"benchmark/git@developer.sourcefind.cn:zhaoyu6/sglang.git" did not exist on "41d1f67704a3761423131f48c357b957452a00a9"
modeling_utils.py 196 KB
Newer Older
1
# coding=utf-8
thomwolf's avatar
thomwolf committed
2
# Copyright 2018 The Google AI Language Team Authors, Facebook AI Research authors and The HuggingFace Inc. team.
3
4
5
6
7
8
9
10
11
12
13
14
15
# Copyright (c) 2018, NVIDIA CORPORATION.  All rights reserved.
#
# 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.
Sylvain Gugger's avatar
Sylvain Gugger committed
16
import collections
17
import gc
18
import importlib.metadata
Yih-Dar's avatar
Yih-Dar committed
19
import inspect
Sylvain Gugger's avatar
Sylvain Gugger committed
20
import json
21
import os
22
import re
Sylvain Gugger's avatar
Sylvain Gugger committed
23
24
import shutil
import tempfile
25
import warnings
26
from contextlib import contextmanager
27
from dataclasses import dataclass
28
from functools import partial, wraps
29
from typing import Any, Callable, Dict, List, Optional, Tuple, Union
30
31

import torch
32
from packaging import version
Sylvain Gugger's avatar
Sylvain Gugger committed
33
from torch import Tensor, nn
34
from torch.nn import CrossEntropyLoss
35

36
from .activations import get_activation
37
from .configuration_utils import PretrainedConfig
38
from .deepspeed import deepspeed_config, is_deepspeed_zero3_enabled
39
from .dynamic_module_utils import custom_object_save
40
from .generation import GenerationConfig, GenerationMixin
41
42
43
44
from .pytorch_utils import (  # noqa: F401
    Conv1D,
    apply_chunking_to_forward,
    find_pruneable_heads_and_indices,
Thomas Wang's avatar
Thomas Wang committed
45
    id_tensor_storage,
46
47
48
49
    prune_conv1d_layer,
    prune_layer,
    prune_linear_layer,
)
50
from .utils import (
Aymeric Augustin's avatar
Aymeric Augustin committed
51
    DUMMY_INPUTS,
52
    FLAX_WEIGHTS_NAME,
53
54
    SAFE_WEIGHTS_INDEX_NAME,
    SAFE_WEIGHTS_NAME,
55
56
    TF2_WEIGHTS_NAME,
    TF_WEIGHTS_NAME,
Sylvain Gugger's avatar
Sylvain Gugger committed
57
    WEIGHTS_INDEX_NAME,
58
    WEIGHTS_NAME,
59
    ContextManagers,
60
    ModelOutput,
Sylvain Gugger's avatar
Sylvain Gugger committed
61
    PushToHubMixin,
62
    cached_file,
63
    copy_func,
64
    download_url,
65
    has_file,
66
    is_accelerate_available,
Marc Sun's avatar
Marc Sun committed
67
    is_auto_gptq_available,
68
    is_bitsandbytes_available,
69
    is_offline_mode,
70
    is_optimum_available,
71
    is_remote_url,
72
    is_safetensors_available,
73
    is_torch_tpu_available,
74
    logging,
Sylvain Gugger's avatar
Sylvain Gugger committed
75
    replace_return_docstrings,
76
)
77
from .utils.hub import convert_file_size_to_int, get_checkpoint_shard_files
78
from .utils.import_utils import ENV_VARS_TRUE_VALUES, is_sagemaker_mp_enabled, is_torch_fx_proxy
Marc Sun's avatar
Marc Sun committed
79
from .utils.quantization_config import BitsAndBytesConfig, GPTQConfig, QuantizationMethod
80
from .utils.versions import require_version_core
81

Aymeric Augustin's avatar
Aymeric Augustin committed
82

83
84
85
XLA_USE_BF16 = os.environ.get("XLA_USE_BF16", "0").upper()
XLA_DOWNCAST_BF16 = os.environ.get("XLA_DOWNCAST_BF16", "0").upper()

86
87
88
if is_accelerate_available():
    from accelerate import dispatch_model, infer_auto_device_map, init_empty_weights
    from accelerate.utils import (
89
        check_tied_parameters_on_same_device,
90
        find_tied_parameters,
91
        get_balanced_memory,
92
93
94
95
96
97
        load_offloaded_weights,
        offload_weight,
        save_offload_index,
        set_module_tensor_to_device,
    )

98
99
100
101
if is_safetensors_available():
    from safetensors import safe_open
    from safetensors.torch import load_file as safe_load_file
    from safetensors.torch import save_file as safe_save_file
102

Lysandre Debut's avatar
Lysandre Debut committed
103
logger = logging.get_logger(__name__)
104

105
106
107
108

_init_weights = True


109
110
111
112
113
114
115
116
117
if is_sagemaker_mp_enabled():
    import smdistributed.modelparallel.torch as smp
    from smdistributed.modelparallel import __version__ as SMP_VERSION

    IS_SAGEMAKER_MP_POST_1_10 = version.parse(SMP_VERSION) >= version.parse("1.10")
else:
    IS_SAGEMAKER_MP_POST_1_10 = False


118
119
120
121
122
123
124
125
@contextmanager
def no_init_weights(_enable=True):
    """
    Context manager to globally disable weight initialization to speed up loading large models.

    TODO(Patrick): Delete safety argument `_enable=True` at next major version. .
    """
    global _init_weights
126
    old_init_weights = _init_weights
127
128
129
130
131
    if _enable:
        _init_weights = False
    try:
        yield
    finally:
132
        _init_weights = old_init_weights
133
134


thomwolf's avatar
thomwolf committed
135
136
137
138
139
try:
    from torch.nn import Identity
except ImportError:
    # Older PyTorch compatibility
    class Identity(nn.Module):
Lysandre's avatar
Lysandre committed
140
        r"""A placeholder identity operator that is argument-insensitive."""
141

thomwolf's avatar
thomwolf committed
142
        def __init__(self, *args, **kwargs):
Julien Chaumond's avatar
Julien Chaumond committed
143
            super().__init__()
thomwolf's avatar
thomwolf committed
144
145
146
147

        def forward(self, input):
            return input

148

Lysandre Debut's avatar
Lysandre Debut committed
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
def get_parameter_device(parameter: Union[nn.Module, GenerationMixin, "ModuleUtilsMixin"]):
    try:
        return next(parameter.parameters()).device
    except StopIteration:
        # For nn.DataParallel compatibility in PyTorch 1.5

        def find_tensor_attributes(module: nn.Module) -> List[Tuple[str, Tensor]]:
            tuples = [(k, v) for k, v in module.__dict__.items() if torch.is_tensor(v)]
            return tuples

        gen = parameter._named_members(get_members_fn=find_tensor_attributes)
        first_tuple = next(gen)
        return first_tuple[1].device


164
165
166
167
def get_first_parameter_dtype(parameter: Union[nn.Module, GenerationMixin, "ModuleUtilsMixin"]):
    """
    Returns the first parameter dtype (can be non-floating) or asserts if none were found.
    """
Lysandre Debut's avatar
Lysandre Debut committed
168
169
170
    try:
        return next(parameter.parameters()).dtype
    except StopIteration:
Sylvain Gugger's avatar
Sylvain Gugger committed
171
        # For nn.DataParallel compatibility in PyTorch > 1.5
Lysandre Debut's avatar
Lysandre Debut committed
172
173
174
175
176
177
178
179
180
181

        def find_tensor_attributes(module: nn.Module) -> List[Tuple[str, Tensor]]:
            tuples = [(k, v) for k, v in module.__dict__.items() if torch.is_tensor(v)]
            return tuples

        gen = parameter._named_members(get_members_fn=find_tensor_attributes)
        first_tuple = next(gen)
        return first_tuple[1].dtype


182
183
def get_parameter_dtype(parameter: Union[nn.Module, GenerationMixin, "ModuleUtilsMixin"]):
    """
Sylvain Gugger's avatar
Sylvain Gugger committed
184
    Returns the first found floating dtype in parameters if there is one, otherwise returns the last dtype it found.
185
    """
Sylvain Gugger's avatar
Sylvain Gugger committed
186
187
188
189
    last_dtype = None
    for t in parameter.parameters():
        last_dtype = t.dtype
        if t.is_floating_point():
190
191
192
            # Adding fix for https://github.com/pytorch/xla/issues/4152
            # Fixes issue where the model code passes a value that is out of range for XLA_USE_BF16=1
            # and XLA_DOWNCAST_BF16=1 so the conversion would cast it to -inf
193
194
195
196
197
            # NOTE: `is_torch_tpu_available()` is checked last as it induces a graph break in torch dynamo
            if XLA_USE_BF16 in ENV_VARS_TRUE_VALUES and is_torch_tpu_available():
                return torch.bfloat16
            if XLA_DOWNCAST_BF16 in ENV_VARS_TRUE_VALUES and is_torch_tpu_available():
                if t.dtype == torch.float:
198
                    return torch.bfloat16
199
200
                if t.dtype == torch.double:
                    return torch.float32
Sylvain Gugger's avatar
Sylvain Gugger committed
201
            return t.dtype
202

Sylvain Gugger's avatar
Sylvain Gugger committed
203
204
205
    if last_dtype is not None:
        # if no floating dtype was found return whatever the first dtype is
        return last_dtype
206

207
208
209
210
211
212
213
214
215
216
217
218
219
    # For nn.DataParallel compatibility in PyTorch > 1.5
    def find_tensor_attributes(module: nn.Module) -> List[Tuple[str, Tensor]]:
        tuples = [(k, v) for k, v in module.__dict__.items() if torch.is_tensor(v)]
        return tuples

    gen = parameter._named_members(get_members_fn=find_tensor_attributes)
    last_tuple = None
    for tuple in gen:
        last_tuple = tuple
        if tuple[1].is_floating_point():
            return tuple[1].dtype

    if last_tuple is not None:
220
221
        # fallback to the last dtype
        return last_tuple[1].dtype
222

223
224
225
226
227
228
229
    # fallback to buffer dtype
    for t in parameter.buffers():
        last_dtype = t.dtype
        if t.is_floating_point():
            return t.dtype
    return last_dtype

230
231
232
233
234
235
236
237
238
239
240
241
242
243

def get_state_dict_float_dtype(state_dict):
    """
    Returns the first found floating dtype in `state_dict` or asserts if none were found.
    """
    for t in state_dict.values():
        if t.is_floating_point():
            return t.dtype

    raise ValueError("couldn't find any floating point dtypes in state_dict")


def get_state_dict_dtype(state_dict):
    """
Sylvain Gugger's avatar
Sylvain Gugger committed
244
    Returns the first found floating dtype in `state_dict` if there is one, otherwise returns the first dtype.
245
246
247
248
249
250
251
    """
    for t in state_dict.values():
        if t.is_floating_point():
            return t.dtype

    # if no floating dtype was found return whatever the first dtype is
    else:
Sylvain Gugger's avatar
Sylvain Gugger committed
252
        return next(state_dict.values()).dtype
253
254


Sylvain Gugger's avatar
Sylvain Gugger committed
255
256
257
258
259
260
261
262
263
264
265
266
267
def dtype_byte_size(dtype):
    """
    Returns the size (in bytes) occupied by one parameter of type `dtype`.

    Example:

    ```py
    >>> dtype_byte_size(torch.float32)
    4
    ```
    """
    if dtype == torch.bool:
        return 1 / 8
268
    bit_search = re.search(r"[^\d](\d+)$", str(dtype))
Sylvain Gugger's avatar
Sylvain Gugger committed
269
270
271
272
273
274
    if bit_search is None:
        raise ValueError(f"`dtype` is not a valid dtype: {dtype}.")
    bit_size = int(bit_search.groups()[0])
    return bit_size // 8


275
276
277
def shard_checkpoint(
    state_dict: Dict[str, torch.Tensor], max_shard_size: Union[int, str] = "10GB", weights_name: str = WEIGHTS_NAME
):
Sylvain Gugger's avatar
Sylvain Gugger committed
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
    """
    Splits a model state dictionary in sub-checkpoints so that the final size of each sub-checkpoint does not exceed a
    given size.

    The sub-checkpoints are determined by iterating through the `state_dict` in the order of its keys, so there is no
    optimization made to make each sub-checkpoint as close as possible to the maximum size passed. For example, if the
    limit is 10GB and we have weights of sizes [6GB, 6GB, 2GB, 6GB, 2GB, 2GB] they will get sharded as [6GB], [6+2GB],
    [6+2+2GB] and not [6+2+2GB], [6+2GB], [6GB].

    <Tip warning={true}>

    If one of the model's weight is bigger that `max_sahrd_size`, it will end up in its own sub-checkpoint which will
    have a size greater than `max_shard_size`.

    </Tip>

    Args:
        state_dict (`Dict[str, torch.Tensor]`): The state dictionary of a model to save.
        max_shard_size (`int` or `str`, *optional*, defaults to `"10GB"`):
            The maximum size of each sub-checkpoint. If expressed as a string, needs to be digits followed by a unit
            (like `"5MB"`).
299
300
        weights_name (`str`, *optional*, defaults to `"pytorch_model.bin"`):
            The name of the model save file.
Sylvain Gugger's avatar
Sylvain Gugger committed
301
302
303
    """
    max_shard_size = convert_file_size_to_int(max_shard_size)

Thomas Wang's avatar
Thomas Wang committed
304
305
    sharded_state_dicts = [{}]
    last_block_size = 0
Sylvain Gugger's avatar
Sylvain Gugger committed
306
    total_size = 0
Thomas Wang's avatar
Thomas Wang committed
307
    storage_id_to_block = {}
Sylvain Gugger's avatar
Sylvain Gugger committed
308
309

    for key, weight in state_dict.items():
310
311
312
313
314
315
        # when bnb serialization is used the weights in the state dict can be strings
        # check: https://github.com/huggingface/transformers/pull/24416 for more details
        if isinstance(weight, str):
            continue
        else:
            storage_id = id_tensor_storage(weight)
Thomas Wang's avatar
Thomas Wang committed
316
317
318
319
320
321
322

        # If a `weight` shares the same underlying storage as another tensor, we put `weight` in the same `block`
        if storage_id in storage_id_to_block:
            block_id = storage_id_to_block[storage_id]
            sharded_state_dicts[block_id][key] = weight
            continue

Sylvain Gugger's avatar
Sylvain Gugger committed
323
324
        weight_size = weight.numel() * dtype_byte_size(weight.dtype)

Sylvain Gugger's avatar
Sylvain Gugger committed
325
326
327
        # If this weight is going to tip up over the maximal size, we split, but only if we have put at least one
        # weight in the current shard.
        if last_block_size + weight_size > max_shard_size and len(sharded_state_dicts[-1]) > 0:
Thomas Wang's avatar
Thomas Wang committed
328
329
            sharded_state_dicts.append({})
            last_block_size = 0
Sylvain Gugger's avatar
Sylvain Gugger committed
330

Thomas Wang's avatar
Thomas Wang committed
331
332
        sharded_state_dicts[-1][key] = weight
        last_block_size += weight_size
Sylvain Gugger's avatar
Sylvain Gugger committed
333
        total_size += weight_size
Thomas Wang's avatar
Thomas Wang committed
334
        storage_id_to_block[storage_id] = len(sharded_state_dicts) - 1
Sylvain Gugger's avatar
Sylvain Gugger committed
335
336
337

    # If we only have one shard, we return it
    if len(sharded_state_dicts) == 1:
338
        return {weights_name: sharded_state_dicts[0]}, None
Sylvain Gugger's avatar
Sylvain Gugger committed
339
340
341
342
343

    # Otherwise, let's build the index
    weight_map = {}
    shards = {}
    for idx, shard in enumerate(sharded_state_dicts):
344
345
346
347
        shard_file = weights_name.replace(".bin", f"-{idx+1:05d}-of-{len(sharded_state_dicts):05d}.bin")
        shard_file = shard_file.replace(
            ".safetensors", f"-{idx + 1:05d}-of-{len(sharded_state_dicts):05d}.safetensors"
        )
Sylvain Gugger's avatar
Sylvain Gugger committed
348
349
350
351
352
353
354
355
356
357
        shards[shard_file] = shard
        for key in shard.keys():
            weight_map[key] = shard_file

    # Add the metadata
    metadata = {"total_size": total_size}
    index = {"metadata": metadata, "weight_map": weight_map}
    return shards, index


358
def load_sharded_checkpoint(model, folder, strict=True, prefer_safe=True):
359
360
361
362
363
364
365
366
367
368
369
370
371
    """
    This is the same as
    [`torch.nn.Module.load_state_dict`](https://pytorch.org/docs/stable/generated/torch.nn.Module.html?highlight=load_state_dict#torch.nn.Module.load_state_dict)
    but for a sharded checkpoint.

    This load is performed efficiently: each checkpoint shard is loaded one by one in RAM and deleted after being
    loaded in the model.

