hf_text-generation-inference/server/text_generation/models/bloom.py

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import torch
import torch.distributed
from typing import List, Optional
from accelerate import init_empty_weights
from safetensors import safe_open
from transformers import AutoTokenizer, AutoModelForCausalLM, AutoConfig
from transformers.models.bloom.parallel_layers import (
TensorParallelColumnLinear,
TensorParallelEmbedding,
TensorParallelRowLinear,
)
from text_generation.models import Model
from text_generation.utils import (
initialize_torch_distributed,
weight_files,
download_weights,
)
HAS_BITS_AND_BYTES = True
try:
import bitsandbytes as bnb
from bitsandbytes.nn import Int8Params
except Exception as e:
HAS_BITS_AND_BYTES = False
torch.manual_seed(0)
class BLOOMSharded(Model):
def __init__(self, model_name: str, quantize: bool = False):
super(Model, self).__init__()
self.process_group, self.rank, self.world_size = initialize_torch_distributed()
self.master = self.rank == 0
if torch.cuda.is_available():
self.device = torch.device(f"cuda:{self.rank}")
dtype = torch.float16
else:
self.device = torch.device("cpu")
dtype = torch.float32
self.tokenizer = AutoTokenizer.from_pretrained(model_name, padding_side="left")
config = AutoConfig.from_pretrained(
model_name, slow_but_exact=False, tp_parallel=True
)
config.pad_token_id = 3
self.num_heads = config.n_head // self.process_group.size()
# The flag below controls whether to allow TF32 on matmul. This flag defaults to False
# in PyTorch 1.12 and later.
torch.backends.cuda.matmul.allow_tf32 = True
# The flag below controls whether to allow TF32 on cuDNN. This flag defaults to True.
torch.backends.cudnn.allow_tf32 = True
# Only download weights for small models
if self.master and model_name == "bigscience/bloom-560m":
download_weights(model_name, extension=".safetensors")
torch.distributed.barrier(group=self.process_group)
filenames = weight_files(model_name, extension=".safetensors")
with init_empty_weights():
model = AutoModelForCausalLM.from_config(config)
torch.distributed.barrier(group=self.process_group)
self.load_weights(
model,
filenames,
quantize=quantize,
device=self.device,
rank=self.rank,
world_size=self.world_size,
)
self.model = model.eval().to(dtype)
torch.distributed.barrier(group=self.process_group)
@staticmethod
def load_weights(
model,
filenames: List[str],
quantize: bool,
device: torch.device,
rank: int,
world_size: int,
):
parameters = dict(model.named_parameters())
for file in filenames:
with safe_open(
file, framework="pt", device=str(device) if not quantize else "cpu"
) as f:
for name in f.keys():
full_name = f"transformer.{name}"
module_name, param_name = full_name.rsplit(".", 1)
module = model.get_submodule(module_name)
current_tensor = parameters[full_name]
slice_ = f.get_slice(name)
if isinstance(module, TensorParallelColumnLinear):
if param_name == "weight":
size = slice_.get_shape()[0]
block_size = size // world_size
start = rank * block_size
stop = (rank + 1) * block_size
tensor = slice_[start:stop]
tensor = tensor.transpose(1, 0)
else:
size = slice_.get_shape()[0]
block_size = size // world_size
start = rank * block_size
stop = (rank + 1) * block_size
tensor = slice_[start:stop]
elif isinstance(module, TensorParallelRowLinear):
if param_name == "weight":
size = slice_.get_shape()[1]
block_size = size // world_size
start = rank * block_size
stop = (rank + 1) * block_size
tensor = slice_[:, start:stop]
tensor = tensor.transpose(1, 0)
else:
tensor = slice_[:]
# XXX: Hack for Rowlinear to add the bias only once.
if rank != 0:
tensor = torch.zeros_like(tensor)
elif isinstance(module, TensorParallelEmbedding):
size = slice_.get_shape()[0]
block_size = size // world_size
start = rank * block_size
stop = (rank + 1) * block_size
tensor = slice_[start:stop]
else:
tensor = slice_[:]
if current_tensor.shape != tensor.shape:
raise ValueError(
f"Name {name} -- Current {current_tensor.shape} and got {tensor.shape}"
)
tensor = tensor.contiguous()
if quantize:
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`."
)
if (
type(module)
in [TensorParallelRowLinear, TensorParallelColumnLinear]
and param_name == "weight"
):
tensor = Int8Params(
tensor.transpose(1, 0),
has_fp16_weights=False,
requires_grad=False,
).to(device)
state = bnb.MatmulLtState()
state.threshold = 6.0
state.has_fp16_weights = False
state.memory_efficient_backward = False
state.use_pool = True
state.CB = tensor.CB
state.SCB = tensor.SCB
tensor.CB = None
tensor.SCB = None
def replace_linear(state, in_features, out_features):
def linear(input, weight, bias):
size_out = input.size()[:-1] + (out_features,)
input = input.view(-1, in_features)
out = torch.empty(
size_out, device=input.device, dtype=input.dtype
)
out = bnb.matmul(
input,
weight,
out=out.view(-1, out_features),
state=state,
threshold=state.threshold,
bias=bias,
)
if state.CB is not None:
# we converted 8-bit row major to turing/ampere format
# in the first inference pass
# we no longer need the row-major weight
del state.CB
weight.data = state.CxB
return out.view(size_out)
return linear
module.linear = replace_linear(
state, module.in_features, module.out_features
)
else:
tensor = tensor.to(device)
module._parameters[param_name] = tensor
if name == "word_embeddings.weight":
model.lm_head._parameters["weight"] = tensor
def forward(self, input_ids, attention_mask, past_key_values: Optional = None):
outputs = self.model.forward(
input_ids=input_ids,
attention_mask=attention_mask,
past_key_values=past_key_values,
use_cache=True,
)
# Logits are sharded, so we need to gather them
logits_shard = outputs.logits[:, -1, :].contiguous()
batch_size, vocab_shard_size = logits_shard.shape
vocab_size = self.world_size * vocab_shard_size
logits = [torch.empty_like(logits_shard) for _ in range(self.world_size)]
torch.distributed.all_gather(logits, logits_shard, group=self.process_group)
logits = torch.cat(logits, dim=1).view(batch_size, 1, vocab_size)
outputs.logits = logits
return outputs