摘要:
A computer system includes a processor configured for detecting initial command response times of a plurality of paths for transmitting signals from the processor to one or more external devices via a plurality of channels, assigning weighted values to the plurality of paths based on the detected initial command response times, and modifying a frequency at which respective paths among the plurality of paths are selected for transmitting the signals based on the weighted values assigned to the respective paths.
摘要:
Processing of out-of-order data transfers is facilitated in computing environments that enable data to be directly transferred between a host bus adapter (or other adapter) and a system without first staging the data in hardware disposed between the host bus adapter and the system. An address to be used in the data transfer is determined, in real-time, by efficiently locating an entry in an address data structure that includes the address to be used in the data transfer.
摘要:
A method includes configuring a processing circuit to perform: receiving a control word for an I/O operation, forwarding a transport command control block (TCCB) from the channel subsystem to a control unit, gathering data associated with the I/O operation, and transmitting the gathered data to the control unit in the I/O processing system. Gathering the data includes accessing entries of a list of storage addresses that collectively specifying the data. Based on an entry of the list comprising a not-set first flag and a corresponding first storage address, gathering data from a corresponding storage location, and based on an entry of the list comprising a set first flag and a corresponding second storage address, obtaining a next entry of the list from a second storage location.
摘要:
A computer program product for performing input/output (I/O) processing is configured for performing a method including: obtaining information relating to an I/O operation at a channel subsystem; generating and storing in local channel memory at least one address control word (ACW) specifying one or more host memory locations for data transfer and including a field for storing header information; generating an address control structure specifying a location in the local channel memory of a corresponding ACW; receiving a data transfer request from a network interface that includes the address control structure; responsive to an input data request, routing the data to at least one host memory location specified by the corresponding ACW and storing header information in the corresponding ACW; and responsive to an output data request, routing the data from a host memory location specified by the ACW to the network interface and appending header information to the data.
摘要:
On embodiment includes a computer program product for performing a method including: obtaining information relating to an I/O operation at a channel subsystem in a host computer system; generating addressing information and forwarding the addressing information from at least one channel to a network interface between the channel subsystem and at least one I/O device, the addressing information specifying a location in a local channel memory; forwarding an I/O command message to the at least one I/O device via the network interface; responsive to the I/O command message, receiving a data transfer request from the network interface that includes the addressing information; responsive to receiving the data transfer request, accessing one of a plurality of address control words (ACWs), each ACW specifying an address of a location in a host computer memory; and routing the data transfer request to the host memory location specified in the ACW.
摘要:
A computer program product is provided for performing input/output (I/O) processing. The computer program product is configured to perform: generating and storing in local channel memory at least one address control word (ACW) specifying one or more host memory locations for data transfer and including a data discard field; generating an address control structure specifying a local channel memory location of a corresponding ACW; receiving one or more data transfer requests from a network interface that each corresponding address control structure information; accessing an ACW and routing the data transfer request to a host memory location specified in the ACW; and responsive to encountering an error during at least one of the accessing and the routing, discarding the one or more data transfer requests and setting the data discard field to a value configured to instruct a channel to discard any subsequent data transfer requests associated with the ACW.
摘要:
A computer program product, an apparatus, and a method for processing communications between a control unit and a channel subsystem in an input/output processing system are provided. The computer program product includes a tangible storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method. The method includes: sending a command from the channel subsystem to the control unit to initiate an input/output operation; setting a time period for completion of the operation; and responsive to the operation not completing within the time period, sending a message to determine whether the control unit has an exchange open for the command.
摘要:
A computer program product, apparatus, and method for handling early termination of an I/O operation at a channel subsystem in an I/O processing system are provided. The computer program product includes a tangible storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method. The method includes receiving a request to terminate an I/O operation, and transmitting an abort command to a control unit in communication with the channel subsystem in response to receiving the request to terminate the I/O operation. The method also includes transmitting a purge path command to purge a path associated with the I/O operation, where the purge path command includes an error code identifying the request to terminate the I/O operation.
摘要:
An encryption method encrypts a clear text twice using a first encryption engine to produce a first cipher text and a second encryption engine to produce a second cipher text. The method compares the first cipher text with the second cipher text, or compares a checksum of the first cipher text with a checksum of the second cipher text. If the comparison succeeds, the method transmits the data. In some embodiments, the method uses a first instance of an encryption key to produce the first cipher text and a second instance of the encryption key to produce the second cipher text.
摘要:
An computer program product, apparatus, and method for facilitating input/output (I/O) processing for an I/O operation at a host computer system configured for communication with a control unit. The computer program product includes a tangible storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method. The method includes the host computer system obtaining a transport command word (TCW) for an I/O operation. The TCW specifies a location of one or more I/O commands and a flag. The flag is set to indicate that the location is an indirect address. The host computer system extracts the location of the one or more I/O commands and the flag from the TCW. The host computer system gathers the one or more I/O commands responsive to the location specified by the TCW and the flag, and then forwards the one or more I/O commands to the control unit for execution.