HPSv2 / src /training /distributed.py
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init
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import os
import torch
import torch.distributed as dist
try:
import horovod.torch as hvd
except ImportError:
hvd = None
def is_global_master(args):
return args.rank == 0
def is_local_master(args):
return args.local_rank == 0
def barrier(args):
if args.distributed:
dist.barrier()
else:
pass
def is_master(args, local=False):
return is_local_master(args) if local else is_global_master(args)
def is_using_horovod():
# NOTE w/ horovod run, OMPI vars should be set, but w/ SLURM PMI vars will be set
# Differentiating between horovod and DDP use via SLURM may not be possible, so horovod arg still required...
ompi_vars = ["OMPI_COMM_WORLD_RANK", "OMPI_COMM_WORLD_SIZE"]
pmi_vars = ["PMI_RANK", "PMI_SIZE"]
if all([var in os.environ for var in ompi_vars]) or all([var in os.environ for var in pmi_vars]):
return True
else:
return False
def is_using_distributed():
if 'WORLD_SIZE' in os.environ:
return int(os.environ['WORLD_SIZE']) > 1
if 'SLURM_NTASKS' in os.environ:
return int(os.environ['SLURM_NTASKS']) > 1
return False
def world_info_from_env():
local_rank = 0
for v in ('LOCAL_RANK', 'MPI_LOCALRANKID', 'SLURM_LOCALID', 'OMPI_COMM_WORLD_LOCAL_RANK'):
if v in os.environ:
local_rank = int(os.environ[v])
break
global_rank = 0
for v in ('RANK', 'PMI_RANK', 'SLURM_PROCID', 'OMPI_COMM_WORLD_RANK'):
if v in os.environ:
global_rank = int(os.environ[v])
break
world_size = 1
for v in ('WORLD_SIZE', 'PMI_SIZE', 'SLURM_NTASKS', 'OMPI_COMM_WORLD_SIZE'):
if v in os.environ:
world_size = int(os.environ[v])
break
return local_rank, global_rank, world_size
def init_distributed_device(args):
# Distributed training = training on more than one GPU.
# Works in both single and multi-node scenarios.
args.distributed = False
args.world_size = 1
args.rank = 0 # global rank
args.local_rank = 0
if args.horovod:
assert hvd is not None, "Horovod is not installed"
hvd.init()
args.local_rank = int(hvd.local_rank())
args.rank = hvd.rank()
args.world_size = hvd.size()
args.distributed = True
os.environ['LOCAL_RANK'] = str(args.local_rank)
os.environ['RANK'] = str(args.rank)
os.environ['WORLD_SIZE'] = str(args.world_size)
elif is_using_distributed():
if 'SLURM_PROCID' in os.environ:
# DDP via SLURM
args.local_rank, args.rank, args.world_size = world_info_from_env()
# SLURM var -> torch.distributed vars in case needed
os.environ['LOCAL_RANK'] = str(args.local_rank)
os.environ['RANK'] = str(args.rank)
os.environ['WORLD_SIZE'] = str(args.world_size)
torch.distributed.init_process_group(
backend=args.dist_backend,
init_method=args.dist_url,
world_size=args.world_size,
rank=args.rank,
)
else:
# DDP via torchrun, torch.distributed.launch
args.local_rank, _, _ = world_info_from_env()
torch.distributed.init_process_group(
backend=args.dist_backend,
init_method=args.dist_url)
args.world_size = torch.distributed.get_world_size()
args.rank = torch.distributed.get_rank()
args.distributed = True
if torch.cuda.is_available():
if args.distributed and not args.no_set_device_rank:
device = 'cuda:%d' % args.local_rank
else:
device = 'cuda:0'
torch.cuda.set_device(device)
else:
device = 'cpu'
args.device = device
device = torch.device(device)
return device
def broadcast_object(args, obj, src=0):
# broadcast a pickle-able python object from rank-0 to all ranks
if args.horovod:
return hvd.broadcast_object(obj, root_rank=src)
else:
if args.rank == src:
objects = [obj]
else:
objects = [None]
dist.broadcast_object_list(objects, src=src)
return objects[0]
def all_gather_object(args, obj, dst=0):
# gather a pickle-able python object across all ranks
if args.horovod:
return hvd.allgather_object(obj)
else:
objects = [None for _ in range(args.world_size)]
dist.all_gather_object(objects, obj)
return objects