View source for Short MPI Tests using Pytorch example code

<pre>
[antony@gpu5 pytorch-nccl-test]$ cat run_dp_mpi.sh
#!/bin/bash

# mpirun --mca pml ucx -np 8 -H gpu0:4,gpu5:4 ./run_dp_mpi.sh

source ~/dp-build/torch-rocm61/bin/activate

export MASTER_ADDR=172.16.16.42
export MASTER_PORT=25252
export NCCL_SOCKET_IFNAME=enp37s0np0,enp12s0np0,enp180s0np0,enp139s0np0
#export NCCL_DEBUG=INFO
export NCCL_IB_GID_INDEX=3
export NCCL_NET_GDR_LEVEL=1

python3.11 /home/antony/dp-build/pytorch-nccl-test/dp_pytorch_mpi.py

</pre>

Then the dp_pytorch_mpi.py file

<pre>
[antony@gpu5 pytorch-nccl-test]$ cat /home/antony/dp-build/pytorch-nccl-test/dp_pytorch_mpi.py
import os
import argparse

import torch
import torch.distributed as dist

# Environment variables set by mpirun
LOCAL_RANK = int(os.environ['OMPI_COMM_WORLD_LOCAL_RANK'])
WORLD_SIZE = int(os.environ['OMPI_COMM_WORLD_SIZE'])
WORLD_RANK = int(os.environ['OMPI_COMM_WORLD_RANK'])

def run(backend):
    tensor = torch.zeros(1)

    # Need to put tensor on a GPU device for nccl backend
    if backend == 'nccl':
        device = torch.device("cuda:{}".format(LOCAL_RANK))
        tensor = tensor.to(device)

    if WORLD_RANK == 0:
        for rank_recv in range(1, WORLD_SIZE):
            dist.send(tensor=tensor, dst=rank_recv)
            print('worker_{} sent data to Rank {}\n'.format(0, rank_recv))
    else:
        dist.recv(tensor=tensor, src=0)
        print('worker_{} has received data from rank {}\n'.format(WORLD_RANK, 0))

def init_processes(backend):
    dist.init_process_group(backend, rank=WORLD_RANK, world_size=WORLD_SIZE)
    run(backend)

if __name__ == "__main__":

    parser = argparse.ArgumentParser()
    parser.add_argument("--local_rank", type=int, help="Local rank. Necessary for using the torch.distributed.launch utility.")
    parser.add_argument("--backend", type=str, default="nccl", choices=['nccl', 'gloo'])
    args = parser.parse_args()

    init_processes(backend=args.backend)
    dist.barrier()
    dist.destroy_process_group()
</pre>


== Another Example ==
Run the job using
<pre>
(torch-rocm61) [antony@gpu0 pytorch-nccl-test]$ /home/shared/apps/openmpi/5.0.3/bin/mpirun -x SCRATCH=55 -x NCCL_DEBUG=INFO -np 16 -H gpu0:8,gpu3:8 run_dp.sh
</pre>

Wrapper script 
<pre>
[antony@lighton-login pytorch-nccl-test]$ cat run_dp.sh
#!/bin/bash

source ~/dp-build/torch-rocm61/bin/activate
python3.11 /home/antony/dp-build/pytorch-nccl-test/test_nccl_dp.py
</pre>

With the following file
<pre>
# cat test_nccl_dp.py
import os

import torch
import torch.distributed as dist

def init_workers_nccl_file():
    rank = int(os.environ['OMPI_COMM_WORLD_RANK'])
    n_ranks = int(os.environ['OMPI_COMM_WORLD_SIZE'])
    sync_file_dir = '%s/tmp' % os.environ['SCRATCH']
    os.makedirs(sync_file_dir, exist_ok=True)
    sync_file = 'file://%s/pytorch_sync_%s' % (
        sync_file_dir, os.environ['OMPI_WORLD_SIZE'])
    dist.init_process_group(backend='nccl', world_size=n_ranks, rank=rank,
                            init_method=sync_file)
    return rank, n_ranks

