Abstract: Provided are a computer program product, system, and method for monitoring correctable errors on a bus interface to determine whether to redirect traffic to another bus interface. A processing unit sends Input/Output (I/O) requests from a host to a storage over a first bus interface to a first device adaptor, wherein the first device adaptor provides a first connection to the storage. A determination is made as to whether a number of correctable errors on the first bus interface exceeds an error threshold. The correctable errors are detected and corrected in the first bus interface by hardware of the first bus interface. In response to determining that the number of correctable errors on the first bus interface exceeds the error threshold, at least a portion of I/O requests are redirected to use a second bus interface to connect to a second device adaptor providing a second connection to the storage.

Abstract: Provided are a computer program product for managing bus interface errors in a storage system coupled to a host and storage. A determination is made as to whether a first number of correctable errors on a first bus interface, connecting a first processing unit to the storage, exceeds a second number of correctable errors on a second bus interface, connecting a second processing unit to the storage, by a difference threshold. The correctable errors in the first and second bus interfaces are detected and corrected in the first and second bus interfaces by first hardware and second hardware, respectively. In response to determining that the first number of correctable errors exceeds the second number of correctable errors by the difference threshold, at least a portion of Input/Output (I/O) requests are redirected to a second processing unit using the second bus interface to connect to the storage.

Abstract: Provided are a computer program product, system, and method for determining cores to assign to cache hostile tasks. A computer system has a plurality of cores. Each core is comprised of a plurality of processing units and at least one cache memory shared by the processing units on the core to cache data from a memory. A task is processed to determine one of the cores on which to dispatch the task. A determination is made as to whether the processed task is classified as cache hostile. A task is classified as cache hostile when the task accesses more than a threshold number of memory address ranges in the memory. The processed task is dispatched to at least one of the cores assigned to process cache hostile tasks.

Abstract: Provided are a computer program product, system, and method for selecting resources to make available in local queues for processors to use. Each processor of a plurality of processors maintains a queue of resources for the processor to use when needed for processor operations. One of processors is selected. The selected processor accesses at least one available resource and includes the accessed at least one resource in the queue of the selected processor.

Abstract: Provided are techniques for lock profiling tool to identify code bottlenecks. A lock spin duration for a lock is determined. It is determined that the lock spin duration is greater than a lock trace threshold. The lock spin duration is classified into a time duration bucket. It is determining whether the lock is found in a list of locks for the time duration bucket. In response to determining that the lock is found in the list of locks, a lock count for the lock is incremented by one. In response to determining that the lock is not found in the list of locks, an entry for the lock is added in the list of locks for the time duration bucket and the lock count for the lock is initialized to one. A total spin duration time for the lock is updated by the lock spin duration.

Abstract: A background process is configured to periodically scrub a boot storage of a storage controller to ensure operational correctness of the boot storage. One or more foreground processes store a system configuration data of the storage controller in the boot storage of the storage controller. The background process and the one or more foreground processes are executed to meet predetermined performance requirements for the background process and the one or more foreground processes.

Abstract: Provided are a computer program product, system, and method for determining cores to assign to cache hostile tasks. A computer system has a plurality of cores. Each core is comprised of a plurality of processing units and at least one cache memory shared by the processing units on the core to cache data from a memory. A task is processed to determine one of the cores on which to dispatch the task. A determination is made as to whether the processed task is classified as cache hostile. A task is classified as cache hostile when the task accesses more than a threshold number of memory address ranges in the memory. The processed task is dispatched to at least one of the cores assigned to process cache hostile tasks.

Abstract: A plurality of processing entities are maintained. A plurality of task control block (TCB) groups are generated, wherein each of the plurality of TCB groups are restricted to one or more different processing entities of the plurality of processing entities. A TCB is assigned to one of the plurality of TCB groups, at TCB creation time.

Abstract: A plurality of ordered lists of dispatch queues corresponding to a plurality of processing entities are maintained, wherein each dispatch queue includes one or more task control blocks or is empty. A determination is made as to whether a primary dispatch queue of a processing entity is empty in an ordered list of dispatch queues for the processing entity. In response to determining that the primary dispatch queue of the processing entity is empty, a task control block is selected for processing by the processing entity from another dispatch queue of the ordered list of dispatch queues for the processing entity, wherein the another dispatch queue from which the task control block is selected meets a threshold criteria for the processing entity.

Abstract: Provided are a computer program product, system, and method for invoking Input/Output (I/O) threads on processors to demote tracks from a cache. An Input/Output (I/O) thread, executed by a processor, processes I/O requests directed to tracks in the storage by accessing the tracks in the cache. After processing at least one I/O request, the I/O thread determines whether a number of free cache segments in the cache is below a free cache segment threshold. The I/O thread processes a demote ready list, indicating tracks eligible to demote from the cache, to demote tracks from the cache in response to determining that the number of free cache segments is below the free cache segment threshold. The I/O thread continues to process I/O requests directed to tracks from the storage stored in the cache after processing the demote ready list to demote tracks in the cache.