    Args:
        model (`torch.nn.Module`): The model in which to load the checkpoint.
        folder (`str` or `os.PathLike`): A path to a folder containing the sharded checkpoint.
        strict (`bool`, *optional`, defaults to `True`):
            Whether to strictly enforce that the keys in the model state dict match the keys in the sharded checkpoint.
372
373
374
        prefer_safe (`bool`, *optional*, defaults to `False`)
            If both safetensors and PyTorch save files are present in checkpoint and `prefer_safe` is True, the
            safetensors files will be loaded. Otherwise, PyTorch files are always loaded when possible.
375
376
377
378
379
380
381
382

    Returns:
        `NamedTuple`: A named tuple with `missing_keys` and `unexpected_keys` fields
            - `missing_keys` is a list of str containing the missing keys
            - `unexpected_keys` is a list of str containing the unexpected keys
    """
    # Load the index
    index_file = os.path.join(folder, WEIGHTS_INDEX_NAME)
383
    safe_index_file = os.path.join(folder, SAFE_WEIGHTS_INDEX_NAME)
384

385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
    index_present = os.path.isfile(index_file)
    safe_index_present = os.path.isfile(safe_index_file)

    if not index_present and not (safe_index_present and is_safetensors_available()):
        filenames = (
            (WEIGHTS_INDEX_NAME, SAFE_WEIGHTS_INDEX_NAME) if is_safetensors_available() else (WEIGHTS_INDEX_NAME,)
        )
        raise ValueError(f"Can't find a checkpoint index ({' or '.join(filenames)}) in {folder}.")

    load_safe = False
    if safe_index_present:
        if prefer_safe:
            if is_safetensors_available():
                load_safe = True  # load safe due to preference
            else:
                logger.warning(
                    f"Cannot load sharded checkpoint at {folder} safely since safetensors is not installed!"
                )
        elif not index_present:
            load_safe = True  # load safe since we have no other choice

    load_index = safe_index_file if load_safe else index_file

    with open(load_index, "r", encoding="utf-8") as f:
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
        index = json.load(f)

    shard_files = list(set(index["weight_map"].values()))

    # If strict=True, error before loading any of the state dicts.
    loaded_keys = index["weight_map"].keys()
    model_keys = model.state_dict().keys()
    missing_keys = [key for key in model_keys if key not in loaded_keys]
    unexpected_keys = [key for key in loaded_keys if key not in model_keys]
    if strict and (len(missing_keys) > 0 or len(unexpected_keys) > 0):
        error_message = f"Error(s) in loading state_dict for {model.__class__.__name__}"
        if len(missing_keys) > 0:
            str_missing_keys = ",".join([f'"{k}"' for k in missing_keys])
            error_message += f"\nMissing key(s): {str_missing_keys}."
        if len(unexpected_keys) > 0:
            str_unexpected_keys = ",".join([f'"{k}"' for k in unexpected_keys])
            error_message += f"\nMissing key(s): {str_unexpected_keys}."
        raise RuntimeError(error_message)

428
429
    loader = safe_load_file if load_safe else partial(torch.load, map_location="cpu")

430
    for shard_file in shard_files:
431
        state_dict = loader(os.path.join(folder, shard_file))
432
433
        model.load_state_dict(state_dict, strict=False)

434
        # Make sure memory is freed before we load the next state dict.
435
436
437
438
439
440
441
        del state_dict
        gc.collect()

    # Return the same thing as PyTorch load_state_dict function.
    return torch.nn.modules.module._IncompatibleKeys(missing_keys, unexpected_keys)


Sylvain Gugger's avatar
Sylvain Gugger committed
442
443
444
445
def load_state_dict(checkpoint_file: Union[str, os.PathLike]):
    """
    Reads a PyTorch checkpoint file, returning properly formatted errors if they arise.
    """
446
447
448
449
450
451
452
453
454
455
456
457
458
459
    if checkpoint_file.endswith(".safetensors") and is_safetensors_available():
        # Check format of the archive
        with safe_open(checkpoint_file, framework="pt") as f:
            metadata = f.metadata()
        if metadata.get("format") not in ["pt", "tf", "flax"]:
            raise OSError(
                f"The safetensors archive passed at {checkpoint_file} does not contain the valid metadata. Make sure "
                "you save your model with the `save_pretrained` method."
            )
        elif metadata["format"] != "pt":
            raise NotImplementedError(
                f"Conversion from a {metadata['format']} safetensors archive to PyTorch is not implemented yet."
            )
        return safe_load_file(checkpoint_file)
Sylvain Gugger's avatar
Sylvain Gugger committed
460
    try:
461
462
463
464
465
        if is_deepspeed_zero3_enabled() and torch.distributed.is_initialized() and torch.distributed.get_rank() > 0:
            map_location = "meta"
        else:
            map_location = "cpu"
        return torch.load(checkpoint_file, map_location=map_location)
Sylvain Gugger's avatar
Sylvain Gugger committed
466
467
468
    except Exception as e:
        try:
            with open(checkpoint_file) as f:
469
                if f.read(7) == "version":
Sylvain Gugger's avatar
Sylvain Gugger committed
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
                    raise OSError(
                        "You seem to have cloned a repository without having git-lfs installed. Please install "
                        "git-lfs and run `git lfs install` followed by `git lfs pull` in the folder "
                        "you cloned."
                    )
                else:
                    raise ValueError(
                        f"Unable to locate the file {checkpoint_file} which is necessary to load this pretrained "
                        "model. Make sure you have saved the model properly."
                    ) from e
        except (UnicodeDecodeError, ValueError):
            raise OSError(
                f"Unable to load weights from pytorch checkpoint file for '{checkpoint_file}' "
                f"at '{checkpoint_file}'. "
                "If you tried to load a PyTorch model from a TF 2.0 checkpoint, please set from_tf=True."
            )


488
489
490
491
492
493
494
495
496
497
498
def set_initialized_submodules(model, state_dict_keys):
    """
    Sets the `_is_hf_initialized` flag in all submodules of a given model when all its weights are in the loaded state
    dict.
    """
    for module_name, module in model.named_modules():
        loaded_keys = [k.replace(f"{module_name}.", "") for k in state_dict_keys if k.startswith(f"{module_name}.")]
        if len(set(module.state_dict().keys()) - set(loaded_keys)) == 0:
            module._is_hf_initialized = True


Sylvain Gugger's avatar
Sylvain Gugger committed
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
def _load_state_dict_into_model(model_to_load, state_dict, start_prefix):
    # Convert old format to new format if needed from a PyTorch state_dict
    old_keys = []
    new_keys = []
    for key in state_dict.keys():
        new_key = None
        if "gamma" in key:
            new_key = key.replace("gamma", "weight")
        if "beta" in key:
            new_key = key.replace("beta", "bias")
        if new_key:
            old_keys.append(key)
            new_keys.append(new_key)
    for old_key, new_key in zip(old_keys, new_keys):
        state_dict[new_key] = state_dict.pop(old_key)

    # copy state_dict so _load_from_state_dict can modify it
    metadata = getattr(state_dict, "_metadata", None)
    state_dict = state_dict.copy()
    if metadata is not None:
        state_dict._metadata = metadata

    error_msgs = []

    # PyTorch's `_load_from_state_dict` does not copy parameters in a module's descendants
    # so we need to apply the function recursively.
525
    def load(module: nn.Module, state_dict, prefix=""):
Sylvain Gugger's avatar
Sylvain Gugger committed
526
527
        local_metadata = {} if metadata is None else metadata.get(prefix[:-1], {})
        args = (state_dict, prefix, local_metadata, True, [], [], error_msgs)
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
        # Parameters of module and children will start with prefix. We can exit early if there are none in this
        # state_dict
        if len([key for key in state_dict if key.startswith(prefix)]) > 0:
            if is_deepspeed_zero3_enabled():
                import deepspeed

                # In sharded models, each shard has only part of the full state_dict, so only gather
                # parameters that are in the current state_dict.
                named_parameters = dict(module.named_parameters(prefix=prefix[:-1], recurse=False))
                params_to_gather = [named_parameters[k] for k in state_dict.keys() if k in named_parameters]
                if len(params_to_gather) > 0:
                    # because zero3 puts placeholders in model params, this context
                    # manager gathers (unpartitions) the params of the current layer, then loads from
                    # the state dict and then re-partitions them again
                    with deepspeed.zero.GatheredParameters(params_to_gather, modifier_rank=0):
                        if torch.distributed.get_rank() == 0:
                            module._load_from_state_dict(*args)
            else:
                module._load_from_state_dict(*args)
Sylvain Gugger's avatar
Sylvain Gugger committed
547
548
549

        for name, child in module._modules.items():
            if child is not None:
550
                load(child, state_dict, prefix + name + ".")
Sylvain Gugger's avatar
Sylvain Gugger committed
551

552
553
554
555
    load(model_to_load, state_dict, prefix=start_prefix)
    # Delete `state_dict` so it could be collected by GC earlier. Note that `state_dict` is a copy of the argument, so
    # it's safe to delete it.
    del state_dict
Sylvain Gugger's avatar
Sylvain Gugger committed
556
557
558
559

    return error_msgs


560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
def find_submodule_and_param_name(model, long_key, start_prefix):
    """
    A helper util to find the last sub-module and the param/buffer name. If `start_prefix` is supplied it'll be removed
    from the start of the key
    """

    if len(start_prefix) > 0 and long_key.startswith(start_prefix):
        long_key = ".".join(long_key.split(".")[1:])

    split_key = long_key.split(".")
    submodule = model
    while len(split_key) > 1:
        if hasattr(submodule, split_key[0]):
            submodule = getattr(submodule, split_key[0])
            del split_key[0]
        else:
            submodule = None
            break
    if submodule == model:
        submodule = None
    return submodule, split_key[0]


def _move_model_to_meta(model, loaded_state_dict_keys, start_prefix):
    """
    Moves `loaded_state_dict_keys` in model to meta device which frees up the memory taken by those params.

    `start_prefix` is used for models which insert their name into model keys, e.g. `bert` in
    `bert.pooler.dense.weight`

    """

    # dematerialize param storage for keys that are going to be replaced by state_dict, by
    # putting those on the meta device
    for k in loaded_state_dict_keys:
        submodule, param_name = find_submodule_and_param_name(model, k, start_prefix)
        if submodule is not None:
            # selectively switch to the meta device only those params/buffers that will
            # be next replaced from state_dict. This a complex way to do p.to_("meta")
            # since we have no in-place to_ for tensors.
            new_val = getattr(submodule, param_name)
            if isinstance(new_val, torch.nn.Parameter):
                # isinstance returns False for Params on meta device, so switch after the check
                new_val = torch.nn.Parameter(new_val.to("meta"))
            else:
                new_val = new_val.to("meta")
            setattr(submodule, param_name, new_val)


609
610
611
612
613
614
615
616
617
618
619
620
def _load_state_dict_into_meta_model(
    model,
    state_dict,
    loaded_state_dict_keys,  # left for now but could be removed, see below
    start_prefix,
    expected_keys,
    device_map=None,
    offload_folder=None,
    offload_index=None,
    state_dict_folder=None,
    state_dict_index=None,
    dtype=None,
621
    is_quantized=False,
Sylvain Gugger's avatar
Sylvain Gugger committed
622
    is_safetensors=False,
623
    keep_in_fp32_modules=None,
624
):
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
    """
    This is somewhat similar to `_load_state_dict_into_model`, but deals with a model that has some or all of its
    params on a `meta` device. It replaces the model params with the data from the `state_dict`, while moving the
    params back to the normal device, but only for `loaded_state_dict_keys`.

    `start_prefix` is used for models which insert their name into model keys, e.g. `bert` in
    `bert.pooler.dense.weight`

    """

    # XXX: remaining features to implement to be fully compatible with _load_state_dict_into_model
    # - deepspeed zero 3 support
    # - need to copy metadata if any - see _load_state_dict_into_model
    # - handling error_msgs - mimicking the error handling in module._load_from_state_dict()
    # - Is there a situation where some keys aren't in `loaded_state_dict_keys` and in which case
    #   they won't get loaded.

642
643
    if is_quantized:
        from .utils.bitsandbytes import set_module_quantized_tensor_to_device
644

645
646
    error_msgs = []

647
648
649
650
651
652
653
654
655
656
657
658
659
    old_keys = []
    new_keys = []
    for key in state_dict.keys():
        new_key = None
        if "gamma" in key:
            new_key = key.replace("gamma", "weight")
        if "beta" in key:
            new_key = key.replace("beta", "bias")
        if new_key:
            old_keys.append(key)
            new_keys.append(new_key)
    for old_key, new_key in zip(old_keys, new_keys):
        state_dict[new_key] = state_dict.pop(old_key)
660

661
662
663
664
665
666
667
668
669
    for param_name, param in state_dict.items():
        # First part of the test is always true as load_state_dict_keys always contains state_dict keys.
        if param_name not in loaded_state_dict_keys or param_name not in expected_keys:
            continue

        if param_name.startswith(start_prefix):
            param_name = param_name[len(start_prefix) :]

        module_name = param_name
670
        set_module_kwargs = {}
671

672
        # We convert floating dtypes to the `dtype` passed. We want to keep the buffers/params
673
674
        # in int/uint/bool and not cast them.
        if dtype is not None and torch.is_floating_point(param):
675
676
677
678
679
680
            if (
                keep_in_fp32_modules is not None
                and any(module_to_keep_in_fp32 in param_name for module_to_keep_in_fp32 in keep_in_fp32_modules)
                and dtype == torch.float16
            ):
                param = param.to(torch.float32)
681
682
683
684
685

                # For backward compatibility with older versions of `accelerate`
                # TODO: @sgugger replace this check with version check at the next `accelerate` release
                if "dtype" in list(inspect.signature(set_module_tensor_to_device).parameters):
                    set_module_kwargs["dtype"] = torch.float32
686
687
            else:
                param = param.to(dtype)
688
689
690
691
692
693
694
695
696
697
698
699

        # For compatibility with PyTorch load_state_dict which converts state dict dtype to existing dtype in model
        if dtype is None:
            old_param = model
            splits = param_name.split(".")
            for split in splits:
                old_param = getattr(old_param, split)
                if old_param is None:
                    break

            if old_param is not None:
                param = param.to(old_param.dtype)
700

701
702
        set_module_kwargs["value"] = param

703
704
705
706
707
708
709
710
711
712
713
        if device_map is None:
            param_device = "cpu"
        else:
            # find next higher level module that is defined in device_map:
            # bert.lm_head.weight -> bert.lm_head -> bert -> ''
            while len(module_name) > 0 and module_name not in device_map:
                module_name = ".".join(module_name.split(".")[:-1])
            if module_name == "" and "" not in device_map:
                # TODO: group all errors and raise at the end.
                raise ValueError(f"{param_name} doesn't have any device set.")
            param_device = device_map[module_name]
714

715
        if param_device == "disk":
Sylvain Gugger's avatar
Sylvain Gugger committed
716
717
            if not is_safetensors:
                offload_index = offload_weight(param, param_name, offload_folder, offload_index)
718
719
        elif param_device == "cpu" and state_dict_index is not None:
            state_dict_index = offload_weight(param, param_name, state_dict_folder, state_dict_index)
720
        elif not is_quantized:
721
722
            # For backward compatibility with older versions of `accelerate`
            set_module_tensor_to_device(model, param_name, param_device, **set_module_kwargs)
723
        else:
724
725
726
727
728
729
            if param.dtype == torch.int8 and param_name.replace("weight", "SCB") in state_dict.keys():
                fp16_statistics = state_dict[param_name.replace("weight", "SCB")]
            else:
                fp16_statistics = None

            if "SCB" not in param_name:
730
                set_module_quantized_tensor_to_device(
731
732
                    model, param_name, param_device, value=param, fp16_statistics=fp16_statistics
                )
733
734

    return error_msgs, offload_index, state_dict_index
735
736


737
738
739
740
741
742
743
744
745
def _add_variant(weights_name: str, variant: Optional[str] = None) -> str:
    if variant is not None:
        splits = weights_name.split(".")
        splits = splits[:-1] + [variant] + splits[-1:]
        weights_name = ".".join(splits)

    return weights_name


746
class ModuleUtilsMixin:
Julien Chaumond's avatar
Julien Chaumond committed
747
    """
748
    A few utilities for `torch.nn.Modules`, to be used as a mixin.
Julien Chaumond's avatar
Julien Chaumond committed
749
750
    """

751
752
753
754
    @staticmethod
    def _hook_rss_memory_pre_forward(module, *args, **kwargs):
        try:
            import psutil
Sylvain Gugger's avatar
Sylvain Gugger committed
755
        except ImportError:
756
757
758
759
760
761
762
763
764
765
766
            raise ImportError("You need to install psutil (pip install psutil) to use memory tracing.")

        process = psutil.Process(os.getpid())
        mem = process.memory_info()
        module.mem_rss_pre_forward = mem.rss
        return None

    @staticmethod
    def _hook_rss_memory_post_forward(module, *args, **kwargs):
        try:
            import psutil
Sylvain Gugger's avatar
Sylvain Gugger committed
767
        except ImportError:
768
769
770
771
772
773
774
775
776
777
            raise ImportError("You need to install psutil (pip install psutil) to use memory tracing.")

        process = psutil.Process(os.getpid())
        mem = process.memory_info()
        module.mem_rss_post_forward = mem.rss
        mem_rss_diff = module.mem_rss_post_forward - module.mem_rss_pre_forward
        module.mem_rss_diff = mem_rss_diff + (module.mem_rss_diff if hasattr(module, "mem_rss_diff") else 0)
        return None

    def add_memory_hooks(self):
Sylvain Gugger's avatar
Sylvain Gugger committed
778
779
780
        """
        Add a memory hook before and after each sub-module forward pass to record increase in memory consumption.

Sylvain Gugger's avatar
Sylvain Gugger committed
781
782
        Increase in memory consumption is stored in a `mem_rss_diff` attribute for each module and can be reset to zero
        with `model.reset_memory_hooks_state()`.
783
784
785
786
787
788
789
        """
        for module in self.modules():
            module.register_forward_pre_hook(self._hook_rss_memory_pre_forward)
            module.register_forward_hook(self._hook_rss_memory_post_forward)
        self.reset_memory_hooks_state()

    def reset_memory_hooks_state(self):
Sylvain Gugger's avatar
Sylvain Gugger committed
790
        """
Sylvain Gugger's avatar
Sylvain Gugger committed
791
        Reset the `mem_rss_diff` attribute of each module (see [`~modeling_utils.ModuleUtilsMixin.add_memory_hooks`]).
Sylvain Gugger's avatar
Sylvain Gugger committed
792
        """
793
794
795
796
797
        for module in self.modules():
            module.mem_rss_diff = 0
            module.mem_rss_post_forward = 0
            module.mem_rss_pre_forward = 0

798
    @property
Sylvain Gugger's avatar
Sylvain Gugger committed
799
    def device(self) -> torch.device:
800
        """
801
        `torch.device`: The device on which the module is (assuming that all the module parameters are on the same
802
        device).
803
        """
Lysandre Debut's avatar
Lysandre Debut committed
804
        return get_parameter_device(self)
805

806
    @property
807
    def dtype(self) -> torch.dtype:
808
        """
809
        `torch.dtype`: The dtype of the module (assuming that all the module parameters have the same dtype).
810
        """
Lysandre Debut's avatar
Lysandre Debut committed
811
        return get_parameter_dtype(self)
812
813

    def invert_attention_mask(self, encoder_attention_mask: Tensor) -> Tensor:
Sylvain Gugger's avatar
Sylvain Gugger committed
814
815
816
817
        """
        Invert an attention mask (e.g., switches 0. and 1.).

