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- # coding=utf-8
- # Copyright 2023 Mistral AI and the HuggingFace Inc. team. All rights reserved.
- #
- # This code is based on EleutherAI's GPT-NeoX library and the GPT-NeoX
- # and OPT implementations in this library. It has been modified from its
- # original forms to accommodate minor architectural differences compared
- # to GPT-NeoX and OPT used by the Meta AI team that trained the model.
- #
- # 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.
- """PyTorch Mixtral model."""
- import math
- from typing import List, Optional, Tuple, Union
- import torch
- import torch.nn.functional as F
- import torch.utils.checkpoint
- from torch import nn
- from ...activations import ACT2FN
- from ...cache_utils import Cache, DynamicCache, SlidingWindowCache, StaticCache
- from ...generation import GenerationMixin
- from ...modeling_attn_mask_utils import AttentionMaskConverter, _prepare_4d_causal_attention_mask
- from ...modeling_outputs import (
- MoeCausalLMOutputWithPast,
- MoeModelOutputWithPast,
- QuestionAnsweringModelOutput,
- SequenceClassifierOutputWithPast,
- TokenClassifierOutput,
- )
- from ...modeling_utils import PreTrainedModel
- from ...pytorch_utils import is_torch_greater_or_equal_than_1_13
- from ...utils import (
- add_code_sample_docstrings,
- add_start_docstrings,
- add_start_docstrings_to_model_forward,
- is_flash_attn_2_available,
- logging,
- replace_return_docstrings,
- )
- from ...utils.import_utils import is_torch_fx_available
- from .configuration_mixtral import MixtralConfig
- if is_flash_attn_2_available():
- from ...modeling_flash_attention_utils import _flash_attention_forward
- # This makes `_prepare_4d_causal_attention_mask` a leaf function in the FX graph.
- # It means that the function will not be traced through and simply appear as a node in the graph.
- if is_torch_fx_available():
- if not is_torch_greater_or_equal_than_1_13:
- import torch.fx
- _prepare_4d_causal_attention_mask = torch.fx.wrap(_prepare_4d_causal_attention_mask)
- logger = logging.get_logger(__name__)
- _CHECKPOINT_FOR_DOC = "mistralai/Mixtral-8x7B-v0.1"
- _CONFIG_FOR_DOC = "MixtralConfig"
- def load_balancing_loss_func(
- gate_logits: Union[torch.Tensor, Tuple[torch.Tensor], None],
- num_experts: Optional[int] = None,
- top_k=2,
- attention_mask: Optional[torch.Tensor] = None,
- ) -> Union[torch.Tensor, int]:
- r"""
- Computes auxiliary load balancing loss as in Switch Transformer - implemented in Pytorch.
- See Switch Transformer (https://arxiv.org/abs/2101.03961) for more details. This function implements the loss
- function presented in equations (4) - (6) of the paper. It aims at penalizing cases where the routing between
- experts is too unbalanced.
- Args:
- gate_logits:
- Logits from the `gate`, should be a tuple of model.config.num_hidden_layers tensors of
- shape [batch_size X sequence_length, num_experts].
- num_experts:
- Number of experts
- top_k:
- The number of experts to route per-token, can be also interpreted as the `top-k` routing
- parameter.
- attention_mask (`torch.Tensor`, *optional*):
- The attention_mask used in forward function
- shape [batch_size X sequence_length] if not None.
- Returns:
- The auxiliary loss.
- """
- if gate_logits is None or not isinstance(gate_logits, tuple):
- return 0
- if isinstance(gate_logits, tuple):
- compute_device = gate_logits[0].device
- concatenated_gate_logits = torch.cat([layer_gate.to(compute_device) for layer_gate in gate_logits], dim=0)
- routing_weights = torch.nn.functional.softmax(concatenated_gate_logits, dim=-1)
- _, selected_experts = torch.topk(routing_weights, top_k, dim=-1)
- expert_mask = torch.nn.functional.one_hot(selected_experts, num_experts)
- if attention_mask is None:
- # Compute the percentage of tokens routed to each experts
- tokens_per_expert = torch.mean(expert_mask.float(), dim=0)
- # Compute the average probability of routing to these experts
- router_prob_per_expert = torch.mean(routing_weights, dim=0)
- else:
- batch_size, sequence_length = attention_mask.shape
- num_hidden_layers = concatenated_gate_logits.shape[0] // (batch_size * sequence_length)
- # Compute the mask that masks all padding tokens as 0 with the same shape of expert_mask
- expert_attention_mask = (
- attention_mask[None, :, :, None, None]
- .expand((num_hidden_layers, batch_size, sequence_length, top_k, num_experts))
- .reshape(-1, top_k, num_experts)
- .to(compute_device)
- )
- # Compute the percentage of tokens routed to each experts
- tokens_per_expert = torch.sum(expert_mask.float() * expert_attention_mask, dim=0) / torch.sum(
- expert_attention_mask, dim=0
- )
- # Compute the mask that masks all padding tokens as 0 with the same shape of tokens_per_expert
- router_per_expert_attention_mask = (
- attention_mask[None, :, :, None]
- .expand((num_hidden_layers, batch_size, sequence_length, num_experts))
- .reshape(-1, num_experts)
- .to(compute_device)
- )
- # Compute the average probability of routing to these experts
- router_prob_per_expert = torch.sum(routing_weights * router_per_expert_attention_mask, dim=0) / torch.sum(
- router_per_expert_attention_mask, dim=0
- )
- overall_loss = torch.sum(tokens_per_expert * router_prob_per_expert.unsqueeze(0))
- return overall_loss * num_experts
- # Copied from transformers.models.llama.modeling_llama.LlamaRMSNorm with Llama->Mixtral
- class MixtralRMSNorm(nn.Module):
- def __init__(self, hidden_size, eps=1e-6):
- """
- MixtralRMSNorm is equivalent to T5LayerNorm
- """
- super().__init__()
- self.weight = nn.Parameter(torch.ones(hidden_size))
- self.variance_epsilon = eps
- def forward(self, hidden_states):
- input_dtype = hidden_states.dtype
- hidden_states = hidden_states.to(torch.float32)
- variance = hidden_states.pow(2).mean(-1, keepdim=True)
- hidden_states = hidden_states * torch.rsqrt(variance + self.variance_epsilon)
- return self.weight * hidden_states.to(input_dtype)
- def extra_repr(self):
- return f"{tuple(self.weight.shape)}, eps={self.variance_epsilon}"
- # copied from transformers.models.mistral.modeling_mistral.MistralRotaryEmbedding with Mistral->Mixtral
- # TODO @longjie no longer copied from Mistral after static cache
- class MixtralRotaryEmbedding(nn.Module):
- def __init__(self, dim, max_position_embeddings=2048, base=10000, device=None):
- super().__init__()
- self.dim = dim
- self.max_position_embeddings = max_position_embeddings
- self.base = base
- inv_freq = 1.0 / (self.base ** (torch.arange(0, self.dim, 2, dtype=torch.int64).float().to(device) / self.dim))
- self.register_buffer("inv_freq", inv_freq, persistent=False)
- # Build here to make `torch.jit.trace` work.
- self._set_cos_sin_cache(
- seq_len=max_position_embeddings, device=self.inv_freq.device, dtype=torch.get_default_dtype()
- )
- def _set_cos_sin_cache(self, seq_len, device, dtype):
- self.max_seq_len_cached = seq_len
- t = torch.arange(self.max_seq_len_cached, device=device, dtype=torch.int64).type_as(self.inv_freq)
- freqs = torch.outer(t, self.inv_freq)
- # Different from paper, but it uses a different permutation in order to obtain the same calculation
- emb = torch.cat((freqs, freqs), dim=-1)
- self.register_buffer("cos_cached", emb.cos().to(dtype), persistent=False)
- self.register_buffer("sin_cached", emb.sin().to(dtype), persistent=False)
- def forward(self, x, seq_len=None):
- # x: [bs, num_attention_heads, seq_len, head_size]
- if seq_len > self.max_seq_len_cached:
- self._set_cos_sin_cache(seq_len=seq_len, device=x.device, dtype=x.dtype)
- return (
- self.cos_cached[:seq_len].to(dtype=x.dtype),
- self.sin_cached[:seq_len].to(dtype=x.dtype),
- )
- # Copied from transformers.models.llama.modeling_llama.rotate_half
- def rotate_half(x):
- """Rotates half the hidden dims of the input."""
