Llama-3.1-8B-DALv0.1
/
venv
/lib
/python3.12
/site-packages
/transformers
/models
/jamba
/modeling_jamba.py
# coding=utf-8 | |
# Copyright 2024 AI21 Labs Ltd. 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 Jamba model.""" | |
import math | |
from typing import Any, Dict, List, Optional, Tuple, Union | |
import torch | |
import torch.nn.functional as F | |
import torch.utils.checkpoint | |
from torch import nn | |
from torch.nn import BCEWithLogitsLoss, CrossEntropyLoss, MSELoss | |
from ...activations import ACT2FN | |
from ...cache_utils import Cache, DynamicCache # we need __iter__ and __len__ of pkv | |
from ...modeling_attn_mask_utils import ( | |
AttentionMaskConverter, | |
) | |
from ...modeling_outputs import ( | |
MoeCausalLMOutputWithPast, | |
MoeModelOutputWithPast, | |
SequenceClassifierOutputWithPast, | |
) | |
from ...modeling_utils import PreTrainedModel | |
from ...utils import ( | |
add_start_docstrings, | |
add_start_docstrings_to_model_forward, | |
logging, | |
replace_return_docstrings, | |
) | |
from ...utils.import_utils import ( | |
is_causal_conv1d_available, | |
is_flash_attn_2_available, | |
is_flash_attn_greater_or_equal_2_10, | |
is_mamba_ssm_available, | |
) | |
from .configuration_jamba import JambaConfig | |
if is_flash_attn_2_available(): | |
from ...modeling_flash_attention_utils import _flash_attention_forward | |
if is_mamba_ssm_available(): | |
from mamba_ssm.ops.selective_scan_interface import mamba_inner_fn, selective_scan_fn | |
from mamba_ssm.ops.triton.selective_state_update import selective_state_update | |
else: | |
selective_state_update, selective_scan_fn, mamba_inner_fn = None, None, None | |
if is_causal_conv1d_available(): | |
from causal_conv1d import causal_conv1d_fn, causal_conv1d_update | |
else: | |
causal_conv1d_update, causal_conv1d_fn = None, None | |
is_fast_path_available = all( | |
(selective_state_update, selective_scan_fn, causal_conv1d_fn, causal_conv1d_update, mamba_inner_fn) | |
) | |
logger = logging.get_logger(__name__) | |
_CONFIG_FOR_DOC = "JambaConfig" | |
# Copied from transformers.models.mixtral.modeling_mixtral.load_balancing_loss_func with gate->router | |
def load_balancing_loss_func( | |
router_logits: torch.Tensor, | |
num_experts: torch.Tensor = None, | |
top_k=2, | |
attention_mask: Optional[torch.Tensor] = None, | |
) -> float: | |
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: | |
router_logits (Union[`torch.Tensor`, Tuple[torch.Tensor]): | |
Logits from the `router`, should be a tuple of model.config.num_hidden_layers tensors of | |
shape [batch_size X sequence_length, num_experts]. | |
attention_mask (`torch.Tensor`, *optional*): | |
The attention_mask used in forward function | |
shape [batch_size X sequence_length] if not None. | |
num_experts (`int`, *optional*): | |
Number of experts | |
Returns: | |
The auxiliary loss. | |
""" | |
if router_logits is None or not isinstance(router_logits, tuple): | |
return 0 | |
if isinstance(router_logits, tuple): | |
compute_device = router_logits[0].device | |
concatenated_router_logits = torch.cat( | |
[layer_router.to(compute_device) for layer_router in router_logits], dim=0 | |
) | |
routing_weights = torch.nn.functional.softmax(concatenated_router_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_router_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->Jamba | |
class JambaRMSNorm(nn.Module): | |
def __init__(self, hidden_size, eps=1e-6): | |
""" | |
JambaRMSNorm 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.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) | |
class HybridMambaAttentionDynamicCache(DynamicCache): | |
""" | |
A dynamic cache that can handle both the attention cache (which has a seq_len dimension) and the mamba cache | |
(which has a constant shape regardless of seq_len). | |
This cache has two sets of lists of tensors: `key_cache` and `value_cache` for attention cache and `conv_states` | |
and `ssm_states` for mamba cache. Each of these lists has `num_layers` tensors. The expected shape for each tensor | |
For attention layers, `key_cache` and `value_cache` have a shape of `(batch_size, num_heads, seq_len, head_dim)`, | |
while `conv_states` and `ssm_states` have a shape of `(batch_size, 0)` (empty tensors). | |
For mamba layers, `key_cache` and `value_cache` have a shape of `(batch_size, 0)` (empty tensors), | |
while `conv_states` represents the convolution state and has a shape of `(batch_size, d_inner, d_conv)`, | |
and `ssm_states` represents the ssm state and has a shape of `(batch_size, d_inner, d_state)`. | |
""" | |
def __init__(self, config, batch_size, dtype=torch.float16, device=None): | |
self.dtype = dtype | |
self.layers_block_type = config.layers_block_type | |
self.has_previous_state = False # only used by mamba | |
intermediate_size = config.mamba_expand * config.hidden_size | |
ssm_state_size = config.mamba_d_state | |
conv_kernel_size = config.mamba_d_conv | |
self.conv_states = [] | |
self.ssm_states = [] | |
self.transformer_layers = [] | |
for i in range(config.num_hidden_layers): | |
if self.layers_block_type[i] == "mamba": | |
self.conv_states += [ | |
