Abstract: Exemplary method, system, and computer program product embodiments for efficient track destage in secondary storage in a more effective manner, are provided. In one embodiment, by way of example only, for temporal bits employed with sequential bits for controlling the timing for destaging the track in a primary storage, the temporal bits and sequential bits are transferred from the primary storage to the secondary storage. The temporal bits are allowed to age on the secondary storage. Additional system and computer program product embodiments are disclosed and provide related advantages.

Abstract: Various embodiments for movement of partial data segments within a computing storage environment having lower and higher levels of cache by a processor are provided. In one such embodiment, a whole data segment containing one of the partial data segments is promoted to both the lower and higher levels of cache. Requested data of the whole data segment is split and positioned at a Most Recently Used (MRU) portion of a demotion queue of the higher level of cache. Unrequested data of the whole data segment is split and positioned at a Least Recently Used (LRU) portion of the demotion queue of the higher level of cache. The unrequested data is pinned in place until a write of the whole data segment to the lower level of cache completes. Additional system and computer program product embodiments are disclosed and provide related advantages.

Abstract: The population of data to be admitted into secondary data storage cache of a data storage system is controlled by determining heat metrics of data of the data storage system. If candidate data is submitted for admission into the secondary cache, data is selected to tentatively be evicted from the secondary cache; candidate data provided to the secondary data storage cache is rejected if its heat metric is less than the heat metric of the tentatively evicted data; and candidate data submitted for admission to the secondary data storage cache is admitted if its heat metric is equal to or greater than the heat metric of the tentatively evicted data.

Abstract: Systems and methods for scanning ports for work are provided. One system includes one or more processors, multiple ports, a first tracking mechanism, and a second tracking mechanism for tracking high priority work and low priority work, respectively. The processor(s) is/are configured to perform the below method. One method includes scanning the ports, finding high priority work on a port, and accepting or declining the high priority work. The method further includes changing a designation of the processor to TRUE in the first tracking mechanism if the processor accepts the high priority work such that the processor is allowed to perform the high priority work on the port. Also provided are computer storage mediums including computer code for performing the above method.

Abstract: Methods are provided in which a standby server, a first main server, and a second main server to control shared input/output (I/O) adapters in a storage system are provided. The standby server is in communication with the first main server and the second main server, and the storage system is configured to operate as a dual node active system. The methods include activating the standby server in response to receiving a communication from the first main server of a fail mode of the second main server. Systems and physical computer storage media are also provided.

Abstract: A method for efficiently using a large secondary cache is disclosed herein. In certain embodiments, such a method may include accumulating, in a secondary cache, a plurality of data tracks. These data tracks may include modified data and/or unmodified data. The method may determine if a subset of the plurality of data tracks makes up a full stride. In the event the subset makes up a full stride, the method may destage the subset from the secondary cache. By destaging full strides, the method reduces the number of disk operations that are required to destage data from the secondary cache. A corresponding computer program product and apparatus are also disclosed herein.

Abstract: Systems and methods for scanning ports for work are provided. One system includes one or more processors, multiple ports, a first tracking mechanism, and a second tracking mechanism for tracking high priority work and low priority work, respectively. The processor(s) is/are configured to perform the below method. One method includes scanning the ports, finding high priority work on a port, and accepting or declining the high priority work. The method further includes changing a designation of the processor to TRUE in the first tracking mechanism if the processor accepts the high priority work such that the processor is allowed to perform the high priority work on the port. Also provided are computer storage mediums including computer code for performing the above method.

Abstract: Provided are a computer program product, system, and method for locking a cache line for a burst write operations on a bus. A cache line is allocated in a cache for a target address. A lock is set for the cache line, wherein setting the lock prevents the data in the cache line from being cast out. Data is written to the cache line. All the data in the cache line is flushed to the target address over a bus in response to completing writing to the cache line.

Abstract: A sleep function capable of putting a fixed high-priority thread to sleep within a time-window is disclosed. After a sleep request has been made by a fixed high-priority thread via the sleep function, a determination is made whether or not the fixed high-priority thread is awoken before a requested sleep duration under the sleep request. If the fixed high-priority thread is awoken before the requested sleep duration, the number of tasks for the fixed high-priority thread to perform is increased in order to delay the start sleep time of the fixed high-priority thread from a point within a first time-window in which the sleep request was made to an end boundary of the first time-window.

Abstract: An apparatus, system, and method are disclosed for reliably controlling an I/O enclosure. A bus module receives two or more Peripheral Component Interconnect Express (“PCIe”) sideband signals via one or more PCIe cables. The one or more PCIe cables are connected between one or more hosts and an I/O enclosure. A decode module determines an asserted value of each of the two or more PCIe sideband signals and combines the PCIe sideband signal asserted values to form a bus value. Each PCIe sideband signal represents a bit in the bus value, and the bus value specifies a command for controlling the I/O enclosure. An execution module executes the specified command to perform control actions on the I/O enclosure.