- x1 = x[..., : x.shape[-1] // 2]
- x2 = x[..., x.shape[-1] // 2 :]
- return torch.cat((-x2, x1), dim=-1)
- # copied from transformers.models.mistral.modeling_mistral.apply_rotary_pos_emb
- # TODO @longjie no longer copied from Mistral after static cache
- def apply_rotary_pos_emb(q, k, cos, sin, position_ids, unsqueeze_dim=1):
- """Applies Rotary Position Embedding to the query and key tensors.
- Args:
- q (`torch.Tensor`): The query tensor.
- k (`torch.Tensor`): The key tensor.
- cos (`torch.Tensor`): The cosine part of the rotary embedding.
- sin (`torch.Tensor`): The sine part of the rotary embedding.
- position_ids (`torch.Tensor`):
- The position indices of the tokens corresponding to the query and key tensors. For example, this can be
- used to pass offsetted position ids when working with a KV-cache.
- unsqueeze_dim (`int`, *optional*, defaults to 1):
- The 'unsqueeze_dim' argument specifies the dimension along which to unsqueeze cos[position_ids] and
- sin[position_ids] so that they can be properly broadcasted to the dimensions of q and k. For example, note
- that cos[position_ids] and sin[position_ids] have the shape [batch_size, seq_len, head_dim]. Then, if q and
- k have the shape [batch_size, heads, seq_len, head_dim], then setting unsqueeze_dim=1 makes
- cos[position_ids] and sin[position_ids] broadcastable to the shapes of q and k. Similarly, if q and k have
- the shape [batch_size, seq_len, heads, head_dim], then set unsqueeze_dim=2.
- Returns:
- `tuple(torch.Tensor)` comprising of the query and key tensors rotated using the Rotary Position Embedding.
- """
- cos = cos[position_ids].unsqueeze(unsqueeze_dim)
- sin = sin[position_ids].unsqueeze(unsqueeze_dim)
- q_embed = (q * cos) + (rotate_half(q) * sin)
- k_embed = (k * cos) + (rotate_half(k) * sin)
- return q_embed, k_embed
- # Copied from transformers.models.llama.modeling_llama.repeat_kv
- def repeat_kv(hidden_states: torch.Tensor, n_rep: int) -> torch.Tensor:
- """
- This is the equivalent of torch.repeat_interleave(x, dim=1, repeats=n_rep). The hidden states go from (batch,
- num_key_value_heads, seqlen, head_dim) to (batch, num_attention_heads, seqlen, head_dim)
- """
- batch, num_key_value_heads, slen, head_dim = hidden_states.shape
- if n_rep == 1:
- return hidden_states
- hidden_states = hidden_states[:, :, None, :, :].expand(batch, num_key_value_heads, n_rep, slen, head_dim)
- return hidden_states.reshape(batch, num_key_value_heads * n_rep, slen, head_dim)
- # copied from transformers.models.mistral.modeling_mistral.MistralAttention with Mistral->Mixtral
- # TODO @longjie no longer copied from Mistral after static cache
- class MixtralAttention(nn.Module):
- """
- Multi-headed attention from 'Attention Is All You Need' paper. Modified to use sliding window attention: Longformer
- and "Generating Long Sequences with Sparse Transformers".
- """
- def __init__(self, config: MixtralConfig, layer_idx: Optional[int] = None):
- super().__init__()
- self.config = config
- self.layer_idx = layer_idx
- if layer_idx is None:
- logger.warning_once(
- f"Instantiating {self.__class__.__name__} without passing a `layer_idx` is not recommended and will "
- "lead to errors during the forward call if caching is used. Please make sure to provide a `layer_idx` "
- "when creating this class."
- )
- self.hidden_size = config.hidden_size
- self.num_heads = config.num_attention_heads
- self.head_dim = self.hidden_size // self.num_heads
- self.num_key_value_heads = config.num_key_value_heads
- self.num_key_value_groups = self.num_heads // self.num_key_value_heads
- self.max_position_embeddings = config.max_position_embeddings
- self.rope_theta = config.rope_theta
- self.is_causal = True
- self.attention_dropout = config.attention_dropout
- if (self.head_dim * self.num_heads) != self.hidden_size:
- raise ValueError(
- f"hidden_size must be divisible by num_heads (got `hidden_size`: {self.hidden_size}"
- f" and `num_heads`: {self.num_heads})."
- )
- self.q_proj = nn.Linear(self.hidden_size, self.num_heads * self.head_dim, bias=False)
- self.k_proj = nn.Linear(self.hidden_size, self.num_key_value_heads * self.head_dim, bias=False)
- self.v_proj = nn.Linear(self.hidden_size, self.num_key_value_heads * self.head_dim, bias=False)
- self.o_proj = nn.Linear(self.num_heads * self.head_dim, self.hidden_size, bias=False)
- self.rotary_emb = MixtralRotaryEmbedding(
- self.head_dim,
- max_position_embeddings=self.max_position_embeddings,
- base=self.rope_theta,
- )
- def _shape(self, tensor: torch.Tensor, seq_len: int, bsz: int):
- return tensor.view(bsz, seq_len, self.num_heads, self.head_dim).transpose(1, 2).contiguous()
- def forward(
- self,
- hidden_states: torch.Tensor,
- attention_mask: Optional[torch.Tensor] = None,
- position_ids: Optional[torch.LongTensor] = None,
- past_key_value: Optional[Cache] = None,
- output_attentions: bool = False,
- use_cache: bool = False,
- cache_position: Optional[torch.LongTensor] = None,
- ) -> Tuple[torch.Tensor, Optional[torch.Tensor], Optional[Tuple[torch.Tensor]]]:
- bsz, q_len, _ = hidden_states.size()
- query_states = self.q_proj(hidden_states)
- key_states = self.k_proj(hidden_states)
- value_states = self.v_proj(hidden_states)
- query_states = query_states.view(bsz, q_len, self.num_heads, self.head_dim).transpose(1, 2)
- key_states = key_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
- value_states = value_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
- kv_seq_len = key_states.shape[-2]
- if past_key_value is not None:
- if self.layer_idx is None:
- raise ValueError(
- f"The cache structure has changed since version v4.36. If you are using {self.__class__.__name__} "
- "for auto-regressive decoding with k/v caching, please make sure to initialize the attention class "
- "with a layer index."
- )
- kv_seq_len += past_key_value.get_usable_length(kv_seq_len, self.layer_idx)
- cos, sin = self.rotary_emb(value_states, seq_len=kv_seq_len)
- query_states, key_states = apply_rotary_pos_emb(query_states, key_states, cos, sin, position_ids)
- if past_key_value is not None:
- cache_kwargs = {"sin": sin, "cos": cos, "cache_position": cache_position} # Specific to RoPE models
- key_states, value_states = past_key_value.update(key_states, value_states, self.layer_idx, cache_kwargs)
- # repeat k/v heads if n_kv_heads < n_heads
- key_states = repeat_kv(key_states, self.num_key_value_groups)
- value_states = repeat_kv(value_states, self.num_key_value_groups)
- attn_weights = torch.matmul(query_states, key_states.transpose(2, 3)) / math.sqrt(self.head_dim)
- if attn_weights.size() != (bsz, self.num_heads, q_len, kv_seq_len):
- raise ValueError(
- f"Attention weights should be of size {(bsz, self.num_heads, q_len, kv_seq_len)}, but is"
- f" {attn_weights.size()}"
- )
- if attention_mask is not None: # no matter the length, we just slice it
- causal_mask = attention_mask[:, :, :, : key_states.shape[-2]]
- attn_weights = attn_weights + causal_mask
- # upcast attention to fp32
- attn_weights = nn.functional.softmax(attn_weights, dim=-1, dtype=torch.float32).to(query_states.dtype)
- attn_weights = nn.functional.dropout(attn_weights, p=self.attention_dropout, training=self.training)
- attn_output = torch.matmul(attn_weights, value_states)
- if attn_output.size() != (bsz, self.num_heads, q_len, self.head_dim):
- raise ValueError(
- f"`attn_output` should be of size {(bsz, self.num_heads, q_len, self.head_dim)}, but is"
- f" {attn_output.size()}"
- )
- attn_output = attn_output.transpose(1, 2).contiguous()
- attn_output = attn_output.reshape(bsz, q_len, self.hidden_size)
- attn_output = self.o_proj(attn_output)
- if not output_attentions:
- attn_weights = None
- return attn_output, attn_weights, past_key_value
- # copied from transformers.models.mistral.modeling_mistral.MistralFlashAttention2 with Mistral->Mixtral
- # TODO @longjie no longer copied from Mistral after static cache
- class MixtralFlashAttention2(MixtralAttention):
- """
- Mixtral flash attention module. This module inherits from `MixtralAttention` as the weights of the module stays
- untouched. The only required change would be on the forward pass where it needs to correctly call the public API of
- flash attention and deal with padding tokens in case the input contains any of them.