torch.zeros(batch_size, intermediate_size, conv_kernel_size, device=device, dtype=dtype) | |
] | |
self.ssm_states += [ | |
torch.zeros(batch_size, intermediate_size, ssm_state_size, device=device, dtype=dtype) | |
] | |
else: | |
self.conv_states += [torch.tensor([[]] * batch_size, device=device)] | |
self.ssm_states += [torch.tensor([[]] * batch_size, device=device)] | |
self.transformer_layers.append(i) | |
self.key_cache = [torch.tensor([[]] * batch_size, device=device) for _ in range(config.num_hidden_layers)] | |
self.value_cache = [torch.tensor([[]] * batch_size, device=device) for _ in range(config.num_hidden_layers)] | |
def update( | |
self, | |
key_states: torch.Tensor, | |
value_states: torch.Tensor, | |
layer_idx: int, | |
cache_kwargs: Optional[Dict[str, Any]] = None, | |
) -> Tuple[torch.Tensor, torch.Tensor]: | |
# Update the cache | |
if self.key_cache[layer_idx].shape[-1] == 0: | |
self.key_cache[layer_idx] = key_states | |
self.value_cache[layer_idx] = value_states | |
else: | |
self.key_cache[layer_idx] = torch.cat([self.key_cache[layer_idx], key_states], dim=2) | |
self.value_cache[layer_idx] = torch.cat([self.value_cache[layer_idx], value_states], dim=2) | |
return self.key_cache[layer_idx], self.value_cache[layer_idx] | |
def reorder_cache(self, beam_idx: torch.LongTensor): | |
"""Reorders the cache for beam search, given the selected beam indices.""" | |
for layer_idx in range(len(self.key_cache)): | |
device = self.key_cache[layer_idx].device | |
self.key_cache[layer_idx] = self.key_cache[layer_idx].index_select(0, beam_idx.to(device)) | |
device = self.value_cache[layer_idx].device | |
self.value_cache[layer_idx] = self.value_cache[layer_idx].index_select(0, beam_idx.to(device)) | |
device = self.conv_states[layer_idx].device | |
self.conv_states[layer_idx] = self.conv_states[layer_idx].index_select(0, beam_idx.to(device)) | |
device = self.ssm_states[layer_idx].device | |
self.ssm_states[layer_idx] = self.ssm_states[layer_idx].index_select(0, beam_idx.to(device)) | |
def get_seq_length(self, layer_idx: Optional[int] = 0) -> int: | |
"""Returns the sequence length of the cached states. A layer index can be optionally passed.""" | |
# take any layer that contains cache and not empty tensor | |
layer_idx = self.transformer_layers[0] if layer_idx not in self.transformer_layers else layer_idx | |
if len(self.key_cache) <= layer_idx: | |
return 0 | |
return self.key_cache[layer_idx].shape[-2] | |
def to_legacy_cache(self) -> Tuple[Tuple[torch.Tensor], Tuple[torch.Tensor]]: | |
raise NotImplementedError("HybridMambaAttentionDynamicCache does not have a legacy cache equivalent.") | |
def from_legacy_cache(cls, past_key_values: Optional[Tuple[Tuple[torch.FloatTensor]]] = None) -> "DynamicCache": | |
raise NotImplementedError("HybridMambaAttentionDynamicCache does not have a legacy cache equivalent.") | |
# Adapted from transformers.models.mistral.modeling_mistral.MistralAttention with Mistral->Jamba | |
class JambaAttention(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: JambaConfig, 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.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) | |
def forward( | |
self, | |
hidden_states: torch.Tensor, | |
attention_mask: Optional[torch.Tensor] = None, | |
position_ids: Optional[torch.LongTensor] = None, | |
past_key_value: Optional[HybridMambaAttentionDynamicCache] = 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) | |
if past_key_value is not None: | |
key_states, value_states = past_key_value.update(key_states, value_states, self.layer_idx) | |
# 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 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 | |
# Adapted from transformers.models.mistral.modeling_mistral.MistralFlashAttention2 with Mistral->Jamba | |
class JambaFlashAttention2(JambaAttention): | |
""" | |
Jamba flash attention module. This module inherits from `JambaAttention` 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. | |
""" | |
# Copied from transformers.models.llama.modeling_llama.LlamaFlashAttention2.__init__ | |
def __init__(self, *args, **kwargs): | |
super().__init__(*args, **kwargs) | |
# TODO: Should be removed once Flash Attention for RoCm is bumped to 2.1. | |
# flash_attn<2.1 generates top-left aligned causal mask, while what is needed here is bottom-right alignement, that was made default for flash_attn>=2.1. This attribute is used to handle this difference. Reference: https://github.com/Dao-AILab/flash-attention/releases/tag/v2.1.0. | |
# Beware that with flash_attn<2.1, using q_seqlen != k_seqlen (except for the case q_seqlen == 1) produces a wrong mask (top-left). | |
self._flash_attn_uses_top_left_mask = not is_flash_attn_greater_or_equal_2_10() | |
def forward( | |
self, | |
hidden_states: torch.Tensor, | |
attention_mask: Optional[torch.Tensor] = None, | |
position_ids: Optional[torch.LongTensor] = None, | |
past_key_value: Optional[HybridMambaAttentionDynamicCache] = None, | |
output_attentions: bool = False, | |
use_cache: bool = False, | |
cache_position: Optional[torch.LongTensor] = None, | |
**kwargs, | |
): | |
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) | |
