[fp8] Disable all_gather intranode. Disable Redundant all_gather fp8 (#6059)

* all_gather only internode, fix pytest

* fix cuda arch <89 compile pytest error

* fix pytest failure

* disable all_gather_into_tensor_flat_fp8

* fix fp8 format

* fix pytest

* fix conversations

* fix chunk tuple to list
This commit is contained in:
Guangyao Zhang
2024-09-14 10:40:01 +08:00
committed by GitHub
parent 696fced0d7
commit f20b066c59
8 changed files with 43 additions and 147 deletions

View File

@@ -10,6 +10,10 @@ from torch.distributed import ReduceOp
SUPPORT_TORCH_COMPILE = Version(torch.__version__) >= Version("2.4.0")
SCALE_BYTES = 4
try:
cuda_arch = int("".join(str(i) for i in torch.cuda.get_device_capability()))
except:
cuda_arch = 0
class Handle:
@@ -185,7 +189,7 @@ def all_reduce_fp8(
return dist.all_reduce(tensor, op=op, group=group, async_op=async_op)
@torch.compile(mode="max-autotune-no-cudagraphs", dynamic=False)
@torch.compile(mode="max-autotune-no-cudagraphs", dynamic=False, disable=cuda_arch < 89)
def _all_to_all_single_fp8(
output, input, output_split_sizes=None, input_split_sizes=None, fp8_format="e5m2", group=None, async_op=False
) -> Optional[Handle]:
@@ -606,79 +610,7 @@ def split_chunk_by_channel(
return chunk.split(sizes)
def all_gather_into_tensor_flat_fp8(
output_tensor: torch.Tensor,
input_tensor: torch.Tensor,
output_shape: torch.Size,
group: dist.ProcessGroup,
fp8_format: str = "e4m3",
async_op: bool = False,
) -> Optional[Handle]:
"""all gather into tensor in fp8 format
Args:
output_tensor (torch.Tensor): output tensor, which is flattened
input_tensor (torch.Tensor): input tensor, which is flattened
group (dist.ProcessGroup): process group
fp8_format (str, optional): fp8 format, e4m3 or e5m2. Defaults to "e4m3".
"""
assert input_tensor.dim() == 1 and output_tensor.dim() == 1, "input/output tensor should be flattened"
world_size = dist.get_world_size(group)
assert (
output_tensor.numel() == input_tensor.numel() * world_size
), "output tensor size should be world_size times of input tensor size"
input_type = output_tensor.dtype
fp8_type = torch.float8_e4m3fn if fp8_format == "e4m3" else torch.float8_e5m2
fp8_max = torch.finfo(fp8_type).max
if len(output_shape) == 2:
per_channel_max = torch.zeros(output_shape[0], device=output_tensor.device, dtype=torch.float)
num_channels, channel_size = output_shape
rank = dist.get_rank(group)
channel_start_idx = (input_tensor.numel() * rank) // channel_size
per_channel_splits = split_chunk_by_channel(input_tensor, channel_size, num_channels, rank, world_size)
for i, per_channel_split in enumerate(per_channel_splits):
idx = i + channel_start_idx
if idx < num_channels:
per_channel_max[idx] = per_channel_split.abs().max().float()
dist.all_reduce(per_channel_max, op=dist.ReduceOp.MAX, group=group)
per_channel_max = torch.where(per_channel_max > 0, per_channel_max, 1.0)
scale = fp8_max / per_channel_max
fp8_input = input_tensor.float()
fp8_per_channel_splits = split_chunk_by_channel(fp8_input, channel_size, num_channels, rank, world_size)
for i, per_channel_split in enumerate(fp8_per_channel_splits):
idx = i + channel_start_idx
if idx < num_channels:
per_channel_split.mul_(scale[idx])
fp8_input = fp8_input.to(fp8_type)
else:
per_tensor_max = input_tensor.abs().max().float()
dist.all_reduce(per_tensor_max, op=dist.ReduceOp.MAX, group=group)
per_tensor_max = torch.where(per_tensor_max > 0, per_tensor_max, 1.0)
scale = fp8_max / per_tensor_max
fp8_input = (scale * input_tensor.float()).to(fp8_type)
scale_inv = 1.0 / scale
buffer = torch.empty_like(output_tensor, dtype=fp8_type)
tensor_handle = dist.all_gather_into_tensor(
buffer.view(torch.uint8), fp8_input.view(torch.uint8), group=group, async_op=async_op
)
def cast_op():
numel = output_shape.numel()
valid_buffer = buffer[:numel].reshape(output_shape)
valid_buffer = cast_from_fp8(valid_buffer, scale_inv, input_type, per_channel_scale=(len(output_shape) == 2))
output_tensor[:numel].copy_(valid_buffer.view(-1))
if async_op:
return Handle([tensor_handle], cast_op)
else:
cast_op()
@torch.compile(mode="max-autotune-no-cudagraphs", dynamic=False)
@torch.compile(mode="max-autotune-no-cudagraphs", dynamic=False, disable=cuda_arch < 89)
def _all_to_all_fp8(output_list, input_list, group=None, fp8_format="e5m2", async_op=False):
world_size = dist.get_world_size(group)
input_type = input_list[0].dtype
@@ -718,8 +650,8 @@ def all_to_all_fp8(output_list, input_list, group=None, fp8_format="e5m2", async
return _all_to_all_fp8(output_list, input_list, group=group, fp8_format=fp8_format, async_op=async_op)
def gather_fp8(output_list, input_, group=None, fp8_format="e5m2", async_op: bool = False) -> Optional[Handle]:
@torch.compile(mode="max-autotune-no-cudagraphs", dynamic=False, disable=cuda_arch < 89)
def _all_gather_fp8(output_list, input_, group=None, fp8_format="e5m2", async_op: bool = False) -> Optional[Handle]:
world_size = dist.get_world_size(group)
input_type = input_.dtype
@@ -743,8 +675,17 @@ def gather_fp8(output_list, input_, group=None, fp8_format="e5m2", async_op: boo
cast_op()
@torch.compile(mode="max-autotune-no-cudagraphs", dynamic=False)
def all_gather_fp8(output_list, input_, group=None, fp8_format="e5m2", async_op: bool = False) -> Optional[Handle]:
if process_group_is_intranode(group):
return dist.all_gather(output_list, input_, group=group, async_op=async_op)
else:
return _all_gather_fp8(output_list, input_, group=group, fp8_format=fp8_format, async_op=async_op)
@torch.compile(mode="max-autotune-no-cudagraphs", dynamic=False, disable=cuda_arch < 89)
def all_gather_fp8_lagacy(
output_list, input_, group=None, fp8_format="e5m2", async_op: bool = False
) -> Optional[Handle]:
world_size = dist.get_world_size(group)
shape = input_.shape
input_type = input_.dtype
@@ -769,7 +710,7 @@ def all_gather_fp8(output_list, input_, group=None, fp8_format="e5m2", async_op:
# out.copy_(output[i].view(shape))
@torch.compile(mode="max-autotune-no-cudagraphs", dynamic=False)
@torch.compile(mode="max-autotune-no-cudagraphs", dynamic=False, disable=cuda_arch < 89)
def all_gather_fp8_ring(output_list, input_, group=None, fp8_format="e5m2", async_op: bool = False) -> Optional[Handle]:
world_size = dist.get_world_size(group)
rank = dist.get_rank(group)