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Multi-Domain-Expert-Learning/given-mpt-7b

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modeling_mpt.py318 linesDownload Raw Back to root
1"""A simple, flexible implementation of a GPT model.2 3Inspired by https://github.com/karpathy/minGPT/blob/master/mingpt/model.py4"""5import math6import warnings7from typing import List, Optional, Tuple, Union8import torch9import torch.nn as nn10import torch.nn.functional as F11from transformers import PreTrainedModel, PreTrainedTokenizer, PreTrainedTokenizerFast12from transformers.modeling_outputs import BaseModelOutputWithPast, CausalLMOutputWithPast13from .attention import attn_bias_shape, build_attn_bias14from .blocks import MPTBlock15from .custom_embedding import SharedEmbedding16from .norm import NORM_CLASS_REGISTRY17from .configuration_mpt import MPTConfig18from .adapt_tokenizer import AutoTokenizerForMOD, adapt_tokenizer_for_denoising19from .hf_prefixlm_converter import add_bidirectional_mask_if_missing, convert_hf_causal_lm_to_prefix_lm20from .meta_init_context import init_empty_weights21from .param_init_fns import MODEL_INIT_REGISTRY, generic_param_init_fn_22try:23    from .flash_attn_triton import flash_attn_func24except:25    pass26Tokenizer = Union[PreTrainedTokenizer, PreTrainedTokenizerFast]27 28class MPTPreTrainedModel(PreTrainedModel):29    config_class = MPTConfig30    base_model_prefix = 'model'31    _no_split_modules = ['MPTBlock']32 33class MPTModel(MPTPreTrainedModel):34 35    def __init__(self, config: MPTConfig):36        config._validate_config()37        super().__init__(config)38        self.attn_impl = config.attn_config['attn_impl']39        self.prefix_lm = config.attn_config['prefix_lm']40        self.attn_uses_sequence_id = config.attn_config['attn_uses_sequence_id']41        self.alibi = config.attn_config['alibi']42        self.alibi_bias_max = config.attn_config['alibi_bias_max']43        if config.init_device == 'mixed':44            if dist.get_local_rank() == 0:45                config.init_device = 'cpu'46            else:47                config.init_device = 'meta'48        if config.norm_type.lower() not in NORM_CLASS_REGISTRY.keys():49            norm_options = ' | '.join(NORM_CLASS_REGISTRY.keys())50            raise NotImplementedError(f'Requested norm type ({config.norm_type}) is not implemented within this repo (Options: {norm_options}).')51        norm_class = NORM_CLASS_REGISTRY[config.norm_type.lower()]52        self.embedding_fraction = config.embedding_fraction53        self.wte = SharedEmbedding(config.vocab_size, config.d_model, device=config.init_device)54        if not self.alibi:55            self.wpe = torch.nn.Embedding(config.max_seq_len, config.d_model, device=config.init_device)56        self.emb_drop = nn.Dropout(config.emb_pdrop)57        self.blocks = nn.ModuleList([MPTBlock(device=config.init_device, **config.to_dict()) for _ in range(config.n_layers)])58        self.norm_f = norm_class(config.d_model, device=config.init_device)59        if config.init_device != 'meta':60            print(f'You are using config.init_device={config.init_device!r}, but you can also use config.init_device="meta" with Composer + FSDP for fast initialization.')61            self.apply(self.param_init_fn)62        self.is_causal = not self.prefix_lm63        self._attn_bias_initialized = False64        self.attn_bias = None65        self.attn_bias_shape = attn_bias_shape(self.attn_impl, config.n_heads, config.max_seq_len, self.alibi, prefix_lm=self.prefix_lm, causal=self.is_causal, use_sequence_id=self.attn_uses_sequence_id)66        if config.no_bias:67            for module in self.modules():68                if hasattr(module, 'bias') and isinstance(module.bias, nn.Parameter):69                    if config.verbose:70                        warnings.warn(f'Removing bias ({module.bias}) from {module}.')71                    module.register_parameter('bias', None)72        if config.verbose and config.verbose > 2:73            print(self)74        if 'verbose' not in self.config.init_config:75            self.config.init_config['verbose'] = self.config.verbose76        if self.config.init_config['verbose'] > 1:77            init_fn_name = self.config.init_config['name']78            warnings.warn(f'Using {init_fn_name} initialization.')79 80    def get_input_embeddings(self):81        return self.wte82 83    def set_input_embeddings(self, value):84        self.wte = value85 86    @torch.no_grad()87    def _attn_bias(self, device, dtype, attention_mask: Optional[torch.ByteTensor]=None, prefix_mask: Optional[torch.ByteTensor]=None, sequence_id: Optional[torch.LongTensor]=None):88        if not self._attn_bias_initialized:89            if self.attn_bias_shape:90                self.attn_bias = torch.zeros(self.attn_bias_shape, device=device, dtype=dtype)91                