        Args:
818
            encoder_attention_mask (`torch.Tensor`): An attention mask.
Sylvain Gugger's avatar
Sylvain Gugger committed
819
820

        Returns:
821
            `torch.Tensor`: The inverted attention mask.
Sylvain Gugger's avatar
Sylvain Gugger committed
822
        """
823
824
825
826
827
828
829
830
831
832
        if encoder_attention_mask.dim() == 3:
            encoder_extended_attention_mask = encoder_attention_mask[:, None, :, :]
        if encoder_attention_mask.dim() == 2:
            encoder_extended_attention_mask = encoder_attention_mask[:, None, None, :]
        # T5 has a mask that can compare sequence ids, we can simulate this here with this transposition
        # Cf. https://github.com/tensorflow/mesh/blob/8d2465e9bc93129b913b5ccc6a59aa97abd96ec6/mesh_tensorflow
        # /transformer/transformer_layers.py#L270
        # encoder_extended_attention_mask = (encoder_extended_attention_mask ==
        # encoder_extended_attention_mask.transpose(-1, -2))
        encoder_extended_attention_mask = encoder_extended_attention_mask.to(dtype=self.dtype)  # fp16 compatibility
Yih-Dar's avatar
Yih-Dar committed
833
        encoder_extended_attention_mask = (1.0 - encoder_extended_attention_mask) * torch.finfo(self.dtype).min
834

835
836
        return encoder_extended_attention_mask

837
    @staticmethod
838
839
840
841
842
843
844
    def create_extended_attention_mask_for_decoder(input_shape, attention_mask, device=None):
        if device is not None:
            warnings.warn(
                "The `device` argument is deprecated and will be removed in v5 of Transformers.", FutureWarning
            )
        else:
            device = attention_mask.device
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
        batch_size, seq_length = input_shape
        seq_ids = torch.arange(seq_length, device=device)
        causal_mask = seq_ids[None, None, :].repeat(batch_size, seq_length, 1) <= seq_ids[None, :, None]
        # in case past_key_values are used we need to add a prefix ones mask to the causal mask
        # causal and attention masks must have same type with pytorch version < 1.3
        causal_mask = causal_mask.to(attention_mask.dtype)

        if causal_mask.shape[1] < attention_mask.shape[1]:
            prefix_seq_len = attention_mask.shape[1] - causal_mask.shape[1]
            causal_mask = torch.cat(
                [
                    torch.ones((batch_size, seq_length, prefix_seq_len), device=device, dtype=causal_mask.dtype),
                    causal_mask,
                ],
                axis=-1,
            )

        extended_attention_mask = causal_mask[:, None, :, :] * attention_mask[:, None, None, :]
        return extended_attention_mask

865
    def get_extended_attention_mask(
866
        self, attention_mask: Tensor, input_shape: Tuple[int], device: torch.device = None, dtype: torch.float = None
867
    ) -> Tensor:
Sylvain Gugger's avatar
Sylvain Gugger committed
868
869
        """
        Makes broadcastable attention and causal masks so that future and masked tokens are ignored.
870
871

        Arguments:
872
            attention_mask (`torch.Tensor`):
Sylvain Gugger's avatar
Sylvain Gugger committed
873
                Mask with ones indicating tokens to attend to, zeros for tokens to ignore.
874
            input_shape (`Tuple[int]`):
Sylvain Gugger's avatar
Sylvain Gugger committed
875
                The shape of the input to the model.
876
877

        Returns:
878
            `torch.Tensor` The extended attention mask, with a the same dtype as `attention_mask.dtype`.
879
        """
Yih-Dar's avatar
Yih-Dar committed
880
881
882
        if dtype is None:
            dtype = self.dtype

883
884
885
886
887
888
        if not (attention_mask.dim() == 2 and self.config.is_decoder):
            # show warning only if it won't be shown in `create_extended_attention_mask_for_decoder`
            if device is not None:
                warnings.warn(
                    "The `device` argument is deprecated and will be removed in v5 of Transformers.", FutureWarning
                )
889
890
891
892
893
894
895
896
897
        # We can provide a self-attention mask of dimensions [batch_size, from_seq_length, to_seq_length]
        # ourselves in which case we just need to make it broadcastable to all heads.
        if attention_mask.dim() == 3:
            extended_attention_mask = attention_mask[:, None, :, :]
        elif attention_mask.dim() == 2:
            # Provided a padding mask of dimensions [batch_size, seq_length]
            # - if the model is a decoder, apply a causal mask in addition to the padding mask
            # - if the model is an encoder, make the mask broadcastable to [batch_size, num_heads, seq_length, seq_length]
            if self.config.is_decoder:
898
                extended_attention_mask = ModuleUtilsMixin.create_extended_attention_mask_for_decoder(
899
900
                    input_shape, attention_mask, device
                )
901
902
903
904
            else:
                extended_attention_mask = attention_mask[:, None, None, :]
        else:
            raise ValueError(
905
                f"Wrong shape for input_ids (shape {input_shape}) or attention_mask (shape {attention_mask.shape})"
906
907
908
909
            )

        # Since attention_mask is 1.0 for positions we want to attend and 0.0 for
        # masked positions, this operation will create a tensor which is 0.0 for
910
        # positions we want to attend and the dtype's smallest value for masked positions.
911
912
        # Since we are adding it to the raw scores before the softmax, this is
        # effectively the same as removing these entirely.
Yih-Dar's avatar
Yih-Dar committed
913
914
        extended_attention_mask = extended_attention_mask.to(dtype=dtype)  # fp16 compatibility
        extended_attention_mask = (1.0 - extended_attention_mask) * torch.finfo(dtype).min
915
916
        return extended_attention_mask

Sylvain Gugger's avatar
Sylvain Gugger committed
917
918
919
    def get_head_mask(
        self, head_mask: Optional[Tensor], num_hidden_layers: int, is_attention_chunked: bool = False
    ) -> Tensor:
920
        """
Sylvain Gugger's avatar
Sylvain Gugger committed
921
922
923
        Prepare the head mask if needed.

        Args:
924
            head_mask (`torch.Tensor` with shape `[num_heads]` or `[num_hidden_layers x num_heads]`, *optional*):
Sylvain Gugger's avatar
Sylvain Gugger committed
925
                The mask indicating if we should keep the heads or not (1.0 for keep, 0.0 for discard).
926
            num_hidden_layers (`int`):
Sylvain Gugger's avatar
Sylvain Gugger committed
927
                The number of hidden layers in the model.
928
            is_attention_chunked (`bool`, *optional*, defaults to `False`):
Sylvain Gugger's avatar
Sylvain Gugger committed
929
930
                Whether or not the attentions scores are computed by chunks or not.

931
        Returns:
Sylvain Gugger's avatar
Sylvain Gugger committed
932
933
            `torch.Tensor` with shape `[num_hidden_layers x batch x num_heads x seq_length x seq_length]` or list with
            `[None]` for each layer.
934
935
936
        """
        if head_mask is not None:
            head_mask = self._convert_head_mask_to_5d(head_mask, num_hidden_layers)
Patrick von Platen's avatar
Patrick von Platen committed
937
938
            if is_attention_chunked is True:
                head_mask = head_mask.unsqueeze(-1)
939
940
941
942
943
944
945
946
947
948
949
950
951
        else:
            head_mask = [None] * num_hidden_layers

        return head_mask

    def _convert_head_mask_to_5d(self, head_mask, num_hidden_layers):
        """-> [num_hidden_layers x batch x num_heads x seq_length x seq_length]"""
        if head_mask.dim() == 1:
            head_mask = head_mask.unsqueeze(0).unsqueeze(0).unsqueeze(-1).unsqueeze(-1)
            head_mask = head_mask.expand(num_hidden_layers, -1, -1, -1, -1)
        elif head_mask.dim() == 2:
            head_mask = head_mask.unsqueeze(1).unsqueeze(-1).unsqueeze(-1)  # We can specify head_mask for each layer
        assert head_mask.dim() == 5, f"head_mask.dim != 5, instead {head_mask.dim()}"
952
        head_mask = head_mask.to(dtype=self.dtype)  # switch to float if need + fp16 compatibility
953
954
        return head_mask

955
956
957
958
959
    def num_parameters(self, only_trainable: bool = False, exclude_embeddings: bool = False) -> int:
        """
        Get number of (optionally, trainable or non-embeddings) parameters in the module.

        Args:
960
            only_trainable (`bool`, *optional*, defaults to `False`):
961
962
                Whether or not to return only the number of trainable parameters

963
            exclude_embeddings (`bool`, *optional*, defaults to `False`):
964
965
966
                Whether or not to return only the number of non-embeddings parameters

        Returns:
967
            `int`: The number of parameters.
968
969
        """

970
971
972
973
974
975
976
977
978
979
        if exclude_embeddings:
            embedding_param_names = [
                f"{name}.weight" for name, module_type in self.named_modules() if isinstance(module_type, nn.Embedding)
            ]
            non_embedding_parameters = [
                parameter for name, parameter in self.named_parameters() if name not in embedding_param_names
            ]
            return sum(p.numel() for p in non_embedding_parameters if p.requires_grad or not only_trainable)
        else:
            return sum(p.numel() for p in self.parameters() if p.requires_grad or not only_trainable)
980
981
982
983
984
985

    def estimate_tokens(self, input_dict: Dict[str, Union[torch.Tensor, Any]]) -> int:
        """
        Helper function to estimate the total number of tokens from the model inputs.

        Args:
986
            inputs (`dict`): The model inputs.
987
988

        Returns:
989
            `int`: The total number of tokens.
990
        """
991
992
        if not hasattr(self, "warnings_issued"):
            self.warnings_issued = {}
993
994
        if self.main_input_name in input_dict:
            return input_dict[self.main_input_name].numel()
995
        elif "estimate_tokens" not in self.warnings_issued:
996
            logger.warning(
997
998
                "Could not estimate the number of tokens of the input, floating-point operations will not be computed"
            )
999
1000
            self.warnings_issued["estimate_tokens"] = True
        return 0
1001
1002
1003
1004
1005
1006
1007

    def floating_point_ops(
        self, input_dict: Dict[str, Union[torch.Tensor, Any]], exclude_embeddings: bool = True
    ) -> int:
        """
        Get number of (optionally, non-embeddings) floating-point operations for the forward and backward passes of a
        batch with this transformer model. Default approximation neglects the quadratic dependency on the number of
Sylvain Gugger's avatar
Sylvain Gugger committed
1008
1009
        tokens (valid if `12 * d_model << sequence_length`) as laid out in [this
        paper](https://arxiv.org/pdf/2001.08361.pdf) section 2.1. Should be overridden for transformers with parameter
Sylvain Gugger's avatar
Sylvain Gugger committed
1010
        re-use e.g. Albert or Universal Transformers, or if doing long-range modeling with very high sequence lengths.
1011
1012

        Args:
1013
            batch_size (`int`):
1014
1015
                The batch size for the forward pass.

1016
            sequence_length (`int`):
1017
1018
                The number of tokens in each line of the batch.

1019
            exclude_embeddings (`bool`, *optional*, defaults to `True`):
1020
1021
1022
                Whether or not to count embedding and softmax operations.

        Returns:
1023
            `int`: The number of floating-point operations.
1024
1025
1026
1027
        """

        return 6 * self.estimate_tokens(input_dict) * self.num_parameters(exclude_embeddings=exclude_embeddings)

Julien Chaumond's avatar
Julien Chaumond committed
1028

Sylvain Gugger's avatar
Sylvain Gugger committed
1029
class PreTrainedModel(nn.Module, ModuleUtilsMixin, GenerationMixin, PushToHubMixin):
1030
1031
    r"""
    Base class for all models.
1032

Sylvain Gugger's avatar
Sylvain Gugger committed
1033
1034
    [`PreTrainedModel`] takes care of storing the configuration of the models and handles methods for loading,
    downloading and saving models as well as a few methods common to all models to:
1035

1036
1037
        - resize the input embeddings,
        - prune heads in the self-attention heads.
1038

1039
    Class attributes (overridden by derived classes):
Sylvain Gugger's avatar
Sylvain Gugger committed
1040

Sylvain Gugger's avatar
Sylvain Gugger committed
1041
1042
1043
1044
        - **config_class** ([`PretrainedConfig`]) -- A subclass of [`PretrainedConfig`] to use as configuration class
          for this model architecture.
        - **load_tf_weights** (`Callable`) -- A python *method* for loading a TensorFlow checkpoint in a PyTorch model,
          taking as arguments:
1045

Sylvain Gugger's avatar
Sylvain Gugger committed
1046
1047
            - **model** ([`PreTrainedModel`]) -- An instance of the model on which to load the TensorFlow checkpoint.
            - **config** ([`PreTrainedConfig`]) -- An instance of the configuration associated to the model.
1048
            - **path** (`str`) -- A path to the TensorFlow checkpoint.
1049

Sylvain Gugger's avatar
Sylvain Gugger committed
1050
1051
        - **base_model_prefix** (`str`) -- A string indicating the attribute associated to the base model in derived
          classes of the same architecture adding modules on top of the base model.
1052
        - **is_parallelizable** (`bool`) -- A flag indicating whether this model supports model parallelization.
Sylvain Gugger's avatar
Sylvain Gugger committed
1053
1054
        - **main_input_name** (`str`) -- The name of the principal input to the model (often `input_ids` for NLP
          models, `pixel_values` for vision models and `input_values` for speech models).
1055
    """
1056
    config_class = None
1057
    base_model_prefix = ""
1058
    main_input_name = "input_ids"
1059
    _auto_class = None
1060
    _no_split_modules = None
1061
    _skip_keys_device_placement = None
1062
    _keep_in_fp32_modules = None
1063

1064
1065
    # a list of `re` patterns of `state_dict` keys that should be removed from the list of missing
    # keys we find (keys inside the model but not in the checkpoint) and avoid unnecessary warnings.
1066
    _keys_to_ignore_on_load_missing = None
1067
1068
1069
    # a list of `re` patterns of `state_dict` keys that should be removed from the list of
    # unexpected keys we find (keys inside the checkpoint but not the model) and avoid unnecessary
    # warnings.
1070
    _keys_to_ignore_on_load_unexpected = None
1071
1072
    # a list of `state_dict` keys to ignore when saving the model (useful for keys that aren't
    # trained, but which are either deterministic or tied variables)
1073
    _keys_to_ignore_on_save = None
Sylvain Gugger's avatar
Sylvain Gugger committed
1074
1075
    # a list of `state_dict` keys that are potentially tied to another key in the state_dict.
    _tied_weights_keys = None
1076

1077
    is_parallelizable = False
1078
    supports_gradient_checkpointing = False
1079

1080
    @property
1081
    def dummy_inputs(self) -> Dict[str, torch.Tensor]:
1082
        """
1083
        `Dict[str, torch.Tensor]`: Dummy inputs to do a forward pass in the network.
1084
        """
1085
        return {"input_ids": torch.tensor(DUMMY_INPUTS)}
1086

1087
1088
1089
1090
1091
1092
1093
    @property
    def framework(self) -> str:
        """
        :str: Identifies that this is a PyTorch model.
        """
        return "pt"

1094
    def __init__(self, config: PretrainedConfig, *inputs, **kwargs):
Julien Chaumond's avatar
Julien Chaumond committed
1095
        super().__init__()
1096
1097
        if not isinstance(config, PretrainedConfig):
            raise ValueError(
1098
1099
1100
                f"Parameter config in `{self.__class__.__name__}(config)` should be an instance of class "
                "`PretrainedConfig`. To create a model from a pretrained model use "
                f"`model = {self.__class__.__name__}.from_pretrained(PRETRAINED_MODEL_NAME)`"
1101
            )
1102
        # Save config and origin of the pretrained weights if given in model
1103
        self.config = config
1104
        self.name_or_path = config.name_or_path
1105
        self.warnings_issued = {}
1106
        self.generation_config = GenerationConfig.from_model_config(config) if self.can_generate() else None
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120

    def post_init(self):
        """
        A method executed at the end of each Transformer model initialization, to execute code that needs the model's
        modules properly initialized (such as weight initialization).
        """
        self.init_weights()
        self._backward_compatibility_gradient_checkpointing()

    def _backward_compatibility_gradient_checkpointing(self):
        if self.supports_gradient_checkpointing and getattr(self.config, "gradient_checkpointing", False):
            self.gradient_checkpointing_enable()
            # Remove the attribute now that is has been consumed, so it's no saved in the config.
            delattr(self.config, "gradient_checkpointing")
1121

1122
1123
1124
1125
1126
1127
    @classmethod
    def _from_config(cls, config, **kwargs):
        """
        All context managers that the model should be initialized under go here.

        Args:
1128
1129
            torch_dtype (`torch.dtype`, *optional*):
                Override the default `torch.dtype` and load the model under this dtype.
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
        """
        torch_dtype = kwargs.pop("torch_dtype", None)

        # override default dtype if needed
        dtype_orig = None
        if torch_dtype is not None:
            dtype_orig = cls._set_default_torch_dtype(torch_dtype)

        if is_deepspeed_zero3_enabled():
            import deepspeed

            logger.info("Detected DeepSpeed ZeRO-3: activating zero.init() for this model")
            # this immediately partitions the model across all gpus, to avoid the overhead in time
            # and memory copying it on CPU or each GPU first
1144
            with deepspeed.zero.Init(config_dict_or_path=deepspeed_config()):
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
                model = cls(config, **kwargs)
        else:
            model = cls(config, **kwargs)

        # restore default dtype if it was modified
        if dtype_orig is not None:
            torch.set_default_dtype(dtype_orig)

        return model

    @classmethod
    def _set_default_torch_dtype(cls, dtype: torch.dtype) -> torch.dtype:
        """
        Change the default dtype and return the previous one. This is needed when wanting to instantiate the model
        under specific dtype.

        Args:
1162
            dtype (`torch.dtype`):
1163
1164
1165
                a floating dtype to set to.

        Returns:
Sylvain Gugger's avatar
Sylvain Gugger committed
1166
1167
            `torch.dtype`: the original `dtype` that can be used to restore `torch.set_default_dtype(dtype)` if it was
            modified. If it wasn't, returns `None`.
1168

1169
1170
        Note `set_default_dtype` currently only works with floating-point types and asserts if for example,
        `torch.int64` is passed. So if a non-float `dtype` is passed this functions will throw an exception.
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
        """
        if not dtype.is_floating_point:
            raise ValueError(
                f"Can't instantiate {cls.__name__} model under dtype={dtype} since it is not a floating point dtype"
            )

        logger.info(f"Instantiating {cls.__name__} model under default dtype {dtype}.")
        dtype_orig = torch.get_default_dtype()
        torch.set_default_dtype(dtype)
        return dtype_orig

1182
    @property
1183
1184
    def base_model(self) -> nn.Module:
        """
1185
        `torch.nn.Module`: The main body of the model.
1186
        """
1187
        return getattr(self, self.base_model_prefix, self)
thomwolf's avatar
thomwolf committed
1188

1189
1190
    @classmethod
    def can_generate(cls) -> bool:
1191
1192
1193
1194
1195
1196
1197
        """
        Returns whether this model can generate sequences with `.generate()`.

        Returns:
            `bool`: Whether this model can generate sequences with `.generate()`.
        """
        # Detects whether `prepare_inputs_for_generation` has been overwritten, which is a requirement for generation
1198
        if "GenerationMixin" in str(cls.prepare_inputs_for_generation):
1199
1200
1201
            return False
        return True

1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
    def enable_input_require_grads(self):
        """
        Enables the gradients for the input embeddings. This is useful for fine-tuning adapter weights while keeping
        the model weights fixed.
        """

        def make_inputs_require_grads(module, input, output):
            output.requires_grad_(True)

        self._require_grads_hook = self.get_input_embeddings().register_forward_hook(make_inputs_require_grads)

    def disable_input_require_grads(self):
        """
        Removes the `_require_grads_hook`.
        """
        self._require_grads_hook.remove()

1219
    def get_input_embeddings(self) -> nn.Module:
1220
1221
1222
1223
        """
        Returns the model's input embeddings.