# Flash attention requires the input to have the shape | |
# batch_size x seq_length x head_dim x hidden_dim | |
# therefore we just need to keep the original shape | |
query_states = query_states.view(bsz, q_len, self.num_heads, self.head_dim) | |
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 = cache_position[-1] | |
if past_key_value is not None: | |
# Activate slicing cache only if the config has a value `sliding_windows` attribute | |
cache_has_contents = cache_position[0] > 0 | |
if ( | |
getattr(self.config, "sliding_window", None) is not None | |
and kv_seq_len > self.config.sliding_window | |
and cache_has_contents | |
): | |
slicing_tokens = 1 - self.config.sliding_window | |
past_key = past_key_value[self.layer_idx][0] | |
past_value = past_key_value[self.layer_idx][1] | |
past_key = past_key[:, :, slicing_tokens:, :].contiguous() | |
past_value = past_value[:, :, slicing_tokens:, :].contiguous() | |
if past_key.shape[-2] != self.config.sliding_window - 1: | |
raise ValueError( | |
f"past key must have a shape of (`batch_size, num_heads, self.config.sliding_window-1, head_dim`), got" | |
f" {past_key.shape}" | |
) | |
if attention_mask is not None: | |
attention_mask = attention_mask[:, slicing_tokens:] | |
attention_mask = torch.cat([attention_mask, torch.ones_like(attention_mask[:, -1:])], dim=-1) | |
key_states, value_states = past_key_value.update(key_states, value_states, self.layer_idx) | |
# 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 | |
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, | |
dropout=dropout_rate, | |
sliding_window=getattr(self.config, "sliding_window", None), | |
is_causal=self.is_causal, | |
use_top_left_mask=self._flash_attn_uses_top_left_mask, | |
) | |
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 | |
# Adapted from transformers.models.mistral.modeling_mistral.MistralSdpaAttention with Mistral->Jamba | |
class JambaSdpaAttention(JambaAttention): | |
""" | |
Jamba attention module using torch.nn.functional.scaled_dot_product_attention. This module inherits from | |
`JambaAttention` as the weights of the module stays untouched. The only changes are on the forward pass to adapt to | |
SDPA API. | |
""" | |
# Adapted from JambaAttention.forward | |
def forward( | |
self, | |
hidden_states: torch.Tensor, | |
attention_mask: Optional[torch.Tensor] = None, | |
position_ids: Optional[torch.LongTensor] = None, | |
past_key_value: Optional[HybridMambaAttentionDynamicCache] = 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( | |
"JambaModel is using JambaSdpaAttention, 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) | |
if past_key_value is not None: | |
key_states, value_states = past_key_value.update(key_states, value_states, self.layer_idx) | |
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: | |
causal_mask = causal_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 self.is_causal and 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 | |
JAMBA_ATTENTION_CLASSES = { | |
"eager": JambaAttention, | |
"flash_attention_2": JambaFlashAttention2, | |
"sdpa": JambaSdpaAttention, | |
} | |
# Adapted from transformers.models.mamba.modeling_mamba.MambaMixer | |
class JambaMambaMixer(nn.Module): | |
""" | |
Compute ∆, A, B, C, and D the state space parameters and compute the `contextualized_states`. | |
A, D are input independent (see Mamba paper [1] Section 3.5.2 "Interpretation of A" for why A isn't selective) | |
∆, B, C are input-dependent (this is a key difference between Mamba and the linear time invariant S4, | |
and is why Mamba is called **selective** state spaces) | |
""" | |
def __init__(self, config: JambaConfig, layer_idx): | |
super().__init__() | |
self.config = config | |
self.layer_idx = layer_idx | |
self.hidden_size = config.hidden_size | |
self.ssm_state_size = config.mamba_d_state | |
self.conv_kernel_size = config.mamba_d_conv | |
self.intermediate_size = config.mamba_expand * config.hidden_size | |
self.time_step_rank = config.mamba_dt_rank | |
self.use_conv_bias = config.mamba_conv_bias | |
self.use_bias = config.mamba_proj_bias | |
self.conv1d = nn.Conv1d( | |
in_channels=self.intermediate_size, | |
out_channels=self.intermediate_size, | |
bias=self.use_conv_bias, | |
kernel_size=self.conv_kernel_size, | |
groups=self.intermediate_size, | |
padding=self.conv_kernel_size - 1, | |
) | |
self.activation = config.hidden_act | |
self.act = ACT2FN[config.hidden_act] | |
self.use_fast_kernels = config.use_mamba_kernels | |
# projection of the input hidden states | |
self.in_proj = nn.Linear(self.hidden_size, self.intermediate_size * 2, bias=self.use_bias) | |
# selective projection used to make dt, B and C input dependant | |
self.x_proj = nn.Linear(self.intermediate_size, self.time_step_rank + self.ssm_state_size * 2, bias=False) | |
# time step projection (discretization) | |
self.dt_proj = nn.Linear(self.time_step_rank, self.intermediate_size, bias=True) | |
# S4D real initialization. These are not discretized! | |
# The core is to load them, compute the discrete states, then write the updated state. Keeps the memory bounded | |
A = torch.arange(1, self.ssm_state_size + 1, dtype=torch.float32)[None, :] | |
A = A.expand(self.intermediate_size, -1).contiguous() | |
