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Init code
97069e1
import math
import pickle
import torch
from torch import distributed as dist
from torch.utils.data.sampler import Sampler
def get_rank():
if not dist.is_available():
return 0
if not dist.is_initialized():
return 0
return dist.get_rank()
def synchronize():
if not dist.is_available():
return
if not dist.is_initialized():
return
world_size = dist.get_world_size()
if world_size == 1:
return
dist.barrier()
def get_world_size():
if not dist.is_available():
return 1
if not dist.is_initialized():
return 1
return dist.get_world_size()
def reduce_sum(tensor):
if not dist.is_available():
return tensor
if not dist.is_initialized():
return tensor
tensor = tensor.clone()
dist.all_reduce(tensor, op=dist.ReduceOp.SUM)
return tensor
def gather_grad(params):
world_size = get_world_size()
if world_size == 1:
return
for param in params:
if param.grad is not None:
dist.all_reduce(param.grad.data, op=dist.ReduceOp.SUM)
param.grad.data.div_(world_size)
def all_gather(data):
world_size = get_world_size()
if world_size == 1:
return [data]
buffer = pickle.dumps(data)
storage = torch.ByteStorage.from_buffer(buffer)
tensor = torch.ByteTensor(storage).to('cuda')
local_size = torch.IntTensor([tensor.numel()]).to('cuda')
size_list = [torch.IntTensor([0]).to('cuda') for _ in range(world_size)]
dist.all_gather(size_list, local_size)
size_list = [int(size.item()) for size in size_list]
max_size = max(size_list)
tensor_list = []
for _ in size_list:
tensor_list.append(torch.ByteTensor(size=(max_size,)).to('cuda'))
if local_size != max_size:
padding = torch.ByteTensor(size=(max_size - local_size,)).to('cuda')
tensor = torch.cat((tensor, padding), 0)
dist.all_gather(tensor_list, tensor)
data_list = []
for size, tensor in zip(size_list, tensor_list):
buffer = tensor.cpu().numpy().tobytes()[:size]
data_list.append(pickle.loads(buffer))
return data_list
def reduce_loss_dict(loss_dict):
world_size = get_world_size()
if world_size < 2:
return loss_dict
with torch.no_grad():
keys = []
losses = []
for k in sorted(loss_dict.keys()):
keys.append(k)
losses.append(loss_dict[k])
losses = torch.stack(losses, 0)
dist.reduce(losses, dst=0)
if dist.get_rank() == 0:
losses /= world_size
reduced_losses = {k: v for k, v in zip(keys, losses)}
return reduced_losses