A thread holding a lock notifies a sleeping thread that is waiting on the lock that the lock holding thread is about to release the lock. In response to the notification, the waiting thread is woken up. While the waiting thread is woken up, the lock holding thread completes other operations prior to actually releasing the lock and then releases the lock. The notification to the waiting thread hides latency associated with waking up the waiting thread by allowing operations that wake up the waiting thread to occur while the lock holding thread is performing the other operations prior to releasing the thread.

A distributed system is provided that includes member nodes and a leader node. Each member node stores a database and updates the database by performing common ones of a plurality of transactions. The leader node generates a batch, to be executed by each member node, which includes two or more transactions lacking an access conflict from among the plurality of transactions. The leader node includes: a section that generates an access set as a set of database entries to be accessed by each transaction to be executed; a section that generates the batch, based on the access set of each transaction to be executed; and a leader-side section that performs a consensus process for the batch among the leader and member nodes. Each member node includes the database; a member-side section that performs a consensus process for the batch; and a section that performs parallel execution of batch transactions.

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.

Systems, apparatuses, and methods for performing efficient memory accesses for a computing system are disclosed. In various embodiments, a computing system includes a computing resource and a memory controller coupled to a memory device. The computing resource selectively generates a hint that includes a target address of a memory request generated by the processor. The hint is sent outside the primary communication fabric to the memory controller. The hint conditionally triggers a data access in the memory device. When no page in a bank targeted by the hint is open, the memory controller processes the hint by opening a target page of the hint without retrieving data. The memory controller drops the hint if there are other pending requests that target the same page or the target page is already open.

Apparatus and methods are disclosed for controlling execution of register access instructions in a block-based processor architecture using a hardware structure that indicates a relative ordering of register access instruction in an instruction block. In one example of the disclosed technology, a method of operating a processor includes selecting a register access instruction of the plurality of instructions to execute based at least in part on dependencies encoded within a previous block of instructions and on stored data indicating which of the register write instructions have executed for the previous block, and executing the selected instruction. In some examples, one or more of a write mask, a read mask, a register write vector register, or a counter are used to determine register read/write dependences. Based on the encoded dependencies and the masked write vector, the next instruction block can issue when its register dependencies are available.

According to an aspect, there is provided a computer-implemented method of operating a first node. The first node has an algorithm for evaluating input data from another node, with the input data having a plurality of different attributes. The method comprises receiving, from a second node, a proposal for the evaluation of a first set of input data by the algorithm; estimating the performance of the algorithm in evaluating the first set of input data based on the proposal; and outputting, to the second node, an indication of the estimated performance of the algorithm. A corresponding first node is also provided.

A transactional memory system uses a volatile memory as primary storage for transactions. Data is selectively stored in a non-volatile memory to impart durability to the transactional memory system to allow the transactional memory system to be restored to a consistent state in the event of data loss to the volatile memory.

An apparatus for processing memory requests from a functional unit in a computing system is disclosed. The apparatus may include an interface that may be configured to receive a request from the functional. Circuitry may be configured initiate a speculative read access command to a memory in response to a determination that the received request is a request for data from the memory. The circuitry may be further configured to determine, in parallel with the speculative read access, if the speculative read will result in an ordering or coherence violation.

A disclosed example apparatus includes memory; and processor circuitry to: identify a lock-protected section of instructions in the memory; replace lock/unlock instructions with transactional lock acquire and transactional lock release instructions to form a transactional process; and execute the transactional process in a speculative execution.

A method may include determining a threshold quantity of attempts to optimistically perform a first transaction operating data stored in a database. The threshold quantity of attempts may be determined based on an expected workload of the first transaction and/or a workload at the database. The first transaction may be performed optimistically including by tracking cache lines accessed by the first transaction and detecting, based on a second transaction writing to a cache line accessed by the first transaction, a conflict between the first transaction and the second transaction. If the first transaction is not successful performed after the threshold quantity of attempts to optimistically perform the first transaction, the first transaction may be performed in a fallback mode including by acquiring a lock to prevent the second transaction from accessing a same data in the database as the first transaction. Related systems and articles of manufacture are also provided.