- """
- def forward(
- self,
- hidden_states: torch.Tensor,
- attention_mask: Optional[torch.Tensor] = None,
- position_ids: Optional[torch.LongTensor] = None,
- past_key_value: Optional[Cache] = None,
- output_attentions: bool = False,
- use_cache: bool = False,
- cache_position: Optional[torch.LongTensor] = None,
- ):
- bsz, q_len, _ = hidden_states.size()
- query_states = self.q_proj(hidden_states)
- key_states = self.k_proj(hidden_states)
- value_states = self.v_proj(hidden_states)
- query_states = query_states.view(bsz, q_len, self.num_heads, self.head_dim).transpose(1, 2)
- key_states = key_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
- value_states = value_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
- kv_seq_len = key_states.shape[-2]
- if past_key_value is not None:
- if self.layer_idx is None:
- raise ValueError(
- f"The cache structure has changed since version v4.36. If you are using {self.__class__.__name__} "
- "for auto-regressive decoding with k/v caching, please make sure to initialize the attention class "
- "with a layer index."
- )
- kv_seq_len += past_key_value.get_usable_length(kv_seq_len, self.layer_idx)
- # Because the input can be padded, the absolute sequence length depends on the max position id.
- rotary_seq_len = (
- max(kv_seq_len, position_ids[:, -1].max().item() + 1) if position_ids is not None else kv_seq_len
- )
- cos, sin = self.rotary_emb(value_states, seq_len=rotary_seq_len)
- query_states, key_states = apply_rotary_pos_emb(query_states, key_states, cos, sin, position_ids)
- if past_key_value is not None:
- cache_kwargs = {"sin": sin, "cos": cos, "cache_position": cache_position} # Specific to RoPE models
- key_states, value_states = past_key_value.update(key_states, value_states, self.layer_idx, cache_kwargs)
- # repeat k/v heads if n_kv_heads < n_heads
- key_states = repeat_kv(key_states, self.num_key_value_groups)
- value_states = repeat_kv(value_states, self.num_key_value_groups)
- dropout_rate = 0.0 if not self.training else self.attention_dropout
- # In PEFT, usually we cast the layer norms in float32 for training stability reasons
- # therefore the input hidden states gets silently casted in float32. Hence, we need
- # cast them back in float16 just to be sure everything works as expected.
- input_dtype = query_states.dtype
- if input_dtype == torch.float32:
- if torch.is_autocast_enabled():
- target_dtype = torch.get_autocast_gpu_dtype()
- # Handle the case where the model is quantized
- elif hasattr(self.config, "_pre_quantization_dtype"):
- target_dtype = self.config._pre_quantization_dtype
- else:
- target_dtype = self.q_proj.weight.dtype
- logger.warning_once(
- f"The input hidden states seems to be silently casted in float32, this might be related to"
- f" the fact you have upcasted embedding or layer norm layers in float32. We will cast back the input in"
- f" {target_dtype}."
- )
- query_states = query_states.to(target_dtype)
- key_states = key_states.to(target_dtype)
- value_states = value_states.to(target_dtype)
- # Reashape to the expected shape for Flash Attention
- query_states = query_states.transpose(1, 2)
- key_states = key_states.transpose(1, 2)
- value_states = value_states.transpose(1, 2)
- attn_output = _flash_attention_forward(
- query_states,
- key_states,
- value_states,
- attention_mask,
- q_len,
- position_ids=position_ids,
- dropout=dropout_rate,
- sliding_window=getattr(self.config, "sliding_window", None),
- is_causal=self.is_causal,
- )
- attn_output = attn_output.reshape(bsz, q_len, self.hidden_size).contiguous()
- attn_output = self.o_proj(attn_output)
- if not output_attentions:
- attn_weights = None
- return attn_output, attn_weights, past_key_value
- # copied from transformers.models.mistral.modeling_mistral.MistralSdpaAttention with Mistral->Mixtral
- # TODO @longjie no longer copied from Mistral after static cache
- class MixtralSdpaAttention(MixtralAttention):
- """
- Mixtral attention module using torch.nn.functional.scaled_dot_product_attention. This module inherits from
- `MixtralAttention` as the weights of the module stays untouched. The only changes are on the forward pass to adapt to
- SDPA API.
- """
- # Adapted from MixtralAttention.forward
- def forward(
- self,
- hidden_states: torch.Tensor,
- attention_mask: Optional[torch.Tensor] = None,
- position_ids: Optional[torch.LongTensor] = None,
- past_key_value: Optional[Cache] = None,
- output_attentions: bool = False,
- use_cache: bool = False,
- cache_position: Optional[torch.LongTensor] = None,
- ) -> Tuple[torch.Tensor, Optional[torch.Tensor], Optional[Tuple[torch.Tensor]]]:
- if output_attentions:
- # TODO: Improve this warning with e.g. `model.config.attn_implementation = "manual"` once this is implemented.
- logger.warning_once(
- "MixtralModel is using MixtralSdpaAttention, but `torch.nn.functional.scaled_dot_product_attention` does not support `output_attentions=True`. Falling back to the manual attention implementation, "
- 'but specifying the manual implementation will be required from Transformers version v5.0.0 onwards. This warning can be removed using the argument `attn_implementation="eager"` when loading the model.'
- )
- return super().forward(
- hidden_states=hidden_states,
- attention_mask=attention_mask,
- position_ids=position_ids,
- past_key_value=past_key_value,
- output_attentions=output_attentions,
- use_cache=use_cache,
- )
- bsz, q_len, _ = hidden_states.size()
- query_states = self.q_proj(hidden_states)
- key_states = self.k_proj(hidden_states)
- value_states = self.v_proj(hidden_states)
- query_states = query_states.view(bsz, q_len, self.num_heads, self.head_dim).transpose(1, 2)
- key_states = key_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
- value_states = value_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
- kv_seq_len = key_states.shape[-2]
- if past_key_value is not None:
- kv_seq_len += past_key_value.get_usable_length(kv_seq_len, self.layer_idx)
- cos, sin = self.rotary_emb(value_states, seq_len=kv_seq_len)
- query_states, key_states = apply_rotary_pos_emb(query_states, key_states, cos, sin, position_ids)
- if past_key_value is not None:
- cache_kwargs = {"sin": sin, "cos": cos, "cache_position": cache_position} # Specific to RoPE models
- key_states, value_states = past_key_value.update(key_states, value_states, self.layer_idx, cache_kwargs)
- key_states = repeat_kv(key_states, self.num_key_value_groups)
- value_states = repeat_kv(value_states, self.num_key_value_groups)
- causal_mask = attention_mask
- if attention_mask is not None: # no matter the length, we just slice it
- causal_mask = attention_mask[:, :, :, : key_states.shape[-2]]
- # SDPA with memory-efficient backend is currently (torch==2.1.2) bugged with non-contiguous inputs with custom attn_mask,
- # Reference: https://github.com/pytorch/pytorch/issues/112577.
- if query_states.device.type == "cuda" and attention_mask is not None:
- query_states = query_states.contiguous()
- key_states = key_states.contiguous()
- value_states = value_states.contiguous()
- # We dispatch to SDPA's Flash Attention or Efficient kernels via this `is_causal` if statement instead of an inline conditional assignment
- # in SDPA to support both torch.compile's dynamic shapes and full graph options. An inline conditional prevents dynamic shapes from compiling.
- # The q_len > 1 is necessary to match with AttentionMaskConverter.to_causal_4d that does not create a causal mask in case q_len == 1.