        Returns:
1224
            `nn.Module`: A torch module mapping vocabulary to hidden states.
thomwolf's avatar
thomwolf committed
1225
        """
1226
        base_model = getattr(self, self.base_model_prefix, self)
thomwolf's avatar
thomwolf committed
1227
1228
1229
1230
        if base_model is not self:
            return base_model.get_input_embeddings()
        else:
            raise NotImplementedError
thomwolf's avatar
thomwolf committed
1231

1232
    def set_input_embeddings(self, value: nn.Module):
1233
        """
Sylvain Gugger's avatar
Sylvain Gugger committed
1234
        Set model's input embeddings.
1235
1236

        Args:
1237
            value (`nn.Module`): A module mapping vocabulary to hidden states.
thomwolf's avatar
thomwolf committed
1238
1239
1240
1241
1242
1243
        """
        base_model = getattr(self, self.base_model_prefix, self)
        if base_model is not self:
            base_model.set_input_embeddings(value)
        else:
            raise NotImplementedError
thomwolf's avatar
thomwolf committed
1244

1245
    def get_output_embeddings(self) -> nn.Module:
1246
1247
1248
1249
        """
        Returns the model's output embeddings.

        Returns:
1250
            `nn.Module`: A torch module mapping hidden states to vocabulary.
thomwolf's avatar
thomwolf committed
1251
        """
1252
        return None  # Overwrite for models with output embeddings
thomwolf's avatar
thomwolf committed
1253

1254
1255
1256
1257
    def _init_weights(self, module):
        """
        Initialize the weights. This method should be overridden by derived class.
        """
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
        pass

    def _initialize_weights(self, module):
        """
        Initialize the weights if they are not already initialized.
        """
        if getattr(module, "_is_hf_initialized", False):
            return
        self._init_weights(module)
        module._is_hf_initialized = True
1268

1269
    def tie_weights(self):
1270
1271
        """
        Tie the weights between the input embeddings and the output embeddings.
1272

Sylvain Gugger's avatar
Sylvain Gugger committed
1273
1274
        If the `torchscript` flag is set in the configuration, can't handle parameter sharing so we are cloning the
        weights instead.
thomwolf's avatar
thomwolf committed
1275
        """
1276
1277
1278
1279
        if getattr(self.config, "tie_word_embeddings", True):
            output_embeddings = self.get_output_embeddings()
            if output_embeddings is not None:
                self._tie_or_clone_weights(output_embeddings, self.get_input_embeddings())
thomwolf's avatar
thomwolf committed
1280

1281
        if getattr(self.config, "is_encoder_decoder", False) and getattr(self.config, "tie_encoder_decoder", False):
Weizhen's avatar
Weizhen committed
1282
1283
            if hasattr(self, self.base_model_prefix):
                self = getattr(self, self.base_model_prefix)
1284
1285
            self._tie_encoder_decoder_weights(self.encoder, self.decoder, self.base_model_prefix)

Sylvain Gugger's avatar
Sylvain Gugger committed
1286
1287
1288
1289
        for module in self.modules():
            if hasattr(module, "_tie_weights"):
                module._tie_weights()

1290
1291
1292
    @staticmethod
    def _tie_encoder_decoder_weights(encoder: nn.Module, decoder: nn.Module, base_model_prefix: str):
        uninitialized_encoder_weights: List[str] = []
Weizhen's avatar
Weizhen committed
1293
1294
        if decoder.__class__ != encoder.__class__:
            logger.info(
Sylvain Gugger's avatar
Sylvain Gugger committed
1295
1296
                f"{decoder.__class__} and {encoder.__class__} are not equal. In this case make sure that all encoder"
                " weights are correctly initialized."
Weizhen's avatar
Weizhen committed
1297
            )
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307

        def tie_encoder_to_decoder_recursively(
            decoder_pointer: nn.Module,
            encoder_pointer: nn.Module,
            module_name: str,
            uninitialized_encoder_weights: List[str],
            depth=0,
        ):
            assert isinstance(decoder_pointer, nn.Module) and isinstance(
                encoder_pointer, nn.Module
1308
            ), f"{decoder_pointer} and {encoder_pointer} have to be of type nn.Module"
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
            if hasattr(decoder_pointer, "weight"):
                assert hasattr(encoder_pointer, "weight")
                encoder_pointer.weight = decoder_pointer.weight
                if hasattr(decoder_pointer, "bias"):
                    assert hasattr(encoder_pointer, "bias")
                    encoder_pointer.bias = decoder_pointer.bias
                return

            encoder_modules = encoder_pointer._modules
            decoder_modules = decoder_pointer._modules
            if len(decoder_modules) > 0:
                assert (
                    len(encoder_modules) > 0
                ), f"Encoder module {encoder_pointer} does not match decoder module {decoder_pointer}"

1324
                all_encoder_weights = {module_name + "/" + sub_name for sub_name in encoder_modules.keys()}
1325
1326
1327
1328
1329
                encoder_layer_pos = 0
                for name, module in decoder_modules.items():
                    if name.isdigit():
                        encoder_name = str(int(name) + encoder_layer_pos)
                        decoder_name = name
Weizhen's avatar
Weizhen committed
1330
1331
1332
                        if not isinstance(decoder_modules[decoder_name], type(encoder_modules[encoder_name])) and len(
                            encoder_modules
                        ) != len(decoder_modules):
1333
1334
                            # this can happen if the name corresponds to the position in a list module list of layers
                            # in this case the decoder has added a cross-attention that the encoder does not have
1335
                            # thus skip this step and subtract one layer pos from encoder
1336
1337
1338
1339
1340
1341
                            encoder_layer_pos -= 1
                            continue
                    elif name not in encoder_modules:
                        continue
                    elif depth > 500:
                        raise ValueError(
Sylvain Gugger's avatar
Sylvain Gugger committed
1342
1343
                            "Max depth of recursive function `tie_encoder_to_decoder` reached. It seems that there is"
                            " a circular dependency between two or more `nn.Modules` of your model."
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
                        )
                    else:
                        decoder_name = encoder_name = name
                    tie_encoder_to_decoder_recursively(
                        decoder_modules[decoder_name],
                        encoder_modules[encoder_name],
                        module_name + "/" + name,
                        uninitialized_encoder_weights,
                        depth=depth + 1,
                    )
                    all_encoder_weights.remove(module_name + "/" + encoder_name)

                uninitialized_encoder_weights += list(all_encoder_weights)

        # tie weights recursively
        tie_encoder_to_decoder_recursively(decoder, encoder, base_model_prefix, uninitialized_encoder_weights)
        if len(uninitialized_encoder_weights) > 0:
            logger.warning(
                f"The following encoder weights were not tied to the decoder {uninitialized_encoder_weights}"
            )

1365
    def _tie_or_clone_weights(self, output_embeddings, input_embeddings):
Lysandre's avatar
Lysandre committed
1366
        """Tie or clone module weights depending of whether we are using TorchScript or not"""
thomwolf's avatar
thomwolf committed
1367
        if self.config.torchscript:
1368
            output_embeddings.weight = nn.Parameter(input_embeddings.weight.clone())
thomwolf's avatar
thomwolf committed
1369
        else:
1370
            output_embeddings.weight = input_embeddings.weight
thomwolf's avatar
thomwolf committed
1371

Sam Shleifer's avatar
Sam Shleifer committed
1372
        if getattr(output_embeddings, "bias", None) is not None:
1373
            output_embeddings.bias.data = nn.functional.pad(
1374
                output_embeddings.bias.data,
Lysandre's avatar
Lysandre committed
1375
1376
1377
1378
                (
                    0,
                    output_embeddings.weight.shape[0] - output_embeddings.bias.shape[0],
                ),
1379
1380
                "constant",
                0,
1381
            )
1382
        if hasattr(output_embeddings, "out_features") and hasattr(input_embeddings, "num_embeddings"):
1383
            output_embeddings.out_features = input_embeddings.num_embeddings
1384

1385
1386
1387
    def resize_token_embeddings(
        self, new_num_tokens: Optional[int] = None, pad_to_multiple_of: Optional[int] = None
    ) -> nn.Embedding:
1388
        """
1389
        Resizes input token embeddings matrix of the model if `new_num_tokens != config.vocab_size`.
1390

1391
        Takes care of tying weights embeddings afterwards if the model class has a `tie_weights()` method.
thomwolf's avatar
thomwolf committed
1392

1393
        Arguments:
1394
            new_num_tokens (`int`, *optional*):
1395
                The number of new tokens in the embedding matrix. Increasing the size will add newly initialized
Sylvain Gugger's avatar
Sylvain Gugger committed
1396
1397
                vectors at the end. Reducing the size will remove vectors from the end. If not provided or `None`, just
                returns a pointer to the input tokens `torch.nn.Embedding` module of the model without doing anything.
1398
1399
1400
1401
1402
1403
1404
            pad_to_multiple_of (`int`, *optional*):
                If set will pad the embedding matrix to a multiple of the provided value.

                This is especially useful to enable the use of Tensor Cores on NVIDIA hardware with compute capability
                `>= 7.5` (Volta), or on TPUs which benefit from having sequence lengths be a multiple of 128. For more
                details about this, or help on choosing the correct value for resizing, refer to this guide:
                https://docs.nvidia.com/deeplearning/performance/dl-performance-matrix-multiplication/index.html#requirements-tc
1405
1406

        Return:
1407
            `torch.nn.Embedding`: Pointer to the input tokens Embeddings Module of the model.
thomwolf's avatar
thomwolf committed
1408
        """
1409
        model_embeds = self._resize_token_embeddings(new_num_tokens, pad_to_multiple_of)
thomwolf's avatar
thomwolf committed
1410
1411
        if new_num_tokens is None:
            return model_embeds
thomwolf's avatar
thomwolf committed
1412
1413
1414

        # Update base model and current model config
        self.config.vocab_size = new_num_tokens
1415
        self.vocab_size = new_num_tokens
thomwolf's avatar
thomwolf committed
1416
1417

        # Tie weights again if needed
1418
        self.tie_weights()
thomwolf's avatar
thomwolf committed
1419

thomwolf's avatar
thomwolf committed
1420
1421
        return model_embeds

1422
    def _resize_token_embeddings(self, new_num_tokens, pad_to_multiple_of=None):
thomwolf's avatar
thomwolf committed
1423
        old_embeddings = self.get_input_embeddings()
1424
        new_embeddings = self._get_resized_embeddings(old_embeddings, new_num_tokens, pad_to_multiple_of)
thomwolf's avatar
thomwolf committed
1425
        self.set_input_embeddings(new_embeddings)
1426
1427
1428
1429

        # if word embeddings are not tied, make sure that lm head is resized as well
        if self.get_output_embeddings() is not None and not self.config.tie_word_embeddings:
            old_lm_head = self.get_output_embeddings()
1430
            new_lm_head = self._get_resized_lm_head(old_lm_head, new_embeddings.weight.shape[0])
1431
1432
            self.set_output_embeddings(new_lm_head)

thomwolf's avatar
thomwolf committed
1433
        return self.get_input_embeddings()
1434

1435
    def _get_resized_embeddings(
1436
1437
1438
1439
        self,
        old_embeddings: nn.Embedding,
        new_num_tokens: Optional[int] = None,
        pad_to_multiple_of: Optional[int] = None,
1440
    ) -> nn.Embedding:
1441
1442
1443
        """
        Build a resized Embedding Module from a provided token Embedding Module. Increasing the size will add newly
        initialized vectors at the end. Reducing the size will remove vectors from the end
1444
1445

        Args:
1446
            old_embeddings (`torch.nn.Embedding`):
1447
                Old embeddings to be resized.
1448
            new_num_tokens (`int`, *optional*):
1449
                New number of tokens in the embedding matrix.
1450
1451

                Increasing the size will add newly initialized vectors at the end. Reducing the size will remove
1452
                vectors from the end. If not provided or `None`, just returns a pointer to the input tokens
1453
                `torch.nn.Embedding` module of the model without doing anything.
1454
1455
1456
1457
1458
1459
1460
1461
            pad_to_multiple_of (`int`, *optional*):
                If set will pad the embedding matrix to a multiple of the provided value.

                This is especially useful to enable the use of Tensor Cores on NVIDIA hardware with compute capability
                `>= 7.5` (Volta), or on TPUs which benefit from having sequence lengths be a multiple of 128. For more
                details about this, or help on choosing the correct value for resizing, refer to this guide:
                https://docs.nvidia.com/deeplearning/performance/dl-performance-matrix-multiplication/index.html#requirements-tc

1462
1463

        Return:
1464
1465
            `torch.nn.Embedding`: Pointer to the resized Embedding Module or the old Embedding Module if
            `new_num_tokens` is `None`
1466
        """
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483

        if pad_to_multiple_of is not None:
            if not isinstance(pad_to_multiple_of, int):
                raise ValueError(
                    f"Asking to pad the embedding matrix to a multiple of `{pad_to_multiple_of}`, which is not and integer. Please make sure to pass an integer"
                )
            if new_num_tokens is None:
                new_num_tokens = old_embeddings.weight.shape[0]
            new_num_tokens = ((new_num_tokens // pad_to_multiple_of) + 1) * pad_to_multiple_of
        else:
            logger.warning(
                "You are resizing the embedding layer without providing a `pad_to_multiple_of` parameter. This means that the new embeding"
                f" dimension will be {new_num_tokens}. This might induce some performance reduction as *Tensor Cores* will not be available."
                " For more details  about this, or help on choosing the correct value for resizing, refer to this guide:"
                " https://docs.nvidia.com/deeplearning/performance/dl-performance-matrix-multiplication/index.html#requirements-tc"
            )

1484
1485
1486
        if new_num_tokens is None:
            return old_embeddings

1487
1488
1489
1490
1491
1492
1493
1494
        if is_deepspeed_zero3_enabled():
            import deepspeed

            with deepspeed.zero.GatheredParameters(old_embeddings.weight, modifier_rank=None):
                old_num_tokens, old_embedding_dim = old_embeddings.weight.size()
        else:
            old_num_tokens, old_embedding_dim = old_embeddings.weight.size()

1495
1496
1497
        if old_num_tokens == new_num_tokens:
            return old_embeddings

1498
1499
        if not isinstance(old_embeddings, nn.Embedding):
            raise TypeError(
Sylvain Gugger's avatar
Sylvain Gugger committed
1500
1501
1502
                f"Old embeddings are of type {type(old_embeddings)}, which is not an instance of {nn.Embedding}. You"
                " should either use a different resize function or make sure that `old_embeddings` are an instance of"
                f" {nn.Embedding}."
1503
1504
            )

1505
1506
1507
1508
1509
        # numbers of tokens to copy
        n = min(old_num_tokens, new_num_tokens)
        if is_deepspeed_zero3_enabled():
            import deepspeed

1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
            with deepspeed.zero.Init(config_dict_or_path=deepspeed_config()):
                # Build new embeddings
                new_embeddings = nn.Embedding(
                    new_num_tokens,
                    old_embedding_dim,
                    device=old_embeddings.weight.device,
                    dtype=old_embeddings.weight.dtype,
                )

            params = [old_embeddings.weight, new_embeddings.weight]
            with deepspeed.zero.GatheredParameters(params, modifier_rank=0):
                # initialize all new embeddings (in particular added tokens)
                self._init_weights(new_embeddings)

                # Copy token embeddings from the previous weights
                new_embeddings.weight.data[:n, :] = old_embeddings.weight.data[:n, :]
1526
        else:
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
            # Build new embeddings
            new_embeddings = nn.Embedding(
                new_num_tokens,
                old_embedding_dim,
                device=old_embeddings.weight.device,
                dtype=old_embeddings.weight.dtype,
            )

            # initialize all new embeddings (in particular added tokens)
            self._init_weights(new_embeddings)

            # Copy token embeddings from the previous weights
1539
            new_embeddings.weight.data[:n, :] = old_embeddings.weight.data[:n, :]
1540
1541
1542

        return new_embeddings

1543
    def _get_resized_lm_head(
1544
1545
        self, old_lm_head: nn.Linear, new_num_tokens: Optional[int] = None, transposed: Optional[bool] = False
    ) -> nn.Linear:
1546
1547
1548
1549
1550
        """
        Build a resized Linear Module from a provided old Linear Module. Increasing the size will add newly initialized
        vectors at the end. Reducing the size will remove vectors from the end

        Args:
1551
            old_lm_head (`torch.nn.Linear`):
1552
                Old lm head liner layer to be resized.
1553
            new_num_tokens (`int`, *optional*):
1554
1555
1556
                New number of tokens in the linear matrix.