self.attn_bias = build_attn_bias(self.attn_impl, self.attn_bias, self.config.n_heads, self.config.max_seq_len, causal=self.is_causal, alibi=self.alibi, alibi_bias_max=self.alibi_bias_max)92            self._attn_bias_initialized = True93        if self.attn_impl == 'flash':94            return (self.attn_bias, attention_mask)95        if self.attn_bias is not None:96            self.attn_bias = self.attn_bias.to(dtype=dtype, device=device)97        attn_bias = self.attn_bias98        if self.prefix_lm:99            assert isinstance(attn_bias, torch.Tensor)100            assert isinstance(prefix_mask, torch.Tensor)101            attn_bias = self._apply_prefix_mask(attn_bias, prefix_mask)102        if self.attn_uses_sequence_id and sequence_id is not None:103            assert isinstance(attn_bias, torch.Tensor)104            attn_bias = self._apply_sequence_id(attn_bias, sequence_id)105        if attention_mask is not None:106            s_k = attention_mask.shape[-1]107            if attn_bias is None:108                attn_bias = torch.zeros((1, 1, 1, s_k), device=device, dtype=dtype)109            else:110                _s_k = max(0, attn_bias.size(-1) - s_k)111                attn_bias = attn_bias[:, :, :, _s_k:]112            if prefix_mask is not None and attention_mask.shape != prefix_mask.shape:113                raise ValueError(f'attention_mask shape={attention_mask.shape} ' + f'and prefix_mask shape={prefix_mask.shape} are not equal.')114            min_val = torch.finfo(attn_bias.dtype).min115            attn_bias = attn_bias.masked_fill(~attention_mask.view(-1, 1, 1, s_k), min_val)116        return (attn_bias, None)117 118    def _apply_prefix_mask(self, attn_bias: torch.Tensor, prefix_mask: torch.Tensor):119        (s_k, s_q) = attn_bias.shape[-2:]120        if s_k != self.config.max_seq_len or s_q != self.config.max_seq_len:121            raise ValueError('attn_bias does not match the expected shape. ' + f'The last two dimensions should both be {self.config.max_length} ' + f'but are {s_k} and {s_q}.')122        seq_len = prefix_mask.shape[-1]123        if seq_len > self.config.max_seq_len:124            raise ValueError(f'prefix_mask sequence length cannot exceed max_seq_len={self.config.max_seq_len}')125        attn_bias = attn_bias[..., :seq_len, :seq_len]126        causal = torch.tril(torch.ones((seq_len, seq_len), dtype=torch.bool, device=prefix_mask.device)).view(1, 1, seq_len, seq_len)127        prefix = prefix_mask.view(-1, 1, 1, seq_len)128        cannot_attend = ~torch.logical_or(causal, prefix.bool())129        min_val = torch.finfo(attn_bias.dtype).min130        attn_bias = attn_bias.masked_fill(cannot_attend, min_val)131        return attn_bias132 133    def _apply_sequence_id(self, attn_bias: torch.Tensor, sequence_id: torch.LongTensor):134        seq_len = sequence_id.shape[-1]135        if seq_len > self.config.max_seq_len:136            raise ValueError(f'sequence_id sequence length cannot exceed max_seq_len={self.config.max_seq_len}')137        attn_bias = attn_bias[..., :seq_len, :seq_len]138        cannot_attend = torch.logical_not(torch.eq(sequence_id.view(-1, seq_len, 1), sequence_id.view(-1, 1, seq_len))).unsqueeze(1)139        min_val = torch.finfo(attn_bias.dtype).min140        attn_bias = attn_bias.masked_fill(cannot_attend, min_val)141        return attn_bias142 143    def forward(self, input_ids: torch.LongTensor, past_key_values: Optional[List[Tuple[torch.FloatTensor]]]=None, attention_mask: Optional[torch.ByteTensor]=None, prefix_mask: Optional[torch.ByteTensor]=None, sequence_id: Optional[torch.LongTensor]=None, return_dict: Optional[bool]=None, output_attentions: Optional[bool]=None, output_hidden_states: Optional[bool]=None, use_cache: Optional[bool]=None):144        return_dict = return_dict if return_dict is not None else self.config.return_dict145        use_cache = use_cache if use_cache is not None else self.config.use_cache146        if attention_mask is not None:147            attention_mask = attention_mask.bool()148        if prefix_mask is not None:149            prefix_mask = prefix_mask.bool()150        if not return_dict:151            raise NotImplementedError('return_dict False is not implemented yet for MPT')152        if output_attentions:153            if self.attn_impl != 'torch':154                raise NotImplementedError('output_attentions is not implemented for MPT when using attn_impl `flash` or `triton`.')155        if attention_mask is not None and attention_mask[:, 0].sum() != attention_mask.shape[0] and self.training:156            raise NotImplementedError('MPT does not support training with left padding.')157        if self.prefix_lm and prefix_mask is None:158            raise ValueError('prefix_mask is a required argument when MPT is configured with prefix_lm=True.')159        if self.training:160            if self.attn_uses_sequence_id