# Print pytorch version
print('Pytorch version', torch.__version__)

# Configuration
ranks_per_node = 8
shape = 2**17
dtype = torch.float32

# Initialize MPI
rank, n_ranks = init_workers_nccl_file()
local_rank = rank % ranks_per_node

# Allocate a small tensor on every gpu from every rank.
# This is an attempt to force creation of all device contexts.
for i in range(ranks_per_node):
    _ = torch.randn(1).to(torch.device('cuda', i))

# Select our gpu
device = torch.device('cuda', local_rank)
print('Rank', rank, 'size', n_ranks, 'device', device, 'count', torch.cuda.device_count())

print('Torch NCCL version', torch.cuda.nccl.version())

# Allocate a tensor on the gpu
x = torch.randn(shape, dtype=dtype).to(device)
print('local result:', x.sum())

# Do a broadcast from rank 0
dist.broadcast(x, 0)
print('broadcast result:', x.sum())

# Do an all-reduce
dist.all_reduce(x)
print('allreduce result:', x.sum())

# close out
dist.barrier()
dist.destroy_process_group()
</pre>

Notes from Victor at AMD

<pre>
virobles
  8:10 PM
pip wheel
8:13
#Environment:
conda create -n torchrun python=3.9
pip3 install torch torchvision torchaudio --index-url https://download.pytorch.org/whl/rocm6.0
# Log into GPU0 and run:
export NCCL_SOCKET_IFNAME="enp12s0np0,enp139s0np0,enp180s0np0,enp37s0np0"
export NCCL_IB_GID_INDEX=3
export NCCL_NET_GDR_LEVEL=1
conda activate torchrun
torchrun --nproc_per_node=8 --nnodes=2 --node_rank=0 --master_port=29600 --master_addr=172.16.16.38 /home/shared/scripts/multinode.py 50 10
# Log into GPU5 and run:
export NCCL_SOCKET_IFNAME="enp12s0np0,enp139s0np0,enp180s0np0,enp37s0np0"
export NCCL_IB_GID_INDEX=3
export NCCL_NET_GDR_LEVEL=1
conda activate torchrun
torchrun --nproc_per_node=8 --nnodes=2 --node_rank=1 --master_port=29600 --master_addr=172.16.16.38 /home/shared/scripts/multinode.py 50 10
8:15
You're probably already familiar with the NCCL env vars so I won't elaborate on those. But to get Pytorch to work for me I had to specify the IB GID INDEX as 3 and force to use GPU Direct RDMA only when GPU and NIC are on the same PCI switch (with the NCCL_NET_GDR_LEVEL env var set to 1) (edited) 
</pre>


Full output

<pre>
[hpc@nscale-perf-cluster-compute-top500-15 nccl-python-testing]$ mpirun -x SCRATCH=55 -x NCCL_DEBUG=INFO -np 2 singularity run /tmp/dp-singularity/pytorch-nightly_latest.sif python ./test-nccl.py
Pytorch version 2.6.0a0+gitd2207c5
Pytorch version 2.6.0a0+gitd2207c5
Rank 0 size 2 device cuda:0 count 8
Torch NCCL version (2, 20, 5)
local result: tensor(618.5157, device='cuda:0')
nscale-perf-cluster-compute-top500-15:142876:142876 [0] NCCL INFO Bootstrap : Using enp37s0np0:172.16.18.118<0>
nscale-perf-cluster-compute-top500-15:142876:142876 [0] NCCL INFO NET/Plugin : dlerror=librccl-net.so: cannot open shared object file: No such file or directory No plugin found (librccl-net.so), using internal implementation