                Increasing the size will add newly initialized vectors at the end. Reducing the size will remove
1557
                vectors from the end. If not provided or `None`, just returns a pointer to the input tokens
1558
1559
1560
                `torch.nn.Linear` module of the model without doing anything. transposed (`bool`, *optional*, defaults
                to `False`): Whether `old_lm_head` is transposed or not. If True `old_lm_head.size()` is `lm_head_dim,
                vocab_size` else `vocab_size, lm_head_dim`.
1561
1562

        Return:
Sylvain Gugger's avatar
Sylvain Gugger committed
1563
1564
            `torch.nn.Linear`: Pointer to the resized Linear Module or the old Linear Module if `new_num_tokens` is
            `None`
1565
1566
1567
1568
        """
        if new_num_tokens is None:
            return old_lm_head

1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
        if is_deepspeed_zero3_enabled():
            import deepspeed

            with deepspeed.zero.GatheredParameters(old_lm_head.weight, modifier_rank=None):
                old_num_tokens, old_lm_head_dim = (
                    old_lm_head.weight.size() if not transposed else old_lm_head.weight.t().size()
                )
        else:
            old_num_tokens, old_lm_head_dim = (
                old_lm_head.weight.size() if not transposed else old_lm_head.weight.t().size()
            )
1580
1581
1582
1583
1584
1585

        if old_num_tokens == new_num_tokens:
            return old_lm_head

        if not isinstance(old_lm_head, nn.Linear):
            raise TypeError(
Sylvain Gugger's avatar
Sylvain Gugger committed
1586
1587
1588
                f"Old language model head is of type {type(old_lm_head)}, which is not an instance of {nn.Linear}. You"
                " should either use a different resize function or make sure that `old_lm_head` are an instance of"
                f" {nn.Linear}."
1589
1590
1591
1592
1593
1594
1595
1596
            )

        # Build new lm head
        new_lm_head_shape = (old_lm_head_dim, new_num_tokens) if not transposed else (new_num_tokens, old_lm_head_dim)
        has_new_lm_head_bias = old_lm_head.bias is not None

        num_tokens_to_copy = min(old_num_tokens, new_num_tokens)

1597
1598
1599
1600
        # XXX: put the long block of code in a wrapper
        if is_deepspeed_zero3_enabled():
            import deepspeed

1601
1602
1603
1604
1605
1606
1607
            with deepspeed.zero.Init(config_dict_or_path=deepspeed_config()):
                new_lm_head = nn.Linear(
                    *new_lm_head_shape,
                    bias=has_new_lm_head_bias,
                    device=old_lm_head.weight.device,
                    dtype=old_lm_head.weight.dtype,
                )
1608
1609
            params = [old_lm_head.weight, old_lm_head.bias, new_lm_head.weight, new_lm_head.bias]
            with deepspeed.zero.GatheredParameters(params, modifier_rank=0):
1610
1611
1612
1613
1614
1615
                self._init_weights(new_lm_head)
                # Copy old lm head weights to new lm head
                if not transposed:
                    new_lm_head.weight.data[:num_tokens_to_copy, :] = old_lm_head.weight.data[:num_tokens_to_copy, :]
                else:
                    new_lm_head.weight.data[:, :num_tokens_to_copy] = old_lm_head.weight.data[:, :num_tokens_to_copy]
1616

1617
1618
1619
                # Copy bias weights to new lm head
                if has_new_lm_head_bias:
                    new_lm_head.bias.data[:num_tokens_to_copy] = old_lm_head.bias.data[:num_tokens_to_copy]
1620
        else:
1621
1622
1623
1624
1625
1626
1627
            new_lm_head = nn.Linear(
                *new_lm_head_shape,
                bias=has_new_lm_head_bias,
                device=old_lm_head.weight.device,
                dtype=old_lm_head.weight.dtype,
            )
            self._init_weights(new_lm_head)
1628
1629
1630
1631
1632
            # Copy old lm head weights to new lm head
            if not transposed:
                new_lm_head.weight.data[:num_tokens_to_copy, :] = old_lm_head.weight.data[:num_tokens_to_copy, :]
            else:
                new_lm_head.weight.data[:, :num_tokens_to_copy] = old_lm_head.weight.data[:, :num_tokens_to_copy]
1633

1634
1635
1636
            # Copy bias weights to new lm head
            if has_new_lm_head_bias:
                new_lm_head.bias.data[:num_tokens_to_copy] = old_lm_head.bias.data[:num_tokens_to_copy]
1637
1638
1639

        return new_lm_head

1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
    def resize_position_embeddings(self, new_num_position_embeddings: int):
        raise NotImplementedError(
            f"`resize_position_embeddings` is not implemented for {self.__class__}`. To implement it, you should "
            f"overwrite this method in the class {self.__class__} in `modeling_{self.__class__.__module__}.py`"
        )

    def get_position_embeddings(self) -> Union[nn.Embedding, Tuple[nn.Embedding]]:
        raise NotImplementedError(
            f"`get_position_embeddings` is not implemented for {self.__class__}`. To implement it, you should "
            f"overwrite this method in the class {self.__class__} in `modeling_{self.__class__.__module__}.py`"
        )

1652
    def init_weights(self):
1653
        """
1654
1655
        If needed prunes and maybe initializes weights. If using a custom `PreTrainedModel`, you need to implement any
        initialization logic in `_init_weights`.
1656
        """
1657
1658
1659
1660
        # Prune heads if needed
        if self.config.pruned_heads:
            self.prune_heads(self.config.pruned_heads)

1661
1662
        if _init_weights:
            # Initialize weights
1663
            self.apply(self._initialize_weights)
1664
1665
1666
1667

            # Tie weights should be skipped when not initializing all weights
            # since from_pretrained(...) calls tie weights anyways
            self.tie_weights()
1668

1669
1670
1671
    def prune_heads(self, heads_to_prune: Dict[int, List[int]]):
        """
        Prunes heads of the base model.
1672

1673
        Arguments:
1674
            heads_to_prune (`Dict[int, List[int]]`):
Sylvain Gugger's avatar
Sylvain Gugger committed
1675
1676
1677
                Dictionary with keys being selected layer indices (`int`) and associated values being the list of heads
                to prune in said layer (list of `int`). For instance {1: [0, 2], 2: [2, 3]} will prune heads 0 and 2 on
                layer 1 and heads 2 and 3 on layer 2.
thomwolf's avatar
thomwolf committed
1678
        """
1679
        # save new sets of pruned heads as union of previously stored pruned heads and newly pruned heads
1680
        for layer, heads in heads_to_prune.items():
1681
1682
1683
            union_heads = set(self.config.pruned_heads.get(layer, [])) | set(heads)
            self.config.pruned_heads[layer] = list(union_heads)  # Unfortunately we have to store it as list for JSON

1684
        self.base_model._prune_heads(heads_to_prune)
thomwolf's avatar
thomwolf committed
1685

1686
    def gradient_checkpointing_enable(self):
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
        """
        Activates gradient checkpointing for the current model.

        Note that in other frameworks this feature can be referred to as "activation checkpointing" or "checkpoint
        activations".
        """
        if not self.supports_gradient_checkpointing:
            raise ValueError(f"{self.__class__.__name__} does not support gradient checkpointing.")
        self.apply(partial(self._set_gradient_checkpointing, value=True))

1697
    def gradient_checkpointing_disable(self):
1698
1699
1700
1701
1702
1703
1704
1705
1706
        """
        Deactivates gradient checkpointing for the current model.

        Note that in other frameworks this feature can be referred to as "activation checkpointing" or "checkpoint
        activations".
        """
        if self.supports_gradient_checkpointing:
            self.apply(partial(self._set_gradient_checkpointing, value=False))

1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
    @property
    def is_gradient_checkpointing(self) -> bool:
        """
        Whether gradient checkpointing is activated for this model or not.

        Note that in other frameworks this feature can be referred to as "activation checkpointing" or "checkpoint
        activations".
        """
        return any(hasattr(m, "gradient_checkpointing") and m.gradient_checkpointing for m in self.modules())

1717
1718
1719
    def save_pretrained(
        self,
        save_directory: Union[str, os.PathLike],
1720
        is_main_process: bool = True,
1721
1722
        state_dict: Optional[dict] = None,
        save_function: Callable = torch.save,
Sylvain Gugger's avatar
Sylvain Gugger committed
1723
        push_to_hub: bool = False,
Sylvain Gugger's avatar
Sylvain Gugger committed
1724
        max_shard_size: Union[int, str] = "10GB",
1725
        safe_serialization: bool = False,
1726
        variant: Optional[str] = None,
1727
        token: Optional[Union[str, bool]] = None,
Sylvain Gugger's avatar
Sylvain Gugger committed
1728
        **kwargs,
1729
    ):
1730
1731
        """
        Save a model and its configuration file to a directory, so that it can be re-loaded using the
1732
        [`~PreTrainedModel.from_pretrained`] class method.
1733

1734
        Arguments:
1735
            save_directory (`str` or `os.PathLike`):
1736
                Directory to which to save. Will be created if it doesn't exist.
1737
1738
1739
1740
            is_main_process (`bool`, *optional*, defaults to `True`):
                Whether the process calling this is the main process or not. Useful when in distributed training like
                TPUs and need to call this function on all processes. In this case, set `is_main_process=True` only on
                the main process to avoid race conditions.
1741
            state_dict (nested dictionary of `torch.Tensor`):
Sylvain Gugger's avatar
Sylvain Gugger committed
1742
1743
1744
                The state dictionary of the model to save. Will default to `self.state_dict()`, but can be used to only
                save parts of the model or if special precautions need to be taken when recovering the state dictionary
                of a model (like when using model parallelism).
1745
            save_function (`Callable`):
1746
                The function to use to save the state dictionary. Useful on distributed training like TPUs when one
1747
1748
                need to replace `torch.save` by another method.
            push_to_hub (`bool`, *optional*, defaults to `False`):
1749
1750
1751
                Whether or not to push your model to the Hugging Face model hub after saving it. You can specify the
                repository you want to push to with `repo_id` (will default to the name of `save_directory` in your
                namespace).
Sylvain Gugger's avatar
Sylvain Gugger committed
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
            max_shard_size (`int` or `str`, *optional*, defaults to `"10GB"`):
                The maximum size for a checkpoint before being sharded. Checkpoints shard will then be each of size
                lower than this size. If expressed as a string, needs to be digits followed by a unit (like `"5MB"`).

                <Tip warning={true}>

                If a single weight of the model is bigger than `max_shard_size`, it will be in its own checkpoint shard
                which will be bigger than `max_shard_size`.

                </Tip>

1763
1764
            safe_serialization (`bool`, *optional*, defaults to `False`):
                Whether to save the model using `safetensors` or the traditional PyTorch way (that uses `pickle`).
1765
1766
            variant (`str`, *optional*):
                If specified, weights are saved in the format pytorch_model.<variant>.bin.
1767
1768
1769
            token (`str` or `bool`, *optional*):
                The token to use as HTTP bearer authorization for remote files. If `True`, or not specified, will use
                the token generated when running `huggingface-cli login` (stored in `~/.huggingface`).
1770
            kwargs (`Dict[str, Any]`, *optional*):
1771
                Additional key word arguments passed along to the [`~utils.PushToHubMixin.push_to_hub`] method.
1772
        """
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
        use_auth_token = kwargs.pop("use_auth_token", None)

        if use_auth_token is not None:
            warnings.warn(
                "The `use_auth_token` argument is deprecated and will be removed in v5 of Transformers.", FutureWarning
            )
            if token is not None:
                raise ValueError(
                    "`token` and `use_auth_token` are both specified. Please set only the argument `token`."
                )
            token = use_auth_token

        if token is not None:
            kwargs["token"] = token

1788
        # Checks if the model has been loaded in 8-bit
1789
        if getattr(self, "is_loaded_in_8bit", False) and getattr(self, "is_8bit_serializable", False):
1790
1791
            warnings.warn(
                "You are calling `save_pretrained` to a 8-bit converted model you may likely encounter unexepected"
1792
                " behaviors. If you want to save 8-bit models, make sure to have `bitsandbytes>0.37.2` installed.",
1793
1794
1795
                UserWarning,
            )

1796
1797
1798
1799
1800
        if getattr(self, "is_loaded_in_4bit", False):
            raise NotImplementedError(
                "You are calling `save_pretrained` on a 4-bit converted model. This is currently not supported"
            )

1801
1802
1803
1804
1805
        if "save_config" in kwargs:
            warnings.warn(
                "`save_config` is deprecated and will be removed in v5 of Transformers. Use `is_main_process` instead."
            )
            is_main_process = kwargs.pop("save_config")
1806
1807
        if safe_serialization and not is_safetensors_available():
            raise ImportError("`safe_serialization` requires the `safetensors library: `pip install safetensors`.")
1808

1809
        if os.path.isfile(save_directory):
1810
            logger.error(f"Provided path ({save_directory}) should be a directory, not a file")
1811
            return
1812

1813
1814
        os.makedirs(save_directory, exist_ok=True)

1815
1816
        if push_to_hub:
            commit_message = kwargs.pop("commit_message", None)
1817
            repo_id = kwargs.pop("repo_id", save_directory.split(os.path.sep)[-1])
1818
            repo_id = self._create_repo(repo_id, **kwargs)
1819
            files_timestamps = self._get_files_timestamps(save_directory)
1820

Julien Chaumond's avatar
Julien Chaumond committed
1821
        # Only save the model itself if we are using distributed training
1822
        model_to_save = unwrap_model(self)
1823

1824
1825
1826
1827
1828
        # save the string version of dtype to the config, e.g. convert torch.float32 => "float32"
        # we currently don't use this setting automatically, but may start to use with v5
        dtype = get_parameter_dtype(model_to_save)
        model_to_save.config.torch_dtype = str(dtype).split(".")[1]

Julien Chaumond's avatar
Julien Chaumond committed
1829
1830
1831
        # Attach architecture to the config
        model_to_save.config.architectures = [model_to_save.__class__.__name__]

1832
1833
1834
1835
1836
        # If we have a custom model, we copy the file defining it in the folder and set the attributes so it can be
        # loaded from the Hub.
        if self._auto_class is not None:
            custom_object_save(self, save_directory, config=self.config)

1837
        # Save the config
1838
        if is_main_process:
1839
            model_to_save.config.save_pretrained(save_directory)
1840
1841
            if self.can_generate():
                model_to_save.generation_config.save_pretrained(save_directory)
1842
1843
1844
1845

        # Save the model
        if state_dict is None:
            state_dict = model_to_save.state_dict()
1846

1847
1848
1849
1850
1851
        # Translate state_dict from smp to hf if saving with smp >= 1.10
        if IS_SAGEMAKER_MP_POST_1_10:
            for smp_to_hf, _ in smp.state.module_manager.translate_functions:
                state_dict = smp_to_hf(state_dict)

1852
        # Handle the case where some state_dict keys shouldn't be saved
1853
        if self._keys_to_ignore_on_save is not None:
1854
            for ignore_key in self._keys_to_ignore_on_save:
1855
1856
                if ignore_key in state_dict.keys():
                    del state_dict[ignore_key]
1857
1858
1859
1860
1861
        if safe_serialization:
            # Safetensors does not allow tensor aliasing.
            # We're going to remove aliases before saving
            ptrs = collections.defaultdict(list)
            for name, tensor in state_dict.items():
Sylvain Gugger's avatar
Sylvain Gugger committed
1862
                ptrs[id_tensor_storage(tensor)].append(name)
1863
1864
1865
1866
1867
1868
1869

            # These are all the pointers of shared tensors.
            shared_ptrs = {ptr: names for ptr, names in ptrs.items() if len(names) > 1}
            warn_names = set()
            for names in shared_ptrs.values():
                # Removing the keys which are declared as known duplicates on
                # load. This allows to make sure the name which is kept is consistent.
Sylvain Gugger's avatar
Sylvain Gugger committed
1870
                if self._tied_weights_keys is not None:
1871
1872
                    found = 0
                    for name in sorted(names):
Sylvain Gugger's avatar
Sylvain Gugger committed
1873
                        matches_pattern = any(re.search(pat, name) for pat in self._tied_weights_keys)
1874
                        if matches_pattern and name in state_dict:
1875
1876
1877
                            found += 1
                            if found < len(names):
                                del state_dict[name]
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894

                # When not all duplicates have been cleaned, still remove those keys, but put a clear warning.
                # If the link between tensors was done at runtime then `from_pretrained` will not get
                # the key back leading to random tensor. A proper warning will be shown
                # during reload (if applicable), but since the file is not necessarily compatible with
                # the config, better show a proper warning.
                found = 0
                for name in names:
                    if name in state_dict:
                        found += 1
                        if found > 1:
                            del state_dict[name]
                            warn_names.add(name)
            if len(warn_names) > 0:
                logger.warning_once(
                    f"Removed shared tensor {warn_names} while saving. This should be OK, but check by verifying that you don't receive any warning while reloading",
                )
1895

Sylvain Gugger's avatar
Sylvain Gugger committed
1896
        # Shard the model if it is too big.
1897
        weights_name = SAFE_WEIGHTS_NAME if safe_serialization else WEIGHTS_NAME
1898
1899
        weights_name = _add_variant(weights_name, variant)

1900
        shards, index = shard_checkpoint(state_dict, max_shard_size=max_shard_size, weights_name=weights_name)
Sylvain Gugger's avatar
Sylvain Gugger committed
1901
1902
1903
1904

        # Clean the folder from a previous save
        for filename in os.listdir(save_directory):
            full_filename = os.path.join(save_directory, filename)
1905
1906
            # If we have a shard file that is not going to be replaced, we delete it, but only from the main process
            # in distributed settings to avoid race conditions.
1907
            weights_no_suffix = weights_name.replace(".bin", "").replace(".safetensors", "")
1908
1909
1910

            # make sure that file to be deleted matches format of sharded file, e.g. pytorch_model-00001-of-00005
            filename_no_suffix = filename.replace(".bin", "").replace(".safetensors", "")
1911
            reg = re.compile(r"(.*?)-\d{5}-of-\d{5}")
1912

1913
            if (
1914
                filename.startswith(weights_no_suffix)
1915
1916
1917
                and os.path.isfile(full_filename)
                and filename not in shards.keys()
                and is_main_process
1918
                and reg.fullmatch(filename_no_suffix) is not None
1919
            ):
Sylvain Gugger's avatar
Sylvain Gugger committed
1920
                os.remove(full_filename)
1921

Sylvain Gugger's avatar
Sylvain Gugger committed
1922
1923
        # Save the model
        for shard_file, shard in shards.items():
1924
1925
1926
1927
1928
1929
            if safe_serialization:
                # At some point we will need to deal better with save_function (used for TPU and other distributed
                # joyfulness), but for now this enough.
                safe_save_file(shard, os.path.join(save_directory, shard_file), metadata={"format": "pt"})
            else:
                save_function(shard, os.path.join(save_directory, shard_file))
Sylvain Gugger's avatar
Sylvain Gugger committed
1930
1931

        if index is None:
1932
1933
            path_to_weights = os.path.join(save_directory, _add_variant(WEIGHTS_NAME, variant))
            logger.info(f"Model weights saved in {path_to_weights}")
Sylvain Gugger's avatar
Sylvain Gugger committed
1934
        else:
1935
            save_index_file = SAFE_WEIGHTS_INDEX_NAME if safe_serialization else WEIGHTS_INDEX_NAME
1936
            save_index_file = os.path.join(save_directory, _add_variant(save_index_file, variant))
Sylvain Gugger's avatar
Sylvain Gugger committed
1937
1938
1939
1940
1941
1942
1943
1944
1945
            # Save the index as well
            with open(save_index_file, "w", encoding="utf-8") as f:
                content = json.dumps(index, indent=2, sort_keys=True) + "\n"
                f.write(content)
            logger.info(
                f"The model is bigger than the maximum size per checkpoint ({max_shard_size}) and is going to be "
                f"split in {len(shards)} checkpoint shards. You can find where each parameters has been saved in the "
                f"index located at {save_index_file}."
            )
1946

Sylvain Gugger's avatar
Sylvain Gugger committed
1947
        if push_to_hub:
1948
            self._upload_modified_files(
1949
1950
1951
1952
                save_directory,
                repo_id,
                files_timestamps,
                commit_message=commit_message,
1953
                token=token,
1954
            )
Sylvain Gugger's avatar
Sylvain Gugger committed
1955

1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
    def get_memory_footprint(self, return_buffers=True):
        r"""
        Get the memory footprint of a model. This will return the memory footprint of the current model in bytes.
        Useful to benchmark the memory footprint of the current model and design some tests. Solution inspired from the
        PyTorch discussions: https://discuss.pytorch.org/t/gpu-memory-that-model-uses/56822/2

        Arguments:
            return_buffers (`bool`, *optional*, defaults to `True`):
                Whether to return the size of the buffer tensors in the computation of the memory footprint. Buffers
                are tensors that do not require gradients and not registered as parameters. E.g. mean and std in batch
                norm layers. Please see: https://discuss.pytorch.org/t/what-pytorch-means-by-buffers/120266/2
        """
        mem = sum([param.nelement() * param.element_size() for param in self.parameters()])
        if return_buffers:
            mem_bufs = sum([buf.nelement() * buf.element_size() for buf in self.buffers()])
            mem = mem + mem_bufs
        return mem