- is_causal = True if causal_mask is None and q_len > 1 else False
- attn_output = torch.nn.functional.scaled_dot_product_attention(
- query_states,
- key_states,
- value_states,
- attn_mask=causal_mask,
- dropout_p=self.attention_dropout if self.training else 0.0,
- is_causal=is_causal,
- )
- attn_output = attn_output.transpose(1, 2).contiguous()
- attn_output = attn_output.view(bsz, q_len, self.hidden_size)
- attn_output = self.o_proj(attn_output)
- return attn_output, None, past_key_value
- MIXTRAL_ATTENTION_CLASSES = {
- "eager": MixtralAttention,
- "flash_attention_2": MixtralFlashAttention2,
- "sdpa": MixtralSdpaAttention,
- }
- class MixtralBlockSparseTop2MLP(nn.Module):
- def __init__(self, config: MixtralConfig):
- super().__init__()
- self.ffn_dim = config.intermediate_size
- self.hidden_dim = config.hidden_size
- self.w1 = nn.Linear(self.hidden_dim, self.ffn_dim, bias=False)
- self.w2 = nn.Linear(self.ffn_dim, self.hidden_dim, bias=False)
- self.w3 = nn.Linear(self.hidden_dim, self.ffn_dim, bias=False)
- self.act_fn = ACT2FN[config.hidden_act]
- def forward(self, hidden_states):
- current_hidden_states = self.act_fn(self.w1(hidden_states)) * self.w3(hidden_states)
- current_hidden_states = self.w2(current_hidden_states)
- return current_hidden_states
- class MixtralSparseMoeBlock(nn.Module):
- """
- This implementation is
- strictly equivalent to standard MoE with full capacity (no
- dropped tokens). It's faster since it formulates MoE operations
- in terms of block-sparse operations to accomodate imbalanced
- assignments of tokens to experts, whereas standard MoE either
- (1) drop tokens at the cost of reduced performance or (2) set
- capacity factor to number of experts and thus waste computation
- and memory on padding.
- """
- def __init__(self, config):
- super().__init__()
- self.hidden_dim = config.hidden_size
- self.ffn_dim = config.intermediate_size
- self.num_experts = config.num_local_experts
- self.top_k = config.num_experts_per_tok
- # gating
- self.gate = nn.Linear(self.hidden_dim, self.num_experts, bias=False)
- self.experts = nn.ModuleList([MixtralBlockSparseTop2MLP(config) for _ in range(self.num_experts)])
- # Jitter parameters
- self.jitter_noise = config.router_jitter_noise
- def forward(self, hidden_states: torch.Tensor) -> torch.Tensor:
- """ """
- batch_size, sequence_length, hidden_dim = hidden_states.shape
- if self.training and self.jitter_noise > 0:
- hidden_states *= torch.empty_like(hidden_states).uniform_(1.0 - self.jitter_noise, 1.0 + self.jitter_noise)
- hidden_states = hidden_states.view(-1, hidden_dim)
- # router_logits: (batch * sequence_length, n_experts)
- router_logits = self.gate(hidden_states)
- routing_weights = F.softmax(router_logits, dim=1, dtype=torch.float)
- routing_weights, selected_experts = torch.topk(routing_weights, self.top_k, dim=-1)
- routing_weights /= routing_weights.sum(dim=-1, keepdim=True)
- # we cast back to the input dtype
- routing_weights = routing_weights.to(hidden_states.dtype)
- final_hidden_states = torch.zeros(
- (batch_size * sequence_length, hidden_dim), dtype=hidden_states.dtype, device=hidden_states.device
- )
- # One hot encode the selected experts to create an expert mask
- # this will be used to easily index which expert is going to be sollicitated
- expert_mask = torch.nn.functional.one_hot(selected_experts, num_classes=self.num_experts).permute(2, 1, 0)
- # Loop over all available experts in the model and perform the computation on each expert
- for expert_idx in range(self.num_experts):
- expert_layer = self.experts[expert_idx]
- idx, top_x = torch.where(expert_mask[expert_idx])
- # Index the correct hidden states and compute the expert hidden state for
- # the current expert. We need to make sure to multiply the output hidden
- # states by `routing_weights` on the corresponding tokens (top-1 and top-2)
- current_state = hidden_states[None, top_x].reshape(-1, hidden_dim)
- current_hidden_states = expert_layer(current_state) * routing_weights[top_x, idx, None]
- # However `index_add_` only support torch tensors for indexing so we'll use
- # the `top_x` tensor here.
- final_hidden_states.index_add_(0, top_x, current_hidden_states.to(hidden_states.dtype))
- final_hidden_states = final_hidden_states.reshape(batch_size, sequence_length, hidden_dim)
- return final_hidden_states, router_logits
- class MixtralDecoderLayer(nn.Module):
- def __init__(self, config: MixtralConfig, layer_idx: int):
- super().__init__()
- self.hidden_size = config.hidden_size
- self.self_attn = MIXTRAL_ATTENTION_CLASSES[config._attn_implementation](config, layer_idx)
- self.block_sparse_moe = MixtralSparseMoeBlock(config)
- self.input_layernorm = MixtralRMSNorm(config.hidden_size, eps=config.rms_norm_eps)
- self.post_attention_layernorm = MixtralRMSNorm(config.hidden_size, eps=config.rms_norm_eps)
- def forward(
- self,
- hidden_states: torch.Tensor,
- attention_mask: Optional[torch.Tensor] = None,
- position_ids: Optional[torch.LongTensor] = None,
- past_key_value: Optional[Tuple[torch.Tensor]] = None,
- output_attentions: Optional[bool] = False,
- output_router_logits: Optional[bool] = False,
- use_cache: Optional[bool] = False,
- cache_position: Optional[torch.LongTensor] = None,
- **kwargs,
- ) -> Tuple[torch.FloatTensor, Optional[Tuple[torch.FloatTensor, torch.FloatTensor]]]:
- """
- Args:
- hidden_states (`torch.FloatTensor`): input to the layer of shape `(batch, seq_len, embed_dim)`
- attention_mask (`torch.FloatTensor`, *optional*): attention mask of size
- `(batch, sequence_length)` where padding elements are indicated by 0.
- past_key_value (`Tuple(torch.FloatTensor)`, *optional*): cached past key and value projection states
- output_attentions (`bool`, *optional*):
- Whether or not to return the attentions tensors of all attention layers. See `attentions` under
- returned tensors for more detail.
- output_router_logits (`bool`, *optional*):
- Whether or not to return the logits of all the routers. They are useful for computing the router loss, and
- should not be returned during inference.
- use_cache (`bool`, *optional*):
- If set to `True`, `past_key_values` key value states are returned and can be used to speed up decoding
- (see `past_key_values`).
- cache_position (`torch.LongTensor` of shape `(sequence_length)`, *optional*):
- Indices depicting the position of the input sequence tokens in the sequence.
- kwargs (`dict`, *optional*):
- Arbitrary kwargs to be ignored, used for FSDP and other methods that injects code
- into the model
- """
- residual = hidden_states
- hidden_states = self.input_layernorm(hidden_states)
- # Self Attention
- hidden_states, self_attn_weights, present_key_value = self.self_attn(
- hidden_states=hidden_states,
- attention_mask=attention_mask,
- position_ids=position_ids,
- past_key_value=past_key_value,
- output_attentions=output_attentions,
- use_cache=use_cache,
- cache_position=cache_position,
- )
- hidden_states = residual + hidden_states
- # Fully Connected
- residual = hidden_states
- hidden_states = self.post_attention_layernorm(hidden_states)
- hidden_states, router_logits = self.block_sparse_moe(hidden_states)
- hidden_states = residual + hidden_states
- outputs = (hidden_states,)
- if output_attentions:
- outputs += (self_attn_weights,)
- if use_cache:
- outputs += (present_key_value,)
- if output_router_logits:
- outputs += (router_logits,)
- return outputs
- MIXTRAL_START_DOCSTRING = r"""
- This model inherits from [`PreTrainedModel`]. Check the superclass documentation for the generic methods the
- library implements for all its model (such as downloading or saving, resizing the input embeddings, pruning heads
- etc.)
- This model is also a PyTorch [torch.nn.Module](https://pytorch.org/docs/stable/nn.html#torch.nn.Module) subclass.
- Use it as a regular PyTorch Module and refer to the PyTorch documentation for all matter related to general usage
- and behavior.
- Parameters:
- config ([`MixtralConfig`]):
- Model configuration class with all the parameters of the model. Initializing with a config file does not
- load the weights associated with the model, only the configuration. Check out the
- [`~PreTrainedModel.from_pretrained`] method to load the model weights.
