Design and performance of a scalable GPU-based AO RTC prototype
Design and performance of a scalable GPU-based AO RTC prototype
复制标题
基于 GPU 的可扩展 AO RTC 原型的设计和性能
DOI：
--
复制
发表时间：
2018
期刊：
影响因子：
--
通讯作者：
D. Gratadour
中科院分区：
文献类型：
--
作者：
J. Bernard;D. Perret;A. Sevin;M. Lainé;T. Buey;D. Gratadour
在绿色Flash项目的背景下，我们已经组装了一个基于GPU技术的E-ELT第一光AO RTC的全尺寸演示器。这种设计用于实时驱动AO系统的设施由实时核心和监控模块组成，实时核心处理来自传感器的流数据并控制可变形光学器件，监控模块通过根据观察条件的演变以定期速率提供控制矩阵的更新版本来优化控制回路。该RTC原型设计用于评估各种配置中的系统性能，从E-ELT的单共轭AO，即来自单个传感器的约10 Gb/s的流数据和约100 GMAC/s的所需性能;到具有100 Gb/s的流数据和1.5 TMAC/s性能的MCAO系统的尺寸。这两个概念依赖于相同的架构，后者是前者的缩放版本。我们选择了一种非常低级的方法，在GPU上使用持久内核策略来处理所有计算步骤，包括像素校准，斜率和命令向量计算。这种方法通过减少通信简化了延迟管理，但导致我们重新实现了一些GPU标准功能：通信机制（保护，对等），算法（广义矩阵向量乘法，减少/全部减少）和多节点多GPU系统上的新同步机制。为了评估在现实条件下的完整AO RTC原型的性能，我们同时实现了一个实时模拟器，能够通过模拟传感器数据传输协议和与模拟可变形光学器件交互来向实时核心提供数据。实时模拟器能够提供高精度的模拟数据，并模拟SCAO案例的整个反作用回路，从而实现原型的全尺寸/全功能测试。本文报道了在SCAO模式下AORTC原型的设计和性能表征，并讨论了其在热成像AO模式下的集成策略。
In the context of the Green Flash project we have assembled a full scale demonstrator for an E-ELT first light AO RTC, based on the GPU technology. Such facility, designed to drive in real-time the AO system, is composed of a real-time core, processing streaming data from sensors and controlling deformable optics, and a supervisor module, optimizing the control loop by providing updated versions of the control matrix at a regular rate depending on the observing conditions evolution. This RTC prototype is designed to assess the system performance in various configurations from single conjugate AO for the E-ELT, i.e. about 10 Gb/s of streaming data from a single sensor and a required performance of about 100 GMAC/s; to the dimensioning of a MCAO system with 100 Gb/s of streaming data and 1.5 TMAC/s performance. Both concepts rely on the same architecture, the latter being a scaled version of the former. We chose a very low level approach using a persistent kernel strategy on the GPUs to handle all the computation steps including pixel calibration, slopes and command vector computation. This approach simplifies the latency management by reducing the communication but led us to re-implement some GPUs standard features : communication mechanisms (guard, peer-to-peer), algorithms (generalized matrix-vector multiplication, reduce/all reduce) and new synchronization mechanisms on a multi node - multi GPUs system. In order to assess the performance of the full AO RTC prototype under realistic conditions, we have concurrently implemented a real-time simulator able to feed the real-time core with data by emulating the sensors data transfer protocols and interacting with simulated deformable optics. The real-time simulator is able to deliver high precision simulated data and simulate the whole retro-action loop for the SCAO case, enabling a full scale / full feature test of the prototype. In this paper, we report on the design and characterization the AO RTC prototype performance in SCAO mode and discuss a strategy for its integration in tmographic AO mode.
使用新兴高性能计算技术和 Green Flash 项目对 AO RTC 进行原型设计
DOI：
10.1117/12.2312686
发表时间：
2018
期刊：
--
影响因子：
--
作者：
Doucet N
通讯作者：
Doucet N