|
"""A HuggingFace-style model configuration.""" |
|
import warnings |
|
from typing import Any, Dict, Optional, Union |
|
from transformers import PretrainedConfig |
|
attn_config_defaults: Dict = {'attn_type': 'multihead_attention', 'attn_pdrop': 0.0, 'attn_impl': 'triton', 'qk_ln': False, 'clip_qkv': None, 'softmax_scale': None, 'prefix_lm': False, 'attn_uses_sequence_id': False, 'alibi': False, 'alibi_bias_max': 8} |
|
ffn_config_defaults: Dict = {'ffn_type': 'mptmlp'} |
|
init_config_defaults: Dict = {'name': 'kaiming_normal_', 'fan_mode': 'fan_in', 'init_nonlinearity': 'relu', 'init_div_is_residual': True, 'emb_init_std': None, 'emb_init_uniform_lim': None, 'init_std': None, 'init_gain': 0.0} |
|
|
|
class MPTConfig(PretrainedConfig): |
|
model_type = 'mpt' |
|
|
|
def __init__(self, hidden_size: int=2048, n_heads: int=16, n_layers: int=24, expansion_ratio: int=4, max_seq_len: int=2048, vocab_size: int=50368, resid_pdrop: float=0.0, emb_pdrop: float=0.0, learned_pos_emb: bool=True, attn_config: Dict=attn_config_defaults, ffn_config: Dict=ffn_config_defaults, init_device: str='cpu', logit_scale: Optional[Union[float, str]]=None, no_bias: bool=False, embedding_fraction: float=1.0, norm_type: str='low_precision_layernorm', use_cache: bool=False, init_config: Dict=init_config_defaults, fc_type: str='torch', verbose: Optional[int]=None, **kwargs: Any): |
|
"""The MPT configuration class. |
|
|
|
Args: |
|
hidden_size (int): The size of the embedding dimension of the model. |
|
n_heads (int): The number of attention heads. |
|
n_layers (int): The number of layers in the model. |
|
expansion_ratio (int): The ratio of the up/down scale in the ffn. |
|
max_seq_len (int): The maximum sequence length of the model. |
|
vocab_size (int): The size of the vocabulary. |
|
resid_pdrop (float): The dropout probability applied to the attention output before combining with residual. |
|
emb_pdrop (float): The dropout probability for the embedding layer. |
|
learned_pos_emb (bool): Whether to use learned positional embeddings |
|
attn_config (Dict): A dictionary used to configure the model's attention module: |
|
attn_type (str): type of attention to use. Options: multihead_attention, multiquery_attention, grouped_query_attention |
|
attn_pdrop (float): The dropout probability for the attention layers. |
|
attn_impl (str): The attention implementation to use. One of 'torch', 'flash', or 'triton'. |
|
qk_ln (bool): Whether to apply layer normalization to the queries and keys in the attention layer. |
|
clip_qkv (Optional[float]): If not None, clip the queries, keys, and values in the attention layer to |
|
this value. |
|
softmax_scale (Optional[float]): If not None, scale the softmax in the attention layer by this value. If None, |
|
use the default scale of ``1/sqrt(d_keys)``. |
|
prefix_lm (Optional[bool]): Whether the model should operate as a Prefix LM. This requires passing an |
|
extra `prefix_mask` argument which indicates which tokens belong to the prefix. Tokens in the prefix |
|
can attend to one another bi-directionally. Tokens outside the prefix use causal attention. |
|
attn_uses_sequence_id (Optional[bool]): Whether to restrict attention to tokens that have the same sequence_id. |
|
When the model is in `train` mode, this requires passing an extra `sequence_id` argument which indicates |
|
which sub-sequence each token belongs to. |
|
Defaults to ``False`` meaning any provided `sequence_id` will be ignored. |
|
alibi (bool): Whether to use the alibi bias instead of position embeddings. |
|
alibi_bias_max (int): The maximum value of the alibi bias. |
|
kv_n_heads (Optional[int]): For grouped_query_attention only, allow user to specify number of kv heads. |
|
ffn_config (Dict): A dictionary used to configure the model's ffn module: |
|
ffn_type (str): type of ffn to use. Options: mptmlp, te_ln_mlp |
|
init_device (str): The device to use for parameter initialization. |
|
logit_scale (Optional[Union[float, str]]): If not None, scale the logits by this value. |
|
no_bias (bool): Whether to use bias in all layers. |
|
verbose (int): The verbosity level. 0 is silent. |
|
embedding_fraction (float): The fraction to scale the gradients of the embedding layer by. |
|
norm_type (str): choose type of norm to use |
|
use_cache (bool): Whether or not the model should return the last key/values attentions |
|
init_config (Dict): A dictionary used to configure the model initialization: |
|
init_config.name: The parameter initialization scheme to use. Options: 'default_', 'baseline_', |
|
'kaiming_uniform_', 'kaiming_normal_', 'neox_init_', 'small_init_', 'xavier_uniform_', or |
|
'xavier_normal_'. These mimic the parameter initialization methods in PyTorch. |
|
init_div_is_residual (Union[int, float, str, bool]): Value to divide initial weights by if ``module._is_residual`` is True. |
|
emb_init_std (Optional[float]): The standard deviation of the normal distribution used to initialize the embedding layer. |
|
emb_init_uniform_lim (Optional[Union[Tuple[float, float], float]]): The lower and upper limits of the uniform distribution |
