论文标题
全波形反演中的有损检查点压缩:具有ZFPV0.5.5的案例研究和推翻模型
Lossy Checkpoint Compression in Full Waveform Inversion: a case study with ZFPv0.5.5 and the Overthrust Model
论文作者
论文摘要
本文提出了一种新方法,该方法将检查指点方法与错误控制的损耗压缩结合在一起,用于大规模高性能全波倒置(FWI),这是一种在地球物理探索中常用的逆问题。这种组合可以大大减少数据移动,从而减少运行时间和峰值内存。在Exascale计算时代,频繁的数据传输(例如,存储器带宽,GPU或网络的PCIE带宽)是性能瓶颈,而不是处理单元的峰值触发器。像许多其他基于伴随的优化问题一样,FWI在浮点操作的数量,返回过程中的大量内存足迹和数据传输开销方面成本高昂。过去的伴随方法的工作已经开发了检查点方法,以减少倒流期间的峰值内存需求,而费用是其他浮点计算。将这种传统检查点与错误控制的有损压缩相结合,我们探讨了内存,精度和解决方案时间之间的三向权衡。我们研究了向前溶液的有损压缩引入的近似误差如何影响目标函数梯度和最终倒置解决方案。这些数值实验的经验结果表明,高损耗压缩率(压缩因子范围高达100个)对收敛速率和最终溶液质量的影响相对较小。
This paper proposes a new method that combines check-pointing methods with error-controlled lossy compression for large-scale high-performance Full-Waveform Inversion (FWI), an inverse problem commonly used in geophysical exploration. This combination can significantly reduce data movement, allowing a reduction in run time as well as peak memory. In the Exascale computing era, frequent data transfer (e.g., memory bandwidth, PCIe bandwidth for GPUs, or network) is the performance bottleneck rather than the peak FLOPS of the processing unit. Like many other adjoint-based optimization problems, FWI is costly in terms of the number of floating-point operations, large memory footprint during backpropagation, and data transfer overheads. Past work for adjoint methods has developed checkpointing methods that reduce the peak memory requirements during backpropagation at the cost of additional floating-point computations. Combining this traditional checkpointing with error-controlled lossy compression, we explore the three-way tradeoff between memory, precision, and time to solution. We investigate how approximation errors introduced by lossy compression of the forward solution impact the objective function gradient and final inverted solution. Empirical results from these numerical experiments indicate that high lossy-compression rates (compression factors ranging up to 100) have a relatively minor impact on convergence rates and the quality of the final solution.