and sequence_id is None:161                raise ValueError('sequence_id is a required argument when MPT is configured with attn_uses_sequence_id=True ' + 'and the model is in train mode.')162            elif self.attn_uses_sequence_id is False and sequence_id is not None:163                warnings.warn('MPT received non-None input for `sequence_id` but is configured with attn_uses_sequence_id=False. ' + 'This input will be ignored. If you want the model to use `sequence_id`, set attn_uses_sequence_id to True.')164        S = input_ids.size(1)165        assert S <= self.config.max_seq_len, f'Cannot forward input with seq_len={S}, this model only supports seq_len<={self.config.max_seq_len}'166        tok_emb = self.wte(input_ids)167        if self.alibi:168            x = tok_emb169        else:170            past_position = 0171            if past_key_values is not None:172                if len(past_key_values) != self.config.n_layers:173                    raise ValueError(f'past_key_values must provide a past_key_value for each attention ' + f'layer in the network (len(past_key_values)={len(past_key_values)!r}; self.config.n_layers={self.config.n_layers!r}).')174                past_position = past_key_values[0][0].size(1)175                if self.attn_impl == 'torch':176                    past_position = past_key_values[0][0].size(3)177            if S + past_position > self.config.max_seq_len:178                raise ValueError(f'Cannot forward input with past sequence length {past_position} and current sequence length {S + 1}, this model only supports total sequence length <= {self.config.max_seq_len}.')179            pos = torch.arange(past_position, S + past_position, dtype=torch.long, device=input_ids.device).unsqueeze(0)180            if attention_mask is not None:181                pos = torch.clamp(pos - torch.cumsum((~attention_mask).to(torch.int32), dim=1)[:, past_position:], min=0)182            pos_emb = self.wpe(pos)183            x = tok_emb + pos_emb184        if self.embedding_fraction == 1:185            x = self.emb_drop(x)186        else:187            x_shrunk = x * self.embedding_fraction + x.detach() * (1 - self.embedding_fraction)188            assert isinstance(self.emb_drop, nn.Module)189            x = self.emb_drop(x_shrunk)190        (attn_bias, attention_mask) = self._attn_bias(device=x.device, dtype=torch.float32, attention_mask=attention_mask, prefix_mask=prefix_mask, sequence_id=sequence_id)191        if use_cache and past_key_values is None:192            past_key_values = [() for _ in range(self.config.n_layers)]193        all_hidden_states = () if output_hidden_states else None194        all_self_attns = () if output_attentions else None195        for (b_idx, block) in enumerate(self.blocks):196            if output_hidden_states:197                assert all_hidden_states is not None198                all_hidden_states = all_hidden_states + (x,)199            past_key_value = past_key_values[b_idx] if past_key_values is not None else None200            (x, attn_weights, past_key_value) = block(x, past_key_value=past_key_value, attn_bias=attn_bias, attention_mask=attention_mask, is_causal=self.is_causal)201            if past_key_values is not None:202                past_key_values[b_idx] = past_key_value203            if output_attentions:204                assert all_self_attns is not None205                all_self_attns = all_self_attns + (attn_weights,)206        x = self.norm_f(x)207        if output_hidden_states:208            assert all_hidden_states is not None209            all_hidden_states = all_hidden_states + (x,)210        return BaseModelOutputWithPast(last_hidden_state=x, past_key_values=past_key_values, hidden_states=all_hidden_states, attentions=all_self_attns)211 212    def param_init_fn(self, module):213        init_fn_name = self.config.init_config['name']214        MODEL_INIT_REGISTRY[init_fn_name](module=module, n_layers=self.config.n_layers, d_model=self.config.d_model, **self.config.init_config)215 216    def fsdp_wrap_fn(self, module):217        return isinstance(module, MPTBlock)218 219    def activation_checkpointing_fn(self, module):220        return isinstance(module, MPTBlock)221 222class MPTForCausalLM(MPTPreTrainedModel):223 224    def __init__(self, config: MPTConfig):225        super().