Abstract: A method for efficiently using a large secondary cache is disclosed herein. In certain embodiments, such a method may include accumulating, in a secondary cache, a plurality of data tracks. These data tracks may include modified data and/or unmodified data. The method may determine if a subset of the plurality of data tracks makes up a full stride. In the event the subset makes up a full stride, the method may destage the subset from the secondary cache. By destaging full strides, the method reduces the number of disk operations that are required to destage data from the secondary cache. A corresponding computer program product and apparatus are also disclosed and claimed herein.

Abstract: An apparatus, system, and method are disclosed for adapter card failover. A switch module connects a first processor complex to an adapter card through a first port as an owner processor complex. The owner processor complex manages the adapter card except for a second port and receives error messages from the adapter card. The switch module further connects a second processor complex to the adapter card through the second port as a non-owner processor complex. The non-owner processor complex manages the second port. A detection module detects a failure of the first processor complex. A setup module modifies the switch module to logically connect the second processor complex to the adapter card as the owner processor complex and to logically disconnect the first processor complex from the adapter card in response to detecting the failure.

Abstract: An apparatus, system, and method are disclosed for reliably controlling an I/O enclosure. A bus module receives two or more Peripheral Component Interconnect Express (“PCIe”) sideband signals via one or more PCIe cables. The one or more PCIe cables are connected between one or more hosts and an I/O enclosure. A decode module determines an asserted value of each of the two or more PCIe sideband signals and combines the PCIe sideband signal asserted values to form a bus value. Each PCIe sideband signal represents a bit in the bus value, and the bus value specifies a command for controlling the I/O enclosure. An execution module executes the specified command to perform control actions on the I/O enclosure.

Abstract: A method to enable a user mode process to operate in a privileged execution mode is disclosed. Applicants' method provides an operating system comprising a privileged execution mode and a non-privileged execution mode, and a plurality of user mode strings operating in the non-privileged execution mode. The computing device receives a request from a first user mode string to operate in the privileged execution mode to perform one or more designated tasks. Applicants' method authorizes the first user mode string to operate in the privileged execution mode, and the first user mode string performs those one or more designated tasks using the privileged execution mode. Applicants' method continues to permit the first user mode string to operate in the privileged execution mode after completion of the one or more designated tasks.

Abstract: One embodiment of an adapter card in accordance with the invention includes a circuit board connectable to a motherboard of a computer system. A logic chip is connected to the circuit board to provide functionality to the adapter card. One or more programmable devices are connected to the circuit board and store data read by the logic chip upon initialization. This data may include first character data to program the logic chip to have a first character and second character data to program the logic chip to have a second character. A switching mechanism is provided to switch between the first and second character data in response to an external input, thereby causing the logic chip to read one of the first and second character data.

Abstract: Updating code of a single processor in a multi-processor system includes halting transactions processed by a first processor in the system and processing of transactions by a second processor in the system are maintained. The first processor then receives new code and an operating system running on the first processor is terminated whereby all processes and threads being executed by the first processor are terminated. Execution of a self-reset of the first processor is commenced and interrupts associated with the first processor are disabled. Only those system resources exclusively associated with the first processor are reset, and memory transactions associated with the first processor are disabled. An image of the new code is copied into memory associated with the first processor, registers associated with the first processor are reset and the new code is booted by the first processor.

Abstract: One embodiment of an adapter card in accordance with the invention includes a circuit board connectable to a motherboard of a computer system. A logic chip is connected to the circuit board to provide functionality to the adapter card. One or more programmable devices are connected to the circuit board and store data read by the logic chip upon initialization. This data may include first character data to program the logic chip to have a first character and second character data to program the logic chip to have a second character. A switching mechanism is provided to switch between the first and second character data in response to an external input, thereby causing the logic chip to read one of the first and second character data.

Abstract: An apparatus, system, and method are disclosed for adapter card failover. A switch module connects a first processor complex to an adapter card through a first port as an owner processor complex. The owner processor complex manages the adapter card except for a second port and receives error messages from the adapter card. The switch module further connects a second processor complex to the adapter card through the second port as a non-owner processor complex. The non-owner processor complex manages the second port. A detection module detects a failure of the first processor complex. A setup module modifies the switch module to logically connect the second processor complex to the adapter card as the owner processor complex and to logically disconnect the first processor complex from the adapter card in response to detecting the failure.

Abstract: An apparatus, system, and method are disclosed for adapter card failover. A switch module connects a first processor complex to an adapter card through a first port as an owner processor complex. The owner processor complex manages the adapter card except for a second port and receives error messages from the adapter card. The switch module further connects a second processor complex to the adapter card through the second port as a non-owner processor complex. The non-owner processor complex manages the second port. A detection module detects a failure of the first processor complex. A setup module modifies the switch module to logically connect the second processor complex to the adapter card as the owner processor complex and to logically disconnect the first processor complex from the adapter card in response to detecting the failure.

Abstract: A sleep function capable of putting a fixed high-priority thread to sleep within a time-window is disclosed. After a sleep request has been made by a fixed high-priority thread via the sleep function, a determination is made whether or not the fixed high-priority thread is awoken before a requested sleep duration under the sleep request. If the fixed high-priority thread is awoken before the requested sleep duration, the number of tasks for the fixed high-priority thread to perform is increased in order to delay the start sleep time of the fixed high-priority thread from a point within a first time-window in which the sleep request was made to an end boundary of the first time-window.