nscale-perf-cluster-compute-top500-15:142876:142876 [0] /long_pathname_so_that_rpms_can_package_the_debug_info/src/extlibs/rccl/build/hipify/src/init.cc:115 NCCL WARN NUMA auto balancing enabled which can lead to variability in the RCCL performance! Disable by "sudo sysctl kernel.numa_balancing=0"
nscale-perf-cluster-compute-top500-15:142876:142876 [0] NCCL INFO Kernel version: 4.18.0-513.24.1.el8_9.x86_64
nscale-perf-cluster-compute-top500-15:142876:142876 [0] NCCL INFO ROCr version 1.14
nscale-perf-cluster-compute-top500-15:142876:142876 [0] NCCL INFO Dmabuf feature disabled without NCCL_DMABUF_ENABLE=1
RCCL version 2.20.5+hip6.2 HEAD:45b618a+
Rank 1 size 2 device cuda:1 count 8
Torch NCCL version (2, 20, 5)
local result: tensor(-332.1474, device='cuda:1')
nscale-perf-cluster-compute-top500-15:142875:142875 [1] NCCL INFO ROCr version 1.14
nscale-perf-cluster-compute-top500-15:142875:142875 [1] NCCL INFO Dmabuf feature disabled without NCCL_DMABUF_ENABLE=1
nscale-perf-cluster-compute-top500-15:142875:142875 [1] NCCL INFO Bootstrap : Using enp37s0np0:172.16.18.118<0>
nscale-perf-cluster-compute-top500-15:142875:142875 [1] NCCL INFO NET/Plugin : dlerror=librccl-net.so: cannot open shared object file: No such file or directory No plugin found (librccl-net.so), using internal implementation

