changed association between the at least one source device and the at least one target device to enable routing of data from the at least one source device to the at least one target device.

Abstract: An apparatus and method for communicating with an input/output (I/O) adapter configured to communicate with a locally attached I/O device are provided using cached address translations. With the apparatus and method, in response to receiving a storage transaction request, a queue element is created in a command queue specifying an untranslated buffer address. The queue element may be retrieved by the I/O adapter and a determination may be made as to whether the queue element contains a read operation command. If so, a translation request may be sent from the I/O adapter to a root complex at substantially a same time as the read operation command is sent to a locally attached external I/O device. The translated address corresponding to the untranslated address of the queue element may be returned and stored in the I/O adapter prior to receiving the data read from the external I/O device.

Abstract: An apparatus and method for communicating with a memory registration enabled adapter, such as an InfiniBand™ host channel adapter, are provided. With the apparatus and method, device driver services may be invoked by a device driver for initializing address translation entries in an address translation data structure of a root complex. An address of a device driver data buffer data structure and registration modifiers may be passed by the device driver to the device driver services. The device driver services may create address translation data structure entries in the address translation data structure associated with the root complex and memory registration (MR) address translation entries in a MR address translation data structure of the adapter. The MR address translation data structure may then be used with I/O operations to bypass the address translation data structure associated with the root complex.

Abstract: An apparatus and method for splitting responsibilities for communicating with an endpoint between a device driver and device driver services are provided. With the apparatus and method, the device driver is responsible for managing queues for communicating requests between applications in a logical partition and the endpoint. The device driver further invokes memory management via device driver services. The device driver services are responsible for managing memory accessible by the endpoint, including the address translation and protection table (ATPT) or a root complex and the address translation caches (ATCs) of the endpoint. The device driver services may associate untranslated addresses for data structures used to communicate between a system image and the endpoint. The endpoint may request translations of the untranslated addresses and may cache the translations in the ATCs.

Abstract: A computer implemented method, data processing system, and computer usable program code are provided for migrating a persistent cache. A priming request is received at an intermediary to prime the persistent cache of a first partition. Data is moved from a disk to the persistent cache and, responsive to the data being moved to the persistent cache, an unmounting command is issued to unmount a first file system in the first partition from the persistent cache. A mounting command is then issued to mount a second file system in a second partition to the persistent cache, wherein the second partition may now use the data contained in the persistent cache.

Abstract: A method and system for detecting and managing an error detected in an iSCSI (Internet Small Computer System Interface) PDU (Protocol Data Unit) by using a RDMA (Remote Direct Memory Access) dedicated receive error queue for error recovery.

Abstract: A distributed computer system includes a source endnode including a source process which produces message data and a send work queue having work queue elements that describe the message data for sending. A destination endnode includes a destination process and a receive work queue having work queue elements that describe where to place incoming message data. A communication fabric provides communication between the source endnode and the destination endnode. An end-to-end context is provided at the source endnode and the destination endnode storing state information to ensure the reception and sequencing of message data sent from the source endnode to the destination endnode permitting reliable datagram service between the source endnode and the destination endnode.

Abstract: A distributed computer system includes a first subnet including a first group of endnodes, each endnode in the first group of endnodes having a unique destination location identification (DLID) within the first subnet. A second subnet in the distributed computer system includes a second group of endnodes, each endnode in the second group of endnodes having a unique DLID within the second subnet. A communication fabric is physically coupled to the first group of endnodes and the second group of endnodes. A partitioning mechanism associates a first partition key to every DLID in the first subnet for enabling communication between the first group of endnodes over the communication fabric. The partitioning mechanism associates a second partition key to every DLID in the second subnet for enabling communication between the second group of endnodes over the communication fabric.

Abstract: A distributed computer system includes links and routing devices coupled between the links and routing frames between the links. Each of the routing devices includes a congestion control mechanism for detecting congestion at the routing device and responding to detected congestion by gradually reducing an injection rate of frames routed from the routing device.