1883 lines
86 KiB
Python
1883 lines
86 KiB
Python
# coding=utf-8
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# Copyright 2024 AI21 Labs Ltd. and the HuggingFace Inc. team. All rights reserved.
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#
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# This code is based on EleutherAI's GPT-NeoX library and the GPT-NeoX
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# and OPT implementations in this library. It has been modified from its
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# original forms to accommodate minor architectural differences compared
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# to GPT-NeoX and OPT used by the Meta AI team that trained the model.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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""" PyTorch Jamba model."""
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import inspect
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import math
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from typing import Any, Dict, List, Optional, Tuple, Union
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import torch
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import torch.nn.functional as F
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import torch.utils.checkpoint
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from torch import nn
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from torch.nn import BCEWithLogitsLoss, CrossEntropyLoss, MSELoss
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from ...activations import ACT2FN
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from ...cache_utils import DynamicCache # we need __iter__ and __len__ of pkv
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from ...modeling_attn_mask_utils import (
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AttentionMaskConverter,
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)
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from ...modeling_outputs import (
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MoeCausalLMOutputWithPast,
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MoeModelOutputWithPast,
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SequenceClassifierOutputWithPast,
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)
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from ...modeling_utils import PreTrainedModel
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from ...utils import (
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add_start_docstrings,
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add_start_docstrings_to_model_forward,
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is_flash_attn_greater_or_equal_2_10,
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logging,
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replace_return_docstrings,
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)
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from ...utils.import_utils import (
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is_causal_conv1d_available,
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is_flash_attn_2_available,
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is_mamba_ssm_available,
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)
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from .configuration_jamba import JambaConfig
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if is_flash_attn_2_available():
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from flash_attn import flash_attn_func, flash_attn_varlen_func
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from flash_attn.bert_padding import index_first_axis, pad_input, unpad_input # noqa
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_flash_supports_window_size = "window_size" in list(inspect.signature(flash_attn_func).parameters)
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if is_mamba_ssm_available():
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from mamba_ssm.ops.selective_scan_interface import mamba_inner_fn, selective_scan_fn
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from mamba_ssm.ops.triton.selective_state_update import selective_state_update
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else:
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selective_state_update, selective_scan_fn, mamba_inner_fn = None, None, None
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if is_causal_conv1d_available():
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from causal_conv1d import causal_conv1d_fn, causal_conv1d_update
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else:
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causal_conv1d_update, causal_conv1d_fn = None, None
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is_fast_path_available = all(
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(selective_state_update, selective_scan_fn, causal_conv1d_fn, causal_conv1d_update, mamba_inner_fn)
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)
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logger = logging.get_logger(__name__)
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_CONFIG_FOR_DOC = "JambaConfig"
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# Copied from transformers.models.mixtral.modeling_mixtral.load_balancing_loss_func with gate->router
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def load_balancing_loss_func(
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router_logits: torch.Tensor,
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num_experts: torch.Tensor = None,
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top_k=2,
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attention_mask: Optional[torch.Tensor] = None,
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) -> float:
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r"""
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Computes auxiliary load balancing loss as in Switch Transformer - implemented in Pytorch.
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See Switch Transformer (https://arxiv.org/abs/2101.03961) for more details. This function implements the loss
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function presented in equations (4) - (6) of the paper. It aims at penalizing cases where the routing between
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experts is too unbalanced.
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Args:
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router_logits (Union[`torch.Tensor`, Tuple[torch.Tensor]):
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Logits from the `router`, should be a tuple of model.config.num_hidden_layers tensors of
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shape [batch_size X sequence_length, num_experts].
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attention_mask (`torch.Tensor`, None):
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The attention_mask used in forward function
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shape [batch_size X sequence_length] if not None.
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num_experts (`int`, *optional*):
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Number of experts
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Returns:
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The auxiliary loss.