nscale-perf-cluster-compute-top500-15:142875:142875 [1] /long_pathname_so_that_rpms_can_package_the_debug_info/src/extlibs/rccl/build/hipify/src/init.cc:115 NCCL WARN NUMA auto balancing enabled which can lead to variability in the RCCL performance! Disable by "sudo sysctl kernel.numa_balancing=0"
nscale-perf-cluster-compute-top500-15:142875:142875 [1] NCCL INFO Kernel version: 4.18.0-513.24.1.el8_9.x86_64
libibverbs: Warning: couldn't open config directory '/etc/libibverbs.d'.
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO NET/IB : No device found.
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO NET/Socket : Using [0]enp37s0np0:172.16.18.118<0> [1]enp12s0np0:172.16.18.120<0> [2]enp180s0np0:172.16.18.116<0> [3]enp139s0np0:172.16.18.114<0> [4]bond0:192.168.7.139<0>
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Using non-device net plugin version 0
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Using network Socket
libibverbs: Warning: couldn't open config directory '/etc/libibverbs.d'.
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO NET/IB : No device found.
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO NET/Socket : Using [0]enp37s0np0:172.16.18.118<0> [1]enp12s0np0:172.16.18.120<0> [2]enp180s0np0:172.16.18.116<0> [3]enp139s0np0:172.16.18.114<0> [4]bond0:192.168.7.139<0>
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Using non-device net plugin version 0
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Using network Socket
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO comm 0xbf44640 rank 1 nranks 2 cudaDev 1 busId 34000 commId 0xfe20596e81efe06c - Init START
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO comm 0xa966300 rank 0 nranks 2 cudaDev 0 busId 31000 commId 0xfe20596e81efe06c - Init START
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO [node_id = 8; gpu_id = 14571; unique_id = 1707942351238735562; location_id = 12544; bdf = 12544; domain = 0; partition = 0],
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO [node_id = 10; gpu_id = 57586; unique_id = 1879117630712565286; location_id = 4352; bdf = 4352; domain = 0; partition = 0],
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO [node_id = 12; gpu_id = 41154; unique_id = 12764043078489004147; location_id = 44544; bdf = 44544; domain = 0; partition = 0],
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO [node_id = 15; gpu_id = 8466; unique_id = 14583621907896286631; location_id = 37632; bdf = 37632; domain = 0; partition = 0],
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO [node_id = 9; gpu_id = 27432; unique_id = 16692116773638566847; location_id = 13312; bdf = 13312; domain = 0; partition = 0],
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO [node_id = 13; gpu_id = 63755; unique_id = 16987650277263352869; location_id = 45824; bdf = 45824; domain = 0; partition = 0],
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO [node_id = 14; gpu_id = 30939; unique_id = 17411672822274508524; location_id = 36352; bdf = 36352; domain = 0; partition = 0],
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO [node_id = 11; gpu_id = 45873; unique_id = 17784246647738402691; location_id = 5120; bdf = 5120; domain = 0; partition = 0],
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO [node_id = 8; gpu_id = 14571; unique_id = 1707942351238735562; location_id = 12544; bdf = 12544; domain = 0; partition = 0],
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO [node_id = 10; gpu_id = 57586; unique_id = 1879117630712565286; location_id = 4352; bdf = 4352; domain = 0; partition = 0],
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO [node_id = 12; gpu_id = 41154; unique_id = 12764043078489004147; location_id = 44544; bdf = 44544; domain = 0; partition = 0],
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO [node_id = 15; gpu_id = 8466; unique_id = 14583621907896286631; location_id = 37632; bdf = 37632; domain = 0; partition = 0],
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO [node_id = 9; gpu_id = 27432; unique_id = 16692116773638566847; location_id = 13312; bdf = 13312; domain = 0; partition = 0],
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO [node_id = 13; gpu_id = 63755; unique_id = 16987650277263352869; location_id = 45824; bdf = 45824; domain = 0; partition = 0],
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO [node_id = 14; gpu_id = 30939; unique_id = 17411672822274508524; location_id = 36352; bdf = 36352; domain = 0; partition = 0],
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO [node_id = 11; gpu_id = 45873; unique_id = 17784246647738402691; location_id = 5120; bdf = 5120; domain = 0; partition = 0],
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO initialized internal alternative rsmi functionality
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO initialized internal alternative rsmi functionality
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO comm 0xbf44640 rank 1 nRanks 2 nNodes 1 localRanks 2 localRank 1 MNNVL 0
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Trees [0] -1/-1/-1->1->0 [1] -1/-1/-1->1->0 [2] -1/-1/-1->1->0 [3] 0/-1/-1->1->-1 [4] 0/-1/-1->1->-1 [5] 0/-1/-1->1->-1 [6] -1/-1/-1->1->0 [7] -1/-1/-1->1->0 [8] -1/-1/-1->1->0 [9] 0/-1/-1->1->-1 [10] 0/-1/-1->1->-1 [11] 0/-1/-1->1->-1 [12] -1/-1/-1->1->0 [13] -1/-1/-1->1->0 [14] -1/-1/-1->1->0 [15] 0/-1/-1->1->-1 [16] 0/-1/-1->1->-1 [17] 0/-1/-1->1->-1 [18] -1/-1/-1->1->0 [19] -1/-1/-1->1->0 [20] -1/-1/-1->1->0 [21] 0/-1/-1->1->-1 [22] 0/-1/-1->1->-1 [23] 0/-1/-1->1->-1 comm 0xbf44640 nRanks 02 busId 34000