- """
- @add_start_docstrings(
- "The bare Mixtral Model outputting raw hidden-states without any specific head on top.",
- MIXTRAL_START_DOCSTRING,
- )
- # copied from transformers.models.qwen2.modeling_qwen2.Qwen2PreTrainedModel with Qwen2->Mixtral
- # TODO (Raushan): bring back copied after compile compatibility
- class MixtralPreTrainedModel(PreTrainedModel):
- config_class = MixtralConfig
- base_model_prefix = "model"
- supports_gradient_checkpointing = True
- _no_split_modules = ["MixtralDecoderLayer"]
- _skip_keys_device_placement = "past_key_values"
- _supports_flash_attn_2 = True
- _supports_sdpa = True
- _supports_cache_class = True
- def _init_weights(self, module):
- std = self.config.initializer_range
- if isinstance(module, nn.Linear):
- module.weight.data.normal_(mean=0.0, std=std)
- if module.bias is not None:
- module.bias.data.zero_()
- elif isinstance(module, nn.Embedding):
- module.weight.data.normal_(mean=0.0, std=std)
- if module.padding_idx is not None:
- module.weight.data[module.padding_idx].zero_()
- MIXTRAL_INPUTS_DOCSTRING = r"""
- Args:
- input_ids (`torch.LongTensor` of shape `(batch_size, sequence_length)`):
- Indices of input sequence tokens in the vocabulary. Padding will be ignored by default should you provide
- it.
- Indices can be obtained using [`AutoTokenizer`]. See [`PreTrainedTokenizer.encode`] and
- [`PreTrainedTokenizer.__call__`] for details.
- [What are input IDs?](../glossary#input-ids)
- attention_mask (`torch.Tensor` of shape `(batch_size, sequence_length)`, *optional*):
- Mask to avoid performing attention on padding token indices. Mask values selected in `[0, 1]`:
- - 1 for tokens that are **not masked**,
- - 0 for tokens that are **masked**.
- [What are attention masks?](../glossary#attention-mask)
- Indices can be obtained using [`AutoTokenizer`]. See [`PreTrainedTokenizer.encode`] and
- [`PreTrainedTokenizer.__call__`] for details.
- If `past_key_values` is used, optionally only the last `decoder_input_ids` have to be input (see
- `past_key_values`).
- If you want to change padding behavior, you should read [`modeling_opt._prepare_decoder_attention_mask`]
- and modify to your needs. See diagram 1 in [the paper](https://arxiv.org/abs/1910.13461) for more
- information on the default strategy.
- - 1 indicates the head is **not masked**,
- - 0 indicates the head is **masked**.
- position_ids (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*):
- Indices of positions of each input sequence tokens in the position embeddings. Selected in the range `[0,
- config.n_positions - 1]`.
- [What are position IDs?](../glossary#position-ids)
- past_key_values (`tuple(tuple(torch.FloatTensor))`, *optional*, returned when `use_cache=True` is passed or when `config.use_cache=True`):
- Tuple of `tuple(torch.FloatTensor)` of length `config.n_layers`, with each tuple having 2 tensors of shape
- `(batch_size, num_heads, sequence_length, embed_size_per_head)`) and 2 additional tensors of shape
- `(batch_size, num_heads, encoder_sequence_length, embed_size_per_head)`.
- Contains pre-computed hidden-states (key and values in the self-attention blocks and in the cross-attention
- blocks) that can be used (see `past_key_values` input) to speed up sequential decoding.
- If `past_key_values` are used, the user can optionally input only the last `decoder_input_ids` (those that
- don't have their past key value states given to this model) of shape `(batch_size, 1)` instead of all
- `decoder_input_ids` of shape `(batch_size, sequence_length)`.
- inputs_embeds (`torch.FloatTensor` of shape `(batch_size, sequence_length, hidden_size)`, *optional*):
- Optionally, instead of passing `input_ids` you can choose to directly pass an embedded representation. This
- is useful if you want more control over how to convert `input_ids` indices into associated vectors than the
- model's internal embedding lookup matrix.
- use_cache (`bool`, *optional*):
- If set to `True`, `past_key_values` key value states are returned and can be used to speed up decoding (see
- `past_key_values`).
- output_attentions (`bool`, *optional*):
- Whether or not to return the attentions tensors of all attention layers. See `attentions` under returned
- tensors for more detail.
- output_hidden_states (`bool`, *optional*):
- Whether or not to return the hidden states of all layers. See `hidden_states` under returned tensors for
- more detail.
- output_router_logits (`bool`, *optional*):
- Whether or not to return the logits of all the routers. They are useful for computing the router loss, and
- should not be returned during inference.
- return_dict (`bool`, *optional*):
- Whether or not to return a [`~utils.ModelOutput`] instead of a plain tuple.
- cache_position (`torch.LongTensor` of shape `(sequence_length)`, *optional*):
- Indices depicting the position of the input sequence tokens in the sequence. Contrarily to `position_ids`,
- this tensor is not affected by padding. It is used to update the cache in the correct position and to infer
- the complete sequence length.
- """
- @add_start_docstrings(
- "The bare Mixtral Model outputting raw hidden-states without any specific head on top.",
- MIXTRAL_START_DOCSTRING,
- )
- # copied from transformers.models.mistral.modeling_mistral.MistralModel with MISTRAL->MIXTRAL,Mistral->Mixtral
- # TODO @longjie no longer copied from Mistral after static cache
- class MixtralModel(MixtralPreTrainedModel):
- """
- Transformer decoder consisting of *config.num_hidden_layers* layers. Each layer is a [`MixtralDecoderLayer`]
- Args:
- config: MixtralConfig
- """
- def __init__(self, config: MixtralConfig):
- super().__init__(config)
- self.padding_idx = config.pad_token_id
- self.vocab_size = config.vocab_size
- self.embed_tokens = nn.Embedding(config.vocab_size, config.hidden_size, self.padding_idx)
- self.layers = nn.ModuleList(
- [MixtralDecoderLayer(config, layer_idx) for layer_idx in range(config.num_hidden_layers)]
- )
- self._attn_implementation = config._attn_implementation
- self.norm = MixtralRMSNorm(config.hidden_size, eps=config.rms_norm_eps)
- self.gradient_checkpointing = False
- # Initialize weights and apply final processing
- self.post_init()
- def get_input_embeddings(self):
- return self.embed_tokens
- def set_input_embeddings(self, value):
- self.embed_tokens = value
- # Ignore copy
- @add_start_docstrings_to_model_forward(MIXTRAL_INPUTS_DOCSTRING)
- def forward(
- self,
- input_ids: torch.LongTensor = None,
- attention_mask: Optional[torch.Tensor] = None,
- position_ids: Optional[torch.LongTensor] = None,
- past_key_values: Optional[List[torch.FloatTensor]] = None,
- inputs_embeds: Optional[torch.FloatTensor] = None,
- use_cache: Optional[bool] = None,
- output_attentions: Optional[bool] = None,
- output_hidden_states: Optional[bool] = None,
- output_router_logits: Optional[bool] = None,
- return_dict: Optional[bool] = None,
- cache_position: Optional[torch.LongTensor] = None,
- ) -> Union[Tuple, MoeModelOutputWithPast]:
- output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
- output_router_logits = (
- output_router_logits if output_router_logits is not None else self.config.output_router_logits
- )
- output_hidden_states = (
- output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
- )
- use_cache = use_cache if use_cache is not None else self.config.use_cache
- return_dict = return_dict if return_dict is not None else self.config.use_return_dict
- if (input_ids is None) ^ (inputs_embeds is not None):
- raise ValueError("You must specify exactly one of input_ids or inputs_embeds")
- if self.gradient_checkpointing and self.training:
- if use_cache:
- logger.warning_once(
- "`use_cache=True` is incompatible with gradient checkpointing. Setting `use_cache=False`..."
