doi: 10.3850/978-3-9815370-4-8_0724


An Online Thermal-Constrained Task Scheduler for 3D Multi-Core Processors


Chien-Hui Liao1, Charles H.-P. Wen2 and Krishnendu Chakrabarty3

1Inst. of Communications Engineering, National Chiao Tung University, Hsinchu, Taiwan.

liangel.cm97g@g2.nctu.edu.tw

2Electrical and Computer Engineering, National Chiao Tung University, Hsinchu, Taiwan.

opwen@g2.nctu.edu.tw

3Electrical and Computer Engineering, Duke University, Durham, NC, USA.

krish@ee.duke.edu

ABSTRACT

Hotspots occur frequently in 3D multi-core processors (3D-MCPs) and they can adversely impact system reliability and lifetime. Moreover, frequent occurrences of hotspots lead to more dynamic voltage and frequency scaling (DVFS), resulting in degraded throughput. Therefore, a new thermal-constrained task scheduler based on thermal-pattern-aware voltage assignment (TPAVA) is proposed in this paper. By analyzing temperature profiles of different voltage assignments, TPAVA pre-emptively assigns different operating-voltage levels to cores for reducing temperature increase in 3D-MCPs. Moreover, the proposed task scheduler integrates a vertical-grouping voltage scaling (VGVS) strategy that considers thermal correlation in 3D-MCPs. Experimental results show that, compared with two previous methods, the proposed task scheduler can respectively lower hotspot occurrences by 47:13% and 53:91%, and improve throughput by 6:50% and 32:06%. As a result, TPAVA and VGVS are effectively for reducing occurrences of hotspots and optimizing throughput for 3D-MCPs under thermal constraints.



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