嵌入式设备在调度多核多任务时,由于引入的处理器数量增多,导致调度效率低,以及能耗大等问题。基于此,提出基于实时动态电压频率调整(Dynamic voltage and frequency scaling,DVFS)的嵌入式多核多任务调度算法。构建嵌入式多核多任务能...嵌入式设备在调度多核多任务时,由于引入的处理器数量增多,导致调度效率低,以及能耗大等问题。基于此,提出基于实时动态电压频率调整(Dynamic voltage and frequency scaling,DVFS)的嵌入式多核多任务调度算法。构建嵌入式多核多任务能耗模型,得到不同情况下设备的能量消耗情况;建立多核多任务调度数学模型,在策略集合中找到合适的调度策略,保持时间值始终为最小;利用多核多任务调度算法机制,通过计算嵌入式设备中各个处理核的潜在负载能力,找出与预期负载最接近的处理核,并将任务分配到该任务核中,实现多核多任务的合理调度。实验结果表明,所提方法的调度效率高,且能量消耗低于3.5mW。展开更多
数据中心以可接受的成本,承载着超大规模的互联网应用.数据中心的能源消耗直接影响着数据中心的一次性建造成本和长期维护成本,是数据中心总体持有成本的重要组成部分.现代的数据中心普遍采用动态电压频率调节(dynamic voltage frequenc...数据中心以可接受的成本,承载着超大规模的互联网应用.数据中心的能源消耗直接影响着数据中心的一次性建造成本和长期维护成本,是数据中心总体持有成本的重要组成部分.现代的数据中心普遍采用动态电压频率调节(dynamic voltage frequency scaling,简称DVFS)来提升单节点的能耗表现.但是,DVFS这一类机制同时影响到应用的能源消耗和性能,而这一问题尚未被深入探索.专注于DVFS机制对应用程序性能的影响,提出了一个分析模型用来量化地刻画应用程序的性能与处理器频率之间的关系,可以预测程序在任意频率下的性能.具体来说,依据执行时访问内存子系统资源的不同,把程序的指令分为两部分——片上指令和片外指令,并分别独立建模.片上指令是指仅需访问片上资源就可以完成执行的指令,其执行时间与处理器频率呈线性关系;片外指令是指需要访问主存的指令,其执行时间与处理器频率无关.通过上述划分和对每一部分执行时间的分别建模,可以获得应用程序的执行时间与处理器频率之间的量化模型.使用两个不同的平台和SPEC 2006中的所有标准程序验证该模型,平均误差不超过1.34%.展开更多
针对动态电压/频率调整系统芯片中时钟同步问题,设计一个具有宽工作频率范围和固定锁定周期的快速锁定全数字逐次逼近延时锁定环,采用改进的可复位数字控制延时线方法,在减小面积和提高最高工作频率的同时,有效地解决传统全数字逐次逼...针对动态电压/频率调整系统芯片中时钟同步问题,设计一个具有宽工作频率范围和固定锁定周期的快速锁定全数字逐次逼近延时锁定环,采用改进的可复位数字控制延时线方法,在减小面积和提高最高工作频率的同时,有效地解决传统全数字逐次逼近延时锁定环的谐波锁定和零延时陷阱问题。整个延时锁定环采用TSMC-65 nm CM OS工艺标准单元库实现,仿真结果表明,在典型工艺角和25℃情况下,工作频率范围为250 M Hz^2 GHz,锁定时间为固定的18个输入时钟周期,当电源电压为1.2 V、输入时钟频率为2 GHz时,功耗为0.4 m W。展开更多
The increase in computing capacity caused a rapid and sudden increase in the Operational Expenses (OPEX) of data centers. OPEX reduction is a big concern and a key target in modern data centers. In this study, the sca...The increase in computing capacity caused a rapid and sudden increase in the Operational Expenses (OPEX) of data centers. OPEX reduction is a big concern and a key target in modern data centers. In this study, the scalability of the Dynamic Voltage and Frequency Scaling (DVFS) power management technique is studied under multiple different workloads. The environment of this study is a 3-Tier data center. We conducted multiple experiments to find the impact of using DVFS on energy reduction under two scheduling techniques, namely: Round Robin and Green. We observed that the amount of energy reduction varies according to data center load. When the data center load increases, the energy reduction decreases. Experiments using Green scheduler showed around 83% decrease in power consumption when DVFS is enabled and DC is lightly loaded. In case the DC is fully loaded, in which case the servers’ CPUs are constantly busy with no idle time, the effect of DVFS decreases and stabilizes to less than 10%. Experiments using Round Robin scheduler showed less energy saving by DVFS, specifically, around 25% in light DC load and less than 5% in heavy DC load. In order to find the effect of task weight on energy consumption, a set of experiments were conducted through applying thin and fat tasks. A thin task has much less instructions compared to fat tasks. We observed, through the simulation, that the difference in power reduction between both types of tasks when using DVFS is less than 1%.展开更多
Dynamic Voltage Frequency Scaling (DVFS) techniques are used to improve energy efficiency of GPUs. Literature survey and thorough analysis of various schemes on DVFS techniques during the last decade are presented in ...Dynamic Voltage Frequency Scaling (DVFS) techniques are used to improve energy efficiency of GPUs. Literature survey and thorough analysis of various schemes on DVFS techniques during the last decade are presented in this paper. Detailed analysis of the schemes is included with respect to comparison of various DVFS techniques over the years. To endow with knowledge of various power management techniques that utilize DVFS during the last decade is the main objective of this paper. During the study, we find that DVFS not only work solely but also in coordination with other power optimization techniques like load balancing and task mapping where performance and energy efficiency are affected by varying the platform and benchmark. Thorough analysis of various schemes on DVFS techniques is presented in this paper such that further research in the field of DVFS can be enhanced.展开更多