self.A_log = nn.Parameter(torch.log(A)) | |
self.D = nn.Parameter(torch.ones(self.intermediate_size)) | |
self.out_proj = nn.Linear(self.intermediate_size, self.hidden_size, bias=self.use_bias) | |
self.dt_layernorm = JambaRMSNorm(self.time_step_rank, eps=config.rms_norm_eps) | |
self.b_layernorm = JambaRMSNorm(self.ssm_state_size, eps=config.rms_norm_eps) | |
self.c_layernorm = JambaRMSNorm(self.ssm_state_size, eps=config.rms_norm_eps) | |
if not is_fast_path_available: | |
logger.warning_once( | |
"The fast path is not available because on of `(selective_state_update, selective_scan_fn, causal_conv1d_fn, causal_conv1d_update, mamba_inner_fn)`" | |
" is None. To install follow https://github.com/state-spaces/mamba/#installation and" | |
" https://github.com/Dao-AILab/causal-conv1d. If you want to use the naive implementation, set `use_mamba_kernels=False` in the model config" | |
) | |
def cuda_kernels_forward(self, hidden_states: torch.Tensor, cache_params: HybridMambaAttentionDynamicCache = None): | |
batch_size, seq_len, _ = hidden_states.shape | |
use_precomputed_states = ( | |
cache_params is not None | |
and cache_params.has_previous_state | |
and seq_len == 1 | |
and cache_params.conv_states[self.layer_idx].shape[0] | |
== cache_params.ssm_states[self.layer_idx].shape[0] | |
== batch_size | |
) | |
# 1. Gated MLP's linear projection | |
projected_states = self.in_proj(hidden_states).transpose(1, 2) | |
# We can't use `mamba_inner_fn` even if in training and without cache params because we have the | |
# inner layernorms which isn't supported by this fused kernel | |
hidden_states, gate = projected_states.chunk(2, dim=1) | |
# 2. Convolution sequence transformation | |
conv_weights = self.conv1d.weight.view(self.conv1d.weight.size(0), self.conv1d.weight.size(2)) | |
if use_precomputed_states: | |
hidden_states = causal_conv1d_update( | |
hidden_states.squeeze(-1), | |
cache_params.conv_states[self.layer_idx], | |
conv_weights, | |
self.conv1d.bias, | |
self.activation, | |
) | |
hidden_states = hidden_states.unsqueeze(-1) | |
else: | |
if cache_params is not None: | |
conv_states = nn.functional.pad(hidden_states, (self.conv_kernel_size - hidden_states.shape[-1], 0)) | |
cache_params.conv_states[self.layer_idx].copy_(conv_states) | |
hidden_states = causal_conv1d_fn(hidden_states, conv_weights, self.conv1d.bias, activation=self.activation) | |
# 3. State Space Model sequence transformation | |
# 3.a. input varying initialization of time_step, B and C | |
ssm_parameters = self.x_proj(hidden_states.transpose(1, 2)) | |
time_step, B, C = torch.split( | |
ssm_parameters, [self.time_step_rank, self.ssm_state_size, self.ssm_state_size], dim=-1 | |
) | |
time_step = self.dt_layernorm(time_step) | |
B = self.b_layernorm(B) | |
C = self.c_layernorm(C) | |
# Here we need to apply dt_proj without the bias, as the bias is added in the selective scan kernel. | |
# This is a hack to apply dt_proj while still using the forward pass of `torch.nn.Linear`, which is needed | |
# in order to make quantization work. Quantization code replaces `torch.nn.Linear` layers with quantized | |
# linear layers, and requires to call the forward pass directly. | |
# The original code here was: ```discrete_time_step = self.dt_proj.weight @ time_step.transpose(1, 2)``` | |
time_proj_bias = self.dt_proj.bias | |
self.dt_proj.bias = None | |
discrete_time_step = self.dt_proj(time_step).transpose(1, 2) | |
self.dt_proj.bias = time_proj_bias | |
A = -torch.exp(self.A_log.float()) | |
# 3.c perform the recurrence y ← SSM(A, B, C)(x) | |
time_proj_bias = time_proj_bias.float() if time_proj_bias is not None else None | |
if use_precomputed_states: | |
scan_outputs = selective_state_update( | |
cache_params.ssm_states[self.layer_idx], | |
hidden_states[..., 0], | |
discrete_time_step[..., 0], | |
A, | |
B[:, 0], | |
C[:, 0], | |
self.D, | |
gate[..., 0], | |
time_proj_bias, | |
dt_softplus=True, | |
).unsqueeze(-1) | |
else: | |
scan_outputs, ssm_state = selective_scan_fn( | |
hidden_states, | |
discrete_time_step, | |
A, | |
B.transpose(1, 2), | |
C.transpose(1, 2), | |
self.D.float(), | |
gate, | |
time_proj_bias, | |
delta_softplus=True, | |
return_last_state=True, | |
) | |
if ssm_state is not None and cache_params is not None: | |
cache_params.ssm_states[self.layer_idx].copy_(ssm_state) | |
# 4. Final linear projection | |
contextualized_states = self.out_proj(scan_outputs.transpose(1, 2)) | |
return contextualized_states | |
# fmt: off | |
def slow_forward(self, input_states, cache_params: HybridMambaAttentionDynamicCache = None): | |
batch_size, seq_len, _ = input_states.shape | |
dtype = input_states.dtype | |
# 1. Gated MLP's linear projection | |
projected_states = self.in_proj(input_states).transpose(1, 2) # [batch, 2 * intermediate_size, seq_len] | |
hidden_states, gate = projected_states.chunk(2, dim=1) | |
use_cache = isinstance(cache_params,HybridMambaAttentionDynamicCache) | |
# 2. Convolution sequence transformation | |
if use_cache and cache_params.ssm_states[self.layer_idx].shape[0] == batch_size: | |
if self.training: | |
