负载均衡的处理器运算资源分配方法  

Computing Resources Allocation with Load Balance in Modern Processor

作　　者：王国澎 杨剑新 尹飞 蒋生健 WANG Guo-peng;YANG Jian-xin;YIN Fei;JIANG Sheng-jian(Shanghai High Performance IC Design Center,Shanghai 201204,China)

机构地区：[1]上海高性能集成电路设计中心,上海201204

出　　处：《计算机科学》2020年第8期41-48,共8页Computer Science

基　　金：“核高基”重大专项课题(2018ZX01029101)。

摘　　要：现代超标量处理器通常设置有多套计算部件支持指令并行执行,以提高程序的运行效率。运算资源分配策略在很大程度上决定了处理器能否充分利用计算部件并行加速计算,具有重要作用。就指令调度以及运算资源分配问题而言,当前的研究以软件编译优化方法居多。但编译优化是一种静态方法,优化排布的指令无法再次改变次序,且缺乏运行时信息,灵活性不够。为了降低因运算资源分配不当导致的指令阻塞,充分释放其运算能力,从硬件自动调度和实现的角度分析了这个问题,研究了对称情形和非对称情形下运算资源的细粒度自动分配方法,进而提出了负载均衡的贪心分配策略。实验结果表明,提出的运算资源分配方法可以有效减弱现代超标量处理器中指令发射不公平所带来的负面影响,能更好地利用片上缓冲资源和计算资源,且处理器中运算资源越多,发射缓冲深度越大,负载均衡方法获得的性能提升就越明显。To improve the efficiency of program,it is used to arrange multiple function units in modern superscalar processor,supporting to execute instructions in parallel.The allocation policy of computing resources plays an important role in taking full advantage of multiple function units.Although the policy of how to allocate computing resources and schedule instruction has been well studied in literature,the proposed solutions almost concentrate on optimization methods at compile time,which is mostlystatic,inflexible and inefficient because of lack of computing pipeline information at run time.To mitigate the negative impacts of improper computing resource allocation and maximize the power of multiple function units,this paper abstracts the mathematical model of resource allocation problem at run time and makes a study of hardware fine-grained automatic method based on symmetric and asymmetric configuration of function units,in order to make dynamic and wise computing resource allocating decision when instructions are issued in general situation.As a result,a load-balanced greedy resource allocation strategy is proposed and evaluated.The experimental results show that our policy is efficient to minimize blocking time caused by unfair allocation of computing resources.Furthermore,the more computing resources are provided,the better performance our policy can yield.

关 键 词：负载均衡 资源分配 指令调度 指令发射 流水线 

分 类 号：TP302[自动化与计算机技术—计算机系统结构]