ColossalAI/colossalai/legacy/nn/layer/parallel_1d/_operation.py
Edenzzzz f5c84af0b0
[Feature] Zigzag Ring attention (#5905)
* halfway

* fix cross-PP-stage position id length diff bug

* fix typo

* fix typo

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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* unified cross entropy func for all shardformer models

* remove redundant lines

* add basic ring attn; debug cross entropy

* fwd bwd logic complete

* fwd bwd logic complete; add experimental triton rescale

* precision tests passed

* precision tests passed

* fix typos and remove misc files

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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* add sp_mode to benchmark; fix varlen interface

* update softmax_lse shape by new interface

* change tester name

* remove buffer clone; support packed seq layout

* add varlen tests

* fix typo

* all tests passed

* add dkv_group; fix mask

* remove debug statements

---------

Co-authored-by: Edenzzzz <wtan45@wisc.edu>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
2024-08-16 13:56:38 +08:00

99 lines
3.7 KiB
Python

import torch
import torch.distributed as dist
from colossalai.legacy.core import global_context as gpc
try:
import fused_mix_prec_layer_norm_cuda
except:
fused_mix_prec_layer_norm_cuda = None
class FusedLayerNormAffineFunction1D(torch.autograd.Function):
r"""Layernorm
Args:
input: input matrix.
weight: weight matrix.
bias: bias matrix.
normalized_shape: input shape from an expected input of size.
:math:`[* \times \text{normalized_shape}[0] \times \text{normalized_shape}[1] \times \ldots \times \text{normalized_shape}[-1]]`
If a single integer is used, it is treated as a singleton list, and this module will
normalize over the last dimension which is expected to be of that specific size.
eps: a value added to the denominator for numerical stability
"""
@staticmethod
def forward(ctx, input, weight, bias, normalized_shape, eps):
ctx.normalized_shape = normalized_shape
ctx.eps = eps
input_ = input.contiguous()
weight_ = weight.contiguous()
bias_ = bias.contiguous()
output, mean, invvar = fused_mix_prec_layer_norm_cuda.forward_affine(
input_, ctx.normalized_shape, weight_, bias_, ctx.eps
)
ctx.save_for_backward(input_, weight_, bias_, mean, invvar)
return output
@staticmethod
def backward(ctx, grad_output):
input_, weight_, bias_, mean, invvar = ctx.saved_tensors
grad_input = grad_weight = grad_bias = None
grad_input, grad_weight, grad_bias = fused_mix_prec_layer_norm_cuda.backward_affine(
grad_output.contiguous(), mean, invvar, input_, ctx.normalized_shape, weight_, bias_, ctx.eps
)
return grad_input, grad_weight, grad_bias, None, None
class LinearWithAsyncCommunication(torch.autograd.Function):
"""
Linear layer execution with asynchronous communication in backprop.
"""
@staticmethod
def forward(ctx, input_, weight, bias, parallel_mode, async_grad_allreduce):
ctx.save_for_backward(input_, weight)
ctx.use_bias = bias is not None
ctx.parallel_mode = parallel_mode
ctx.async_grad_allreduce = async_grad_allreduce
output = torch.matmul(input_, weight.t())
if bias is not None:
output = output + bias
return output
@staticmethod
def backward(ctx, grad_output):
input, weight = ctx.saved_tensors
use_bias = ctx.use_bias
total_input = input
grad_input = grad_output.matmul(weight)
# Convert the tensor shapes to 2D for execution compatibility
grad_output = grad_output.view(grad_output.shape[0] * grad_output.shape[1], grad_output.shape[2])
total_input = total_input.view(total_input.shape[0] * total_input.shape[1], total_input.shape[2])
if ctx.async_grad_allreduce:
# Asynchronous all-reduce
handle = dist.all_reduce(grad_input, group=gpc.get_group(ctx.parallel_mode), async_op=True)
# Delay the start of weight gradient computation shortly (3us) to have
# all-reduce scheduled first and have GPU resources allocated
# TODO: This seems to only work if you add torch.cuda.Event.wait()
# _ = torch.zeros(1, device=grad_output.device)
grad_weight = grad_output.t().matmul(total_input)
grad_bias = grad_output.sum(dim=0) if use_bias else None
if ctx.async_grad_allreduce:
handle.wait()
return grad_input, grad_weight, grad_bias, None, None, None
def linear_with_async_comm(input_, weight, bias, parallel_mode, async_grad_allreduce):
return LinearWithAsyncCommunication.apply(input_, weight, bias, parallel_mode, async_grad_allreduce)