# In training mode, we don't want to perform in-place operations on ssm_state so we can compute the backwards pass | |
ssm_state = cache_params.ssm_states[self.layer_idx].clone() | |
else: | |
ssm_state = cache_params.ssm_states[self.layer_idx] | |
ssm_state = ssm_state.to(hidden_states.device) | |
if cache_params.has_previous_state and seq_len == 1 and \ | |
cache_params.conv_states[self.layer_idx].shape[0] == batch_size: | |
conv_state = cache_params.conv_states[self.layer_idx] # [batch, intermediate_size, conv_kernel_size] | |
conv_state = torch.roll(conv_state, shifts=-1, dims=-1) | |
conv_state[:, :, -1] = hidden_states[:, :, 0] | |
cache_params.conv_states[self.layer_idx] = conv_state | |
hidden_states = torch.sum(conv_state * self.conv1d.weight[:, 0, :], dim=-1) | |
if self.use_conv_bias: | |
hidden_states += self.conv1d.bias | |
hidden_states = self.act(hidden_states).to(dtype).unsqueeze(-1) # [batch, intermediate_size, 1] : decoding | |
else: | |
conv_state = nn.functional.pad( | |
hidden_states, | |
(self.conv_kernel_size - hidden_states.shape[-1], 0) | |
) | |
cache_params.conv_states[self.layer_idx] = conv_state | |
hidden_states = self.act(self.conv1d(hidden_states)[..., :seq_len]) # [batch, intermediate_size, seq_len] | |
else: | |
ssm_state = torch.zeros( | |
(batch_size, self.intermediate_size, self.ssm_state_size), | |
device=hidden_states.device, dtype=dtype | |
) | |
hidden_states = self.act(self.conv1d(hidden_states)[..., :seq_len]) # [batch, intermediate_size, seq_len] | |
# 3. State Space Model sequence transformation | |
# 3.a. Selection: [batch, seq_len, self.time_step_rank + self.ssm_state_size * 2] | |
ssm_parameters = self.x_proj(hidden_states.transpose(1, 2)) | |
time_step, B, C = torch.split( | |
ssm_parameters, [self.time_step_rank, self.ssm_state_size, self.ssm_state_size], dim=-1 | |
) | |
time_step = self.dt_layernorm(time_step) | |
B = self.b_layernorm(B) | |
C = self.c_layernorm(C) | |
discrete_time_step = self.dt_proj(time_step) # [batch, seq_len, intermediate_size] | |
discrete_time_step = nn.functional.softplus(discrete_time_step).transpose(1, 2) # [batch, intermediate_size, seq_len] | |
# 3.b. Discretization: B and C to [batch, seq_len, intermediate_size, ssm_state_size] (SRAM) | |
A = -torch.exp(self.A_log.float()) # [intermediate_size, ssm_state_size] | |
discrete_A = torch.exp(A[None, :, None, :] * discrete_time_step[:, :, :, None]) # [batch, intermediate_size, seq_len, ssm_state_size] | |
discrete_B = discrete_time_step[:, :, :, None] * B[:, None, :, :].float() # [batch, intermediate_size, seq_len, ssm_state_size] | |
deltaB_u = discrete_B * hidden_states[:, :, :, None].float() | |
# 3.c perform the recurrence y ← SSM(A, B, C)(x) | |
scan_outputs = [] | |
for i in range(seq_len): | |
ssm_state = discrete_A[:, :, i, :] * ssm_state + deltaB_u[:, :, i, :] # [batch, intermediate_size, ssm_state] | |
scan_output = torch.matmul(ssm_state.to(dtype), C[:, i, :].unsqueeze(-1)) # [batch, intermediate_size, 1] | |
scan_outputs.append(scan_output[:, :, 0]) | |
scan_output = torch.stack(scan_outputs, dim=-1) # [batch, intermediate_size, seq_len] | |
scan_output = scan_output + (hidden_states * self.D[None, :, None]) | |
scan_output = (scan_output * self.act(gate)) | |
if use_cache: | |
cache_params.ssm_states[self.layer_idx] = ssm_state | |
# 4. Final linear projection | |
contextualized_states = self.out_proj(scan_output.transpose(1, 2)) # [batch, seq_len, hidden_size] | |
return contextualized_states | |
# fmt: on | |
def forward(self, hidden_states, cache_params: HybridMambaAttentionDynamicCache = None): | |
if self.use_fast_kernels: | |
if not is_fast_path_available or "cuda" not in self.x_proj.weight.device.type: | |
raise ValueError( | |
"Fast Mamba kernels are not available. Make sure to they are installed and that the mamba module is on a CUDA device" | |
) | |
return self.cuda_kernels_forward(hidden_states, cache_params) | |
return self.slow_forward(hidden_states, cache_params) | |
# Copied from transformers.models.mistral.modeling_mistral.MistralMLP with Mistral->Jamba | |
class JambaMLP(nn.Module): | |
def __init__(self, config): | |
super().__init__() | |
self.hidden_size = config.hidden_size | |
self.intermediate_size = config.intermediate_size | |
self.gate_proj = nn.Linear(self.hidden_size, self.intermediate_size, bias=False) | |
self.up_proj = nn.Linear(self.hidden_size, self.intermediate_size, bias=False) | |
self.down_proj = nn.Linear(self.intermediate_size, self.hidden_size, bias=False) | |
self.act_fn = ACT2FN[config.hidden_act] | |
def forward(self, hidden_state): | |
return self.down_proj(self.act_fn(self.gate_proj(hidden_state)) * self.up_proj(hidden_state)) | |
# Adapted from transformers.models.mixtral.modeling_mixtral.MixtralSparseMoeBlock with Mistral->Jamba | |
class JambaSparseMoeBlock(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: JambaConfig): | |
super().__init__() | |
self.hidden_dim = config.hidden_size | |
self.ffn_dim = config.intermediate_size | |
self.num_experts = config.num_experts | |
self.top_k = config.num_experts_per_tok | |
self.router = nn.Linear(self.hidden_dim, self.num_experts, bias=False) | |
self.experts = nn.ModuleList([JambaMLP(config) for _ in range(self.num_experts)]) | |
