[zero] refactor model data tracing (#522)

pull/528/head^2
Jiarui Fang 2022-03-25 18:03:32 +08:00 committed by GitHub
parent 3601b2bad0
commit 8d8c5407c0
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8 changed files with 128 additions and 28 deletions

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@ -22,6 +22,7 @@ class ModelDataTracer(metaclass=SingletonMeta):
def __init__(self) -> None:
self._cuda_usage = 0
self._cpu_usage = 0
self._start_flag = False
def start(self) -> None:
@ -30,22 +31,33 @@ class ModelDataTracer(metaclass=SingletonMeta):
def close(self) -> None:
self._start_flag = False
def add_tensor(self, t: torch.Tensor) -> None:
def add_tensor(self, t: Union[torch.Tensor, ShardedTensor]) -> None:
if not self._start_flag:
return
assert isinstance(t, torch.Tensor), f"ModelDataTracer add_tensor() should accept a torch.Tensor"
mem_use = _col_tensor_mem_usage(t)
self._cuda_usage += mem_use
t_payload = t.payload if isinstance(t, ShardedTensor) else t
mem_use = _col_tensor_mem_usage(t_payload)
if t_payload.device.type == 'cuda':
self._cuda_usage += mem_use
elif t_payload.device.type == 'cpu':
self._cpu_usage += mem_use
else:
raise TypeError
def delete_tensor(self, t: torch.Tensor) -> None:
def delete_tensor(self, t: Union[torch.Tensor, ShardedTensor]) -> None:
if not self._start_flag:
return
assert isinstance(t, torch.Tensor), f"ModelDataTracer delete_tensor() should accept a torch.Tensor"
mem_use = _col_tensor_mem_usage(t)
self._cuda_usage -= mem_use
t_payload = t.payload if isinstance(t, ShardedTensor) else t
mem_use = _col_tensor_mem_usage(t_payload)
if t_payload.device.type == 'cuda':
self._cuda_usage -= mem_use
elif t_payload.device.type == 'cpu':
self._cpu_usage -= mem_use
else:
raise TypeError
def clear(self) -> None:
self._cuda_usage = 0
self._cpu_usage = 0
@property
def cpu_usage(self):

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@ -3,7 +3,7 @@ from colossalai.utils import get_current_device
from colossalai.zero.sharded_param.sharded_tensor import ShardedTensor
from colossalai.utils.memory_tracer.model_data_memtracer import GLOBAL_MODEL_DATA_TRACER
from typing import Union, Optional
from typing import Union
_GLOBAL_CUDA_MEM_FRACTION = 1.0
@ -52,11 +52,9 @@ def colo_model_data_tensor_move(src_t: Union[ShardedTensor, torch.Tensor], tgt_t
tgt_t_payload = tgt_t.data
tgt_dev = tgt_t_payload.device
if src_dev.type == 'cuda' and tgt_dev.type == 'cpu':
GLOBAL_MODEL_DATA_TRACER.delete_tensor(src_t_payload)
elif src_dev.type == 'cpu' and tgt_dev.type == 'cuda':
GLOBAL_MODEL_DATA_TRACER.add_tensor(tgt_t_payload)
GLOBAL_MODEL_DATA_TRACER.delete_tensor(src_t_payload)
tgt_t_payload.copy_(src_t_payload)
GLOBAL_MODEL_DATA_TRACER.add_tensor(tgt_t_payload)
# remove payload of src_t
if isinstance(src_t, ShardedTensor):
@ -65,7 +63,9 @@ def colo_model_data_tensor_move(src_t: Union[ShardedTensor, torch.Tensor], tgt_t
src_t.data = torch.tensor([], device=src_dev, dtype=src_t_payload.dtype)
def colo_model_data_tensor_move_inline(t: Union[ShardedTensor, torch.Tensor], target_device: torch.device) -> None:
def colo_model_data_tensor_move_inline(t: Union[ShardedTensor, torch.Tensor],
target_device: torch.device,
use_tracer: bool = True) -> None:
"""
move a tensor to the target_device
Args:
@ -84,13 +84,11 @@ def colo_model_data_tensor_move_inline(t: Union[ShardedTensor, torch.Tensor], ta
# deal with torch.device('cpu') and torch.device('cpu:0)
if t_payload.device.type == target_device.type:
return
if target_device.type == 'cuda':
GLOBAL_MODEL_DATA_TRACER.add_tensor(t_payload)
elif target_device.type == 'cpu':
if use_tracer:
GLOBAL_MODEL_DATA_TRACER.delete_tensor(t_payload)
t_payload.data = t_payload.data.to(target_device)
if use_tracer:
GLOBAL_MODEL_DATA_TRACER.add_tensor(t_payload)
def colo_model_data_move_to_cpu(t: Union[ShardedTensor, torch.Tensor]) -> None:
@ -115,3 +113,4 @@ def colo_model_data_move_to_cpu(t: Union[ShardedTensor, torch.Tensor]) -> None:
# TODO() optimize the tensor moving with non-blocking
GLOBAL_MODEL_DATA_TRACER.delete_tensor(t_payload)
t_payload.data = t_payload.data.cpu()
GLOBAL_MODEL_DATA_TRACER.add_tensor(t_payload)