1974
    @wraps(torch.nn.Module.cuda)
1975
1976
    def cuda(self, *args, **kwargs):
        # Checks if the model has been loaded in 8-bit
Marc Sun's avatar
Marc Sun committed
1977
        if getattr(self, "quantization_method", None) == QuantizationMethod.BITS_AND_BYTES:
1978
1979
1980
1981
1982
1983
1984
            raise ValueError(
                "Calling `cuda()` is not supported for `4-bit` or `8-bit` quantized models. Please use the model as it is, since the"
                " model has already been set to the correct devices and casted to the correct `dtype`."
            )
        else:
            return super().cuda(*args, **kwargs)

1985
    @wraps(torch.nn.Module.to)
1986
1987
    def to(self, *args, **kwargs):
        # Checks if the model has been loaded in 8-bit
Marc Sun's avatar
Marc Sun committed
1988
        if getattr(self, "quantization_method", None) == QuantizationMethod.BITS_AND_BYTES:
1989
            raise ValueError(
Marc Sun's avatar
Marc Sun committed
1990
                "`.to` is not supported for `4-bit` or `8-bit` bitsandbytes models. Please use the model as it is, since the"
1991
1992
1993
1994
1995
1996
                " model has already been set to the correct devices and casted to the correct `dtype`."
            )
        else:
            return super().to(*args, **kwargs)

    def half(self, *args):
Marc Sun's avatar
Marc Sun committed
1997
        # Checks if the model is quantized
1998
        if getattr(self, "is_quantized", False):
1999
            raise ValueError(
Marc Sun's avatar
Marc Sun committed
2000
                "`.half()` is not supported for quantized model. Please use the model as it is, since the"
2001
2002
2003
2004
2005
2006
                " model has already been casted to the correct `dtype`."
            )
        else:
            return super().half(*args)

    def float(self, *args):
Marc Sun's avatar
Marc Sun committed
2007
        # Checks if the model is quantized
2008
        if getattr(self, "is_quantized", False):
2009
            raise ValueError(
Marc Sun's avatar
Marc Sun committed
2010
                "`.float()` is not supported for quantized model. Please use the model as it is, since the"
2011
2012
2013
2014
2015
                " model has already been casted to the correct `dtype`."
            )
        else:
            return super().float(*args)

2016
    @classmethod
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
    def from_pretrained(
        cls,
        pretrained_model_name_or_path: Optional[Union[str, os.PathLike]],
        *model_args,
        config: Optional[Union[PretrainedConfig, str, os.PathLike]] = None,
        cache_dir: Optional[Union[str, os.PathLike]] = None,
        ignore_mismatched_sizes: bool = False,
        force_download: bool = False,
        local_files_only: bool = False,
        token: Optional[Union[str, bool]] = None,
        revision: str = "main",
        use_safetensors: bool = None,
        **kwargs,
    ):
2031
2032
        r"""
        Instantiate a pretrained pytorch model from a pre-trained model configuration.
2033

Sylvain Gugger's avatar
Sylvain Gugger committed
2034
2035
        The model is set in evaluation mode by default using `model.eval()` (Dropout modules are deactivated). To train
        the model, you should first set it back in training mode with `model.train()`.
2036

2037
        The warning *Weights from XXX not initialized from pretrained model* means that the weights of XXX do not come
2038
2039
        pretrained with the rest of the model. It is up to you to train those weights with a downstream fine-tuning
        task.
2040

2041
        The warning *Weights from XXX not used in YYY* means that the layer XXX is not used by YYY, therefore those
2042
        weights are discarded.
2043

2044
        Parameters:
2045
            pretrained_model_name_or_path (`str` or `os.PathLike`, *optional*):
2046
2047
                Can be either:

2048
                    - A string, the *model id* of a pretrained model hosted inside a model repo on huggingface.co.
Sylvain Gugger's avatar
Sylvain Gugger committed
2049
2050
                      Valid model ids can be located at the root-level, like `bert-base-uncased`, or namespaced under a
                      user or organization name, like `dbmdz/bert-base-german-cased`.
2051
2052
2053
                    - A path to a *directory* containing model weights saved using
                      [`~PreTrainedModel.save_pretrained`], e.g., `./my_model_directory/`.
                    - A path or url to a *tensorflow index checkpoint file* (e.g, `./tf_model/model.ckpt.index`). In
Sylvain Gugger's avatar
Sylvain Gugger committed
2054
2055
2056
                      this case, `from_tf` should be set to `True` and a configuration object should be provided as
                      `config` argument. This loading path is slower than converting the TensorFlow checkpoint in a
                      PyTorch model using the provided conversion scripts and loading the PyTorch model afterwards.
2057
                    - A path or url to a model folder containing a *flax checkpoint file* in *.msgpack* format (e.g,
Sylvain Gugger's avatar
Sylvain Gugger committed
2058
2059
                      `./flax_model/` containing `flax_model.msgpack`). In this case, `from_flax` should be set to
                      `True`.
2060
2061
2062
2063
2064
                    - `None` if you are both providing the configuration and state dictionary (resp. with keyword
                      arguments `config` and `state_dict`).
            model_args (sequence of positional arguments, *optional*):
                All remaining positional arguments will be passed to the underlying model's `__init__` method.
            config (`Union[PretrainedConfig, str, os.PathLike]`, *optional*):
2065
2066
                Can be either:

2067
2068
                    - an instance of a class derived from [`PretrainedConfig`],
                    - a string or path valid as input to [`~PretrainedConfig.from_pretrained`].
2069

2070
                Configuration for the model to use instead of an automatically loaded configuration. Configuration can
2071
2072
                be automatically loaded when:

2073
                    - The model is a model provided by the library (loaded with the *model id* string of a pretrained
2074
                      model).
Sylvain Gugger's avatar
Sylvain Gugger committed
2075
2076
                    - The model was saved using [`~PreTrainedModel.save_pretrained`] and is reloaded by supplying the
                      save directory.
2077
2078
2079
                    - The model is loaded by supplying a local directory as `pretrained_model_name_or_path` and a
                      configuration JSON file named *config.json* is found in the directory.
            state_dict (`Dict[str, torch.Tensor]`, *optional*):
2080
2081
2082
                A state dictionary to use instead of a state dictionary loaded from saved weights file.

                This option can be used if you want to create a model from a pretrained configuration but load your own
Sylvain Gugger's avatar
Sylvain Gugger committed
2083
                weights. In this case though, you should check if using [`~PreTrainedModel.save_pretrained`] and
2084
2085
                [`~PreTrainedModel.from_pretrained`] is not a simpler option.
            cache_dir (`Union[str, os.PathLike]`, *optional*):
2086
2087
                Path to a directory in which a downloaded pretrained model configuration should be cached if the
                standard cache should not be used.
2088
            from_tf (`bool`, *optional*, defaults to `False`):
2089
                Load the model weights from a TensorFlow checkpoint save file (see docstring of
2090
2091
                `pretrained_model_name_or_path` argument).
            from_flax (`bool`, *optional*, defaults to `False`):
2092
                Load the model weights from a Flax checkpoint save file (see docstring of
2093
2094
                `pretrained_model_name_or_path` argument).
            ignore_mismatched_sizes (`bool`, *optional*, defaults to `False`):
2095
2096
2097
                Whether or not to raise an error if some of the weights from the checkpoint do not have the same size
                as the weights of the model (if for instance, you are instantiating a model with 10 labels from a
                checkpoint with 3 labels).
2098
            force_download (`bool`, *optional*, defaults to `False`):
2099
2100
                Whether or not to force the (re-)download of the model weights and configuration files, overriding the
                cached versions if they exist.
2101
            resume_download (`bool`, *optional*, defaults to `False`):
2102
2103
                Whether or not to delete incompletely received files. Will attempt to resume the download if such a
                file exists.
2104
            proxies (`Dict[str, str]`, *optional*):
Sylvain Gugger's avatar
Sylvain Gugger committed
2105
2106
                A dictionary of proxy servers to use by protocol or endpoint, e.g., `{'http': 'foo.bar:3128',
                'http://hostname': 'foo.bar:4012'}`. The proxies are used on each request.
2107
            output_loading_info(`bool`, *optional*, defaults to `False`):
Sylvain Gugger's avatar
Sylvain Gugger committed
2108
                Whether ot not to also return a dictionary containing missing keys, unexpected keys and error messages.
2109
            local_files_only(`bool`, *optional*, defaults to `False`):
Stas Bekman's avatar
Stas Bekman committed
2110
                Whether or not to only look at local files (i.e., do not try to download the model).
2111
            token (`str` or `bool`, *optional*):
2112
2113
                The token to use as HTTP bearer authorization for remote files. If `True`, or not specified, will use
                the token generated when running `huggingface-cli login` (stored in `~/.huggingface`).
2114
            revision (`str`, *optional*, defaults to `"main"`):
Julien Chaumond's avatar
Julien Chaumond committed
2115
                The specific model version to use. It can be a branch name, a tag name, or a commit id, since we use a
2116
                git-based system for storing models and other artifacts on huggingface.co, so `revision` can be any
Julien Chaumond's avatar
Julien Chaumond committed
2117
                identifier allowed by git.
2118
2119
2120
2121
2122
2123
2124

                <Tip>

                To test a pull request you made on the Hub, you can pass `revision="refs/pr/<pr_number>".

                </Tip>

2125
            mirror (`str`, *optional*):
Sylvain Gugger's avatar
Sylvain Gugger committed
2126
2127
2128
                Mirror source to accelerate downloads in China. If you are from China and have an accessibility
                problem, you can set this option to resolve it. Note that we do not guarantee the timeliness or safety.
                Please refer to the mirror site for more information.
2129
            _fast_init(`bool`, *optional*, defaults to `True`):
2130
2131
                Whether or not to disable fast initialization.

2132
2133
                <Tip warning={true}>

Sylvain Gugger's avatar
Sylvain Gugger committed
2134
2135
2136
                One should only disable *_fast_init* to ensure backwards compatibility with `transformers.__version__ <
                4.6.0` for seeded model initialization. This argument will be removed at the next major version. See
                [pull request 11471](https://github.com/huggingface/transformers/pull/11471) for more information.
2137

2138
                </Tip>
2139

2140
2141
2142
            > Parameters for big model inference

            low_cpu_mem_usage(`bool`, *optional*):
2143
2144
2145
                Tries to not use more than 1x model size in CPU memory (including peak memory) while loading the model.
                This is an experimental feature and a subject to change at any moment.
            torch_dtype (`str` or `torch.dtype`, *optional*):
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
                Override the default `torch.dtype` and load the model under a specific `dtype`. The different options
                are:

                1. `torch.float16` or `torch.bfloat16` or `torch.float`: load in a specified
                  `dtype`, ignoring the model's `config.torch_dtype` if one exists. If not specified
                  - the model will get loaded in `torch.float` (fp32).

                2. `"auto"` - A `torch_dtype` entry in the `config.json` file of the model will be
                  attempted to be used. If this entry isn't found then next check the `dtype` of the first weight in
                  the checkpoint that's of a floating point type and use that as `dtype`. This will load the model
                  using the `dtype` it was saved in at the end of the training. It can't be used as an indicator of how
                  the model was trained. Since it could be trained in one of half precision dtypes, but saved in fp32.

                <Tip>

                For some models the `dtype` they were trained in is unknown - you may try to check the model's paper or
                reach out to the authors and ask them to add this information to the model's card and to insert the
                `torch_dtype` entry in `config.json` on the hub.

                </Tip>

2167
            device_map (`str` or `Dict[str, Union[int, str, torch.device]]` or `int` or `torch.device`, *optional*):
2168
2169
                A map that specifies where each submodule should go. It doesn't need to be refined to each
                parameter/buffer name, once a given module name is inside, every submodule of it will be sent to the
2170
2171
2172
                same device. If we only pass the device (*e.g.*, `"cpu"`, `"cuda:1"`, `"mps"`, or a GPU ordinal rank
                like `1`) on which the model will be allocated, the device map will map the entire model to this
                device. Passing `device_map = 0` means put the whole model on GPU 0.
2173

2174
2175
                To have Accelerate compute the most optimized `device_map` automatically, set `device_map="auto"`. For
                more information about each option see [designing a device
Patrick von Platen's avatar
Patrick von Platen committed
2176
                map](https://hf.co/docs/accelerate/main/en/usage_guides/big_modeling#designing-a-device-map).
2177
2178
2179
            max_memory (`Dict`, *optional*):
                A dictionary device identifier to maximum memory. Will default to the maximum memory available for each
                GPU and the available CPU RAM if unset.
2180
2181
            offload_folder (`str` or `os.PathLike`, *optional*):
                If the `device_map` contains any value `"disk"`, the folder where we will offload weights.
2182
            offload_state_dict (`bool`, *optional*):
2183
                If `True`, will temporarily offload the CPU state dict to the hard drive to avoid getting out of CPU
2184
2185
                RAM if the weight of the CPU state dict + the biggest shard of the checkpoint does not fit. Defaults to
                `True` when there is some disk offload.
2186
2187
            load_in_8bit (`bool`, *optional*, defaults to `False`):
                If `True`, will convert the loaded model into mixed-8bit quantized model. To use this feature please
2188
2189
2190
2191
                install `bitsandbytes` (`pip install -U bitsandbytes`).
            load_in_4bit (`bool`, *optional*, defaults to `False`):
                If `True`, will convert the loaded model into 4bit precision quantized model. To use this feature
                install the latest version of `bitsandbytes` (`pip install -U bitsandbytes`).
Marc Sun's avatar
Marc Sun committed
2192
2193
2194
            quantization_config (`Union[QuantizationConfigMixin,Dict]`, *optional*):
                A dictionary of configuration parameters or a QuantizationConfigMixin object for quantization (e.g
                bitsandbytes, gptq)
2195
2196
2197
            subfolder (`str`, *optional*, defaults to `""`):
                In case the relevant files are located inside a subfolder of the model repo on huggingface.co, you can
                specify the folder name here.
2198
2199
2200
            variant (`str`, *optional*):
                If specified load weights from `variant` filename, *e.g.* pytorch_model.<variant>.bin. `variant` is
                ignored when using `from_tf` or `from_flax`.
2201
2202
2203
            use_safetensors (`bool`, *optional*, defaults to `None`):
                Whether or not to use `safetensors` checkpoints. Defaults to `None`. If not specified and `safetensors`
                is not installed, it will be set to `False`.
2204

2205
            kwargs (remaining dictionary of keyword arguments, *optional*):
2206
                Can be used to update the configuration object (after it being loaded) and initiate the model (e.g.,
2207
                `output_attentions=True`). Behaves differently depending on whether a `config` is provided or
2208
2209
                automatically loaded:

2210
2211
                    - If a configuration is provided with `config`, `**kwargs` will be directly passed to the
                      underlying model's `__init__` method (we assume all relevant updates to the configuration have
2212
                      already been done)
2213
                    - If a configuration is not provided, `kwargs` will be first passed to the configuration class
Sylvain Gugger's avatar
Sylvain Gugger committed
2214
2215
2216
2217
                      initialization function ([`~PretrainedConfig.from_pretrained`]). Each key of `kwargs` that
                      corresponds to a configuration attribute will be used to override said attribute with the
                      supplied `kwargs` value. Remaining keys that do not correspond to any configuration attribute
                      will be passed to the underlying model's `__init__` function.
2218
2219
2220

        <Tip>

Sylvain Gugger's avatar
Sylvain Gugger committed
2221
2222
        Activate the special ["offline-mode"](https://huggingface.co/transformers/installation.html#offline-mode) to
        use this method in a firewalled environment.
2223
2224
2225
2226
2227
2228
2229

        </Tip>

        Examples:

        ```python
        >>> from transformers import BertConfig, BertModel
Sylvain Gugger's avatar
Sylvain Gugger committed
2230

2231
        >>> # Download model and configuration from huggingface.co and cache.
Sylvain Gugger's avatar
Sylvain Gugger committed
2232
        >>> model = BertModel.from_pretrained("bert-base-uncased")
2233
        >>> # Model was saved using *save_pretrained('./test/saved_model/')* (for example purposes, not runnable).
Sylvain Gugger's avatar
Sylvain Gugger committed
2234
        >>> model = BertModel.from_pretrained("./test/saved_model/")
2235
        >>> # Update configuration during loading.
Sylvain Gugger's avatar
Sylvain Gugger committed
2236
        >>> model = BertModel.from_pretrained("bert-base-uncased", output_attentions=True)
2237
2238
        >>> assert model.config.output_attentions == True
        >>> # Loading from a TF checkpoint file instead of a PyTorch model (slower, for example purposes, not runnable).
Sylvain Gugger's avatar
Sylvain Gugger committed
2239
2240
        >>> config = BertConfig.from_json_file("./tf_model/my_tf_model_config.json")
        >>> model = BertModel.from_pretrained("./tf_model/my_tf_checkpoint.ckpt.index", from_tf=True, config=config)
2241
        >>> # Loading from a Flax checkpoint file instead of a PyTorch model (slower)
Sylvain Gugger's avatar
Sylvain Gugger committed
2242
        >>> model = BertModel.from_pretrained("bert-base-uncased", from_flax=True)
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
        ```

        * `low_cpu_mem_usage` algorithm:

        This is an experimental function that loads the model using ~1x model size CPU memory

        Here is how it works:

        1. save which state_dict keys we have
        2. drop state_dict before the model is created, since the latter takes 1x model size CPU memory
        3. after the model has been instantiated switch to the meta device all params/buffers that
        are going to be replaced from the loaded state_dict
        4. load state_dict 2nd time
        5. replace the params/buffers from the state_dict

        Currently, it can't handle deepspeed ZeRO stage 3 and ignores loading errors

        """
2261
2262
        state_dict = kwargs.pop("state_dict", None)
        from_tf = kwargs.pop("from_tf", False)
2263
        from_flax = kwargs.pop("from_flax", False)
2264
2265
2266
        resume_download = kwargs.pop("resume_download", False)
        proxies = kwargs.pop("proxies", None)
        output_loading_info = kwargs.pop("output_loading_info", False)
2267
        use_auth_token = kwargs.pop("use_auth_token", None)
2268
        trust_remote_code = kwargs.pop("trust_remote_code", None)
Sylvain Gugger's avatar
Sylvain Gugger committed
2269
        _ = kwargs.pop("mirror", None)
2270
2271
        from_pipeline = kwargs.pop("_from_pipeline", None)
        from_auto_class = kwargs.pop("_from_auto", False)
2272
        _fast_init = kwargs.pop("_fast_init", True)
2273
        torch_dtype = kwargs.pop("torch_dtype", None)
2274
2275
        low_cpu_mem_usage = kwargs.pop("low_cpu_mem_usage", None)
        device_map = kwargs.pop("device_map", None)
2276
        max_memory = kwargs.pop("max_memory", None)
2277
        offload_folder = kwargs.pop("offload_folder", None)
2278
2279
        offload_state_dict = kwargs.pop("offload_state_dict", False)
        load_in_8bit = kwargs.pop("load_in_8bit", False)
2280
        load_in_4bit = kwargs.pop("load_in_4bit", False)
2281
        quantization_config = kwargs.pop("quantization_config", None)
2282
        subfolder = kwargs.pop("subfolder", "")
2283
        commit_hash = kwargs.pop("_commit_hash", None)
2284
        variant = kwargs.pop("variant", None)
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297

        if use_auth_token is not None:
            warnings.warn(
                "The `use_auth_token` argument is deprecated and will be removed in v5 of Transformers.", FutureWarning
            )
            if token is not None:
                raise ValueError(
                    "`token` and `use_auth_token` are both specified. Please set only the argument `token`."
                )
            token = use_auth_token

        if use_safetensors is None and not is_safetensors_available():
            use_safetensors = False
2298