def forward(self, hidden_states: torch.Tensor) -> Tuple[torch.Tensor, torch.Tensor]: | |
""" """ | |
batch_size, sequence_length, hidden_dim = hidden_states.shape | |
hidden_states = hidden_states.view(-1, hidden_dim) | |
# router_logits: (batch * sequence_length, n_experts) | |
router_logits = self.router(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) | |
# 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]) | |
if top_x.shape[0] == 0: | |
continue | |
# 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 JambaAttentionDecoderLayer(nn.Module): | |
def __init__(self, config: JambaConfig, layer_idx: int): | |
super().__init__() | |
num_experts = config.layers_num_experts[layer_idx] | |
self.self_attn = JAMBA_ATTENTION_CLASSES[config._attn_implementation](config, layer_idx) | |
ffn_layer_class = JambaSparseMoeBlock if num_experts > 1 else JambaMLP | |
self.feed_forward = ffn_layer_class(config) | |
self.input_layernorm = JambaRMSNorm(config.hidden_size, eps=config.rms_norm_eps) | |
self.pre_ff_layernorm = JambaRMSNorm(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[HybridMambaAttentionDynamicCache] = None, | |
output_attentions: Optional[bool] = False, | |
output_router_logits: Optional[bool] = False, | |
use_cache: Optional[bool] = False, | |
cache_position: Optional[torch.LongTensor] = None, | |
) -> 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 (`HybridMambaAttentionDynamicCache`, *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. | |
""" | |
residual = hidden_states | |
hidden_states = self.input_layernorm(hidden_states) | |
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, | |
) | |
# residual connection after attention | |
hidden_states = residual + hidden_states | |
# feed-forward (experts/MLP) | |
residual = hidden_states | |
hidden_states = self.pre_ff_layernorm(hidden_states) | |
ff_outputs = self.feed_forward(hidden_states) | |
if isinstance(ff_outputs, tuple): | |
hidden_states, router_logits = ff_outputs | |
else: | |
hidden_states, router_logits = ff_outputs, None | |
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 | |
class JambaMambaDecoderLayer(nn.Module): | |
def __init__(self, config: JambaConfig, layer_idx: int): | |
super().__init__() | |
num_experts = config.layers_num_experts[layer_idx] | |
self.mamba = JambaMambaMixer(config=config, layer_idx=layer_idx) | |
ffn_layer_class = JambaSparseMoeBlock if num_experts > 1 else JambaMLP | |
self.feed_forward = ffn_layer_class(config) | |
self.input_layernorm = JambaRMSNorm(config.hidden_size, eps=config.rms_norm_eps) | |
self.pre_ff_layernorm = JambaRMSNorm(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[HybridMambaAttentionDynamicCache] = None, | |
output_attentions: Optional[bool] = False, | |
output_router_logits: Optional[bool] = False, | |
use_cache: Optional[bool] = False, | |
cache_position: Optional[torch.LongTensor] = None, | |
) -> 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 (`HybridMambaAttentionDynamicCache`, *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. | |
""" | |
residual = hidden_states | |
hidden_states = self.input_layernorm(hidden_states) | |
hidden_states = self.mamba( | |
hidden_states=hidden_states, | |
cache_params=past_key_value, | |
) | |
self_attn_weights = None | |
# residual connection after mamba | |
hidden_states = residual + hidden_states | |
# feed-forward (experts/MLP) | |
residual = hidden_states | |
hidden_states = self.pre_ff_layernorm(hidden_states) | |
ff_outputs = self.feed_forward(hidden_states) | |
if isinstance(ff_outputs, tuple): | |
hidden_states, router_logits = ff_outputs | |
else: | |
hidden_states, router_logits = ff_outputs, None | |
hidden_states = residual + hidden_states | |
outputs = (hidden_states,) | |
if output_attentions: | |
outputs += (self_attn_weights,) | |
if use_cache: | |
outputs += (past_key_value,) | |
if output_router_logits: | |
outputs += (router_logits,) | |
return outputs | |
JAMBA_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 ([`JambaConfig`]): | |
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. | |
""" | |
class JambaPreTrainedModel(PreTrainedModel): | |
config_class = JambaConfig | |
base_model_prefix = "model" | |
supports_gradient_checkpointing = True | |
_no_split_modules = ["JambaAttentionDecoderLayer", "JambaMambaDecoderLayer"] | |
_skip_keys_device_placement = "past_key_values" | |
_supports_flash_attn_2 = True | |
_supports_sdpa = True | |
_supports_cache_class = True # Note: only supports HybridMambaAttentionDynamicCache | |
_is_stateful = True | |
def _init_weights(self, module): | |
std = self.config.initializer_range | |
if isinstance(module, (nn.Linear, nn.Conv1d)): | |
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_() | |
JAMBA_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 `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 (`HybridMambaAttentionDynamicCache`, *optional*, returned when `use_cache=True` is passed or when `config.use_cache=True`): | |
A HybridMambaAttentionDynamicCache object containing pre-computed hidden-states (keys and values in the | |
self-attention blocks and convolution and ssm states in the mamba blocks) that can be used (see | |
