configuration_btlm.py

# coding=utf-8
# Copyright 2023 The OpenAI Team Authors and HuggingFace Inc. team.
# Copyright (c) 2018, NVIDIA CORPORATION.  All rights reserved.
# Copyright 2023 Cerebras Systems.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
""" BTLM configuration"""

from transformers.configuration_utils import PretrainedConfig
from transformers.utils import logging


logger = logging.get_logger(__name__)

BTLM_PRETRAINED_CONFIG_ARCHIVE_MAP = {
    "cerebras/btlm-3b-8k-base": "https://huggingface.co/cerebras/btlm-3b-8k-base/resolve/main/config.json",
}


class BTLMConfig(PretrainedConfig):
    """
    This is the configuration class to store the configuration of a [`BTLMModel`]. It is used to instantiate a BTLM
    model according to the specified arguments, defining the model architecture.

    Configuration objects inherit from [`PretrainedConfig`] and can be used to control the model outputs. Read the
    documentation from [`PretrainedConfig`] for more information.


    Args:
        vocab_size (`int`, *optional*, defaults to 50257):
            Vocabulary size of the BTLM model. Defines the number of different tokens that can be represented by the
            `inputs_ids` passed when calling [`BTLMModel`].
        n_positions (`int`, *optional*, defaults to 1024):
            The maximum sequence length that this model might ever be used with. Typically set this to something large
            just in case (e.g., 512 or 1024 or 2048).
        n_embd (`int`, *optional*, defaults to 768):
            Dimensionality of the embeddings and hidden states.
        n_layer (`int`, *optional*, defaults to 12):
            Number of hidden layers in the Transformer encoder.
        n_head (`int`, *optional*, defaults to 12):
            Number of attention heads for each attention layer in the Transformer encoder.
        n_inner (`int`, *optional*, defaults to None):
            Dimensionality of the inner feed-forward layers. `None` will set it to 4 times n_embd
        activation_function (`str`, *optional*, defaults to `"gelu"`):
            Activation function, to be selected in the list `["relu", "silu", "gelu", "tanh", "gelu_new", "swiglu"]`.
        resid_pdrop (`float`, *optional*, defaults to 0.1):
            The dropout probability for all fully connected layers in the embeddings, encoder, and pooler.
        embd_pdrop (`float`, *optional*, defaults to 0.1):
            The dropout ratio for the embeddings.
        attn_pdrop (`float`, *optional*, defaults to 0.1):
            The dropout ratio for the attention.
        layer_norm_epsilon (`float`, *optional*, defaults to 1e-5):
            The epsilon to use in the layer normalization layers.
        initializer_range (`float`, *optional*, defaults to 0.02):
            The standard deviation of the truncated_normal_initializer for initializing all weight matrices.
        scale_attn_weights (`bool`, *optional*, defaults to `True`):
            Scale attention weights by dividing by sqrt(hidden_size)..
        use_cache (`bool`, *optional*, defaults to `True`):
            Whether or not the model should return the last key/values attentions (not used by all models).
        scale_attn_by_inverse_layer_idx (`bool`, *optional*, defaults to `False`):
            Whether to additionally scale attention weights by `1 / layer_idx + 1`.
        reorder_and_upcast_attn (`bool`, *optional*, defaults to `False`):
            Whether to scale keys (K) prior to computing attention (dot-product) and upcast attention
            dot-product/softmax to float() when training with mixed precision.
        position_embedding_type (`str`, *optional*, defaults to `"learned"`):
            Positional embedding can be either `"alibi"` or `"learned"`.
        mup_width_scale (`float`, *optional*, defaults to 1.0):
            muP parameter to scale learning rate and initializers. Calculated as (`d_model,0 / d_model`), where
            `d_model` is the model's width and `d_model,0` is the proxy model's width.
        mup_embeddings_scale (`float`, *optional*, defaults to 1.0):
            muP parameter to scale token and position embeddings.
        mup_output_alpha (`float`, *optional*, defaults to 1.0):
            muP parameter to scale output logits (`output_logits_scale = mup_output_alpha * mup_width_scale`).
        mup_scale_qk_dot_by_d (`bool`, *optional*, defaults to `False`):
            Scale attention weights by dividing by hidden_size instead of sqrt(hidden_size). Need to set
            scale_attn_weights to `True` as well.
        alibi_scaling (`Dict`, *optional*):
            Dictionary containing the scaling configuration for ALiBi embeddings. Currently only supports linear
            scaling strategy. Can specify either the scaling `factor` (must be a float greater than 1) for fixed scaling 
            or `train_seq_len` for dynamic scaling on input samples with sequence length > `train_seq_len`. The expected
            formats are `{"type": strategy name, "factor": scaling factor}` or
            `{"type": strategy name, "train_seq_len": training sequence length}`.