2299
        if is_bitsandbytes_available():
2300
            is_8bit_serializable = version.parse(importlib.metadata.version("bitsandbytes")) > version.parse("0.37.2")
2301
2302
2303
        else:
            is_8bit_serializable = False

2304
2305
2306
2307
2308
        if trust_remote_code is True:
            logger.warning(
                "The argument `trust_remote_code` is to be used with Auto classes. It has no effect here and is"
                " ignored."
            )
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328

        # change device_map into a map if we passed an int, a str or a torch.device
        if isinstance(device_map, torch.device):
            device_map = {"": device_map}
        elif isinstance(device_map, str) and device_map not in ["auto", "balanced", "balanced_low_0", "sequential"]:
            try:
                device_map = {"": torch.device(device_map)}
            except RuntimeError:
                raise ValueError(
                    "When passing device_map as a string, the value needs to be a device name (e.g. cpu, cuda:0) or "
                    f"'auto', 'balanced', 'balanced_low_0', 'sequential' but found {device_map}."
                )
        elif isinstance(device_map, int):
            if device_map < 0:
                raise ValueError(
                    "You can't pass device_map as a negative int. If you want to put the model on the cpu, pass device_map = 'cpu' "
                )
            else:
                device_map = {"": device_map}

2329
2330
2331
2332
2333
2334
2335
        if device_map is not None:
            if low_cpu_mem_usage is None:
                low_cpu_mem_usage = True
            elif not low_cpu_mem_usage:
                raise ValueError("Passing along a `device_map` requires `low_cpu_mem_usage=True`")

        if low_cpu_mem_usage:
2336
            if device_map is not None:
2337
2338
                # The max memory utils require PyTorch >= 1.10 to have torch.cuda.mem_get_info.
                require_version_core("torch>=1.10")
2339
2340
2341
2342
2343
2344
2345
2346
2347

            if is_deepspeed_zero3_enabled():
                raise ValueError(
                    "DeepSpeed Zero-3 is not compatible with `low_cpu_mem_usage=True` or with passing a `device_map`."
                )
            elif not is_accelerate_available():
                raise ImportError(
                    "Using `low_cpu_mem_usage=True` or a `device_map` requires Accelerate: `pip install accelerate`"
                )
2348

Marc Sun's avatar
Marc Sun committed
2349
2350
2351
2352
2353
2354
2355
2356
        quantization_method_from_args = None
        if quantization_config is not None:
            quantization_method_from_args = getattr(
                quantization_config, "quant_method", QuantizationMethod.BITS_AND_BYTES
            )

        if quantization_config is None and (load_in_8bit or load_in_4bit):
            quantization_method_from_args = QuantizationMethod.BITS_AND_BYTES
2357
            quantization_config, kwargs = BitsAndBytesConfig.from_dict(
2358
2359
2360
                config_dict={"load_in_8bit": load_in_8bit, "load_in_4bit": load_in_4bit},
                return_unused_kwargs=True,
                **kwargs,
2361
            )
Marc Sun's avatar
Marc Sun committed
2362
        elif quantization_method_from_args == QuantizationMethod.BITS_AND_BYTES:
2363
            load_in_8bit = quantization_config.load_in_8bit
2364
            load_in_4bit = quantization_config.load_in_4bit
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375

            quantization_config_kwargs = {
                k: v for k, v in kwargs.items() if k in inspect.signature(BitsAndBytesConfig).parameters
            }

            if len(quantization_config_kwargs) > 0:
                raise ValueError(
                    "You can't pass `load_in_8bit` or any other `BitsAndBytesConfig` argument as a kwarg when passing "
                    "`quantization_config` argument at the same time."
                )

2376
        if load_in_8bit or load_in_4bit:
2377
2378
2379
2380
2381
2382
            if not (is_accelerate_available() and is_bitsandbytes_available()):
                raise ImportError(
                    "Using `load_in_8bit=True` requires Accelerate: `pip install accelerate` and the latest version of"
                    " bitsandbytes `pip install -i https://test.pypi.org/simple/ bitsandbytes` or"
                    " pip install bitsandbytes` "
                )
2383
2384

            if torch_dtype is None:
2385
                # We force the `dtype` to be float16, this is a requirement from `bitsandbytes`
2386
                logger.info(
2387
                    f"Overriding torch_dtype={torch_dtype} with `torch_dtype=torch.float16` due to "
2388
                    "requirements of `bitsandbytes` to enable model loading in 8-bit or 4-bit. "
2389
2390
                    "Pass your own torch_dtype to specify the dtype of the remaining non-linear layers or pass"
                    " torch_dtype=torch.float16 to remove this warning."
2391
                )
2392
                torch_dtype = torch.float16
2393

2394
            if device_map is None:
2395
2396
2397
2398
2399
2400
2401
2402
                if torch.cuda.is_available():
                    device_map = {"": torch.cuda.current_device()}
                else:
                    raise RuntimeError("No GPU found. A GPU is needed for quantization.")
                logger.info(
                    "The device_map was not initialized."
                    "Setting device_map to {'':torch.cuda.current_device()}."
                    "If you want to use the model for inference, please set device_map ='auto' "
2403
                )
2404
2405
2406
                if low_cpu_mem_usage is None:
                    low_cpu_mem_usage = True

2407
2408
            if from_tf or from_flax:
                raise ValueError(
2409
                    "Converting into 4-bit or 8-bit weights from tf/flax weights is currently not supported, please make"
2410
2411
2412
                    " sure the weights are in PyTorch format."
                )

2413
        from_pt = not (from_tf | from_flax)
2414
2415
2416
2417

        user_agent = {"file_type": "model", "framework": "pytorch", "from_auto_class": from_auto_class}
        if from_pipeline is not None:
            user_agent["using_pipeline"] = from_pipeline
thomwolf's avatar
thomwolf committed
2418

2419
2420
2421
2422
        if is_offline_mode() and not local_files_only:
            logger.info("Offline mode: forcing local_files_only=True")
            local_files_only = True

2423
2424
2425
        # Load config if we don't provide a configuration
        if not isinstance(config, PretrainedConfig):
            config_path = config if config is not None else pretrained_model_name_or_path
2426
            config, model_kwargs = cls.config_class.from_pretrained(
2427
2428
2429
                config_path,
                cache_dir=cache_dir,
                return_unused_kwargs=True,
2430
                force_download=force_download,
2431
                resume_download=resume_download,
2432
                proxies=proxies,
2433
                local_files_only=local_files_only,
2434
                token=token,
Julien Chaumond's avatar
Julien Chaumond committed
2435
                revision=revision,
2436
                subfolder=subfolder,
2437
2438
                _from_auto=from_auto_class,
                _from_pipeline=from_pipeline,
2439
                **kwargs,
2440
2441
2442
            )
        else:
            model_kwargs = kwargs
2443

Marc Sun's avatar
Marc Sun committed
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
        quantizer = None
        quantization_method_from_config = None
        if hasattr(config, "quantization_config"):
            quantization_method_from_config = config.quantization_config.get(
                "quant_method", QuantizationMethod.BITS_AND_BYTES
            )

        if quantization_method_from_config == QuantizationMethod.GPTQ and quantization_method_from_args is not None:
            loading_attr_dict = quantization_config.get_loading_attributes()
            for attr, val in loading_attr_dict.items():
                config.quantization_config[attr] = val
            quantization_method_from_args = None
            logger.warning(
                "You passed `quantization_config` to `from_pretrained` but the model you're loading already has a "
                "`quantization_config` attribute and has already quantized weights. However, loading attributes"
                " (e.g. disable_exllama, use_cuda_fp16) will be overwritten with the one you passed to `from_pretrained`. The rest will be ignored."
            )
        if (
            quantization_method_from_args == QuantizationMethod.GPTQ
            or quantization_method_from_config == QuantizationMethod.GPTQ
        ):
            if not torch.cuda.is_available():
                raise RuntimeError("GPU is required to quantize or run quantize model.")
            elif not (is_optimum_available() and is_auto_gptq_available()):
                raise ImportError(
                    "Loading GPTQ quantized model requires optimum library : `pip install optimum` and auto-gptq library 'pip install auto-gptq'"
                )
            else:
                # Need to protect the import
                from optimum.gptq import GPTQQuantizer
            if quantization_method_from_config == QuantizationMethod.GPTQ:
                quantization_config = GPTQConfig.from_dict(config.quantization_config)
                config.quantization_config = quantization_config
            logger.info(
                f"Overriding torch_dtype={torch_dtype} with `torch_dtype=torch.float16` due to "
                "requirements of `auto-gptq` to enable model quantization "
            )
            torch_dtype = torch.float16
            quantizer = GPTQQuantizer.from_dict(quantization_config.to_dict())

        if (
            is_8bit_serializable
            and quantization_method_from_args == QuantizationMethod.BITS_AND_BYTES
            and load_in_8bit
        ):
            if quantization_method_from_config == QuantizationMethod.BITS_AND_BYTES:
2490
2491
2492
2493
2494
2495
                logger.warning(
                    "You passed `quantization_config` to `from_pretrained` but the model you're loading already has a"
                    " `quantization_config` attribute. The `quantization_config` attribute will be overwritten with the"
                    " one you passed to `from_pretrained`."
                )
            config.quantization_config = quantization_config
Marc Sun's avatar
Marc Sun committed
2496
2497
2498
2499
2500
        elif (
            is_8bit_serializable
            and not load_in_8bit
            and quantization_method_from_config == QuantizationMethod.BITS_AND_BYTES
        ):
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
            quantization_config = config.quantization_config
            if isinstance(quantization_config, dict):
                quantization_config = BitsAndBytesConfig.from_dict(quantization_config, return_unused_kwargs=False)
            elif isinstance(quantization_config, BitsAndBytesConfig):
                pass
            else:
                raise ValueError(
                    f"Invalid type for `quantization_config`: {type(quantization_config)}. Should be a `dict` or a"
                    " `BitsAndBytesConfig` instance."
                )

            load_in_8bit = quantization_config.load_in_8bit

            if load_in_8bit:
2515
2516
                if torch_dtype is None:
                    torch_dtype = torch.float16
2517
                if device_map is None:
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
                    if torch.cuda.is_available():
                        device_map = {"": torch.cuda.current_device()}
                    else:
                        raise RuntimeError("No GPU found. A GPU is needed for quantization.")
                    logger.info(
                        "The device_map was not initialized."
                        "Setting device_map to {'':torch.cuda.current_device()}."
                        "If you want to use the model for inference, please set device_map ='auto' "
                    )
                    if low_cpu_mem_usage is None:
                        low_cpu_mem_usage = True
2529

Marc Sun's avatar
Marc Sun committed
2530
2531
2532
2533
2534
        elif (
            not is_8bit_serializable
            and not load_in_8bit
            and quantization_method_from_config == QuantizationMethod.BITS_AND_BYTES
        ):
2535
2536
2537
2538
2539
2540
            logger.warning(
                "Detected the presence of a `quantization_config` attribute in the model's configuration but you don't have the correct"
                " `bitsandbytes` version to support int8 serialization. Please install the latest version of `bitsandbytes` with "
                " `pip install --upgrade bitsandbytes`."
            )

2541
2542
2543
        if commit_hash is None:
            commit_hash = getattr(config, "_commit_hash", None)

Sylvain Gugger's avatar
Sylvain Gugger committed
2544
2545
2546
2547
        # This variable will flag if we're loading a sharded checkpoint. In this case the archive file is just the
        # index of the files.
        is_sharded = False
        sharded_metadata = None
thomwolf's avatar
thomwolf committed
2548
        # Load model
Yih-Dar's avatar
Yih-Dar committed
2549
2550
        loading_info = None

2551
2552
2553
2554
        # Keep in fp32 modules
        keep_in_fp32_modules = None
        use_keep_in_fp32_modules = False

thomwolf's avatar
thomwolf committed
2555
        if pretrained_model_name_or_path is not None:
2556
            pretrained_model_name_or_path = str(pretrained_model_name_or_path)
2557
2558
            is_local = os.path.isdir(pretrained_model_name_or_path)
            if is_local:
2559
2560
2561
                if from_tf and os.path.isfile(
                    os.path.join(pretrained_model_name_or_path, subfolder, TF_WEIGHTS_NAME + ".index")
                ):
2562
                    # Load from a TF 1.0 checkpoint in priority if from_tf
2563
2564
2565
2566
                    archive_file = os.path.join(pretrained_model_name_or_path, subfolder, TF_WEIGHTS_NAME + ".index")
                elif from_tf and os.path.isfile(
                    os.path.join(pretrained_model_name_or_path, subfolder, TF2_WEIGHTS_NAME)
                ):
2567
                    # Load from a TF 2.0 checkpoint in priority if from_tf
2568
2569
2570
2571
                    archive_file = os.path.join(pretrained_model_name_or_path, subfolder, TF2_WEIGHTS_NAME)
                elif from_flax and os.path.isfile(
                    os.path.join(pretrained_model_name_or_path, subfolder, FLAX_WEIGHTS_NAME)
                ):
2572
                    # Load from a Flax checkpoint in priority if from_flax
2573
                    archive_file = os.path.join(pretrained_model_name_or_path, subfolder, FLAX_WEIGHTS_NAME)
2574
                elif use_safetensors is not False and os.path.isfile(
2575
                    os.path.join(pretrained_model_name_or_path, subfolder, _add_variant(SAFE_WEIGHTS_NAME, variant))
2576
2577
                ):
                    # Load from a safetensors checkpoint
2578
2579
2580
                    archive_file = os.path.join(
                        pretrained_model_name_or_path, subfolder, _add_variant(SAFE_WEIGHTS_NAME, variant)
                    )
2581
                elif use_safetensors is not False and os.path.isfile(
2582
2583
2584
                    os.path.join(
                        pretrained_model_name_or_path, subfolder, _add_variant(SAFE_WEIGHTS_INDEX_NAME, variant)
                    )
2585
2586
                ):
                    # Load from a sharded safetensors checkpoint
2587
2588
2589
                    archive_file = os.path.join(
                        pretrained_model_name_or_path, subfolder, _add_variant(SAFE_WEIGHTS_INDEX_NAME, variant)
                    )
2590
                    is_sharded = True
2591
2592
2593
                elif os.path.isfile(
                    os.path.join(pretrained_model_name_or_path, subfolder, _add_variant(WEIGHTS_NAME, variant))
                ):
thomwolf's avatar
thomwolf committed
2594
                    # Load from a PyTorch checkpoint
2595
2596
2597
2598
2599
2600
                    archive_file = os.path.join(
                        pretrained_model_name_or_path, subfolder, _add_variant(WEIGHTS_NAME, variant)
                    )
                elif os.path.isfile(
                    os.path.join(pretrained_model_name_or_path, subfolder, _add_variant(WEIGHTS_INDEX_NAME, variant))
                ):
Sylvain Gugger's avatar
Sylvain Gugger committed
2601
                    # Load from a sharded PyTorch checkpoint
2602
2603
2604
                    archive_file = os.path.join(
                        pretrained_model_name_or_path, subfolder, _add_variant(WEIGHTS_INDEX_NAME, variant)
                    )
Sylvain Gugger's avatar
Sylvain Gugger committed
2605
                    is_sharded = True
2606
2607
                # At this stage we don't have a weight file so we will raise an error.
                elif os.path.isfile(
2608
2609
                    os.path.join(pretrained_model_name_or_path, subfolder, TF_WEIGHTS_NAME + ".index")
                ) or os.path.isfile(os.path.join(pretrained_model_name_or_path, subfolder, TF2_WEIGHTS_NAME)):
2610
                    raise EnvironmentError(
2611
2612
2613
                        f"Error no file named {_add_variant(WEIGHTS_NAME, variant)} found in directory"
                        f" {pretrained_model_name_or_path} but there is a file for TensorFlow weights. Use"
                        " `from_tf=True` to load this model from those weights."
2614
                    )
2615
                elif os.path.isfile(os.path.join(pretrained_model_name_or_path, subfolder, FLAX_WEIGHTS_NAME)):
2616
                    raise EnvironmentError(
2617
2618
2619
                        f"Error no file named {_add_variant(WEIGHTS_NAME, variant)} found in directory"
                        f" {pretrained_model_name_or_path} but there is a file for Flax weights. Use `from_flax=True`"
                        " to load this model from those weights."
2620
                    )
2621
2622
2623
2624
2625
                elif use_safetensors:
                    raise EnvironmentError(
                        f"Error no file named {_add_variant(SAFE_WEIGHTS_NAME, variant)} found in directory"
                        f" {pretrained_model_name_or_path}."
                    )
thomwolf's avatar
thomwolf committed
2626
                else:
2627
                    raise EnvironmentError(
2628
2629
2630
                        f"Error no file named {_add_variant(WEIGHTS_NAME, variant)}, {TF2_WEIGHTS_NAME},"
                        f" {TF_WEIGHTS_NAME + '.index'} or {FLAX_WEIGHTS_NAME} found in directory"
                        f" {pretrained_model_name_or_path}."
2631
                    )
2632
            elif os.path.isfile(os.path.join(subfolder, pretrained_model_name_or_path)):
2633
                archive_file = pretrained_model_name_or_path
2634
                is_local = True
2635
            elif os.path.isfile(os.path.join(subfolder, pretrained_model_name_or_path + ".index")):
2636
2637
2638
2639
2640
                if not from_tf:
                    raise ValueError(
                        f"We found a TensorFlow checkpoint at {pretrained_model_name_or_path + '.index'}, please set "
                        "from_tf to True to load from this checkpoint."
                    )
2641
                archive_file = os.path.join(subfolder, pretrained_model_name_or_path + ".index")
2642
                is_local = True
2643
            elif is_remote_url(pretrained_model_name_or_path):
2644
                filename = pretrained_model_name_or_path
2645
                resolved_archive_file = download_url(pretrained_model_name_or_path)
2646
            else:
2647
2648
2649
2650
2651
                # set correct filename
                if from_tf:
                    filename = TF2_WEIGHTS_NAME
                elif from_flax:
                    filename = FLAX_WEIGHTS_NAME
2652
                elif use_safetensors is not False:
2653
                    filename = _add_variant(SAFE_WEIGHTS_NAME, variant)
2654
                else:
2655
                    filename = _add_variant(WEIGHTS_NAME, variant)
2656