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"""
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if router_logits is None or not isinstance(router_logits, tuple):
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return 0
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if isinstance(router_logits, tuple):
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compute_device = router_logits[0].device
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concatenated_router_logits = torch.cat(
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[layer_router.to(compute_device) for layer_router in router_logits], dim=0
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)
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routing_weights = torch.nn.functional.softmax(concatenated_router_logits, dim=-1)
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_, selected_experts = torch.topk(routing_weights, top_k, dim=-1)
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expert_mask = torch.nn.functional.one_hot(selected_experts, num_experts)
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if attention_mask is None:
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# Compute the percentage of tokens routed to each experts
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tokens_per_expert = torch.mean(expert_mask.float(), dim=0)
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# Compute the average probability of routing to these experts
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router_prob_per_expert = torch.mean(routing_weights, dim=0)
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else:
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batch_size, sequence_length = attention_mask.shape
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num_hidden_layers = concatenated_router_logits.shape[0] // (batch_size * sequence_length)
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# Compute the mask that masks all padding tokens as 0 with the same shape of expert_mask
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expert_attention_mask = (
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attention_mask[None, :, :, None, None]
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.expand((num_hidden_layers, batch_size, sequence_length, top_k, num_experts))
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.reshape(-1, top_k, num_experts)
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.to(compute_device)
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)
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# Compute the percentage of tokens routed to each experts
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tokens_per_expert = torch.sum(expert_mask.float() * expert_attention_mask, dim=0) / torch.sum(
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expert_attention_mask, dim=0
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)
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# Compute the mask that masks all padding tokens as 0 with the same shape of tokens_per_expert
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router_per_expert_attention_mask = (
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attention_mask[None, :, :, None]
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.expand((num_hidden_layers, batch_size, sequence_length, num_experts))
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.reshape(-1, num_experts)
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.to(compute_device)
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)
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# Compute the average probability of routing to these experts
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router_prob_per_expert = torch.sum(routing_weights * router_per_expert_attention_mask, dim=0) / torch.sum(
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router_per_expert_attention_mask, dim=0
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)
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overall_loss = torch.sum(tokens_per_expert * router_prob_per_expert.unsqueeze(0))
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return overall_loss * num_experts
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# Copied from transformers.models.llama.modeling_llama._get_unpad_data
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def _get_unpad_data(attention_mask):
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seqlens_in_batch = attention_mask.sum(dim=-1, dtype=torch.int32)
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indices = torch.nonzero(attention_mask.flatten(), as_tuple=False).flatten()
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max_seqlen_in_batch = seqlens_in_batch.max().item()
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cu_seqlens = F.pad(torch.cumsum(seqlens_in_batch, dim=0, dtype=torch.int32), (1, 0))
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return (
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indices,
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cu_seqlens,
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max_seqlen_in_batch,
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)
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# Copied from transformers.models.llama.modeling_llama.LlamaRMSNorm with Llama->Jamba
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class JambaRMSNorm(nn.Module):
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def __init__(self, hidden_size, eps=1e-6):
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"""
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JambaRMSNorm is equivalent to T5LayerNorm
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"""
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super().__init__()
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self.weight = nn.Parameter(torch.ones(hidden_size))
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self.variance_epsilon = eps
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def forward(self, hidden_states):
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input_dtype = hidden_states.dtype
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hidden_states = hidden_states.to(torch.float32)
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variance = hidden_states.pow(2).mean(-1, keepdim=True)
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hidden_states = hidden_states * torch.rsqrt(variance + self.variance_epsilon)
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return self.weight * hidden_states.to(input_dtype)
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# Copied from transformers.models.llama.modeling_llama.repeat_kv
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def repeat_kv(hidden_states: torch.Tensor, n_rep: int) -> torch.Tensor:
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"""
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This is the equivalent of torch.repeat_interleave(x, dim=1, repeats=n_rep). The hidden states go from (batch,
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num_key_value_heads, seqlen, head_dim) to (batch, num_attention_heads, seqlen, head_dim)
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"""
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batch, num_key_value_heads, slen, head_dim = hidden_states.shape
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if n_rep == 1:
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return hidden_states
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hidden_states = hidden_states[:, :, None, :, :].expand(batch, num_key_value_heads, n_rep, slen, head_dim)
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return hidden_states.reshape(batch, num_key_value_heads * n_rep, slen, head_dim)
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class HybridMambaAttentionDynamicCache(DynamicCache):
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"""
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A dynamic cache that can handle both the attention cache (which has a seq_len dimension) and the mamba cache
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(which has a constant shape regardless of seq_len).