Abstract: A plurality of processing entities are maintained. An indication is made of a primary processing entities group for a task control block (TCB). An indication is made of a secondary processing entities group for the TCB. In response to determining that the secondary processing entities group has processing cycles available for processing additional TCBs, the TCB is moved from the primary processing entities group to the secondary processing entities group for processing.

Abstract: A plurality of cores are maintained in a processor complex. A core of the plurality of cores is reserved for execution of critical tasks, wherein it is preferable to prioritize execution of critical tasks over non-critical tasks. A scheduler receives a task for scheduling in the plurality of cores. In response to determining that the task is a critical task, the task is scheduled for execution in the reserved core.

Abstract: A plurality of processing entities of a processor complex is maintained, wherein each processing entity has a local cache and the processor complex has a shared cache and a shared memory. One of the plurality of processing entities is allocated for execution of a critical task. In response to the allocating of one of the plurality of processing entities for the execution of the critical task, other processing entities of the plurality of processing entities are folded. The critical task utilizes the local cache of the other processing entities that are folded, the shared memory, and the shared cache, in addition to the local cache of the processing entity allocated for the execution of the critical task.

Abstract: Provided are techniques for detecting a type of storage adapter connected to an Input/Output (I/O) bay and miscabling of a microbay housing the storage adapter. Under control of an Input/Ouput (I/O) bay, cable sidebands are driven high for a predetermined period of time. It is determined whether a cable sidebands response has been detected that indicates that the cable sidebands have been driven low. In response to determining that the cable sidebands response has been detected, it is determined that the I/O bay is connected to a first storage adapter supporting a first protocol for the cable sidebands. In response to determining that the cable sidebands response has not been detected, it is determined that the I/O bay is connected to a second storage adapter supporting a second protocol for the cable sidebands. Moreover, I/O bay and port numbers stored by the microbay are used to determine miscabling.

Abstract: A plurality of ordered lists of dispatch queues corresponding to a plurality of processing entities are maintained, wherein each dispatch queue includes one or more task control blocks or is empty. A determination is made as to whether a primary dispatch queue of a processing entity is empty in an ordered list of dispatch queues for the processing entity. In response to determining that the primary dispatch queue of the processing entity is empty, a task control block is selected for processing by the processing entity from another dispatch queue of the ordered list of dispatch queues for the processing entity, wherein the another dispatch queue from which the task control block is selected meets a threshold criteria for the processing entity.

Abstract: A plurality of processing entities are maintained in a processor complex. In response to determining that a task is a critical task, the critical task is dispatched to a scheduler, wherein it is preferable to prioritize execution of critical tasks over non-critical tasks. In response to dispatching the critical task to the scheduler, the scheduler determines which processing entity of the plurality of processing entities has a least amount of processing remaining to be performed for currently scheduled tasks. Tasks queued on the determined processing entity are moved to other processing entities, and the currently scheduled tasks on the determined processing entity are completed. In response to moving tasks queued on the determined processing entity to other processing entities and completing the currently scheduled tasks on the determined processing entity, the critical task is dispatched on the determined processing entity.

Abstract: A plurality of processing entities of a processor complex is maintained, wherein each processing entity has a local cache and the processor complex has a shared cache and a shared memory. One of the plurality of processing entities is allocated for execution of a critical task. In response to the allocating of one of the plurality of processing entities for the execution of the critical task, other processing entities of the plurality of processing entities are folded. The critical task utilizes the local cache of the other processing entities that are folded, the shared memory, and the shared cache, in addition to the local cache of the processing entity allocated for the execution of the critical task.

Abstract: A computational device maintains a spinlock for exclusive access of a resource by a process of a plurality of processes. In response to determining by the process that a turn for securing the spinlock has not arrived for the process, a sleep duration is determined for the process, prior to making a next attempt to secure the spinlock.

Abstract: An indication is made for each task category of a plurality of task categories, of a first attribute that indicates a data set to be collected, a second attribute that indicates a first predetermined amount of time within which a central processing unit (CPU) stops executing a task of the task category, and a third attribute that indicates a second predetermined amount of time within which the CPU that was executing the task of the task category collects the data set. In response to occurrence of an event, a plurality of CPUs are stopped to collect a plurality of data sets, based on first attributes, second attributes, and third attributes of task categories corresponding to tasks executing on the plurality of CPUs.

Abstract: A plurality of tasks are executed on a plurality of central processing units (CPUs) of a computational device. In response to an occurrence of an event in the computational device, one or more CPUs that are executing tasks associated with an event category to which the event belongs are stopped within a first predetermined amount of time. In response to stopping the one or more CPUs, a data set indicative of a state of the computational device is collected, for at most a second predetermined amount of time.