而IB提供了peer memory的接口，使得ib网卡可以访问其他PCIe空间，nv基于peer memory实现了自己的驱动，使得rdma可以直接注册显存，这样通信就可以避免host和device的内存拷贝，IB可以直接dma显存，即gdr。static ncclResult_t ncclGpuGdrSupport(int* gdrSupport) { int netDevs; NCCLCHECK(ncclNetDevices(&netDevs)...
NCCL 2.6 引入了一种创新的通信算法——CollNet算法,它是建立在SHArP(Scalable Hierarchical Aggregation and Reduction Protocol)基础之上的,专为与InfiniBand(IB)网络配合使用而设计。 SHArP,也被称为NCCL Plugin或NCCL-RDMA-SHARP插件,是提升通信性能的关键工具,它通过优化数据在网络中的传输方式,显著提高了大规模GPU...
NCCLCHECK(ncclNetCloseRecv(rComm)); NCCLCHECK(ncclNetCloseSend(sComm)); NCCLCHECK(ncclNetCloseListen(lComm)); break; } return ncclSuccess; } 这里会遍历每一个网卡,获取网卡的信息,由第一节可以知道这里的ncclNet就是ncclNetIb。 ncclResult_t ncclIbGdrSupport(int ibDev) { static int moduleLoaded...
ncclResult_t initNet() { // Always initialize bootstrap network NCCLCHECK(bootstrapNetInit()); NCCLCHECK(initNetPlugin(&ncclNet, &ncclCollNet)); if (ncclNet != NULL) return ncclSuccess; if (initNet(&ncclNetIb) == ncclSuccess) { ncclNet = &ncclNetIb; } else { NC...
首先执行ncclNetIb的init函数,就是ncclIbInit。 ncclResult_tncclIbInit(ncclDebugLogger_t logFunction){staticintshownIbHcaEnv =0;if(wrap_ibv_symbols() != ncclSuccess) {returnncclInternalError; }if(ncclParamIbDisable())returnncclInternalError;if(ncclNIbDevs ==-1) {pthread_mutex_lock(&ncclIbLock)...
NCCL_IB_AR_THRESHOLD=5242880 AR功能,还没有怎么研究,具体效果需要自己验证。 NCCL_MAX_NCHANNELS 大于32 NCCL_NET_GDR_LEVEL=2 该参数会根据环境自动确定,你也可以根据DEBUG信息,主动设置。 剩下两个是Socket相关的,影响较小(RDMA通信前的“握手”信息),但是蚊子腿也是肉。
MASTER_ADDR="<IP_address_of_node_1>"MASTER_PORT=6000 NNODES=2 NODE_RANK=1 WORLD_SIZE=$(($GPUS_PER_NODE*$NNODES)) The scripts above work fine outside of Docker, but when I run it inside Docker, I get an error sayingNCCL INFO NET/IB : No device foundand ...
ncclNetHandle_t handle; void* gpuPtr = NULL; void* mHandle = NULL; NCCLCHECK(ncclNetListen(dev, &handle, &lComm)); NCCLCHECK(ncclNetConnect(dev, &handle, &sComm)); NCCLCHECK(ncclNetAccept(lComm, &rComm)); CUDACHECK(cudaMalloc(&gpuPtr, GPU_BUF_SIZE)); ...
NCCL_IB_HCA 指定使用哪些RDMA网卡进行通信,请根据机型的RDMA配置填写对应的值,例如:8卡套餐为mlx5_1:1 ~ mlx5_8:1,4卡为mlx5_1:1 ~ mlx5_4:1,单卡为mlx5_1:1。各机型的推荐配置详见下述命令。 NCCL_IB_DISABLE 是否关闭RDMA通信,设置为1表示启用TCP通信(非RDMA),设置为0(推荐)表示启...
Star3.6k Open 2 * 8 H800 , Distributed model training with nccl error The results of executing the command ibdev2netdev on the two servers are different. how to sovle the issue? ths Activity sjeaugey commentedon Feb 5, 2024 sjeaugey...