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This cache has two sets of lists of tensors: `key_cache` and `value_cache` for attention cache and `conv_states`
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and `ssm_states` for mamba cache. Each of these lists has `num_layers` tensors. The expected shape for each tensor
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For attention layers, `key_cache` and `value_cache` have a shape of `(batch_size, num_heads, seq_len, head_dim)`,
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while `conv_states` and `ssm_states` have a shape of `(batch_size, 0)` (empty tensors).
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For mamba layers, `key_cache` and `value_cache` have a shape of `(batch_size, 0)` (empty tensors),
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while `conv_states` represents the convolution state and has a shape of `(batch_size, d_inner, d_conv)`,
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and `ssm_states` represents the ssm state and has a shape of `(batch_size, d_inner, d_state)`.
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"""
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def __init__(self, config, batch_size, dtype=torch.float16, device=None):
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self.dtype = dtype
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self.layers_block_type = config.layers_block_type
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self.has_previous_state = False # only used by mamba
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intermediate_size = config.mamba_expand * config.hidden_size
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ssm_state_size = config.mamba_d_state
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conv_kernel_size = config.mamba_d_conv
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self.conv_states = []
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self.ssm_states = []
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for i in range(config.num_hidden_layers):
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if self.layers_block_type[i] == "mamba":
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self.conv_states += [
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torch.zeros(batch_size, intermediate_size, conv_kernel_size, device=device, dtype=dtype)
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]
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self.ssm_states += [
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torch.zeros(batch_size, intermediate_size, ssm_state_size, device=device, dtype=dtype)
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]
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else:
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self.conv_states += [torch.tensor([[]] * batch_size, device=device)]
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self.ssm_states += [torch.tensor([[]] * batch_size, device=device)]
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self.key_cache = [torch.tensor([[]] * batch_size, device=device) for _ in range(config.num_hidden_layers)]
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self.value_cache = [torch.tensor([[]] * batch_size, device=device) for _ in range(config.num_hidden_layers)]
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def update(
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self,
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key_states: torch.Tensor,
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value_states: torch.Tensor,
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layer_idx: int,
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cache_kwargs: Optional[Dict[str, Any]] = None,
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) -> Tuple[torch.Tensor, torch.Tensor]:
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# Update the cache
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if self.key_cache[layer_idx].shape[-1] == 0:
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self.key_cache[layer_idx] = key_states
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self.value_cache[layer_idx] = value_states
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else:
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self.key_cache[layer_idx] = torch.cat([self.key_cache[layer_idx], key_states], dim=2)
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self.value_cache[layer_idx] = torch.cat([self.value_cache[layer_idx], value_states], dim=2)
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return self.key_cache[layer_idx], self.value_cache[layer_idx]
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def reorder_cache(self, beam_idx: torch.LongTensor):
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"""Reorders the cache for beam search, given the selected beam indices."""
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for layer_idx in range(len(self.key_cache)):
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device = self.key_cache[layer_idx].device
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self.key_cache[layer_idx] = self.key_cache[layer_idx].index_select(0, beam_idx.to(device))
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device = self.value_cache[layer_idx].device
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self.value_cache[layer_idx] = self.value_cache[layer_idx].index_select(0, beam_idx.to(device))
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device = self.conv_states[layer_idx].device
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self.conv_states[layer_idx] = self.conv_states[layer_idx].index_select(0, beam_idx.to(device))
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device = self.ssm_states[layer_idx].device
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self.ssm_states[layer_idx] = self.ssm_states[layer_idx].index_select(0, beam_idx.to(device))
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def to_legacy_cache(self) -> Tuple[Tuple[torch.Tensor], Tuple[torch.Tensor]]:
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raise NotImplementedError("HybridMambaAttentionDynamicCache does not have a legacy cache equivalent.")
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@classmethod
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def from_legacy_cache(cls, past_key_values: Optional[Tuple[Tuple[torch.FloatTensor]]] = None) -> "DynamicCache":
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raise NotImplementedError("HybridMambaAttentionDynamicCache does not have a legacy cache equivalent.")