- )
- use_cache = False
- # kept for BC (non `Cache` `past_key_values` inputs)
- return_legacy_cache = False
- if use_cache and not isinstance(past_key_values, Cache):
- return_legacy_cache = True
- if past_key_values is None:
- past_key_values = DynamicCache()
- else:
- past_key_values = DynamicCache.from_legacy_cache(past_key_values)
- logger.warning_once(
- "We detected that you are passing `past_key_values` as a tuple of tuples. This is deprecated and "
- "will be removed in v4.47. Please convert your cache or use an appropriate `Cache` class "
- "(https://huggingface.co/docs/transformers/kv_cache#legacy-cache-format)"
- )
- if inputs_embeds is None:
- inputs_embeds = self.embed_tokens(input_ids)
- if cache_position is None:
- past_seen_tokens = past_key_values.get_seq_length() if past_key_values is not None else 0
- cache_position = torch.arange(
- past_seen_tokens, past_seen_tokens + inputs_embeds.shape[1], device=inputs_embeds.device
- )
- if position_ids is None:
- position_ids = cache_position.unsqueeze(0)
- causal_mask = self._update_causal_mask(
- attention_mask, inputs_embeds, cache_position, past_key_values, output_attentions
- )
- hidden_states = inputs_embeds
- # decoder layers
- all_hidden_states = () if output_hidden_states else None
- all_self_attns = () if output_attentions else None
- all_router_logits = () if output_router_logits else None
- next_decoder_cache = None
- for decoder_layer in self.layers:
- if output_hidden_states:
- all_hidden_states += (hidden_states,)
- if self.gradient_checkpointing and self.training:
- layer_outputs = self._gradient_checkpointing_func(
- decoder_layer.__call__,
- hidden_states,
- causal_mask,
- position_ids,
- past_key_values,
- output_attentions,
- output_router_logits,
- use_cache,
- cache_position,
- )
- else:
- layer_outputs = decoder_layer(
- hidden_states,
- attention_mask=causal_mask,
- position_ids=position_ids,
- past_key_value=past_key_values,
- output_attentions=output_attentions,
- output_router_logits=output_router_logits,
- use_cache=use_cache,
- cache_position=cache_position,
- )
- hidden_states = layer_outputs[0]
- if use_cache:
- next_decoder_cache = layer_outputs[2 if output_attentions else 1]
- if output_attentions:
- all_self_attns += (layer_outputs[1],)
- if output_router_logits:
- all_router_logits += (layer_outputs[-1],)
- hidden_states = self.norm(hidden_states)
- # add hidden states from the last decoder layer
- if output_hidden_states:
- all_hidden_states += (hidden_states,)
- next_cache = next_decoder_cache if use_cache else None
- if return_legacy_cache:
- next_cache = next_cache.to_legacy_cache()
- if not return_dict:
- return tuple(
- v
- for v in [hidden_states, next_cache, all_hidden_states, all_self_attns, all_router_logits]
- if v is not None
- )
- return MoeModelOutputWithPast(
- last_hidden_state=hidden_states,
- past_key_values=next_cache,
- hidden_states=all_hidden_states,
- attentions=all_self_attns,
- router_logits=all_router_logits,
- )
- # Copied from transformers.models.phi3.modeling_phi3.Phi3Model._update_causal_mask
- def _update_causal_mask(
- self,
- attention_mask: torch.Tensor,
- input_tensor: torch.Tensor,
- cache_position: torch.Tensor,
- past_key_values: Cache,
- output_attentions: bool,
- ):
- if self.config._attn_implementation == "flash_attention_2":
- if attention_mask is not None and 0.0 in attention_mask:
- return attention_mask
- return None
- # For SDPA, when possible, we will rely on its `is_causal` argument instead of its `attn_mask` argument, in
- # order to dispatch on Flash Attention 2. This feature is not compatible with static cache, as SDPA will fail
- # to infer the attention mask.
- past_seen_tokens = past_key_values.get_seq_length() if past_key_values is not None else 0
- using_static_cache = isinstance(past_key_values, StaticCache)
- using_sliding_window_cache = isinstance(past_key_values, SlidingWindowCache)
- # When output attentions is True, sdpa implementation's forward method calls the eager implementation's forward
- if (
- self.config._attn_implementation == "sdpa"
- and not (using_static_cache or using_sliding_window_cache)
- and not output_attentions
- ):
- if AttentionMaskConverter._ignore_causal_mask_sdpa(
- attention_mask,
- inputs_embeds=input_tensor,
- past_key_values_length=past_seen_tokens,
- sliding_window=self.config.sliding_window,
- is_training=self.training,
- ):
- return None
- dtype, device = input_tensor.dtype, input_tensor.device
- min_dtype = torch.finfo(dtype).min
- sequence_length = input_tensor.shape[1]
- # SlidingWindowCache or StaticCache
- if using_sliding_window_cache or using_static_cache:
- target_length = past_key_values.get_max_cache_shape()
- # DynamicCache or no cache
- else:
- target_length = (
- attention_mask.shape[-1]
- if isinstance(attention_mask, torch.Tensor)
- else past_seen_tokens + sequence_length + 1
- )
- # In case the provided `attention` mask is 2D, we generate a causal mask here (4D).
- causal_mask = self._prepare_4d_causal_attention_mask_with_cache_position(
- attention_mask,
- sequence_length=sequence_length,
- target_length=target_length,
- dtype=dtype,
- device=device,
- cache_position=cache_position,
- batch_size=input_tensor.shape[0],
- config=self.config,
- past_key_values=past_key_values,
- )
- if (
- self.config._attn_implementation == "sdpa"
- and attention_mask is not None
- and attention_mask.device.type == "cuda"
- and not output_attentions
- ):
- # Attend to all tokens in fully masked rows in the causal_mask, for example the relevant first rows when
- # using left padding. This is required by F.scaled_dot_product_attention memory-efficient attention path.
- # Details: https://github.com/pytorch/pytorch/issues/110213
- causal_mask = AttentionMaskConverter._unmask_unattended(causal_mask, min_dtype)
- return causal_mask
- @staticmethod
- # Copied from transformers.models.mistral.modeling_mistral.MistralModel._prepare_4d_causal_attention_mask_with_cache_position with Mistral->Mixtral
- def _prepare_4d_causal_attention_mask_with_cache_position(
- attention_mask: torch.Tensor,
- sequence_length: int,
- target_length: int,
- dtype: torch.dtype,
- device: torch.device,
- cache_position: torch.Tensor,
- batch_size: int,
- config: MixtralConfig,
- past_key_values: Cache,
- ):
- """
- Creates a causal 4D mask of shape `(batch_size, 1, query_length, key_value_length)` from a 2D mask of shape
- `(batch_size, key_value_length)`, or if the input `attention_mask` is already 4D, do nothing.
- Args:
- attention_mask (`torch.Tensor`):
- A 2D attention mask of shape `(batch_size, key_value_length)` or a 4D attention mask of shape `(batch_size, 1, query_length, key_value_length)`.
- sequence_length (`int`):
- The sequence length being processed.
- target_length (`int`):
- The target length: when generating with static cache, the mask should be as long as the static cache, to account for the 0 padding, the part of the cache that is not filled yet.
- dtype (`torch.dtype`):
- The dtype to use for the 4D attention mask.
- device (`torch.device`):
- The device to plcae the 4D attention mask on.
- cache_position (`torch.Tensor`):
- Indices depicting the position of the input sequence tokens in the sequence.
- batch_size (`torch.Tensor`):
- Batch size.
- config (`MixtralConfig`):
- The model's configuration class
- past_key_values (`Cache`):
- The cache class that is being used currently to generate
- """
- if attention_mask is not None and attention_mask.dim() == 4:
- # In this case we assume that the mask comes already in inverted form and requires no inversion or slicing.
