Abstract: In example implementations, a method include receiving a request for a lock in a Mellor-Crummey Scott (MCS) lock protocol from a guest user that is context free (e.g., a process that does not bring a queue node). The lock determines that it contains a null value. The lock is granted to the guest user. A pi value is received from the guest user to store in the lock. The pi value notifies subsequent users that the guest user has the lock.

Abstract: Systems and methods for concurrent reading and writing in shared, persistent byte-addressable non-volatile memory is described herein. One method includes in response to initiating a write sequence to one or more memory elements, checking an identifier memory element to determine whether a write sequence is in progress. In addition, the method includes updating an ingress counter. The method also includes adding process identification associated with a writer node to the identifier memory element. Next, a write operation is performed. After the write operation, an egress counter is incremented and the identifier memory element is reset to an expected value.

Abstract: In example implementations, a method include receiving a request for a lock in a Mellor-Crummey Scott (MCS) lock protocol from a guest user that is context free (e.g., a process that does not bring a queue node). The lock determines that it contains a null value. The lock is granted to the guest user. A pi value is received from the guest user to store in the lock. The pi value notifies subsequent users that the guest user has the lock.

Abstract: Systems and methods for concurrent reading and writing in shared, persistent byte-addressable non-volatile memory is described herein. One method includes in response to initiating a write sequence to one or more memory elements, checking an identifier memory element to determine whether a write sequence is in progress. In addition, the method includes updating an ingress counter. The method also includes adding process identification associated with a writer node to the identifier memory element. Next, a write operation is performed. After the write operation, an egress counter is incremented and the identifier memory element is reset to an expected value.

Abstract: Examples disclosed herein relate to path-synchronous performance monitoring of an interconnection network based on source code attribution. A processing node in the interconnection network has a profiler module to select a network transaction to be monitored, determine a source code attribution associated with the network transaction to be monitored, and issue a network command to execute the network transaction to be monitored. A logger module creates, in a buffer, a node temporal log associated with the network transaction and the network command. A drainer module periodically captures the node temporal log. The processing node has a network interface controller to receive the network command and mark a packet generated for the network command to be temporally tracked and attributed back to the source code attribution at each hop of the interconnection network traversed by the marked packet.

Abstract: In example implementations, a method include receiving a request for a lock in a Mellor-Crummey Scott (MCS) lock protocol from a guest user that is context free (e.g., a process that does not bring a queue node). The lock determines that it contains a null value. The lock is granted to the guest user. A pi value is received from the guest user to store in the lock. The pi value notifies subsequent users that the guest user has the lock.

Abstract: In one example in accordance with the present disclosure, a method may include performing a transactional operation such that if one step of the transactional operation is performed, each other step of the transactional operation is performed. The transactional operation may include making a first copy, stored in a first persistent memory, of a next ticket number stored in a second persistent memory and updating the next ticket number in the second persistent memory. The method may also include determining when to serve a first thread based on the first copy of the next ticket number.

Abstract: A memory region has logical partitions. Each logical partition has data packages. The memory region discontiguously stores the data packages of the logical partitions. A writing process can discontiguously generate the data packages of the logical partitions. A reading process can contiguously retrieve the data packages of a selected logical partition.

Abstract: Examples disclosed herein relate to a hierarchical file system. The hierarchical file system may include a first and a second virtual file referencing a stored data set. The first virtual file may include a set of first keys of a first level of specificity, with each key of the set of first keys including a record locator. The second virtual file may include a set of second keys referencing the data set and of a second level of specificity. The set of first keys within the first virtual file is searched in response to a query for data of the data set. A key from the set of second keys is accessed via the record locator from a key from the set of first keys where the data of the data set was not identified by the set of first keys.

Abstract: Examples disclosed herein relate to path-synchronous performance monitoring of an interconnection network based on source code attribution. A processing node in the interconnection network has a profiler module to select a network transaction to be monitored, determine a source code attribution associated with the network transaction to be monitored, and issue a network command to execute the network transaction to be monitored. A logger module creates, in a buffer, a node temporal log associated with the network transaction and the network command. A drainer module periodically captures the node temporal log. The processing node has a network interface controller to receive the network command and mark a packet generated for the network command to be temporally tracked and attributed back to the source code attribution at each hop of the interconnection network traversed by the marked packet.

Abstract: In example implementations, a method include receiving a request for a lock in a Mellor-Crummey Scott (MCS) lock protocol from a guest user that is context free (e.g., a process that does not bring a queue node). The lock determines that it contains a null value. The lock is granted to the guest user. A pi value is received from the guest user to store in the lock. The pi value notifies subsequent users that the guest user has the lock.

Abstract: In one example in accordance with the present disclosure, a method may include performing a transactional operation such that if one step of the transactional operation is performed, each other step of the transactional operation is performed. The transactional operation may include making a first copy, stored in a first persistent memory, of a next ticket number stored in a second persistent memory and updating the next ticket number in the second persistent memory. The method may also include determining when to serve a first thread based on the first copy of the next ticket number.