2026-04-13T03:38:03Zhttps://recercat.cat/oai/request
oai:recercat.cat:2117/4456152026-03-09T04:57:14Zcom_2072_1033col_2072_452950
RECERCAT author Peñacoba Veigas, Raúl author Álvarez Robert, David author Arcila Larrea, Vincent A. author Navarro Muñoz, Antoni author Beltran Querol, Vicenç 2025 The OpenMP 6.0 standard introduces the free-agents feature, which enables a more dynamic execution model to improve application malleability and resource utilization. With free-agents, idle threads within a parallel region can be dynamically reassigned to execute tasks from other parallel regions. However, integrating this feature into complex runtimes, such as LLVM’s libomp, presents significant challenges due to its departure from traditional threading models. This paper presents our implementation of free-agents within the LLVM libomp runtime, which significantly reduces the complexity of implementing free-agents by leveraging the nOS-V threading and tasking library. Moreover, nOS-V also provides support for Task-Aware (TA) libraries and the co-execution of applications. Our enhanced libomp runtime, ported on top of nOS-V (libompv), also leverages these features. With libompv, OpenMP tasks and threads from any parallel region can safely call TA libraries, and independent processes can be efficiently co-executed to improve resource utilization or mitigate load imbalance issues. Experimental results show that libompv with free-agents delivers better performance than the original libomp for load-imbalanced or co-executed applications, while introducing no additional overhead for workloads that do not benefit from these new features.This work was partially supported by the Generalitat de Catalunya (contract 2021-SGR-01007) and the Spanish Government through the Severo Ochoa Program (CEX2021-001148-S/MCIN/AEI/10.13039/501100011033), and it is part of the ST4HPC (PID2023-147979NB-C21) research project, funded by MICIU /AEI/10.13039 /501100011033 and by FEDER, UE. This paper is also cofinanced by the Barcelona Zettaescale Laboratory, promoted by the Ministry for Digital Transformation and the Civil Service, within the framework of the Recovery, Transformation and Resilience Plan - Funded by the European Union - NextGenerationEU.Peer ReviewedPostprint (author's final draft) Restricted access - publisher's policy Àrees temàtiques de la UPC::Informàtica::Arquitectura de computadors OpenMP nOS-V Co-execution Free-agents TAMPI Interoperability HPC Supporting OpenMP free-agents by leveraging nOS-V Conference report