{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,23]],"date-time":"2025-10-23T04:34:50Z","timestamp":1761194090188,"version":"build-2065373602"},"reference-count":20,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2025,10,21]],"date-time":"2025-10-21T00:00:00Z","timestamp":1761004800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Computers"],"abstract":"<jats:p>Real-time task scheduling in multi-core systems is a crucial research area, especially for parallel task scheduling, where the Directed Acyclic Graph (DAG) model is commonly used to represent task dependencies. However, existing research shows that resource utilization and schedulability rates for DAG task set scheduling remain relatively low. Meanwhile, some studies have identified that certain parallel task nodes exhibit \u201cparallelization freedom,\u201d allowing them to be decomposed into sub-threads that can execute concurrently. This presents a promising opportunity for improving task schedulability. Building on this, we propose an approach that optimizes both node parallelization and processor core allocation under federated scheduling. Simulation experiments demonstrate that by parallelizing nodes, we can significantly reduce the number of cores required for each task and increase the percentage of task sets being schedulable.<\/jats:p>","DOI":"10.3390\/computers14100449","type":"journal-article","created":{"date-parts":[[2025,10,21]],"date-time":"2025-10-21T14:53:19Z","timestamp":1761058399000},"page":"449","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Optimizing Federated Scheduling for Real-Time DAG Tasks via Node-Level Parallelization"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1906-4883","authenticated-orcid":false,"given":"Jiaqing","family":"Qiao","sequence":"first","affiliation":[{"name":"School of Electronics and Information Engineering, Harbin Institute of Technology, Harbin 150001, China"}]},{"given":"Sirui","family":"Chen","sequence":"additional","affiliation":[{"name":"School of Electronics and Information Engineering, Harbin Institute of Technology, Harbin 150001, China"}]},{"given":"Tianwen","family":"Chen","sequence":"additional","affiliation":[{"name":"School of Electronics and Information Engineering, Harbin Institute of Technology, Harbin 150001, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7041-5119","authenticated-orcid":false,"given":"Lei","family":"Feng","sequence":"additional","affiliation":[{"name":"School of Electronics and Information Engineering, Harbin Institute of Technology, Harbin 150001, China"}]}],"member":"1968","published-online":{"date-parts":[[2025,10,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Cho, Y., Shin, D., Park, J., and Lee, C. (2021, January 7\u201310). Conditionally Optimal Parallelization of Real-Time DAG Tasks for Global EDF. Proceedings of the 2021 IEEE Real-Time Systems Symposium (RTSS), Virtual Event.","DOI":"10.1109\/RTSS52674.2021.00027"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"66","DOI":"10.1109\/MCSE.2010.69","article-title":"OpenCL: A parallel programming standard for heterogeneous computing systems","volume":"12","author":"Stone","year":"2010","journal-title":"Comput. Sci. Eng."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"2004","DOI":"10.1109\/JPROC.2018.2853600","article-title":"The ongoing evolution of openmp","volume":"106","author":"Scogland","year":"2018","journal-title":"Proc. IEEE"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Kwon, J., Kim, K., Paik, S., Lee, J., and Lee, C. (2015, January 13\u201316). Multicore scheduling of parallel real-time tasks with multiple parallelization options. Proceedings of the 2015 IEEE Real-Time and Embedded Technology and Applications Symposium, Seattle, WA, USA.","DOI":"10.1109\/RTAS.2015.7108446"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1007","DOI":"10.1109\/TC.2018.2793919","article-title":"System-wide time versus density tradeoff in real-time multicore fluid scheduling","volume":"67","author":"Kim","year":"2018","journal-title":"IEEE Trans. Comput."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Park, D., Cho, Y., and Lee, C. (2020, January 9\u201312). Conditionally optimal parallelization for global fp on multi-core systems. Proceedings of the 2020 3rd International Conference on Information and Computer Technologies (ICICT), San Jose, CA, USA.","DOI":"10.1109\/ICICT50521.2020.00071"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Cho, Y., Kim, D.H., Park, D., Lee, S.S., and Lee, C. (2019, January 3\u20136). Conditionally optimal task parallelization for global edf on multi-core systems. Proceedings of the 2019 IEEE Real-Time Systems Symposium (RTSS), Hong Kong, China.","DOI":"10.1109\/RTSS46320.2019.00027"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1077","DOI":"10.1109\/TC.2021.3071730","article-title":"Optimal parallelization of single\/multi-segment real-time tasks for global edf","volume":"71","author":"Cho","year":"2021","journal-title":"IEEE Trans. Comput."