|
used to initialize the embedding layer. Mutually exclusive with ``emb_init_std``. |
|
init_std (float): The standard deviation of the normal distribution used to initialize the model, |
|
if using the baseline_ parameter initialization scheme. |
|
init_gain (float): The gain to use for parameter initialization with kaiming or xavier initialization schemes. |
|
fan_mode (str): The fan mode to use for parameter initialization with kaiming initialization schemes. |
|
init_nonlinearity (str): The nonlinearity to use for parameter initialization with kaiming initialization schemes. |
|
--- |
|
See llmfoundry.models.utils.param_init_fns.py for info on other param init config options |
|
fc_type (str): choose fc layer implementation. Options: torch and te. te layers support fp8 when using H100 GPUs. |
|
""" |
|
self.hidden_size = hidden_size |
|
self.n_heads = n_heads |
|
self.n_layers = n_layers |
|
self.expansion_ratio = expansion_ratio |
|
self.max_seq_len = max_seq_len |
|
self.vocab_size = vocab_size |
|
self.resid_pdrop = resid_pdrop |
|
self.emb_pdrop = emb_pdrop |
|
self.learned_pos_emb = learned_pos_emb |
|
self.attn_config = attn_config |
|
self.ffn_config = ffn_config |
|
self.init_device = init_device |
|
self.logit_scale = logit_scale |
|
self.no_bias = no_bias |
|
self.embedding_fraction = embedding_fraction |
|
self.norm_type = norm_type |
|
self.use_cache = use_cache |
|
self.init_config = init_config |
|
self.fc_type = fc_type |
|
if verbose is not None: |
|
warnings.warn(DeprecationWarning('verbose argument for MPTConfig is now ignored and will be removed. Use python_log_level instead.')) |
|
if 'name' in kwargs: |
|
del kwargs['name'] |
|
if 'loss_fn' in kwargs: |
|
del kwargs['loss_fn'] |
|
if self.attn_config.get('alibi', False): |
|
self.learned_pos_emb = False |
|
warnings.warn(f'alibi is turned on, setting `learned_pos_emb` to `False.`') |
|
super().__init__(**kwargs) |
|
self._validate_config() |
|
|
|
def _set_config_defaults(self, config: Dict[str, Any], config_defaults: Dict[str, Any]) -> Dict[str, Any]: |
|
for (k, v) in config_defaults.items(): |
|
if k not in config: |
|
config[k] = v |
|
return config |
|
|
|
def _validate_config(self) -> None: |
|
self.attn_config = self._set_config_defaults(self.attn_config, attn_config_defaults) |
|
self.ffn_config = self._set_config_defaults(self.ffn_config, ffn_config_defaults) |
|
self.init_config = self._set_config_defaults(self.init_config, init_config_defaults) |
|
if self.hidden_size % self.n_heads != 0: |
|
raise ValueError('hidden_size must be divisible by n_heads') |
|
if any((prob < 0 or prob > 1 for prob in [self.attn_config['attn_pdrop'], self.resid_pdrop, self.emb_pdrop])): |
|
raise ValueError("self.attn_config['attn_pdrop'], resid_pdrop, emb_pdrop are probabilities and must be between 0 and 1") |
|
if self.attn_config['attn_impl'] not in ['torch', 'flash', 'triton']: |
|
raise ValueError(f"Unknown attn_impl={self.attn_config['attn_impl']}") |
|
if self.attn_config['prefix_lm'] and self.attn_config['attn_impl'] not in ['torch', 'triton']: |
|
raise NotImplementedError('prefix_lm only implemented with torch and triton attention.') |
|
if self.attn_config['alibi'] and self.attn_config['attn_impl'] not in ['torch', 'triton']: |
|
raise NotImplementedError('alibi only implemented with torch and triton attention.') |
|
if self.attn_config['attn_uses_sequence_id'] and self.attn_config['attn_impl'] not in ['torch', 'triton']: |
|
raise NotImplementedError('attn_uses_sequence_id only implemented with torch and triton attention.') |
|
if self.embedding_fraction > 1 or self.embedding_fraction <= 0: |
|
raise ValueError('model.embedding_fraction must be between 0 (exclusive) and 1 (inclusive)!') |
|
if isinstance(self.logit_scale, str) and self.logit_scale != 'inv_sqrt_hidden_size': |
|
raise ValueError(f"self.logit_scale={self.logit_scale!r} is not recognized as an option; use numeric value or 'inv_sqrt_hidden_size'.") |
|
if self.init_config.get('name', None) is None: |
|
raise ValueError(f"self.init_config={self.init_config!r} 'name' needs to be set.") |
|
if not self.learned_pos_emb and (not self.attn_config['alibi']): |
|
warnings.warn(f'Positional information not being provided to the model using either learned_pos_emb or alibi.') |
|
if self.fc_type == 'te' or self.ffn_config['ffn_type'] == 'te_ln_mlp': |
|
try: |
|
import transformer_engine.pytorch as te |
|
del te |
|
except: |
|
raise ImportError('TransformerEngine import fail. `fc_type: te` requires TransformerEngine be installed. ' + 'The required version of transformer_engine also requires FlashAttention v1.0.6 is installed:\n' + 'pip install flash-attn==1.0.6 --no-build-isolation \n' + 'pip install git+https://github.com/NVIDIA/TransformerEngine.git@144e4888b2cdd60bd52e706d5b7a79cb9c1a7156') |
|
if self.ffn_config['ffn_type'] == 'mptmlp': |
|
self.ffn_config['fc_type'] = self.fc_type |
|
elif self.ffn_config['ffn_type'] == 'te_ln_mlp': |
|
self.ffn_config['bias'] = not self.no_bias |