hf_text-generation-inference/server/text_generation_server/utils/layers.py

275 lines
8.5 KiB
Python

import torch
from torch import nn
from torch.nn import functional as F
from typing import Optional
HAS_BITS_AND_BYTES = True
try:
from bitsandbytes.nn import Linear8bitLt
except ImportError as e:
HAS_BITS_AND_BYTES = False
class FastLinear(nn.Linear):
def __init__(
self,
in_features: int,
out_features: int,
bias: bool = True,
device=None,
dtype=None,
) -> None:
super(FastLinear, self).__init__(in_features, out_features, bias, device, dtype)
self.quantized = False
self.bnb_linear = None
def prepare_weights(self, quantize: Optional[str] = None):
if quantize == "bitsandbytes":
if not HAS_BITS_AND_BYTES:
raise ImportError(
"bitsandbytes is not available on your machine either because it is not installed "
"or you don't have a GPU.\n"
"You can install it with `pip install bitsandbytes`."
)
self.quantized = True
self.bnb_linear = Linear8bitLt(
self.in_features,
self.out_features,
has_fp16_weights=False,
threshold=6.0,
bias=False,
)
# Copy data to bnb_linear
self.bnb_linear.weight.data = self.weight.data
if self.bias is not None:
self.bnb_linear.bias = nn.Parameter(self.bias)
# Delete reference to data
self.weight = None
self.bias = None
elif quantize == "gptq":
raise NotImplementedError("`gptq` is not implemented for now")
elif quantize is None:
self.weight = nn.Parameter(self.weight.T)
else:
raise ValueError(f"Unexpected quantize `{quantize}`")
def forward(self, input: torch.Tensor) -> torch.Tensor:
if self.quantized:
return self.bnb_linear(input)
else:
if self.bias is not None:
return torch.addmm(self.bias, input, self.weight)
return torch.matmul(input, self.weight)
class TensorParallelColumnLinear(FastLinear):
def __init__(
self,
in_features,
out_features,
process_group: torch.distributed.ProcessGroup,
bias=True,
device=None,
dtype=None,
):
self.process_group = process_group
self.tp_world_size = process_group.size()
assert out_features % self.tp_world_size == 0
out_features = out_features // self.tp_world_size
super().__init__(
in_features=in_features,
out_features=out_features,
bias=bias,
device=device,
dtype=dtype,
)
class TensorParallelRowLinear(FastLinear):
def __init__(
self,
in_features,
out_features,
process_group: torch.distributed.ProcessGroup,
reduce=True,
bias=True,
device=None,
dtype=None,
):
self.process_group = process_group
self.tp_world_size = process_group.size()
self.reduce = reduce
assert in_features % self.tp_world_size == 0
in_features = in_features // self.tp_world_size
super().__init__(
in_features=in_features,
out_features=out_features,
bias=bias,
device=device,
dtype=dtype,
)
def forward(self, input: torch.Tensor) -> torch.Tensor:
out = super(TensorParallelRowLinear, self).forward(input)
if self.reduce:
torch.distributed.all_reduce(out, group=self.process_group)
return out
class TensorParallelEmbedding(nn.Embedding):
def __init__(
self,
num_embeddings,
embedding_dim,
process_group: torch.distributed.ProcessGroup,
reduce=True,
padding_idx=None,
max_norm=None,
norm_type=2.0,
scale_grad_by_freq=False,
sparse=False,
_weight=None,
device=None,
dtype=None,
):
self.reduce = reduce
self.process_group = process_group
self.tp_rank = process_group.rank()
self.tp_world_size = process_group.size()
self.original_num_embeddings = num_embeddings
assert num_embeddings % self.tp_world_size == 0
block_size = num_embeddings // self.tp_world_size
# inputs in `[min_id, max_id[` are handled by `self` to get embeddings
self.min_id = self.tp_rank * block_size
self.max_id = (self.tp_rank + 1) * block_size
# Additional entry that will map to zero
# Used for masking
self.null_idx = block_size
super().__init__(
block_size,
embedding_dim,
padding_idx=padding_idx,
max_norm=max_norm,
norm_type=norm_type,
scale_grad_by_freq=scale_grad_by_freq,
sparse=sparse,
_weight=_weight,
device=device,
dtype=dtype,
)
def add_null_idx(self):
"""Additional 0 entry used for masking"""
self.weight = nn.Parameter(F.pad(self.weight, (0, 0, 0, 1)))
def forward(self, input: torch.Tensor) -> torch.Tensor:
# default all out of bounds values to `self.null_idx` that will then be mapped to 0
# translate for [0, self.max_id - self.min_id[
input = torch.where(
(self.min_id > input) | (input >= self.max_id),
self.null_idx,
input - self.min_id,
)
out = super().forward(input)
if self.reduce:
torch.distributed.all_reduce(out, group=self.process_group)
return out
try:
import dropout_layer_norm
class FastLayerNorm(nn.LayerNorm):
def forward(self, hidden_states, residual=None):
if hidden_states.shape[-1] > 8192:
if residual is not None:
hidden_states += residual
residual = hidden_states
return super(FastLayerNorm, self).forward(hidden_states), residual
else:
(
normed_hidden_states,
residual,
*rest,
) = dropout_layer_norm.dropout_add_ln_fwd(
hidden_states,
residual,
self.weight,
self.bias,
None,
None,
None,
None,
0.0,
self.eps,
1.0,
0,
None,
False,
False,
)
if residual is None:
residual = hidden_states
return normed_hidden_states, residual
except ImportError:
pass
try:
from flash_attn.layers.rotary import RotaryEmbedding
import rotary_emb
class PositionRotaryEmbedding(RotaryEmbedding):
def _update_cos_sin_cache(self, dtype, device, seqlen):
# Reset the tables if the sequence length has changed,
# or if we're on a new device (possibly due to tracing for instance)
if (
seqlen > self._seq_len_cached
or self._cos_cached.device != device
or self._cos_cached.dtype != dtype
):
self._seq_len_cached = seqlen
t = torch.arange(seqlen, device=device, dtype=self.inv_freq.dtype)
# Don't do einsum, it converts fp32 to fp16
# freqs = torch.einsum("i,j->ij", t, self.inv_freq)
freqs = torch.outer(t, self.inv_freq.to(device=t.device))
self._cos_cached = torch.cos(freqs).to(dtype)
self._sin_cached = torch.sin(freqs).to(dtype)
def get_cos_sin(
self, position_ids: torch.Tensor, max_s: int, dtype: torch.dtype
):
"""
Return cos and sin for the asked position ids
"""
self._update_cos_sin_cache(dtype, position_ids.device, max_s)
cos = torch.index_select(self._cos_cached, 0, position_ids)
sin = torch.index_select(self._sin_cached, 0, position_ids)
return cos.unsqueeze(1), sin.unsqueeze(1)
def forward(self, x: torch.Tensor, cos: torch.Tensor, sin: torch.Tensor):
rotary_dim = cos.shape[-1]
x1 = x[..., :rotary_dim]
x2 = x[..., rotary_dim : 2 * rotary_dim]
rotary_emb.apply_rotary(x1, x2, cos, sin, x1, x2, False)
return x
except ImportError:
pass