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Li, J., Chen, J.J., Agrawal, K., Lu, C., Gill, C., and Saifullah, A. (2014, January 8\u201311). Analysis of federated and global scheduling for parallel real-time tasks. Proceedings of the 2014 26th Euromicro Conference on Real-Time Systems, Madrid, Spain.","DOI":"10.1109\/ECRTS.2014.23"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1007\/s11241-023-09397-y","article-title":"The shape of a DAG: Bounding the response time using long paths","volume":"60","author":"He","year":"2023","journal-title":"Real-Time Syst."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Jiang, X., Guan, N., Long, X., and Yi, W. (2017, January 5\u20138). Semi-federated scheduling of parallel real-time tasks on multiprocessors. Proceedings of the 2017 IEEE Real-Time Systems Symposium (RTSS), Paris, France.","DOI":"10.1109\/RTSS.2017.00015"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Ueter, N., Von Der Br\u00fcggen, G., Chen, J., Li, J., and Agrawal, K. (2018, January 11\u201314). Reservation-based federated scheduling for parallel real-time tasks. Proceedings of the 2018 IEEE Real-Time Systems Symposium (RTSS), Nashville, TN, USA.","DOI":"10.1109\/RTSS.2018.00061"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1109\/TPDS.2022.3213024","article-title":"Scheduling Parallel Real-Time Tasks on Virtual Processors","volume":"34","author":"Jiang","year":"2022","journal-title":"IEEE Trans. Parallel Distrib. Syst."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"He, Q., Guan, N., Lv, M., Jiang, X., and Chang, W. (2022, January 5\u20138). Bounding the Response Time of DAG Tasks Using Long Paths. Proceedings of the 2022 IEEE Real-Time Systems Symposium (RTSS), Houston, TX, USA.","DOI":"10.1109\/RTSS55097.2022.00047"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2895","DOI":"10.1109\/TPDS.2023.3310294","article-title":"TDTA: Topology-based Real-Time DAG Task Allocation on Identical Multiprocessor Platforms","volume":"34","author":"Wu","year":"2023","journal-title":"IEEE Trans. Parallel Distrib. Syst."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"101742","DOI":"10.1016\/j.sysarc.2020.101742","article-title":"Real-time scheduling of parallel tasks with tight deadlines","volume":"108","author":"Jiang","year":"2020","journal-title":"J. Syst. Archit."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"3002","DOI":"10.1109\/TC.2023.3280137","article-title":"Parallel Path Progression DAG Scheduling","volume":"72","author":"Ueter","year":"2023","journal-title":"IEEE Trans. Comput."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"471","DOI":"10.1109\/TC.2020.2990282","article-title":"DAG-fluid: A real-time scheduling algorithm for DAGs","volume":"70","author":"Guan","year":"2020","journal-title":"IEEE Trans. Comput."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Li, J., Agrawal, K., Gill, C., and Lu, C. (2014, January 20\u201322). Federated Scheduling for Stochastic Parallel Real-Time Tasks. Proceedings of the 2014 IEEE 20th International Conference on Embedded and Real-Time Computing Systems and Applications, Chongqing, China.","DOI":"10.1109\/RTCSA.2014.6910549"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"13416","DOI":"10.1109\/JIOT.2022.3142324","article-title":"Iterative Probabilistic Performance Prediction for Multiple IoT Applications in Contention","volume":"9","author":"Kocian","year":"2022","journal-title":"IEEE Internet Things J."}],"container-title":["Computers"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-431X\/14\/10\/449\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,23]],"date-time":"2025-10-23T04:33:53Z","timestamp":1761194033000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-431X\/14\/10\/449"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,10,21]]},"references-count":20,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2025,10]]}},"alternative-id":["computers14100449"],"URL":"https:\/\/doi.org\/10.3390\/computers14100449","relation":{},"ISSN":["2073-431X"],"issn-type":[{"type":"electronic","value":"2073-431X"}],"subject":[],"published":{"date-parts":[[2025,10,21]]}}}