`past_key_values` input) to speed up sequential decoding. | |
Key and value cache tensors have shape `(batch_size, num_heads, seq_len, head_dim)`. | |
Convolution and ssm states tensors have shape `(batch_size, d_inner, d_conv)` and | |
`(batch_size, d_inner, d_state)` respectively. | |
See the `HybridMambaAttentionDynamicCache` class for more details. | |
If `past_key_values` are used, the user can optionally input only the last `input_ids` (those that | |
don't have their past key value states given to this model) of shape `(batch_size, 1)` instead of all | |
`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. | |
""" | |
ALL_DECODER_LAYER_TYPES = {"attention": JambaAttentionDecoderLayer, "mamba": JambaMambaDecoderLayer} | |
# Adapted from transformers.models.mistral.modeling_mistral.MistralModel with MISTRAL->JAMBA, Mistral->Jamba | |
class JambaModel(JambaPreTrainedModel): | |
""" | |
Transformer decoder consisting of *config.num_hidden_layers* layers. Each layer is a [`JambaDecoderLayer`] | |
Args: | |
config: JambaConfig | |
""" | |
def __init__(self, config: JambaConfig): | |
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) | |
decoder_layers = [] | |
for i in range(config.num_hidden_layers): | |
layer_class = ALL_DECODER_LAYER_TYPES[config.layers_block_type[i]] | |
decoder_layers.append(layer_class(config, layer_idx=i)) | |
self.layers = nn.ModuleList(decoder_layers) | |
self._attn_implementation = config._attn_implementation | |
self.final_layernorm = JambaRMSNorm(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 | |
def forward( | |
self, | |
input_ids: torch.LongTensor = None, | |
attention_mask: Optional[torch.Tensor] = None, | |
position_ids: Optional[torch.LongTensor] = None, | |
past_key_values: Optional[HybridMambaAttentionDynamicCache] = 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 cannot specify both input_ids and inputs_embeds at the same time, and must specify either one" | |
) | |
if self.gradient_checkpointing and self.training and use_cache: | |
logger.warning_once( | |
"`use_cache=True` is incompatible with gradient checkpointing. Setting `use_cache=False`." | |
) | |
use_cache = False | |
if inputs_embeds is None: | |
inputs_embeds = self.embed_tokens(input_ids) | |
hidden_states = inputs_embeds | |
if use_cache and past_key_values is None: | |
logger.warning_once( | |
"Jamba requires an initialized `HybridMambaAttentionDynamicCache` to return a cache. None was " | |
"provided, so no cache will be returned." | |
) | |
if cache_position is None: | |
cache_position = torch.arange(hidden_states.shape[1], device=hidden_states.device) | |
if position_ids is None: | |
position_ids = cache_position.unsqueeze(0) | |
causal_mask = self._update_causal_mask(attention_mask, inputs_embeds, cache_position) | |
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 | |
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 output_attentions: | |
if layer_outputs[1] is not None: | |
# append attentions only of attention layers. Mamba layers return `None` as the attention weights | |
all_self_attns += (layer_outputs[1],) | |
if output_router_logits: | |
if layer_outputs[-1] is not None: | |
# append router logits only of expert layers. Regular MLP layers return `None` as the router logits | |
all_router_logits += (layer_outputs[-1],) | |
hidden_states = self.final_layernorm(hidden_states) | |
# add hidden states from the last decoder layer | |
if output_hidden_states: | |
all_hidden_states += (hidden_states,) | |
if past_key_values and not past_key_values.has_previous_state: | |
past_key_values.has_previous_state = True | |
next_cache = None if not use_cache else past_key_values | |
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, | |
) | |
def _update_causal_mask(self, attention_mask, input_tensor, cache_position): | |
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 | |
dtype, device = input_tensor.dtype, input_tensor.device | |
min_dtype = torch.finfo(dtype).min | |
sequence_length = input_tensor.shape[1] | |
target_length = cache_position[-1] + 1 | |
causal_mask = torch.full((sequence_length, target_length), fill_value=min_dtype, dtype=dtype, device=device) | |
if sequence_length != 1: | |
causal_mask = torch.triu(causal_mask, diagonal=1) | |
causal_mask *= torch.arange(target_length, device=device) > cache_position.reshape(-1, 1) | |
causal_mask = causal_mask[None, None, :, :].expand(input_tensor.shape[0], 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.dim() == 2: | |
mask_length = attention_mask.shape[-1] | |
padding_mask = causal_mask[..., :mask_length].eq(0.0) * attention_mask[:, None, None, :].eq(0.0) | |
causal_mask[..., :mask_length] = causal_mask[..., :mask_length].masked_fill(padding_mask, min_dtype) | |
if ( | |
self.config._attn_implementation == "sdpa" | |
and attention_mask is not None | |
and attention_mask.device.type == "cuda" | |
): | |
# 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 | |
# Adapted from transformers.models.mixtral.modeling_mixtral.MixtralForCausalLM with MIXTRAL->JAMBA, Mixtral->Jamba | |
class JambaForCausalLM(JambaPreTrainedModel): | |
_tied_weights_keys = ["lm_head.weight"] | |