- causal_mask = attention_mask
- else:
- min_dtype = torch.finfo(dtype).min
- causal_mask = torch.full(
- (sequence_length, target_length), fill_value=min_dtype, dtype=dtype, device=device
- )
- diagonal_attend_mask = torch.arange(target_length, device=device) > cache_position.reshape(-1, 1)
- if config.sliding_window is not None:
- # if we have sliding window, we should not attend to tokens beyond sliding window length, so we mask them out also
- # the check is needed to verify is current checkpoint was trained with sliding window or not
- if not isinstance(past_key_values, SlidingWindowCache) or sequence_length > target_length:
- sliding_attend_mask = torch.arange(target_length, device=device) <= (
- cache_position.reshape(-1, 1) - config.sliding_window
- )
- diagonal_attend_mask.bitwise_or_(sliding_attend_mask)
- causal_mask *= diagonal_attend_mask
- causal_mask = causal_mask[None, None, :, :].expand(batch_size, 1, -1, -1)
- if attention_mask is not None:
- causal_mask = causal_mask.clone() # copy to contiguous memory for in-place edit
- if attention_mask.shape[-1] > target_length:
- attention_mask = attention_mask[:, :target_length]
- mask_length = attention_mask.shape[-1]
- padding_mask = causal_mask[:, :, :, :mask_length] + attention_mask[:, None, None, :]
- padding_mask = padding_mask == 0
- causal_mask[:, :, :, :mask_length] = causal_mask[:, :, :, :mask_length].masked_fill(
- padding_mask, min_dtype
- )
- return causal_mask
- class MixtralForCausalLM(MixtralPreTrainedModel, GenerationMixin):
- _tied_weights_keys = ["lm_head.weight"]
- def __init__(self, config):
- super().__init__(config)
- self.model = MixtralModel(config)
- self.vocab_size = config.vocab_size
- self.lm_head = nn.Linear(config.hidden_size, config.vocab_size, bias=False)
- self.router_aux_loss_coef = config.router_aux_loss_coef
- self.num_experts = config.num_local_experts
- self.num_experts_per_tok = config.num_experts_per_tok
- # Initialize weights and apply final processing
- self.post_init()
- def get_input_embeddings(self):
- return self.model.embed_tokens
- def set_input_embeddings(self, value):
- self.model.embed_tokens = value
- def get_output_embeddings(self):
- return self.lm_head
- def set_output_embeddings(self, new_embeddings):
- self.lm_head = new_embeddings
- def set_decoder(self, decoder):
- self.model = decoder
- def get_decoder(self):
- return self.model
- @add_start_docstrings_to_model_forward(MIXTRAL_INPUTS_DOCSTRING)
- @replace_return_docstrings(output_type=MoeCausalLMOutputWithPast, config_class=_CONFIG_FOR_DOC)
- # Ignore copy
- def forward(
- self,
- input_ids: torch.LongTensor = None,
- attention_mask: Optional[torch.Tensor] = None,
- position_ids: Optional[torch.LongTensor] = None,
- past_key_values: Optional[List[torch.FloatTensor]] = None,
- inputs_embeds: Optional[torch.FloatTensor] = None,
- labels: Optional[torch.LongTensor] = None,
- use_cache: Optional[bool] = None,
- output_attentions: Optional[bool] = None,
- output_hidden_states: Optional[bool] = None,
- output_router_logits: Optional[bool] = None,
- return_dict: Optional[bool] = None,
- cache_position: Optional[torch.LongTensor] = None,
- num_logits_to_keep: int = 0,
- **loss_kwargs,
- ) -> Union[Tuple, MoeCausalLMOutputWithPast]:
- r"""
- Args:
- labels (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*):
- Labels for computing the masked language modeling loss. Indices should either be in `[0, ...,
- config.vocab_size]` or -100 (see `input_ids` docstring). Tokens with indices set to `-100` are ignored
- (masked), the loss is only computed for the tokens with labels in `[0, ..., config.vocab_size]`.
- num_logits_to_keep (`int`, *optional*):
- Calculate logits for the last `num_logits_to_keep` tokens. If `0`, calculate logits for all
- `input_ids` (special case). Only last token logits are needed for generation, and calculating them only for that
- token can save memory, which becomes pretty significant for long sequences or large vocabulary size.
- Returns:
- Example:
- ```python
- >>> from transformers import AutoTokenizer, MixtralForCausalLM
- >>> model = MixtralForCausalLM.from_pretrained("mistralai/Mixtral-8x7B-v0.1")
- >>> tokenizer = AutoTokenizer.from_pretrained("mistralai/Mixtral-8x7B-v0.1")
- >>> prompt = "Hey, are you conscious? Can you talk to me?"
- >>> inputs = tokenizer(prompt, return_tensors="pt")
- >>> # Generate
- >>> generate_ids = model.generate(inputs.input_ids, max_length=30)
- >>> tokenizer.batch_decode(generate_ids, skip_special_tokens=True, clean_up_tokenization_spaces=False)[0]
- "Hey, are you conscious? Can you talk to me?\nI'm not conscious, but I can talk to you."
- ```"""
- output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
- output_router_logits = (
- output_router_logits if output_router_logits is not None else self.config.output_router_logits
- )
- output_hidden_states = (
- output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
- )
- return_dict = return_dict if return_dict is not None else self.config.use_return_dict
- # decoder outputs consists of (dec_features, layer_state, dec_hidden, dec_attn)
- outputs = self.model(
- input_ids=input_ids,
- attention_mask=attention_mask,
- position_ids=position_ids,
- past_key_values=past_key_values,
- inputs_embeds=inputs_embeds,
- use_cache=use_cache,
- output_attentions=output_attentions,
- output_hidden_states=output_hidden_states,
- output_router_logits=output_router_logits,
- return_dict=return_dict,
- cache_position=cache_position,
- )
- hidden_states = outputs[0]
- # Only compute necessary logits, and do not upcast them to float if we are not computing the loss
- logits = self.lm_head(hidden_states[:, -num_logits_to_keep:, :])
- loss = None
- if labels is not None:
- loss = self.loss_function(logits, labels, self.vocab_size, **loss_kwargs)
- aux_loss = None
- if output_router_logits:
- aux_loss = load_balancing_loss_func(
- outputs.router_logits if return_dict else outputs[-1],
- self.num_experts,
- self.num_experts_per_tok,
- attention_mask,
- )
- if labels is not None:
- loss += self.router_aux_loss_coef * aux_loss.to(loss.device) # make sure to reside in the same device
- if not return_dict:
- output = (logits,) + outputs[1:]
- if output_router_logits:
- output = (aux_loss,) + output
- return (loss,) + output if loss is not None else output
- return MoeCausalLMOutputWithPast(
- loss=loss,
- aux_loss=aux_loss,
- logits=logits,
- past_key_values=outputs.past_key_values,
- hidden_states=outputs.hidden_states,
- attentions=outputs.attentions,
- router_logits=outputs.router_logits,
- )
- @add_start_docstrings(
- """
- The Mixtral Model transformer with a sequence classification head on top (linear layer).
- [`MixtralForSequenceClassification`] uses the last token in order to do the classification, as other causal models
- (e.g. GPT-2) do.
- Since it does classification on the last token, it requires to know the position of the last token. If a
- `pad_token_id` is defined in the configuration, it finds the last token that is not a padding token in each row. If
- no `pad_token_id` is defined, it simply takes the last value in each row of the batch. Since it cannot guess the
- padding tokens when `inputs_embeds` are passed instead of `input_ids`, it does the same (take the last value in
- each row of the batch).
- """,
- MIXTRAL_START_DOCSTRING,
- )
- # Copied from transformers.models.llama.modeling_llama.LlamaForSequenceClassification with Llama->Mixtral, LLAMA->MIXTRAL
- class MixtralForSequenceClassification(MixtralPreTrainedModel):
- def __init__(self, config):
- super().__init__(config)
- self.num_labels = config.num_labels
- self.model = MixtralModel(config)
- self.score = nn.Linear(config.hidden_size, self.num_labels, bias=False)
- # Initialize weights and apply final processing
- self.post_init()
- def get_input_embeddings(self):
- return self.model.embed_tokens
- def set_input_embeddings(self, value):
- self.model.embed_tokens = value
- @add_start_docstrings_to_model_forward(MIXTRAL_INPUTS_DOCSTRING)
- def forward(
- self,
- input_ids: Optional[torch.LongTensor] = None,
- attention_mask: Optional[torch.Tensor] = None,
- position_ids: Optional[torch.LongTensor] = None,
- past_key_values: Optional[Union[Cache, List[torch.FloatTensor]]] = None,
- inputs_embeds: Optional[torch.FloatTensor] = None,
- labels: Optional[torch.LongTensor] = None,
- use_cache: Optional[bool] = None,
- output_attentions: Optional[bool] = None,
- output_hidden_states: Optional[bool] = None,
- return_dict: Optional[bool] = None,
- ) -> Union[Tuple, SequenceClassifierOutputWithPast]:
- r"""
- labels (`torch.LongTensor` of shape `(batch_size,)`, *optional*):
- Labels for computing the sequence classification/regression loss. Indices should be in `[0, ...,
- config.num_labels - 1]`. If `config.num_labels == 1` a regression loss is computed (Mean-Square loss), If
- `config.num_labels > 1` a classification loss is computed (Cross-Entropy).
- """
- return_dict = return_dict if return_dict is not None else self.config.use_return_dict
- transformer_outputs = self.model(
- input_ids,
- attention_mask=attention_mask,
- position_ids=position_ids,
- past_key_values=past_key_values,
- inputs_embeds=inputs_embeds,
- use_cache=use_cache,
- output_attentions=output_attentions,
- output_hidden_states=output_hidden_states,
- return_dict=return_dict,
- )
- hidden_states = transformer_outputs[0]
- logits = self.score(hidden_states)
- if input_ids is not None:
- batch_size = input_ids.shape[0]
- else:
- batch_size = inputs_embeds.shape[0]
- if self.config.pad_token_id is None and batch_size != 1:
- raise ValueError("Cannot handle batch sizes > 1 if no padding token is defined.")
