TY - JOUR
T1 - ACCURATE
T2 - Accuracy Maximization for Real-Time Multi-core systems with Energy Efficient Way-sharing Caches
AU - Saha, Sangeet
AU - Chakraborty, Shounak
AU - Zhai, Xiaojun
AU - Ehsan, Shoaib
AU - McDonald-Maier, Klaus
N1 - Publisher Copyright:
Author
PY - 2022/3/22
Y1 - 2022/3/22
N2 - Improving result-accuracy in approximate computing (AC) based real-time applications without violating deadline has recently become an active research domain. Execution-time of AC real-time tasks can individually be separated into: execution of the mandatory part to obtain a result of acceptable quality, followed by a partial/complete execution of the optional part to improve result-accuracy of the initial result within a given deadline. However, obtaining higher result-accuracy at the cost of enhanced execution time may lead to deadline violation, along with higher energy usage.We present ACCURATE, a novel hybrid offline-online approximate real-time scheduling approach that first schedules AC-based tasks on multi-core with an objective to maximize result-accuracy and determines operational processing speeds for each task constrained by system-wide power limit, deadline, and task-dependency. At runtime, by employing a waysharing technique (WH LLC) at the last level cache, ACCURATE improves performance, which is further leveraged, to enhance result-accuracy by executing more from the optional part, and to improve energy efficiency of the cache by turning off a controlled number of cache-ways. ACCURATE also exploits the slacks either to improve result-accuracy of the tasks, or to enhance energy efficiency of the underlying system, or both. ACCURATE achieves 85% QoS with 36% average reduction in cache leakage consumption with a 24% average gain in energy delay product for a 4-core based chip-multiprocessor with 6.4% average improvement in performance.
AB - Improving result-accuracy in approximate computing (AC) based real-time applications without violating deadline has recently become an active research domain. Execution-time of AC real-time tasks can individually be separated into: execution of the mandatory part to obtain a result of acceptable quality, followed by a partial/complete execution of the optional part to improve result-accuracy of the initial result within a given deadline. However, obtaining higher result-accuracy at the cost of enhanced execution time may lead to deadline violation, along with higher energy usage.We present ACCURATE, a novel hybrid offline-online approximate real-time scheduling approach that first schedules AC-based tasks on multi-core with an objective to maximize result-accuracy and determines operational processing speeds for each task constrained by system-wide power limit, deadline, and task-dependency. At runtime, by employing a waysharing technique (WH LLC) at the last level cache, ACCURATE improves performance, which is further leveraged, to enhance result-accuracy by executing more from the optional part, and to improve energy efficiency of the cache by turning off a controlled number of cache-ways. ACCURATE also exploits the slacks either to improve result-accuracy of the tasks, or to enhance energy efficiency of the underlying system, or both. ACCURATE achieves 85% QoS with 36% average reduction in cache leakage consumption with a 24% average gain in energy delay product for a 4-core based chip-multiprocessor with 6.4% average improvement in performance.
KW - Approximated Computing
KW - Dynamic Associativity Management.
KW - Dynamic Cache Way-Shutdown
KW - Energy efficiency
KW - Energy Efficiency
KW - Multi-cores
KW - Processor scheduling
KW - Quality of service
KW - Real-time scheduling
KW - Real-time systems
KW - Runtime
KW - Schedules
KW - Task analysis
UR - http://www.scopus.com/inward/record.url?scp=85127076696&partnerID=8YFLogxK
U2 - 10.1109/TCAD.2022.3161407
DO - 10.1109/TCAD.2022.3161407
M3 - Article
AN - SCOPUS:85127076696
JO - IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
JF - IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
SN - 0278-0070
M1 - 9739790
ER -