Abstract: A system for parallel processing tasks by allocating the use of exclusive locks to process critical sections of a task. The system includes storing update information that is updated in response to acquisition and release of an exclusive lock. When processing a task which includes a critical section containing code affecting execution of the other task, an exclusive execution unit acquires an exclusive lock prior to processing the critical section. When the section has been processed successfully, the lock is released and update information updated. Meanwhile a second task, whose critical section does not contain code affecting execution of the other task may run in parallel, without acquiring an exclusive lock, via a nonexclusive execution unit. The nonexclusive execution unit determines that the second critical section has successfully completed if the update information has not changed during processing of the second critical section.

Abstract: A transactional memory system dynamically predicts the resource requirements of hardware transactions. A processor of the transactional memory system predicts resource requirements of a first hardware transaction to be executed based on any one of a resource hint and a previous execution of a prior hardware transaction. The processor allocates resources for the first hardware transaction based on the predicted resource requirements. The processor executes the first hardware transaction. The processor saves resource usage information of the first hardware transaction for future prediction.

Abstract: A transaction within a computer program or computer application comprises program instructions performing multiple store operations that appear to run and complete as a single, atomic operation. The program instructions forming a current transaction comprise a transaction begin indicator, a plurality of instructions (e.g., store operations), and a transaction end indicator. A near-end of transaction indicator is triggered based on a speculative look ahead operation such that an interfering transaction requiring a halt operation may be delayed to allow the current transaction to end. A halt operation, also referred to as an abort operation, as used herein refers to an operation responsive to a condition where two transactions have been detected to interfere where at least one transaction must be aborted and the state of the processor is reset to the state at the beginning of the aborted transaction by performing a rollback.

Abstract: Embodiments relate to non-default instruction handling within a transaction. An aspect includes entering a transaction, the transaction comprising a first plurality of instructions and a second plurality of instructions, wherein a default manner of handling of instructions in the transaction is one of atomic and non-atomic. Another aspect includes encountering a non-default specification instruction in the transaction, wherein the non-default specification instruction comprises a single instruction that specifies the second plurality of instructions of the transaction for handling in a non-default manner comprising one of atomic and non-atomic, wherein the non-default manner is different from the default manner. Another aspect includes handling the first plurality of instructions in the default manner. Yet another aspect includes handling the second plurality of instructions in the non-default manner.

Abstract: In a multi-processor transaction execution environment a transaction is executed a plurality of times. Based on the executions, a duration is predicted for executing the transaction. Based on the predicted duration, a threshold is determined. Pending aborts of the transaction due to memory conflicts are suppressed based on the transaction exceeding the determined threshold.

Abstract: In a multi-processor transaction execution environment, a transaction executes a hint instruction indicating proximity to completion of the transaction. Pending aborts of the transaction due to memory conflicts are suppressed based on the proximity of the transaction to completion.

Abstract: In some embodiments, an apparatus includes a processor that is configured to execute computer usable program code to perform operations. The operations include executing an atomic transaction in a system having a transactional memory. The operations include receiving a signal interrupt during executing of the atomic transaction. The operations include storing a state of the signal interrupt to enable subsequent execution of the signal interrupt. The operations include returning to executing the atomic transaction until the atomic transaction is at least one of completed and aborted. The operations include after executing the atomic transaction is at least one of completed and aborted, determining whether the signal interrupt is received during executing of the atomic transaction. The operations include after determining that the signal interrupt is received during executing of the atomic transaction, retrieving the state of the signal interrupt.

Abstract: In some embodiments, a method includes executing an atomic transaction in a system having a transactional memory. The method includes receiving a signal interrupt during executing of the atomic transaction. The method includes storing a state of the signal interrupt to enable subsequent execution of the signal interrupt. The method includes returning to executing the atomic transaction until the atomic transaction is at least one of completed and aborted. The method includes after executing the atomic transaction is at least one of completed and aborted, determining whether the signal interrupt is received during executing of the atomic transaction. The method includes after determining that the signal interrupt is received during executing of the atomic transaction, retrieving the state of the signal interrupt. The method includes executing an interrupt handler for processing the signal interrupt and returning from executing of the atomic transaction.

Abstract: Embodiments relate to address probing for a transaction. An aspect includes determining, before starting execution of a transaction, a plurality of addresses that will be used by the transaction during execution. Another aspect includes probing each address of the plurality of addresses to determine whether any of the plurality of addresses has an address conflict. Yet another aspect includes, based on determining that none of the plurality of addresses has an address conflict, starting execution of the transaction.

Abstract: There are provided methods for single-owner multi-consumer work queues for repeatable tasks. A method includes permitting a single owner thread of a single owner, multi-consumer, work queue to access the work queue using atomic instructions limited to only a single access and using non-atomic operations. The method further includes restricting the single owner thread from accessing the work queue using atomic instructions involving more than one access. The method also includes synchronizing amongst other threads with respect to their respective accesses to the work queue.

Abstract: Embodiments relate to address probing for a transaction. An aspect includes determining, before starting execution of a transaction, a plurality of addresses that will be used by the transaction during execution. Another aspect includes probing each address of the plurality of addresses to determine whether any of the plurality of addresses has an address conflict. Yet another aspect includes, based on determining that none of the plurality of addresses has an address conflict, starting execution of the transaction.