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# Adapted from transformers.models.mistral.modeling_mistral.MistralAttention with Mistral->Jamba
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class JambaAttention(nn.Module):
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"""
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Multi-headed attention from 'Attention Is All You Need' paper. Modified to use sliding window attention: Longformer
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and "Generating Long Sequences with Sparse Transformers".
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"""
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def __init__(self, config: JambaConfig, layer_idx: Optional[int] = None):
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super().__init__()
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self.config = config
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self.layer_idx = layer_idx
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if layer_idx is None:
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logger.warning_once(
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f"Instantiating {self.__class__.__name__} without passing a `layer_idx` is not recommended and will "
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"lead to errors during the forward call if caching is used. Please make sure to provide a `layer_idx` "
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"when creating this class."
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)
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self.hidden_size = config.hidden_size
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self.num_heads = config.num_attention_heads
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self.head_dim = self.hidden_size // self.num_heads
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self.num_key_value_heads = config.num_key_value_heads
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self.num_key_value_groups = self.num_heads // self.num_key_value_heads
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self.is_causal = True
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self.attention_dropout = config.attention_dropout
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if (self.head_dim * self.num_heads) != self.hidden_size:
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raise ValueError(
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f"hidden_size must be divisible by num_heads (got `hidden_size`: {self.hidden_size}"
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f" and `num_heads`: {self.num_heads})."
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)
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self.q_proj = nn.Linear(self.hidden_size, self.num_heads * self.head_dim, bias=False)
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self.k_proj = nn.Linear(self.hidden_size, self.num_key_value_heads * self.head_dim, bias=False)
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self.v_proj = nn.Linear(self.hidden_size, self.num_key_value_heads * self.head_dim, bias=False)
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self.o_proj = nn.Linear(self.num_heads * self.head_dim, self.hidden_size, bias=False)
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def forward(
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self,
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hidden_states: torch.Tensor,
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attention_mask: Optional[torch.Tensor] = None,
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position_ids: Optional[torch.LongTensor] = None,
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past_key_value: Optional[HybridMambaAttentionDynamicCache] = None,
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output_attentions: bool = False,
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use_cache: bool = False,
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cache_position: Optional[torch.LongTensor] = None,
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) -> Tuple[torch.Tensor, Optional[torch.Tensor], Optional[Tuple[torch.Tensor]]]:
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bsz, q_len, _ = hidden_states.size()
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query_states = self.q_proj(hidden_states)
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key_states = self.k_proj(hidden_states)
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value_states = self.v_proj(hidden_states)
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query_states = query_states.view(bsz, q_len, self.num_heads, self.head_dim).transpose(1, 2)
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key_states = key_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
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value_states = value_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
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if past_key_value is not None:
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key_states, value_states = past_key_value.update(key_states, value_states, self.layer_idx)
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# repeat k/v heads if n_kv_heads < n_heads
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key_states = repeat_kv(key_states, self.num_key_value_groups)
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value_states = repeat_kv(value_states, self.num_key_value_groups)
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attn_weights = torch.matmul(query_states, key_states.transpose(2, 3)) / math.sqrt(self.head_dim)
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if attention_mask is not None: # no matter the length, we just slice it
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causal_mask = attention_mask[:, :, :, : key_states.shape[-2]]
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attn_weights = attn_weights + causal_mask
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# upcast attention to fp32
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attn_weights = nn.functional.softmax(attn_weights, dim=-1, dtype=torch.float32).to(query_states.dtype)
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attn_weights = nn.functional.dropout(attn_weights, p=self.attention_dropout, training=self.training)
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attn_output = torch.matmul(attn_weights, value_states)
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if attn_output.size() != (bsz, self.num_heads, q_len, self.head_dim):
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raise ValueError(
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f"`attn_output` should be of size {(bsz, self.num_heads, q_len, self.head_dim)}, but is"
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f" {attn_output.size()}"
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)
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attn_output = attn_output.transpose(1, 2).contiguous()
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attn_output = attn_output.reshape(bsz, q_len, self.hidden_size)
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attn_output = self.o_proj(attn_output)
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if not output_attentions:
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attn_weights = None
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return attn_output, attn_weights, past_key_value
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# Adapted from transformers.models.mistral.modeling_mistral.MistralFlashAttention2 with Mistral->Jamba
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class JambaFlashAttention2(JambaAttention):
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"""
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Jamba flash attention module. This module inherits from `JambaAttention` as the weights of the module stays
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untouched. The only required change would be on the forward pass where it needs to correctly call the public API of
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flash attention and deal with padding tokens in case the input contains any of them.