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO P2P Chunksize set to 524288
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO comm 0xa966300 rank 0 nRanks 2 nNodes 1 localRanks 2 localRank 0 MNNVL 0
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 00/24 :    0   1
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 01/24 :    0   1
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 02/24 :    0   1
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 03/24 :    0   1
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 04/24 :    0   1
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 05/24 :    0   1
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 06/24 :    0   1
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 07/24 :    0   1
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 08/24 :    0   1
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 09/24 :    0   1
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 10/24 :    0   1
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 11/24 :    0   1
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 12/24 :    0   1
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 13/24 :    0   1
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 14/24 :    0   1
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 15/24 :    0   1
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 16/24 :    0   1
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 17/24 :    0   1
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 18/24 :    0   1
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 19/24 :    0   1
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 20/24 :    0   1
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 21/24 :    0   1
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 22/24 :    0   1
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 23/24 :    0   1
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Trees [0] 1/-1/-1->0->-1 [1] 1/-1/-1->0->-1 [2] 1/-1/-1->0->-1 [3] -1/-1/-1->0->1 [4] -1/-1/-1->0->1 [5] -1/-1/-1->0->1 [6] 1/-1/-1->0->-1 [7] 1/-1/-1->0->-1 [8] 1/-1/-1->0->-1 [9] -1/-1/-1->0->1 [10] -1/-1/-1->0->1 [11] -1/-1/-1->0->1 [12] 1/-1/-1->0->-1 [13] 1/-1/-1->0->-1 [14] 1/-1/-1->0->-1 [15] -1/-1/-1->0->1 [16] -1/-1/-1->0->1 [17] -1/-1/-1->0->1 [18] 1/-1/-1->0->-1 [19] 1/-1/-1->0->-1 [20] 1/-1/-1->0->-1 [21] -1/-1/-1->0->1 [22] -1/-1/-1->0->1 [23] -1/-1/-1->0->1 comm 0xa966300 nRanks 02 busId 31000
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO P2P Chunksize set to 524288
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Channel 00/0 : 1[34000] -> 0[31000] via P2P/IPC comm 0xbf44640 nRanks 02
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Channel 01/0 : 1[34000] -> 0[31000] via P2P/IPC comm 0xbf44640 nRanks 02
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 00/0 : 0[31000] -> 1[34000] via P2P/IPC comm 0xa966300 nRanks 02
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Channel 02/0 : 1[34000] -> 0[31000] via P2P/IPC comm 0xbf44640 nRanks 02
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Channel 03/0 : 1[34000] -> 0[31000] via P2P/IPC comm 0xbf44640 nRanks 02
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 01/0 : 0[31000] -> 1[34000] via P2P/IPC comm 0xa966300 nRanks 02
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Channel 04/0 : 1[34000] -> 0[31000] via P2P/IPC comm 0xbf44640 nRanks 02
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 02/0 : 0[31000] -> 1[34000] via P2P/IPC comm 0xa966300 nRanks 02
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Channel 05/0 : 1[34000] -> 0[31000] via P2P/IPC comm 0xbf44640 nRanks 02
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 03/0 : 0[31000] -> 1[34000] via P2P/IPC comm 0xa966300 nRanks 02
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Channel 06/0 : 1[34000] -> 0[31000] via P2P/IPC comm 0xbf44640 nRanks 02
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 04/0 : 0[31000] -> 1[34000] via P2P/IPC comm 0xa966300 nRanks 02
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Channel 07/0 : 1[34000] -> 0[31000] via P2P/IPC comm 0xbf44640 nRanks 02
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Channel 08/0 : 1[34000] -> 0[31000] via P2P/IPC comm 0xbf44640 nRanks 02
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 05/0 : 0[31000] -> 1[34000] via P2P/IPC comm 0xa966300 nRanks 02
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Channel 09/0 : 1[34000] -> 0[31000] via P2P/IPC comm 0xbf44640 nRanks 02
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 06/0 : 0[31000] -> 1[34000] via P2P/IPC comm 0xa966300 nRanks 02
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 07/0 : 0[31000] -> 1[34000] via P2P/IPC comm 0xa966300 nRanks 02
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Channel 10/0 : 1[34000] -> 0[31000] via P2P/IPC comm 0xbf44640 nRanks 02
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 08/0 : 0[31000] -> 1[34000] via P2P/IPC comm 0xa966300 nRanks 02
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Channel 11/0 : 1[34000] -> 0[31000] via P2P/IPC comm 0xbf44640 nRanks 02