文摘嵌入式设备在调度多核多任务时,由于引入的处理器数量增多,导致调度效率低,以及能耗大等问题。基于此,提出基于实时动态电压频率调整(Dynamic voltage and frequency scaling,DVFS)的嵌入式多核多任务调度算法。构建嵌入式多核多任务能耗模型,得到不同情况下设备的能量消耗情况;建立多核多任务调度数学模型,在策略集合中找到合适的调度策略,保持时间值始终为最小;利用多核多任务调度算法机制,通过计算嵌入式设备中各个处理核的潜在负载能力,找出与预期负载最接近的处理核,并将任务分配到该任务核中,实现多核多任务的合理调度。实验结果表明,所提方法的调度效率高,且能量消耗低于3.5mW。
文摘数据中心以可接受的成本,承载着超大规模的互联网应用.数据中心的能源消耗直接影响着数据中心的一次性建造成本和长期维护成本,是数据中心总体持有成本的重要组成部分.现代的数据中心普遍采用动态电压频率调节(dynamic voltage frequency scaling,简称DVFS)来提升单节点的能耗表现.但是,DVFS这一类机制同时影响到应用的能源消耗和性能,而这一问题尚未被深入探索.专注于DVFS机制对应用程序性能的影响,提出了一个分析模型用来量化地刻画应用程序的性能与处理器频率之间的关系,可以预测程序在任意频率下的性能.具体来说,依据执行时访问内存子系统资源的不同,把程序的指令分为两部分——片上指令和片外指令,并分别独立建模.片上指令是指仅需访问片上资源就可以完成执行的指令,其执行时间与处理器频率呈线性关系;片外指令是指需要访问主存的指令,其执行时间与处理器频率无关.通过上述划分和对每一部分执行时间的分别建模,可以获得应用程序的执行时间与处理器频率之间的量化模型.使用两个不同的平台和SPEC 2006中的所有标准程序验证该模型,平均误差不超过1.34%.
文摘针对动态电压/频率调整系统芯片中时钟同步问题,设计一个具有宽工作频率范围和固定锁定周期的快速锁定全数字逐次逼近延时锁定环,采用改进的可复位数字控制延时线方法,在减小面积和提高最高工作频率的同时,有效地解决传统全数字逐次逼近延时锁定环的谐波锁定和零延时陷阱问题。整个延时锁定环采用TSMC-65 nm CM OS工艺标准单元库实现,仿真结果表明,在典型工艺角和25℃情况下,工作频率范围为250 M Hz^2 GHz,锁定时间为固定的18个输入时钟周期,当电源电压为1.2 V、输入时钟频率为2 GHz时,功耗为0.4 m W。
文摘The increase in computing capacity caused a rapid and sudden increase in the Operational Expenses (OPEX) of data centers. OPEX reduction is a big concern and a key target in modern data centers. In this study, the scalability of the Dynamic Voltage and Frequency Scaling (DVFS) power management technique is studied under multiple different workloads. The environment of this study is a 3-Tier data center. We conducted multiple experiments to find the impact of using DVFS on energy reduction under two scheduling techniques, namely: Round Robin and Green. We observed that the amount of energy reduction varies according to data center load. When the data center load increases, the energy reduction decreases. Experiments using Green scheduler showed around 83% decrease in power consumption when DVFS is enabled and DC is lightly loaded. In case the DC is fully loaded, in which case the servers’ CPUs are constantly busy with no idle time, the effect of DVFS decreases and stabilizes to less than 10%. Experiments using Round Robin scheduler showed less energy saving by DVFS, specifically, around 25% in light DC load and less than 5% in heavy DC load. In order to find the effect of task weight on energy consumption, a set of experiments were conducted through applying thin and fat tasks. A thin task has much less instructions compared to fat tasks. We observed, through the simulation, that the difference in power reduction between both types of tasks when using DVFS is less than 1%.
文摘Dynamic Voltage Frequency Scaling (DVFS) techniques are used to improve energy efficiency of GPUs. Literature survey and thorough analysis of various schemes on DVFS techniques during the last decade are presented in this paper. Detailed analysis of the schemes is included with respect to comparison of various DVFS techniques over the years. To endow with knowledge of various power management techniques that utilize DVFS during the last decade is the main objective of this paper. During the study, we find that DVFS not only work solely but also in coordination with other power optimization techniques like load balancing and task mapping where performance and energy efficiency are affected by varying the platform and benchmark. Thorough analysis of various schemes on DVFS techniques is presented in this paper such that further research in the field of DVFS can be enhanced.