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"""
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# Copied from transformers.models.llama.modeling_llama.LlamaFlashAttention2.__init__
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def __init__(self, *args, **kwargs):
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super().__init__(*args, **kwargs)
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# TODO: Should be removed once Flash Attention for RoCm is bumped to 2.1.
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# 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.
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# 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).
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self._flash_attn_uses_top_left_mask = not is_flash_attn_greater_or_equal_2_10()
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def forward(
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self,
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hidden_states: torch.Tensor,
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attention_mask: Optional[torch.Tensor] = None,
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position_ids: Optional[torch.LongTensor] = None,
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past_key_value: Optional[HybridMambaAttentionDynamicCache] = None,
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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).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 = cache_position[-1]
|
|
|
|
use_sliding_windows = (
|
|
_flash_supports_window_size
|
|
and getattr(self.config, "sliding_window", None) is not None
|
|
and kv_seq_len > self.config.sliding_window
|
|
)
|
|
|
|
if not _flash_supports_window_size:
|
|
logger.warning_once(
|
|
"The current flash attention version does not support sliding window attention, for a more memory efficient implementation"
|
|
" make sure to upgrade flash-attn library."
|
|
)
|
|
|
|
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
|
|
query_states = query_states.transpose(1, 2)
|
|
key_states = key_states.transpose(1, 2)
|
|
value_states = value_states.transpose(1, 2)
|
|
|
|
attn_output = self._flash_attention_forward(
|
|
query_states,
|
|
key_states,
|
|
value_states,
|
|
attention_mask,
|
|
q_len,
|
|
dropout=dropout_rate,
|
|
use_sliding_windows=use_sliding_windows,
|
|
)
|
|
|
|
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
|
|
|
|
def _flash_attention_forward(
|
|
self,
|
|
query_states,
|
|
key_states,
|
|
value_states,
|
|
attention_mask,
|
|
query_length,
|
|
dropout=0.0,
|
|
softmax_scale=None,
|
|
use_sliding_windows=False,
|
|
):
|
|
"""
|
|
Calls the forward method of Flash Attention - if the input hidden states contain at least one padding token
|
|
first unpad the input, then computes the attention scores and pad the final attention scores.
|
|
|
|
Args:
|
|
query_states (`torch.Tensor`):
|
|
Input query states to be passed to Flash Attention API
|
|
key_states (`torch.Tensor`):
|
|
Input key states to be passed to Flash Attention API
|
|
value_states (`torch.Tensor`):
|
|
Input value states to be passed to Flash Attention API
|
|
attention_mask (`torch.Tensor`):
|
|
The padding mask - corresponds to a tensor of size `(batch_size, seq_len)` where 0 stands for the
|
|
position of padding tokens and 1 for the position of non-padding tokens.
|
|
dropout (`float`, *optional*):
|
|
Attention dropout
|
|
softmax_scale (`float`, *optional*):
|
|
The scaling of QK^T before applying softmax. Default to 1 / sqrt(head_dim)
|
|
use_sliding_windows (`bool`, *optional*):
|
|
Whether to activate sliding window attention.
|
|
"""
|
|
if not self._flash_attn_uses_top_left_mask:
|
|
causal = self.is_causal
|
|
else:
|
|
# TODO: Remove the `query_length != 1` check once Flash Attention for RoCm is bumped to 2.1. For details, please see the comment in LlamaFlashAttention2 __init__.