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 09/0 : 0[31000] -> 1[34000] via P2P/IPC comm 0xa966300 nRanks 02
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Channel 12/0 : 1[34000] -> 0[31000] via P2P/IPC comm 0xbf44640 nRanks 02
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 10/0 : 0[31000] -> 1[34000] via P2P/IPC comm 0xa966300 nRanks 02
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Channel 13/0 : 1[34000] -> 0[31000] via P2P/IPC comm 0xbf44640 nRanks 02
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 11/0 : 0[31000] -> 1[34000] via P2P/IPC comm 0xa966300 nRanks 02
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Channel 14/0 : 1[34000] -> 0[31000] via P2P/IPC comm 0xbf44640 nRanks 02
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 12/0 : 0[31000] -> 1[34000] via P2P/IPC comm 0xa966300 nRanks 02
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Channel 15/0 : 1[34000] -> 0[31000] via P2P/IPC comm 0xbf44640 nRanks 02
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 13/0 : 0[31000] -> 1[34000] via P2P/IPC comm 0xa966300 nRanks 02
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Channel 16/0 : 1[34000] -> 0[31000] via P2P/IPC comm 0xbf44640 nRanks 02
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 14/0 : 0[31000] -> 1[34000] via P2P/IPC comm 0xa966300 nRanks 02
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Channel 17/0 : 1[34000] -> 0[31000] via P2P/IPC comm 0xbf44640 nRanks 02
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 15/0 : 0[31000] -> 1[34000] via P2P/IPC comm 0xa966300 nRanks 02
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Channel 18/0 : 1[34000] -> 0[31000] via P2P/IPC comm 0xbf44640 nRanks 02
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 16/0 : 0[31000] -> 1[34000] via P2P/IPC comm 0xa966300 nRanks 02
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Channel 19/0 : 1[34000] -> 0[31000] via P2P/IPC comm 0xbf44640 nRanks 02
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 17/0 : 0[31000] -> 1[34000] via P2P/IPC comm 0xa966300 nRanks 02
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Channel 20/0 : 1[34000] -> 0[31000] via P2P/IPC comm 0xbf44640 nRanks 02
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 18/0 : 0[31000] -> 1[34000] via P2P/IPC comm 0xa966300 nRanks 02
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Channel 21/0 : 1[34000] -> 0[31000] via P2P/IPC comm 0xbf44640 nRanks 02
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 19/0 : 0[31000] -> 1[34000] via P2P/IPC comm 0xa966300 nRanks 02
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Channel 22/0 : 1[34000] -> 0[31000] via P2P/IPC comm 0xbf44640 nRanks 02
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Channel 23/0 : 1[34000] -> 0[31000] via P2P/IPC comm 0xbf44640 nRanks 02
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 20/0 : 0[31000] -> 1[34000] via P2P/IPC comm 0xa966300 nRanks 02
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 21/0 : 0[31000] -> 1[34000] via P2P/IPC comm 0xa966300 nRanks 02
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 22/0 : 0[31000] -> 1[34000] via P2P/IPC comm 0xa966300 nRanks 02
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Channel 23/0 : 0[31000] -> 1[34000] via P2P/IPC comm 0xa966300 nRanks 02
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Connected all rings comm 0xbf44640 nRanks 02 busId 34000
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO Connected all trees
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO threadThresholds 8/8/64 | 16/8/64 | 256 | 256
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO 24 coll channels, 0 collnet channels, 0 nvls channels, 32 p2p channels, 8 p2p channels per peer
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Connected all rings comm 0xa966300 nRanks 02 busId 31000
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO Connected all trees
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO threadThresholds 8/8/64 | 16/8/64 | 256 | 256
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO 24 coll channels, 0 collnet channels, 0 nvls channels, 32 p2p channels, 8 p2p channels per peer
nscale-perf-cluster-compute-top500-15:142875:142930 [1] NCCL INFO comm 0xbf44640 rank 1 nranks 2 cudaDev 1 busId 34000 commId 0xfe20596e81efe06c localSize 296 used 469861984 bytes - Init COMPLETE
nscale-perf-cluster-compute-top500-15:142876:142929 [0] NCCL INFO comm 0xa966300 rank 0 nranks 2 cudaDev 0 busId 31000 commId 0xfe20596e81efe06c localSize 296 used 469861984 bytes - Init COMPLETE
broadcast result: tensor(618.5157, device='cuda:0')
broadcast result: tensor(618.5157, device='cuda:1')
allreduce result: tensor(1237.0315, device='cuda:0')
allreduce result: tensor(1237.0315, device='cuda:1')
nscale-perf-cluster-compute-top500-15:142875:142932 [1] NCCL INFO [Service thread] Connection closed by localRank 1
nscale-perf-cluster-compute-top500-15:142876:142931 [0] NCCL INFO [Service thread] Connection closed by localRank 0
nscale-perf-cluster-compute-top500-15:142875:142937 [1] NCCL INFO comm 0xbf44640 rank 1 nranks 2 cudaDev 1 busId 34000 - Abort COMPLETE
nscale-perf-cluster-compute-top500-15:142876:142938 [0] NCCL INFO comm 0xa966300 rank 0 nranks 2 cudaDev 0 busId 31000 - Abort COMPLETE
</pre>