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@ -177,13 +177,11 @@ class ZeroInitContext(InsertPostInitMethodToModuleSubClasses):
self.initialized_param_list.append(param)
GLOBAL_MODEL_DATA_TRACER.add_tensor(param.col_attr.sharded_data_tensor)
if self.shard_param:
self.shard_strategy.shard([param.col_attr.sharded_data_tensor], self.dp_process_group)
if param.col_attr.sharded_data_tensor.device.type == 'cuda':
GLOBAL_MODEL_DATA_TRACER.add_tensor(param.col_attr.sharded_data_tensor.payload)
# if param.col_attr.grad and self.shard_grad:
# self.shard_strategy.shard([param.col_attr._grad_sharded_tensor], self.dp_process_group)
# GLOBAL_MODEL_DATA_TRACER.add_tensor(param.col_attr._grad_sharded_tensor.payload)
# We must cast buffers
# If we use BN, buffers may be on CPU and Float
# We must cast them

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@ -7,6 +7,7 @@ from colossalai.zero.sharded_param.sharded_tensor import ShardedTensor
from torch._utils import _flatten_dense_tensors as flatten
from .tensor_shard_strategy import TensorShardStrategy
from colossalai.utils.memory_tracer.model_data_memtracer import GLOBAL_MODEL_DATA_TRACER
class BucketTensorShardStrategy(TensorShardStrategy):
@ -17,6 +18,9 @@ class BucketTensorShardStrategy(TensorShardStrategy):
"""
def gather(self, tensor_list: List[ShardedTensor], process_group: Optional[dist.ProcessGroup] = None):
for t in tensor_list:
GLOBAL_MODEL_DATA_TRACER.delete_tensor(t)
tensor_list: List[ShardedTensor] = [t for t in tensor_list if t.is_sharded]
if len(tensor_list) == 0:
return
@ -46,3 +50,6 @@ class BucketTensorShardStrategy(TensorShardStrategy):
t.reset_payload(gathered_payload)
t.is_sharded = False
offset += tensor_numels[i]
for t in tensor_list:
GLOBAL_MODEL_DATA_TRACER.add_tensor(t)

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@ -3,13 +3,16 @@ from typing import List, Optional
import torch
import torch.distributed as dist
from colossalai.utils import get_current_device
from colossalai.utils.memory_utils.utils import colo_model_data_tensor_move, colo_model_data_tensor_move_inline
from colossalai.zero.shard_utils import BaseShardStrategy
from colossalai.zero.shard_utils.commons import get_shard
from colossalai.zero.sharded_param.sharded_tensor import ShardedTensor
from colossalai.utils.memory_tracer.model_data_memtracer import GLOBAL_MODEL_DATA_TRACER
class TensorShardStrategy(BaseShardStrategy):
"""A naive implementation which shard each tensor evenly over all ranks
"""
A naive implementation which shard each tensor evenly over all ranks
"""
def shard(self, tensor_list: List[ShardedTensor], process_group: Optional[dist.ProcessGroup] = None):
@ -21,13 +24,22 @@ class TensorShardStrategy(BaseShardStrategy):
self._gather_tensor(t, process_group)
def _shard_tensor(self, t: ShardedTensor, process_group: Optional[dist.ProcessGroup] = None):
""" Shard tensor among processes.
Args:
t (ShardedTensor): a tensor to be sharded.
process_group (Optional[dist.ProcessGroup], optional): the process group among which tensor shards.
Defaults to None.
"""
if t.is_sharded:
return
if t.payload.device.type == 'cuda':
assert t.payload.device.index == get_current_device(), f"shard tensor on cuda device index {t.payload.device.index},"\
f" but current cuda device is {get_current_device()}"
GLOBAL_MODEL_DATA_TRACER.delete_tensor(t.payload)
sharded_payload, _ = get_shard(t.payload, dist.get_rank(process_group), dist.get_world_size(process_group))
t.reset_payload(sharded_payload)
GLOBAL_MODEL_DATA_TRACER.add_tensor(t.payload)
t.is_sharded = True
def _gather_tensor(self, t: ShardedTensor, process_group: Optional[dist.ProcessGroup] = None):
@ -44,8 +56,10 @@ class TensorShardStrategy(BaseShardStrategy):
else:
buffer_list.append(torch.zeros(payload_numel, dtype=t.dtype, device=get_current_device()))
GLOBAL_MODEL_DATA_TRACER.delete_tensor(t.payload)
dist.all_gather(buffer_list, buffer_list[rank], group=process_group, async_op=False)
gathered_payload = torch.narrow(torch.cat(buffer_list), 0, 0, t.origin_numel).reshape(t.origin_shape)
t.reset_payload(gathered_payload)
t.to(target_device)
colo_model_data_tensor_move_inline(t, target_device, use_tracer=False)
GLOBAL_MODEL_DATA_TRACER.delete_tensor(t.payload)
t.is_sharded = False