def __init__(self, config: JambaConfig): | |
super().__init__(config) | |
self.model = JambaModel(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_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 | |
# 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[HybridMambaAttentionDynamicCache] = 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: Optional[Union[int, None]] = None, | |
) -> 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` or `None`, *optional*): | |
Calculate logits for the last `num_logits_to_keep` tokens. If `None`, calculate logits for all | |
`input_ids`. 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. | |
Returns: | |
Example: | |
```python | |
>>> from transformers import AutoTokenizer, JambaForCausalLM | |
>>> model = JambaForCausalLM.from_pretrained("ai21labs/Jamba-v0.1") | |
>>> tokenizer = AutoTokenizer.from_pretrained("ai21labs/Jamba-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, | |
cache_position=cache_position, | |
return_dict=return_dict, | |
) | |
hidden_states = outputs[0] | |
if num_logits_to_keep is None: | |
logits = self.lm_head(hidden_states) | |
else: | |
logits = self.lm_head(hidden_states[..., -num_logits_to_keep:, :]) | |
logits = logits.float() | |
loss = None | |
if labels is not None: | |
# Shift so that tokens < n predict n | |
shift_logits = logits[..., :-1, :].contiguous() | |
shift_labels = labels[..., 1:].contiguous() | |
# Flatten the tokens | |
loss_fct = CrossEntropyLoss() | |
shift_logits = shift_logits.view(-1, self.config.vocab_size) | |
shift_labels = shift_labels.view(-1) | |
# Enable model parallelism | |
shift_labels = shift_labels.to(shift_logits.device) | |
loss = loss_fct(shift_logits, shift_labels) | |
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, | |
) | |
def prepare_inputs_for_generation( | |
self, | |
input_ids, | |
past_key_values=None, | |
attention_mask=None, | |
inputs_embeds=None, | |
output_router_logits=False, | |
cache_position=None, | |
position_ids=None, | |
use_cache=True, | |
**kwargs, | |
): | |
empty_past_kv = past_key_values is None | |
# If we have cache: let's slice `input_ids` through `cache_position`, to keep only the unprocessed tokens | |
# Exception 1: when passing input_embeds, input_ids may be missing entries | |
# Exception 2: some generation methods do special slicing of input_ids, so we don't need to do it here | |
if not empty_past_kv: | |
if inputs_embeds is not None: # Exception 1 | |
input_ids = input_ids[:, -cache_position.shape[0] :] | |
elif input_ids.shape[1] != cache_position.shape[0]: # Default case (the "else", a no op, is Exception 2) | |
input_ids = input_ids[:, cache_position] | |
else: | |
past_key_values = HybridMambaAttentionDynamicCache( | |
self.config, input_ids.shape[0], self.dtype, device=self.device | |
) | |
if attention_mask is not None and position_ids is None: | |
# create position_ids on the fly for batch generation | |
position_ids = attention_mask.long().cumsum(-1) - 1 | |
position_ids.masked_fill_(attention_mask == 0, 1) | |
if not empty_past_kv: | |
position_ids = position_ids[:, -input_ids.shape[1] :] | |
# if `inputs_embeds` are passed, we only want to use them in the 1st generation step | |
if inputs_embeds is not None and empty_past_kv: | |
model_inputs = {"inputs_embeds": inputs_embeds} | |
else: | |
model_inputs = {"input_ids": input_ids.contiguous()} # `contiguous()` needed for compilation use cases | |
model_inputs.update( | |
{ | |
"position_ids": position_ids, | |
"past_key_values": past_key_values, | |
"use_cache": use_cache, | |
"attention_mask": attention_mask, | |
"output_router_logits": output_router_logits, | |
"num_logits_to_keep": self.config.num_logits_to_keep, | |
"cache_position": cache_position, | |
} | |
) | |
return model_inputs | |
# Copied from transformers.models.mixtral.modeling_mixtral.MixtralForSequenceClassification with Mixtral->Jamba, MIXTRAL->JAMBA | |
class JambaForSequenceClassification(JambaPreTrainedModel): | |
def __init__(self, config): | |
super().__init__(config) | |
self.num_labels = config.num_labels | |
self.model = JambaModel(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 | |
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: | |
labels = labels.to(logits.device) | |
if self.config.problem_type is None: | |
if self.num_labels == 1: | |
self.config.problem_type = "regression" | |
elif self.num_labels > 1 and (labels.dtype == torch.long or labels.dtype == torch.int): | |
self.config.problem_type = "single_label_classification" | |
else: | |
self.config.problem_type = "multi_label_classification" | |
if self.config.problem_type == "regression": | |
loss_fct = MSELoss() | |
if self.num_labels == 1: | |
loss = loss_fct(pooled_logits.squeeze(), labels.squeeze()) | |
else: | |
loss = loss_fct(pooled_logits, labels) | |
elif self.config.problem_type == "single_label_classification": | |
loss_fct = CrossEntropyLoss() | |
loss = loss_fct(pooled_logits.view(-1, self.num_labels), labels.view(-1)) | |
elif self.config.problem_type == "multi_label_classification": | |
loss_fct = BCEWithLogitsLoss() | |
loss = loss_fct(pooled_logits, labels) | |
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, | |
) | |