Mechanism of supporting sub-communicator collectives with O(64) counters as opposed to one counter for each sub-communicator
Kumar, Sameer; Mamidala, Amith R.; Ratterman, Joseph D.; Blocksome, Michael; Miller, Douglas · OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information) · 2023
A system and method for enhancing barrier collective synchronization on a computer system comprises a computer system including a data storage device. The computer system includes a program stored in the data storage device and steps of the program being executed by a processor. The system includes providing a plurality of communicators for storing state information for a barrier algorithm. Each communicator designates a master core in a multi-processor environment of the computer system. The system allocates or designates one counter for each of a plurality of threads. The system configures a table with a number of entries equal to the maximum number of threads. The system sets a table entry with an ID associated with a communicator when a process thread initiates a collective. The system determines an allocated or designated counter by searching entries in the table.