|
|
causal = self.is_causal and query_length != 1
|
|
|
|
# Contains at least one padding token in the sequence
|
|
if attention_mask is not None:
|
|
batch_size = query_states.shape[0]
|
|
query_states, key_states, value_states, indices_q, cu_seq_lens, max_seq_lens = self._upad_input(
|
|
query_states, key_states, value_states, attention_mask, query_length
|
|
)
|
|
|
|
cu_seqlens_q, cu_seqlens_k = cu_seq_lens
|
|
max_seqlen_in_batch_q, max_seqlen_in_batch_k = max_seq_lens
|
|
|
|
if not use_sliding_windows:
|
|
attn_output_unpad = flash_attn_varlen_func(
|
|
query_states,
|
|
key_states,
|
|
value_states,
|
|
cu_seqlens_q=cu_seqlens_q,
|
|
cu_seqlens_k=cu_seqlens_k,
|
|
max_seqlen_q=max_seqlen_in_batch_q,
|
|
max_seqlen_k=max_seqlen_in_batch_k,
|
|
dropout_p=dropout,
|
|
softmax_scale=softmax_scale,
|
|
causal=causal,
|
|
)
|
|
else:
|
|
attn_output_unpad = flash_attn_varlen_func(
|
|
query_states,
|
|
key_states,
|
|
value_states,
|
|
cu_seqlens_q=cu_seqlens_q,
|
|
cu_seqlens_k=cu_seqlens_k,
|
|
max_seqlen_q=max_seqlen_in_batch_q,
|
|
max_seqlen_k=max_seqlen_in_batch_k,
|
|
dropout_p=dropout,
|
|
softmax_scale=softmax_scale,
|
|
causal=causal,
|
|
window_size=(self.config.sliding_window, self.config.sliding_window),
|
|
)
|
|
|
|
attn_output = pad_input(attn_output_unpad, indices_q, batch_size, query_length)
|
|
else:
|
|
if not use_sliding_windows:
|
|
attn_output = flash_attn_func(
|
|
query_states,
|
|
key_states,
|
|
value_states,
|
|
dropout,
|
|
softmax_scale=softmax_scale,
|
|
causal=causal,
|
|
)
|
|
else:
|
|
attn_output = flash_attn_func(
|
|
query_states,
|
|
key_states,
|
|
value_states,
|
|
dropout,
|
|
softmax_scale=softmax_scale,
|
|
causal=causal,
|
|
window_size=(self.config.sliding_window, self.config.sliding_window),
|
|
)
|
|
|
|
return attn_output
|
|
|
|
# Copied from transformers.models.mixtral.modeling_mixtral.MixtralFlashAttention2._upad_input
|
|
def _upad_input(self, query_layer, key_layer, value_layer, attention_mask, query_length):
|
|
batch_size, kv_seq_len, num_heads, head_dim = key_layer.shape
|
|
|
|
# On the first iteration we need to properly re-create the padding mask
|
|
# by slicing it on the proper place
|
|
if kv_seq_len != attention_mask.shape[-1]:
|
|
attention_mask_num_tokens = attention_mask.shape[-1]
|
|
attention_mask = attention_mask[:, attention_mask_num_tokens - kv_seq_len :]
|
|
|
|
indices_k, cu_seqlens_k, max_seqlen_in_batch_k = _get_unpad_data(attention_mask)
|
|
|
|
key_layer = index_first_axis(key_layer.reshape(batch_size * kv_seq_len, num_heads, head_dim), indices_k)
|
|
value_layer = index_first_axis(value_layer.reshape(batch_size * kv_seq_len, num_heads, head_dim), indices_k)
|
|
|
|
if query_length == kv_seq_len:
|
|
query_layer = index_first_axis(
|
|
query_layer.reshape(batch_size * kv_seq_len, num_heads, head_dim), indices_k
|
|
)
|
|
cu_seqlens_q = cu_seqlens_k
|
|
max_seqlen_in_batch_q = max_seqlen_in_batch_k
|
|
indices_q = indices_k
|
|
elif query_length == 1:
|
|
max_seqlen_in_batch_q = 1
|
|
cu_seqlens_q = torch.arange(
|
|
batch_size + 1, dtype=torch.int32, device=query_layer.device
|
|
) # There is a memcpy here, that is very bad.