__init__(config)226        if not config.tie_word_embeddings:227            raise ValueError('MPTForCausalLM only supports tied word embeddings')228        self.transformer = MPTModel(config)229        for child in self.transformer.children():230            if isinstance(child, torch.nn.ModuleList):231                continue232            if isinstance(child, torch.nn.Module):233                child._fsdp_wrap = True234        self.logit_scale = None235        if config.logit_scale is not None:236            logit_scale = config.logit_scale237            if isinstance(logit_scale, str):238                if logit_scale == 'inv_sqrt_d_model':239                    logit_scale = 1 / math.sqrt(config.d_model)240                else:241                    raise ValueError(f"logit_scale={logit_scale!r} is not recognized as an option; use numeric value or 'inv_sqrt_d_model'.")242            self.logit_scale = logit_scale243 244    def get_input_embeddings(self):245        return self.transformer.wte246 247    def set_input_embeddings(self, value):248        self.transformer.wte = value249 250    def get_output_embeddings(self):251        return self.transformer.wte252 253    def set_output_embeddings(self, new_embeddings):254        self.transformer.wte = new_embeddings255 256    def set_decoder(self, decoder):257        self.transformer = decoder258 259    def get_decoder(self):260        return self.transformer261 262    def forward(self, input_ids: torch.LongTensor, past_key_values: Optional[List[Tuple[torch.FloatTensor]]]=None, attention_mask: Optional[torch.ByteTensor]=None, prefix_mask: Optional[torch.ByteTensor]=None, sequence_id: Optional[torch.LongTensor]=None, labels: Optional[torch.LongTensor]=None, return_dict: Optional[bool]=None, output_attentions: Optional[bool]=None, output_hidden_states: Optional[bool]=None, use_cache: Optional[bool]=None):263        return_dict = return_dict if return_dict is not None else self.config.return_dict264        use_cache = use_cache if use_cache is not None else self.config.use_cache265        outputs = self.transformer(input_ids=input_ids, past_key_values=past_key_values, attention_mask=attention_mask, prefix_mask=prefix_mask, sequence_id=sequence_id, return_dict=return_dict, output_attentions=output_attentions, output_hidden_states=output_hidden_states, use_cache=use_cache)266        logits = self.transformer.wte(outputs.last_hidden_state.to(self.transformer.wte.weight.device), True)267        if self.logit_scale is not None:268            if self.logit_scale == 0:269                warnings.warn(f'Multiplying logits by self.logit_scale={self.logit_scale!r}. This will produce uniform (uninformative) outputs.')270            logits *= self.logit_scale271        loss = None272        if labels is not None:273            labels = torch.roll(labels, shifts=-1)274            labels[:, -1] = -100275            loss = F.cross_entropy(logits.view(-1, logits.size(-1)), labels.to(logits.device).view(-1))276        return CausalLMOutputWithPast(loss=loss, logits=logits, past_key_values=outputs.past_key_values, hidden_states=outputs.hidden_states, attentions=outputs.attentions)277 278    def param_init_fn(self, module):279        init_fn_name = self.config.init_config['name']280        MODEL_INIT_REGISTRY[init_fn_name](module=module, n_layers=self.config.n_layers, d_model=self.config.d_model, **self.config.init_config)281 282    def fsdp_wrap_fn(self, module):283        return isinstance(module, MPTBlock)284 285    def activation_checkpointing_fn(self, module):286        return isinstance(module, MPTBlock)287 288    def prepare_inputs_for_generation(self, input_ids, past_key_values=None, inputs_embeds=None, **kwargs):289        if inputs_embeds is not None:290            raise NotImplementedError('inputs_embeds is not implemented for MPT yet')291        attention_mask = kwargs['attention_mask'].bool()292        if attention_mask[:, -1].sum() != attention_mask.shape[0]:293            raise NotImplementedError('MPT does not support generation with right padding.')294        if self.transformer.attn_uses_sequence_id and self.training:295            sequence_id = torch.zeros_like(input_ids[:1])296        else:297            sequence_id = None298        if past_key_values is not None:299            input_ids = input_ids[:, -1].unsqueeze(-1)300        if self.transformer.prefix_lm:301            prefix_mask = torch.ones_like(attention_mask)302            if kwargs.get('use_cache') == False:303                raise NotImplementedError('MPT with prefix_lm=True does not support use_cache=False.')304        else:305            prefix_mask = None306        return {'input_ids': input_ids, 'attention_mask': attention_mask, 'prefix_mask': prefix_mask, 'sequence_id': sequence_id, 'past_key_values': past_key_values, 'use_cache': kwargs.get('use_cache', True)}307 308    @staticmethod309    def _reorder_cache(past_key_values, beam_idx):310        """Used by HuggingFace generate when using beam search with kv-caching.311 312        See https://github.com/huggingface/transformers/blob/3ec7a47664ebe40c40f4b722f6bb1cd30c3821ec/src/transformers/models/gpt2/modeling_gpt2.py#L1122-L1133313        for an example in transformers.314        """315        reordered_past = []316        for layer_past in past_key_values:317            reordered_past += [tuple((past_state.index_select(0, beam_idx) for past_state in layer_past))]318        return reordered_past