使用网络 RDMA 技术为 SPARK 架构加速.pdf

1、#page#DATA SCIENCE IN PRACTICEMore than 70% of Compute is Spent on Data ProcessingMore time is spent processing datathan any other stageInference Compute required is greater Benefit to developers is highTrainingNVIDIA opportunity is sizableDataProcessing#page#Accelerating the Machine Learning Data P

2、ipelineStreamsMLTrainandOptimizeedis6redis586mrageStoProduction ML Service（inference）#page#RDMA- Remote DMAInfiniBand and RoCE （RDMA over Converged Ethernet）Messages send/receive， remote DMA and remote atomicsHardware transport专山r Kernel and hypervisor bypassAdvantagesF Lower latency- 10us 700ns Hig

3、her message rate-215M messages/sLower CPU utilization-0%RDDMA NIC#page#RDMA写操作过程当数据包到达HCA的时，它会检查地址HCA消耗一个WQE，和内存Key，并直接写入内存读取buffer并发送到远端，产生发送完成信息HostA内存HostB内存发送队列发送队列HCAHCA接收队列完成队列完成队列发送端分配一个发送buffer并在HCA注册，放置一申请分配接收buffer并传送地址和Key到远端个包含远端虚拟地址的发送WQE并“按一下门铃”nVIOIA#page#Enabling Kernel BypassApplica

4、tionApplicationApplication！MiddlewareMiddlewareMiddlewareSeparation of Control and Data pathsVerbsVerbsVerbsData pathRDMARDMARDMALibraryLibraryLibrarySend，Receive，RDMACompletion， Request eventRDWAConnection establishmentStackControl pathDeviceResource setupDriverMemorymanagementConnection establishm

5、entNIC Hardware#page#RDMA over Converged Ethernet (RoCE）BTH+CRCCSEUhL2UDPRoCEv2 PacketPayloadIPInfiniBand PacketWCRCLRHGRHBTHICRCPayloadRDMARDMAO InfiniBand is a centrally managed, lossless high performanceTransportTransportnetwork architectureG Provides specification for the RDMA transportUDPIB Net

6、workLayerIPO RoCE adapts the efficient RDMA transport to run over EthernetnetworksInfiniBandEthernetLinklayerLink layerInfiniBandROCEv2O Standard Ethernet managementInfiniBandEthernet/ipManagementManagement#page#Verbs programming1.Get the device list2. Open the requested device3. Query the device ca