    Example:

    ```python
    >>> from transformers import BTLMConfig, BTLMModel

    >>> # Initializing a BTLM configuration
    >>> configuration = BTLMConfig()

    >>> # Initializing a model (with random weights) from the configuration
    >>> model = BTLMModel(configuration)

    >>> # Accessing the model configuration
    >>> configuration = model.config
    ```"""

    model_type = "btlm"
    keys_to_ignore_at_inference = ["past_key_values"]
    attribute_map = {
        "hidden_size": "n_embd",
        "max_position_embeddings": "n_positions",
        "num_attention_heads": "n_head",
        "num_hidden_layers": "n_layer",
    }

    def __init__(
        self,
        vocab_size=50257,
        n_positions=1024,
        n_embd=768,
        n_layer=12,
        n_head=12,
        n_inner=None,
        activation_function="gelu_new",
        resid_pdrop=0.1,
        embd_pdrop=0.1,
        attn_pdrop=0.1,
        layer_norm_epsilon=1e-5,
        initializer_range=0.02,
        scale_attn_weights=True,
        use_cache=True,
        bos_token_id=50256,
        eos_token_id=50256,
        scale_attn_by_inverse_layer_idx=False,
        reorder_and_upcast_attn=False,
        position_embedding_type="learned",
        mup_width_scale=1.0,
        mup_embeddings_scale=1.0,
        mup_output_alpha=1.0,
        mup_scale_qk_dot_by_d=False,
        alibi_scaling=None,
        **kwargs,
    ):
        self.vocab_size = vocab_size
        self.n_positions = n_positions
        self.n_embd = n_embd
        self.n_layer = n_layer
        self.n_head = n_head
        self.n_inner = n_inner
        self.activation_function = activation_function
        self.resid_pdrop = resid_pdrop
        self.embd_pdrop = embd_pdrop
        self.attn_pdrop = attn_pdrop
        self.layer_norm_epsilon = layer_norm_epsilon
        self.initializer_range = initializer_range
        self.scale_attn_weights = scale_attn_weights
        self.use_cache = use_cache
        self.scale_attn_by_inverse_layer_idx = scale_attn_by_inverse_layer_idx
        self.reorder_and_upcast_attn = reorder_and_upcast_attn

        self.bos_token_id = bos_token_id
        self.eos_token_id = eos_token_id

        self.position_embedding_type = position_embedding_type
        self.mup_width_scale = mup_width_scale
        self.mup_embeddings_scale = mup_embeddings_scale
        self.mup_output_alpha = mup_output_alpha
        self.mup_scale_qk_dot_by_d = mup_scale_qk_dot_by_d

        self.alibi_scaling = alibi_scaling
        self._alibi_scaling_validation()

        super().__init__(bos_token_id=bos_token_id, eos_token_id=eos_token_id, **kwargs)

    def _alibi_scaling_validation(self):
        """
        Validate the `alibi_scaling` configuration.
        """
        if self.alibi_scaling is None:
            return

        if not isinstance(self.alibi_scaling, dict) or len(self.alibi_scaling) != 2:
            raise ValueError(
                "`alibi_scaling` must be a dictionary with two fields, `type` and `factor` or `type` and `train_seq_len`, "
                f"got {self.alibi_scaling}"
            )
        alibi_scaling_type = self.alibi_scaling.get("type", None)
        alibi_scaling_factor = self.alibi_scaling.get("factor", None)
        alibi_dynamic_scaling = self.alibi_scaling.get("train_seq_len", None)
        if alibi_scaling_type is None or alibi_scaling_type != "linear":
            raise ValueError(
                f"`alibi_scaling`'s type field must be 'linear', got {alibi_scaling_type}"
            )
        if alibi_scaling_factor is not None:
            if not isinstance(alibi_scaling_factor, float) or alibi_scaling_factor <= 1.0:
                raise ValueError(f"`alibi_scaling`'s factor field must be a float > 1.0, got {alibi_scaling_factor}")
        if alibi_dynamic_scaling is not None:
            if not isinstance(alibi_dynamic_scaling, int) or alibi_dynamic_scaling <= 1:
                raise ValueError(f"`alibi_scaling`'s `train_seq_len` field must be an integer > 1, got {alibi_dynamic_scaling}")