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@ -56,7 +56,10 @@ class ShardedTensor(object):
return self._origin_dtype
def to(self, device: torch.device):
self._payload = self._payload.to(device)
raise RuntimeError("Use colo_model_tensor_move install of call .to() on ShardedTensor")
def to_(self, device: torch.device):
raise RuntimeError("Use colo_model_tensor_move install of call .to_() on ShardedTensor")
@property
def shape(self):

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@ -0,0 +1,66 @@
import pytest
from colossalai.utils.cuda import get_current_device
from colossalai.utils.memory_tracer.model_data_memtracer import GLOBAL_MODEL_DATA_TRACER
from colossalai.utils.memory_utils.utils import colo_model_data_tensor_move, colo_model_data_tensor_move_inline
from colossalai.zero.sharded_param import ShardedTensor
import colossalai
import torch
from functools import partial
import torch.multiprocessing as mp
from colossalai.utils import free_port
def _run_colo_model_data_tensor_move_inline():
assert (GLOBAL_MODEL_DATA_TRACER.cuda_usage == 0)
GLOBAL_MODEL_DATA_TRACER.start()
for t in [torch.randn(2, 3), ShardedTensor(torch.randn(2, 3))]:
GLOBAL_MODEL_DATA_TRACER.add_tensor(t)
assert GLOBAL_MODEL_DATA_TRACER.cpu_usage == 2 * 3 * 4
assert GLOBAL_MODEL_DATA_TRACER.cuda_usage == 0
colo_model_data_tensor_move_inline(t, torch.device(f"cuda:{get_current_device()}"))
assert t.device == torch.device(f"cuda:{get_current_device()}")
assert GLOBAL_MODEL_DATA_TRACER.cpu_usage == 0
assert GLOBAL_MODEL_DATA_TRACER.cuda_usage == 2 * 3 * 4
GLOBAL_MODEL_DATA_TRACER.clear()
GLOBAL_MODEL_DATA_TRACER.close()
def _run_colo_model_data_tensor_move():
assert (GLOBAL_MODEL_DATA_TRACER.cuda_usage == 0)
GLOBAL_MODEL_DATA_TRACER.start()
for t in [(torch.ones(2, 3), torch.zeros(2, 3).cuda(get_current_device())),
(ShardedTensor(torch.ones(2, 3)), ShardedTensor(torch.zeros(2, 3).cuda(get_current_device())))]:
cpu_t, cuda_t = t
GLOBAL_MODEL_DATA_TRACER.add_tensor(cpu_t)
assert GLOBAL_MODEL_DATA_TRACER.cpu_usage == 2 * 3 * 4
assert GLOBAL_MODEL_DATA_TRACER.cuda_usage == 0
colo_model_data_tensor_move(cpu_t, cuda_t)
assert GLOBAL_MODEL_DATA_TRACER.cpu_usage == 0
assert GLOBAL_MODEL_DATA_TRACER.cuda_usage == 2 * 3 * 4
GLOBAL_MODEL_DATA_TRACER.clear()
GLOBAL_MODEL_DATA_TRACER.close()
def run_dist(rank, world_size, port):
colossalai.launch(config={}, rank=rank, world_size=world_size, host='localhost', port=port, backend='nccl')
_run_colo_model_data_tensor_move_inline()
_run_colo_model_data_tensor_move()
@pytest.mark.dist
@pytest.mark.parametrize("world_size", [1, 4])
def test_tensor_move(world_size):
run_func = partial(run_dist, world_size=world_size, port=free_port())
mp.spawn(run_func, nprocs=world_size)
if __name__ == '__main__':
test_tensor_move(4)

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@ -48,6 +48,8 @@ def run_model_test(init_device_type, shard_strategy_class):
f'{param.col_attr.sharded_data_tensor.payload.device.type} vs. {init_device.type}'
if init_device.type == 'cuda':
assert (GLOBAL_MODEL_DATA_TRACER.cuda_usage > 0)
else:
assert (GLOBAL_MODEL_DATA_TRACER.cpu_usage > 0)
GLOBAL_MODEL_DATA_TRACER.clear()
@ -65,5 +67,4 @@ def test_zero_init_context(world_size):
if __name__ == '__main__':
# test_zero_init_context(2, torch.device('cpu'), TensorShardStrategy)
test_zero_init_context(4)