Abstract: In an approach for resolving terminated transactions in a transactional memory environment, a processor initiates a hardware transaction in a computing environment, wherein the hardware transaction accesses a memory location, and wherein the hardware transaction includes a transaction begin indicator and a transaction end indicator. A processor detects a conflicting access of the memory location while executing the hardware transaction. A processor aborts the hardware transaction based on the conflicting access of the memory location. Hardware determines that the conflicting access of the memory location is a transient condition. A processor reinitiates the hardware transaction.

Abstract: In an approach for resolving terminated transactions in a transactional memory environment, a processor initiates a hardware transaction in a computing environment, wherein the hardware transaction accesses a memory location, and wherein the hardware transaction includes a transaction begin indicator and a transaction end indicator. A processor detects a conflicting access of the memory location while executing the hardware transaction. A processor aborts the hardware transaction based on the conflicting access of the memory location. Hardware determines that the conflicting access of the memory location is a transient condition. A processor reinitiates the hardware transaction.

Abstract: In a transactional memory environment, a computer-implemented method includes receiving one or more memory locations and broadcasting, by a first processor to one or more additional processors, a cross-interrogate. The cross-interrogate includes the one or more memory locations. The computer-implemented method further includes, by the one or more additional processors, receiving the cross-interrogate, not aborting any current transaction based on the cross-interrogate, and generating an indication. The indication comprises whether the one or more memory locations is in use for the current transaction by that of the one or more additional processors. The computer-implemented method further includes sending the indication from each of the one or more additional processors to the first processor and, by the first processor, combining each indication from the one or more additional processors to yield a status code and returning the status code.

Abstract: A transactional memory system determines whether to pass control of a transaction to an about-to-run-out-of-resource handler. A processor of the transactional memory system determines information about an about-to-run-out-of-resource handler for transaction execution of a code region of a hardware transaction. The processor dynamically monitors an amount of available resource for the currently running code region of the hardware transaction. The processor detects that the amount of available resource for transactional execution of the hardware transaction is below a predetermined threshold level. The processor, based on the detecting, saves speculative state information of the hardware transaction, and executes the about-to-run-out-of-resource handler, the about-to-run-out-of-resource handler determining whether the hardware transaction is to be aborted or salvaged.

Abstract: Cache lines in a multi-processor computing environment are configurable with a coherency mode. Cache lines in full-line coherency mode are operated or managed with full-line granularity. Cache lines in sub-line coherency mode are operated or managed as sub-cache line portions of a full cache line. Each cache is associated with a directory having a number of directory entries and with a side table having a smaller number of entries. The directory entry for a cache line associates the cache line with a tag and a set of full-line descriptive bits. Creating a side table entry for the cache line places the cache line in sub-line coherency mode. The side table entry associates each of the sub-cache line portions of the cache line with a set of sub-line descriptive bits. Removing the side table entry may return the cache line to full-line coherency mode.

Abstract: Using hardware transactional memory (HTM) for queue operations includes invoking a first operation for a concurrent linked queue of an interpretive program using a Just-In-Time (JIT) compiler of a virtual machine, wherein the first operation does not use HTM, determining whether a data processing system executing the virtual machine supports HTM, and responsive to determining that the data processing system does support HTM, detecting, using a processor and within the first operation, a call to a second operation that is that is configured, in byte code, to return an indication of a failed hardware transaction. Responsive to detecting the second operation, a machine code implementation of the first operation that includes a machine code implementation of the second operation is generated. The machine code implementation of the second operation is an implementation of the first operation that does use HTM.

Abstract: Transactional execution of a transaction beginning instruction initiates prefetching, by a CPU, of discontiguous storage locations specified by a list. The list includes entries specifying addresses and may also include corresponding metadata. The list may be specified by levels of indirection. Fetching of corresponding discontiguous cache lines is initiated while in TX mode. Additional instructions in the transaction may be executed and use the prefetched cache lines.

Abstract: Techniques relate to handling outstanding cache miss prefetches. A processor pipeline recognizes that a prefetch canceling instruction is being executed. In response to recognizing that the prefetch canceling instruction is being executed, all outstanding prefetches are evaluated according to a criterion as set forth by the prefetch canceling instruction in order to select qualified prefetches. In response to evaluating, a cache subsystem is communicated with to cause canceling of the qualified prefetches that fit the criterion. In response to successful canceling of the qualified prefetches, a local cache is prevented from being updated from the qualified prefetches.

Abstract: In at least some embodiments, a processor core executes a code segment including a memory transaction and a non-transactional memory access instructions preceding the memory transaction in program order. The memory transaction includes at least an initiating instruction, a transactional memory access instruction, and a terminating instruction. The initiating instruction has an implicit barrier that imparts the effect of ordering execution of the transactional memory access instruction within the memory transaction with respect to the non-transactional memory access instructions preceding the memory transaction in program order. Executing the code segment includes executing the transactional memory access instruction within the memory transaction concurrently with at least one of the non-transactional memory access instructions preceding the memory transaction in program order and enforcing the barrier implicit in the initiating instruction following execution of the initiating instruction.