- if self.config.pad_token_id is None:
- sequence_lengths = -1
- else:
- if input_ids is not None:
- # if no pad token found, use modulo instead of reverse indexing for ONNX compatibility
- sequence_lengths = torch.eq(input_ids, self.config.pad_token_id).int().argmax(-1) - 1
- sequence_lengths = sequence_lengths % input_ids.shape[-1]
- sequence_lengths = sequence_lengths.to(logits.device)
- else:
- sequence_lengths = -1
- pooled_logits = logits[torch.arange(batch_size, device=logits.device), sequence_lengths]
- loss = None
- if labels is not None:
- loss = self.loss_function(logits=logits, labels=labels, pooled_logits=pooled_logits, config=self.config)
- if not return_dict:
- output = (pooled_logits,) + transformer_outputs[1:]
- return ((loss,) + output) if loss is not None else output
- return SequenceClassifierOutputWithPast(
- loss=loss,
- logits=pooled_logits,
- past_key_values=transformer_outputs.past_key_values,
- hidden_states=transformer_outputs.hidden_states,
- attentions=transformer_outputs.attentions,
- )
- @add_start_docstrings(
- """
- The Mixtral Model transformer with a token classification head on top (a linear layer on top of the hidden-states
- output) e.g. for Named-Entity-Recognition (NER) tasks.
- """,
- MIXTRAL_START_DOCSTRING,
- )
- # Copied from transformers.models.llama.modeling_llama.LlamaForTokenClassification with Llama->Mixtral, LLAMA->MIXTRAL
- class MixtralForTokenClassification(MixtralPreTrainedModel):
- def __init__(self, config):
- super().__init__(config)
- self.num_labels = config.num_labels
- self.model = MixtralModel(config)
- if getattr(config, "classifier_dropout", None) is not None:
- classifier_dropout = config.classifier_dropout
- elif getattr(config, "hidden_dropout", None) is not None:
- classifier_dropout = config.hidden_dropout
- else:
- classifier_dropout = 0.1
- self.dropout = nn.Dropout(classifier_dropout)
- self.score = nn.Linear(config.hidden_size, config.num_labels)
- # Initialize weights and apply final processing
- self.post_init()
- def get_input_embeddings(self):
- return self.model.embed_tokens
- def set_input_embeddings(self, value):
- self.model.embed_tokens = value
- @add_start_docstrings_to_model_forward(MIXTRAL_INPUTS_DOCSTRING)
- @add_code_sample_docstrings(
- checkpoint=_CHECKPOINT_FOR_DOC,
- output_type=TokenClassifierOutput,
- config_class=_CONFIG_FOR_DOC,
- )
- def forward(
- self,
- input_ids: Optional[torch.LongTensor] = None,
- attention_mask: Optional[torch.Tensor] = None,
- position_ids: Optional[torch.LongTensor] = None,
- past_key_values: Optional[List[torch.FloatTensor]] = None,
- inputs_embeds: Optional[torch.FloatTensor] = None,
- labels: Optional[torch.LongTensor] = None,
- use_cache: Optional[bool] = None,
- output_attentions: Optional[bool] = None,
- output_hidden_states: Optional[bool] = None,
- return_dict: Optional[bool] = None,
- ) -> Union[Tuple, TokenClassifierOutput]:
- r"""
- labels (`torch.LongTensor` of shape `(batch_size,)`, *optional*):
- Labels for computing the sequence classification/regression loss. Indices should be in `[0, ...,
- config.num_labels - 1]`. If `config.num_labels == 1` a regression loss is computed (Mean-Square loss), If
- `config.num_labels > 1` a classification loss is computed (Cross-Entropy).
- """
- return_dict = return_dict if return_dict is not None else self.config.use_return_dict
- outputs = self.model(
- input_ids,
- attention_mask=attention_mask,
- position_ids=position_ids,
- past_key_values=past_key_values,
- inputs_embeds=inputs_embeds,
- use_cache=use_cache,
- output_attentions=output_attentions,
- output_hidden_states=output_hidden_states,
- return_dict=return_dict,
- )
- sequence_output = outputs[0]
- sequence_output = self.dropout(sequence_output)
- logits = self.score(sequence_output)
- loss = None
- if labels is not None:
- loss = self.loss_function(logits, labels, self.config)
- if not return_dict:
- output = (logits,) + outputs[2:]
- return ((loss,) + output) if loss is not None else output
- return TokenClassifierOutput(
- loss=loss,
- logits=logits,
- hidden_states=outputs.hidden_states,
- attentions=outputs.attentions,
- )
- @add_start_docstrings(
- """
- The Mixtral Model transformer with a span classification head on top for extractive question-answering tasks like
- SQuAD (a linear layer on top of the hidden-states output to compute `span start logits` and `span end logits`).
- """,
- MIXTRAL_START_DOCSTRING,
- )
- # Copied from transformers.models.mistral.modeling_mistral.MistralForQuestionAnswering with Mistral->Mixtral, MISTRAL->MIXTRAL
- class MixtralForQuestionAnswering(MixtralPreTrainedModel):
- base_model_prefix = "model"
- # Copied from models.models.bloom.modeling_bloom.BloomForQuestionAnswering.__init__ with Bloom->Mixtral
- def __init__(self, config):
- super().__init__(config)
- self.model = MixtralModel(config)
- self.qa_outputs = nn.Linear(config.hidden_size, 2)
- # Initialize weights and apply final processing
- self.post_init()
- def get_input_embeddings(self):
- return self.model.embed_tokens
- def set_input_embeddings(self, value):
- self.model.embed_tokens = value
- @add_start_docstrings_to_model_forward(MIXTRAL_INPUTS_DOCSTRING)
- def forward(
- self,
- input_ids: Optional[torch.LongTensor] = None,
- attention_mask: Optional[torch.FloatTensor] = None,
- position_ids: Optional[torch.LongTensor] = None,
- past_key_values: Optional[Union[Cache, List[torch.FloatTensor]]] = None,
- inputs_embeds: Optional[torch.FloatTensor] = None,
- start_positions: Optional[torch.LongTensor] = None,
- end_positions: Optional[torch.LongTensor] = None,
- output_attentions: Optional[bool] = None,
- output_hidden_states: Optional[bool] = None,
- return_dict: Optional[bool] = None,
- **kwargs,
- ) -> Union[Tuple, QuestionAnsweringModelOutput]:
- r"""
- start_positions (`torch.LongTensor` of shape `(batch_size,)`, *optional*):
- Labels for position (index) of the start of the labelled span for computing the token classification loss.
- Positions are clamped to the length of the sequence (`sequence_length`). Position outside of the sequence
- are not taken into account for computing the loss.
- end_positions (`torch.LongTensor` of shape `(batch_size,)`, *optional*):
- Labels for position (index) of the end of the labelled span for computing the token classification loss.
- Positions are clamped to the length of the sequence (`sequence_length`). Position outside of the sequence
- are not taken into account for computing the loss.
- """
- return_dict = return_dict if return_dict is not None else self.config.use_return_dict
- outputs = self.model(
- input_ids,
- attention_mask=attention_mask,
- position_ids=position_ids,
- past_key_values=past_key_values,
- inputs_embeds=inputs_embeds,
- output_attentions=output_attentions,
- output_hidden_states=output_hidden_states,
- return_dict=return_dict,
- )
- sequence_output = outputs[0]
- logits = self.qa_outputs(sequence_output)
- start_logits, end_logits = logits.split(1, dim=-1)
- start_logits = start_logits.squeeze(-1).contiguous()
- end_logits = end_logits.squeeze(-1).contiguous()
- loss = None
- if start_positions is not None and end_positions is not None:
- loss = self.loss_function(start_logits, end_logits, start_positions, end_positions, **kwargs)
- if not return_dict:
- output = (start_logits, end_logits) + outputs[2:]
- return ((loss,) + output) if loss is not None else output
- return QuestionAnsweringModelOutput(
- loss=loss,
- start_logits=start_logits,
- end_logits=end_logits,
- hidden_states=outputs.hidden_states,
- attentions=outputs.attentions,
- )
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