|
|
indices_q = cu_seqlens_q[:-1]
|
|
query_layer = query_layer.squeeze(1)
|
|
else:
|
|
# The -q_len: slice assumes left padding.
|
|
attention_mask = attention_mask[:, -query_length:]
|
|
query_layer, indices_q, cu_seqlens_q, max_seqlen_in_batch_q = unpad_input(query_layer, attention_mask)
|
|
|
|
return (
|
|
query_layer,
|
|
key_layer,
|
|
value_layer,
|
|
indices_q,
|
|
(cu_seqlens_q, cu_seqlens_k),
|
|
(max_seqlen_in_batch_q, max_seqlen_in_batch_k),
|
|
)
|
|
|
|
|
|
# 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()
|
|
|
|
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,
|
|
# 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=self.is_causal and attention_mask is None and q_len > 1,
|
|
)
|
|
|
|
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]
|
|
|
|
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, intermediade_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, intermediade_size, ssm_state]
|
|
scan_output = torch.matmul(ssm_state.to(dtype), C[:, i, :].unsqueeze(-1)) # [batch, intermediade_size, 1]
|
|
scan_outputs.append(scan_output[:, :, 0])
|
|
scan_output = torch.stack(scan_outputs, dim=-1) # [batch, intermediade_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.config = config
|
|
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, x):
|
|
return self.down_proj(self.act_fn(self.gate_proj(x)) * self.up_proj(x))
|
|
|
|
|
|
# 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.
|
|
"""
|
|
|
|
|
|
@add_start_docstrings(
|
|
"The bare Jamba Model outputting raw hidden-states without any specific head on top.",
|
|
JAMBA_START_DOCSTRING,
|
|
)
|
|
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
|
|
|
|
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}
|
|
|
|
|
|
@add_start_docstrings(
|
|
"The bare Jamba Model outputting raw hidden-states without any specific head on top.",
|
|
JAMBA_START_DOCSTRING,
|
|
)
|
|
# 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
|
|
|
|
@add_start_docstrings_to_model_forward(JAMBA_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[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
|
|
|
|
@add_start_docstrings_to_model_forward(JAMBA_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[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,
|
|
**kwargs,
|
|
):
|
|
empty_past_kv = past_key_values is None
|
|
|
|
# Omit tokens covered by past_key_values
|
|
if not empty_past_kv:
|
|
past_length = cache_position[0] if cache_position is not None else attention_mask.shape[1]
|
|
max_cache_length = self.config.sliding_window
|
|
# Keep only the unprocessed tokens:
|
|
# 1 - If the length of the attention_mask exceeds the length of input_ids, then we are in a setting where
|
|
# some of the inputs are exclusively passed as part of the cache (e.g. when passing input_embeds as
|
|
# input)
|
|
if attention_mask is not None and attention_mask.shape[1] > input_ids.shape[1]:
|
|
input_ids = input_ids[:, -(attention_mask.shape[1] - past_length) :]
|
|
# 2 - If the past_length is smaller than input_ids', then input_ids holds all input tokens. We can discard
|
|
# input_ids based on the past_length.
|
|
elif past_length < input_ids.shape[1]:
|
|
input_ids = input_ids[:, past_length:]
|
|
# 3 - Otherwise (past_length >= input_ids.shape[1]), let's assume input_ids only has unprocessed tokens.
|
|
|
|
# If we are about to go beyond the maximum cache length, we need to crop the input attention mask.
|
|
if (
|
|
max_cache_length is not None
|
|
and attention_mask is not None
|
|
and past_length + input_ids.shape[1] > max_cache_length
|
|
):
|
|
attention_mask = attention_mask[:, -max_cache_length:]
|
|
else:
|
|
past_key_values = HybridMambaAttentionDynamicCache(
|
|
self.config, input_ids.shape[0], self.dtype, device=self.device
|
|
)
|
|
|
|
position_ids = kwargs.get("position_ids", None)
|
|
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}
|
|
|
|
model_inputs.update(
|
|
{
|
|
"position_ids": position_ids,
|
|
"past_key_values": past_key_values,
|
|
"use_cache": kwargs.get("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
|
|
|
|
|
|
@add_start_docstrings(
|
|
"""
|
|
The Jamba Model with a sequence classification head on top (linear layer).
|
|
|
|
[`JambaForSequenceClassification`] 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).
|
|
""",
|
|
JAMBA_START_DOCSTRING,
|
|
)
|
|
# 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
|
|
|
|
@add_start_docstrings_to_model_forward(JAMBA_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,
|
|
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,
|
|
)
|