File size: 10,369 Bytes
ae81e0f
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
# coding=utf-8
# Copyright 2022 EleutherAI and the HuggingFace Inc. team. All rights reserved.
#
# This code is based on EleutherAI's GPT-NeoX library and the GPT-NeoX
# and OPT implementations in this library. It has been modified from its
# original forms to accommodate minor architectural differences compared
# to GPT-NeoX and OPT used by the Meta AI team that trained the model.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""
Thin wrappers and replacement classes for LlamaForCausalLM
- Simple sharding across multiple GPUs; will be slow but good for quality evals
- May need to update for Llama 405B 
"""
from typing import Optional, Tuple, List, Union

import warnings
import torch
import torch.nn as nn
import torch.nn.functional as F

from transformers.models.llama.modeling_llama import (
    LlamaModel, LlamaForCausalLM, LLAMA_INPUTS_DOCSTRING,
)
from transformers.modeling_outputs import BaseModelOutputWithPast, CausalLMOutputWithPast
from transformers.cache_utils import Cache, DynamicCache
from transformers.utils import (
    add_start_docstrings_to_model_forward, logging,
)

from .convert_model import get_attention_cache

logger = logging.get_logger(__name__)

# Modified from transformers.models.llama.modeling_llama.LlamaModel (v4.43)
class ShardedLolcatsLlamaModel(LlamaModel):
    """
    Wrapper for Llama or Mistral-like base model

    Modified from transformers.models.llama.modeling_llama.LlamaModel
    -> Only difference is using KV state for past_key_values instead of cache
    """
    def __init__(self, *args: any, **kwargs: any):
        super().__init__(*args, **kwargs)
        self.layerwise_cpu = False

    @add_start_docstrings_to_model_forward(LLAMA_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[Union[Cache, List[torch.FloatTensor]]] = None,
        inputs_embeds: Optional[torch.FloatTensor] = None,
        use_cache: Optional[bool] = None,
        output_attentions: Optional[bool] = None,
        output_hidden_states: Optional[bool] = None,
        return_dict: Optional[bool] = None,
        cache_position: Optional[torch.LongTensor] = None,
    ) -> Union[Tuple, BaseModelOutputWithPast]:
        output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
        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

        batch_size, seq_length = input_ids.shape

        if inputs_embeds is None:
            inputs_embeds = self.embed_tokens(input_ids)

        return_legacy_cache = False   
        if use_cache:
            if past_key_values is None or isinstance(past_key_values, DynamicCache): # Determine and setup our KV cache or state
                attention_type = getattr(self.layers[0].self_attn, 'attention_type', None)
                past_key_values = get_attention_cache(attention_type, past_key_values)
            else:
                past_key_values.get_usable_length(seq_length)   
                
        if cache_position is None:
            past_seen_tokens = past_key_values.get_seq_length() if past_key_values is not None else 0
            cache_position = torch.arange(
                past_seen_tokens, past_seen_tokens + inputs_embeds.shape[1], device=inputs_embeds.device
            )
        
        if position_ids is None:
            position_ids = cache_position.unsqueeze(0)

        causal_mask = self._update_causal_mask(
            attention_mask, inputs_embeds, cache_position, past_key_values, output_attentions
        )
        hidden_states = inputs_embeds

        # create position embeddings to be shared across the decoder layers
        # - ignored for linearized models
        position_embeddings = None
        # position_embeddings = self.rotary_emb(hidden_states, position_ids.to(hidden_states.device))

        # decoder layers
        all_hidden_states = () if output_hidden_states else None
        all_self_attns = () if output_attentions else None
        next_decoder_cache = None

        for decoder_layer in self.layers:
            # Move output to right device
            device = decoder_layer.self_attn.q_proj.weight.device
            hidden_states = hidden_states.to(device)
            position_ids = position_ids.to(device)
            if attention_mask is not None:
                attention_mask = attention_mask.to(device)

            if output_hidden_states:
                all_hidden_states += (hidden_states,)


            if getattr(decoder_layer.self_attn, 'converted', False):
                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,
                        use_cache,
                        cache_position,
                        position_embeddings,
                    )
                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,
                        use_cache=use_cache,
                        cache_position=cache_position,
                        position_embeddings=position_embeddings,
                    )
            else:
                with torch.no_grad():
                    layer_outputs = decoder_layer(
                        hidden_states,
                        attention_mask=attention_mask,
                        position_ids=position_ids,
                        past_key_value=past_key_values,
                        output_attentions=output_attentions,
                        use_cache=use_cache,
                        cache_position=cache_position,
                        position_embeddings=position_embeddings,
                    )

            hidden_states = layer_outputs[0]

            if use_cache:
                next_decoder_cache = layer_outputs[2 if output_attentions else 1]

            if output_attentions:
                all_self_attns += (layer_outputs[1],)

        hidden_states = self.norm(hidden_states.to(self.norm.weight.device))

        # add hidden states from the last decoder layer
        if output_hidden_states:
            all_hidden_states += (hidden_states,)

        next_cache = next_decoder_cache if use_cache else None
        if return_legacy_cache:
            next_cache = next_cache.to_legacy_cache()

        if not return_dict:
            return tuple(v for v in [hidden_states, next_cache, all_hidden_states, all_self_attns] if v is not None)
        return BaseModelOutputWithPast(
            last_hidden_state=hidden_states,
            past_key_values=next_cache,
            hidden_states=all_hidden_states,
            attentions=all_self_attns,
        )


class ShardedLolcatsLlamaForCausalLM(LlamaForCausalLM):
    """
    Wrapper for Llama-like autoregressive language model
    """
    def __init__(self, config):
        # Adapt config to LlamaConfig
        if getattr(config, 'attention_bias', None) is None:
            config.attention_bias = False
        if getattr(config, 'rope_scaling', None) is None:
            config.rope_scaling = None
        if getattr(config, 'pretraining_tp', None) is None:
            config.pretraining_tp = 1
        super().__init__(config)
        self.model = ShardedLolcatsLlamaModel(config)
        self.vocab_size = config.vocab_size
        self.lm_head = nn.Linear(config.hidden_size, config.vocab_size, bias=False)

        # Initialize weights and apply final processing
        self.post_init()

    def forward(self, *args: any, labels: Optional[torch.LongTensor] = None, **kwargs: any):
        # decoder outputs consists of (dec_features, layer_state, dec_hidden, dec_attn)
        outputs = self.model(*args, **kwargs)
        hidden_states = outputs[0]
        if getattr(self.model.layers[0].self_attn, 'train_attention', False):
            logits = None
        else:  # regular training
            if self.config.pretraining_tp > 1:
                lm_head_slices = self.lm_head.weight.split(self.vocab_size // self.config.pretraining_tp, dim=0)
                logits = [F.linear(hidden_states, lm_head_slices[i]) 
                          for i in range(self.config.pretraining_tp)]
                logits = torch.cat(logits, dim=-1)
            else:
                logits = self.lm_head(hidden_states)
            logits = logits.float()

        return CausalLMOutputWithPast(
            logits=logits,
            past_key_values=outputs.past_key_values,
            hidden_states=outputs.hidden_states,
            attentions=outputs.attentions,
        )