Static bus schedule aware scratchpad allocation in multiprocessors
Static bus schedule aware scratchpad allocation in multiprocessors
复制标题
多处理器中静态总线调度感知暂存器分配
DOI：
10.1145/1967677.1967680
复制
发表时间：
2011
影响因子：
1.3
通讯作者：
Abhik Roychoudhury
中科院分区：
文献类型：
--
作者：
Sudipta Chattopadhyay;Abhik Roychoudhury
编译器控制的存储器或便签式存储器提供比高速缓冲存储器更可预测的程序执行时间。Scratchpad存储器通常用于多处理器片上系统(MPSoC)平台，这些平台寻求在限制功耗和时序不可预测性的同时满足嵌入式应用的性能需求。ScratchPad分配方案优化了性能，同时确保了可预测的执行时间(与缓存相比)。
在这项工作中，我们开发了一种用于多处理器平台的编译时暂存分配框架，其中处理器(虚拟地)共享片上暂存空间，并且外部存储器通过共享的总线来访问。我们的分配方法考虑了总线访问的等待时间，同时决定将哪些内存块加载到共享的便签式存储器空间中。与在单个处理器中采用局部优化每个处理器的执行时间的局部高速缓冲存储器分配方案相比，将总线调度合并到我们的便签式存储器分配方法中会导致应用程序的全局优化。我们在两个真实的嵌入式应用程序--一个控制无人机的应用程序和一个在轨航天器软件的碎片--上评估了我们的内存分配方案的有效性、敏感度和效率。
Compiler controlled memories or scratchpad memories offer more predictable program execution times than cache memories. Scratchpad memories are often employed in multi-processor system-on-chip (MPSoC) platforms which seek to meet the performance needs of embedded applications while limiting power consumption and timing unpredictability. Scratchpad allocation schemes optimize performance while ensuring predictable execution times (as compared to caches).
In this work, we develop a compile-time scratchpad allocation framework for multi-processor platforms, where the processors (virtually) share on-chip scratchpad space and external memory is accessed through a shared bus. Our allocation method considers the waiting time for bus access while deciding which memory blocks to load into the shared scratchpad memory space. Incorporating the bus schedule into our scratchpad allocation method leads to a global optimization of an application, as compared to employing local scratchpad allocation schemes in individual processors which locally optimize the per-processor execution time. We evaluate the efficacy, sensitivity and efficiency of our memory allocation scheme on two real-world embedded applications - an application controlling an Unmanned Aerial Vehicle (UAV), and a (fragment of) an in-orbit spacecraft software.