2657
2658
                try:
                    # Load from URL or cache if already cached
2659
2660
2661
2662
2663
2664
                    cached_file_kwargs = {
                        "cache_dir": cache_dir,
                        "force_download": force_download,
                        "proxies": proxies,
                        "resume_download": resume_download,
                        "local_files_only": local_files_only,
2665
                        "token": token,
2666
2667
2668
2669
2670
2671
                        "user_agent": user_agent,
                        "revision": revision,
                        "subfolder": subfolder,
                        "_raise_exceptions_for_missing_entries": False,
                        "_commit_hash": commit_hash,
                    }
2672
                    resolved_archive_file = cached_file(pretrained_model_name_or_path, filename, **cached_file_kwargs)
2673

2674
                    # Since we set _raise_exceptions_for_missing_entries=False, we don't get an exception but a None
2675
                    # result when internet is up, the repo and revision exist, but the file does not.
2676
                    if resolved_archive_file is None and filename == _add_variant(SAFE_WEIGHTS_NAME, variant):
2677
2678
                        # Maybe the checkpoint is sharded, we try to grab the index name in this case.
                        resolved_archive_file = cached_file(
2679
2680
2681
                            pretrained_model_name_or_path,
                            _add_variant(SAFE_WEIGHTS_INDEX_NAME, variant),
                            **cached_file_kwargs,
2682
2683
2684
                        )
                        if resolved_archive_file is not None:
                            is_sharded = True
2685
2686
2687
2688
                        elif use_safetensors:
                            raise EnvironmentError(
                                f" {_add_variant(SAFE_WEIGHTS_NAME, variant)} or {_add_variant(SAFE_WEIGHTS_INDEX_NAME, variant)} and thus cannot be loaded with `safetensors`. Please make sure that the model has been saved with `safe_serialization=True` or do not set `use_safetensors=True`."
                            )
2689
2690
                        else:
                            # This repo has no safetensors file of any kind, we switch to PyTorch.
2691
                            filename = _add_variant(WEIGHTS_NAME, variant)
2692
                            resolved_archive_file = cached_file(
2693
                                pretrained_model_name_or_path, filename, **cached_file_kwargs
2694
                            )
2695
                    if resolved_archive_file is None and filename == _add_variant(WEIGHTS_NAME, variant):
Sylvain Gugger's avatar
Sylvain Gugger committed
2696
                        # Maybe the checkpoint is sharded, we try to grab the index name in this case.
2697
                        resolved_archive_file = cached_file(
2698
2699
2700
                            pretrained_model_name_or_path,
                            _add_variant(WEIGHTS_INDEX_NAME, variant),
                            **cached_file_kwargs,
2701
                        )
2702
2703
2704
                        if resolved_archive_file is not None:
                            is_sharded = True
                    if resolved_archive_file is None:
Sylvain Gugger's avatar
Sylvain Gugger committed
2705
2706
2707
2708
2709
                        # Otherwise, maybe there is a TF or Flax model file.  We try those to give a helpful error
                        # message.
                        has_file_kwargs = {
                            "revision": revision,
                            "proxies": proxies,
2710
                            "token": token,
Sylvain Gugger's avatar
Sylvain Gugger committed
2711
2712
2713
                        }
                        if has_file(pretrained_model_name_or_path, TF2_WEIGHTS_NAME, **has_file_kwargs):
                            raise EnvironmentError(
Sylvain Gugger's avatar
Sylvain Gugger committed
2714
                                f"{pretrained_model_name_or_path} does not appear to have a file named"
2715
2716
                                f" {_add_variant(WEIGHTS_NAME, variant)} but there is a file for TensorFlow weights."
                                " Use `from_tf=True` to load this model from those weights."
Sylvain Gugger's avatar
Sylvain Gugger committed
2717
2718
2719
                            )
                        elif has_file(pretrained_model_name_or_path, FLAX_WEIGHTS_NAME, **has_file_kwargs):
                            raise EnvironmentError(
Sylvain Gugger's avatar
Sylvain Gugger committed
2720
                                f"{pretrained_model_name_or_path} does not appear to have a file named"
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
                                f" {_add_variant(WEIGHTS_NAME, variant)} but there is a file for Flax weights. Use"
                                " `from_flax=True` to load this model from those weights."
                            )
                        elif variant is not None and has_file(
                            pretrained_model_name_or_path, WEIGHTS_NAME, **has_file_kwargs
                        ):
                            raise EnvironmentError(
                                f"{pretrained_model_name_or_path} does not appear to have a file named"
                                f" {_add_variant(WEIGHTS_NAME, variant)} but there is a file without the variant"
                                f" {variant}. Use `variant=None` to load this model from those weights."
Sylvain Gugger's avatar
Sylvain Gugger committed
2731
2732
2733
                            )
                        else:
                            raise EnvironmentError(
2734
2735
2736
                                f"{pretrained_model_name_or_path} does not appear to have a file named"
                                f" {_add_variant(WEIGHTS_NAME, variant)}, {TF2_WEIGHTS_NAME}, {TF_WEIGHTS_NAME} or"
                                f" {FLAX_WEIGHTS_NAME}."
Sylvain Gugger's avatar
Sylvain Gugger committed
2737
                            )
2738
2739
2740
2741
2742
2743
                except EnvironmentError:
                    # Raise any environment error raise by `cached_file`. It will have a helpful error message adapted
                    # to the original exception.
                    raise
                except Exception:
                    # For any other exception, we throw a generic error.
2744
                    raise EnvironmentError(
2745
2746
2747
                        f"Can't load the model for '{pretrained_model_name_or_path}'. If you were trying to load it"
                        " from 'https://huggingface.co/models', make sure you don't have a local directory with the"
                        f" same name. Otherwise, make sure '{pretrained_model_name_or_path}' is the correct path to a"
2748
2749
                        f" directory containing a file named {_add_variant(WEIGHTS_NAME, variant)},"
                        f" {TF2_WEIGHTS_NAME}, {TF_WEIGHTS_NAME} or {FLAX_WEIGHTS_NAME}."
2750
                    )
2751

2752
            if is_local:
2753
                logger.info(f"loading weights file {archive_file}")
2754
                resolved_archive_file = archive_file
2755
            else:
2756
                logger.info(f"loading weights file {filename} from cache at {resolved_archive_file}")
2757
        else:
thomwolf's avatar
thomwolf committed
2758
            resolved_archive_file = None
2759

Sylvain Gugger's avatar
Sylvain Gugger committed
2760
2761
        # We'll need to download and cache each checkpoint shard if the checkpoint is sharded.
        if is_sharded:
2762
            # rsolved_archive_file becomes a list of files that point to the different checkpoint shards in this case.
Sylvain Gugger's avatar
Sylvain Gugger committed
2763
2764
2765
2766
2767
2768
2769
2770
            resolved_archive_file, sharded_metadata = get_checkpoint_shard_files(
                pretrained_model_name_or_path,
                resolved_archive_file,
                cache_dir=cache_dir,
                force_download=force_download,
                proxies=proxies,
                resume_download=resume_download,
                local_files_only=local_files_only,
2771
                token=token,
Sylvain Gugger's avatar
Sylvain Gugger committed
2772
2773
                user_agent=user_agent,
                revision=revision,
2774
                subfolder=subfolder,
2775
                _commit_hash=commit_hash,
Sylvain Gugger's avatar
Sylvain Gugger committed
2776
2777
            )

2778
2779
        # load pt weights early so that we know which dtype to init the model under
        if from_pt:
2780
            if not is_sharded and state_dict is None:
Sylvain Gugger's avatar
Sylvain Gugger committed
2781
2782
                # Time to load the checkpoint
                state_dict = load_state_dict(resolved_archive_file)
2783

2784
2785
2786
            # set dtype to instantiate the model under:
            # 1. If torch_dtype is not None, we use that dtype
            # 2. If torch_dtype is "auto", we auto-detect dtype from the loaded state_dict, by checking its first
2787
            #    weights entry that is of a floating type - we assume all floating dtype weights are of the same dtype
2788
2789
            # we also may have config.torch_dtype available, but we won't rely on it till v5
            dtype_orig = None
2790

2791
2792
2793
            if torch_dtype is not None:
                if isinstance(torch_dtype, str):
                    if torch_dtype == "auto":
2794
2795
2796
                        if hasattr(config, "torch_dtype") and config.torch_dtype is not None:
                            torch_dtype = config.torch_dtype
                            logger.info(f"Will use torch_dtype={torch_dtype} as defined in model's config object")
Sylvain Gugger's avatar
Sylvain Gugger committed
2797
                        else:
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
                            if is_sharded and "dtype" in sharded_metadata:
                                torch_dtype = sharded_metadata["dtype"]
                            elif not is_sharded:
                                torch_dtype = get_state_dict_dtype(state_dict)
                            else:
                                one_state_dict = load_state_dict(resolved_archive_file[0])
                                torch_dtype = get_state_dict_dtype(one_state_dict)
                                del one_state_dict  # free CPU memory
                            logger.info(
                                "Since the `torch_dtype` attribute can't be found in model's config object, "
                                "will use torch_dtype={torch_dtype} as derived from model's weights"
                            )
2810
2811
                    else:
                        raise ValueError(
2812
                            f'`torch_dtype` can be either `torch.dtype` or `"auto"`, but received {torch_dtype}'
2813
2814
2815
                        )
                dtype_orig = cls._set_default_torch_dtype(torch_dtype)

2816
2817
            # Check if `_keep_in_fp32_modules` is not None
            use_keep_in_fp32_modules = (
2818
2819
2820
                (cls._keep_in_fp32_modules is not None)
                and is_accelerate_available()
                and (torch_dtype == torch.float16 or load_in_4bit or load_in_8bit)
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
            )
            if (
                (cls._keep_in_fp32_modules is not None)
                and not is_accelerate_available()
                and torch_dtype == torch.float16
            ):
                logger.warning(
                    "For stability purposes, it is recommended to have accelerate installed when using this model in"
                    " torch.float16, please install it with `pip install accelerate`"
                )

2832
2833
2834
            if is_sharded:
                loaded_state_dict_keys = sharded_metadata["all_checkpoint_keys"]
            else:
2835
                loaded_state_dict_keys = list(state_dict.keys())
2836
            if low_cpu_mem_usage or use_keep_in_fp32_modules:
2837
                state_dict = None
2838

2839
2840
        config.name_or_path = pretrained_model_name_or_path

2841
        # Instantiate model.
2842
2843
        init_contexts = [no_init_weights(_enable=_fast_init)]

2844
2845
2846
2847
        if is_deepspeed_zero3_enabled():
            import deepspeed

            logger.info("Detected DeepSpeed ZeRO-3: activating zero.init() for this model")
2848
            init_contexts = [deepspeed.zero.Init(config_dict_or_path=deepspeed_config())] + init_contexts
2849
        elif load_in_8bit or load_in_4bit or low_cpu_mem_usage:
2850
2851
2852
2853
2854
            init_contexts.append(init_empty_weights())

        with ContextManagers(init_contexts):
            model = cls(config, *model_args, **model_kwargs)

2855
2856
2857
2858
2859
2860
2861
        # Check first if we are `from_pt`
        if use_keep_in_fp32_modules:
            low_cpu_mem_usage = True
            keep_in_fp32_modules = model._keep_in_fp32_modules
        else:
            keep_in_fp32_modules = []

2862
2863
        if load_in_8bit or load_in_4bit:
            from .utils.bitsandbytes import get_keys_to_not_convert, replace_with_bnb_linear
2864

2865
            llm_int8_skip_modules = quantization_config.llm_int8_skip_modules
2866
            load_in_8bit_fp32_cpu_offload = quantization_config.llm_int8_enable_fp32_cpu_offload
2867
2868
2869
2870
            if load_in_8bit:
                logger.info("Detected 8-bit loading: activating 8-bit loading for this model")
            else:
                logger.info("Detected 4-bit loading: activating 4-bit loading for this model")
2871

2872
            # We keep some modules such as the lm_head in their original dtype for numerical stability reasons
2873
            if llm_int8_skip_modules is None:
2874
2875
                modules_to_not_convert = get_keys_to_not_convert(model)
            else:
2876
                modules_to_not_convert = llm_int8_skip_modules
2877
2878
2879
2880
2881
2882

            if not isinstance(modules_to_not_convert, list):
                modules_to_not_convert = [modules_to_not_convert]

            modules_to_not_convert.extend(keep_in_fp32_modules)

2883
2884
2885
2886
2887
2888
2889
            # Extend the modules to not convert to keys that are supposed to be offloaded to `cpu` or `disk`
            if isinstance(device_map, dict) and len(device_map.keys()) > 1:
                keys_on_cpu = [key for key, value in device_map.items() if value in ["disk", "cpu"]]

                if len(keys_on_cpu) > 0 and not load_in_8bit_fp32_cpu_offload:
                    raise ValueError(
                        "If you want to offload some keys to `cpu` or `disk`, you need to set "
Younes Belkada's avatar
Younes Belkada committed
2890
                        "`llm_int8_enable_fp32_cpu_offload=True`. Note that these modules will not be "
2891
2892
2893
2894
2895
                        " converted to 8-bit but kept in 32-bit."
                    )

                modules_to_not_convert.extend(keys_on_cpu)

2896
            supports_4bit = version.parse(importlib.metadata.version("bitsandbytes")) >= version.parse("0.39.0")
2897
2898
2899
2900
2901
2902
2903
2904
2905

            if load_in_4bit and not supports_4bit:
                raise ValueError(
                    "You have a version of `bitsandbytes` that is not compatible with 4bit inference and training"
                    " make sure you have the latest version of `bitsandbytes` installed"
                )

            model = replace_with_bnb_linear(
                model, modules_to_not_convert=modules_to_not_convert, quantization_config=quantization_config
2906
            )
2907
            # training in 8-bit is only available in 0.37.0+
2908
            model._is_quantized_training_enabled = version.parse(
2909
                importlib.metadata.version("bitsandbytes")
2910
            ) >= version.parse("0.37.0")
2911

2912
2913
2914
            model.config.quantization_config = quantization_config
            model.is_8bit_serializable = is_8bit_serializable

2915
2916
2917
        if load_in_8bit and torch_dtype is None:
            logger.warning(
                "You are loading your model in 8bit but you did not specify a `torch_dtype` attribute."
2918
2919
                "All non-linear modules will be loaded in full precision."
                " If you want to load the other modules in other precision, please specify a `torch_dtype` attribute."
2920
            )
Marc Sun's avatar
Marc Sun committed
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
        if quantization_method_from_config == QuantizationMethod.GPTQ:
            model = quantizer.convert_model(model)
            model._is_quantized_training_enabled = True

        if quantization_method_from_config is not None:
            model.quantization_method = quantization_method_from_config
        elif quantization_method_from_args is not None:
            model.quantization_method = quantization_method_from_args
        if hasattr(model, "quantization_method"):
            model.is_quantized = True
2931

2932
        if isinstance(device_map, str):
2933
            special_dtypes = {}
2934
            if load_in_8bit or load_in_4bit:
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
                special_dtypes.update(
                    {
                        name: torch_dtype
                        for name, _ in model.named_parameters()
                        if any(m in name for m in modules_to_not_convert)
                    }
                )

            special_dtypes.update(
                {
                    name: torch.float32
                    for name, _ in model.named_parameters()
                    if any(m in name for m in keep_in_fp32_modules)
                }
            )

2951
2952
2953
            target_dtype = torch_dtype

            if load_in_4bit:
2954
                if version.parse(importlib.metadata.version("accelerate")) > version.parse("0.19.0"):
2955
2956
2957
2958
2959
2960
2961
                    from accelerate.utils import CustomDtype

                    target_dtype = CustomDtype.INT4
                else:
                    raise ValueError(
                        "You are using `device_map='auto'` on a 4bit loaded version of the model. To automatically compute"
                        " the appropriate device map, you should upgrade your `accelerate` library,"
2962
                        "`pip install --upgrade accelerate` or install it from source to support fp4 auto device map"
2963
2964
2965
2966
2967
                        "calculation. You may encounter unexpected behavior, or pass your own device map"
                    )
            elif load_in_8bit:
                target_dtype = torch.int8

2968
            if model._no_split_modules is None:
2969
2970
2971
2972
                raise ValueError(
                    f"{model.__class__.__name__} does not support `device_map='{device_map}'`. To implement support, the model"
                    "class needs to implement the `_no_split_modules` attribute."
                )
2973
            no_split_modules = model._no_split_modules
2974
2975
2976
2977
2978
            if device_map not in ["auto", "balanced", "balanced_low_0", "sequential"]:
                raise ValueError(
                    "If passing a string for `device_map`, please choose 'auto', 'balanced', 'balanced_low_0' or "
                    "'sequential'."
                )
2979

2980
            device_map_kwargs = {"no_split_module_classes": no_split_modules}
2981
            if "special_dtypes" in inspect.signature(infer_auto_device_map).parameters:
2982
                device_map_kwargs["special_dtypes"] = special_dtypes
2983
            elif len(special_dtypes) > 0:
2984
                logger.warning(
2985
2986
2987
                    "This model has some weights that should be kept in higher precision, you need to upgrade "
                    "`accelerate` to properly deal with them (`pip install --upgrade accelerate`)."
                )
2988
            if device_map != "sequential":
2989
2990
                max_memory = get_balanced_memory(
                    model,
2991
                    dtype=target_dtype,
2992
                    low_zero=(device_map == "balanced_low_0"),
2993
                    max_memory=max_memory,
2994
                    **device_map_kwargs,
2995
                )
2996
            device_map_kwargs["max_memory"] = max_memory
2997
2998
            # Make sure tied weights are tied before creating the device map.
            model.tie_weights()
2999
            device_map = infer_auto_device_map(model, dtype=target_dtype, **device_map_kwargs)
3000

3001
            if load_in_8bit or load_in_4bit:
3002
                # The LM head / tied weights or any last module can stay on disk / CPU
3003
                device_map_without_lm_head = {
3004
                    key: device_map[key] for key in device_map.keys() if key not in modules_to_not_convert
3005
3006
                }
                if "cpu" in device_map_without_lm_head.values() or "disk" in device_map_without_lm_head.values():
3007
3008
3009
                    raise ValueError(
                        """
                        Some modules are dispatched on the CPU or the disk. Make sure you have enough GPU RAM to fit
3010
3011
3012
3013
3014
                        the quantized model. If you want to dispatch the model on the CPU or the disk while keeping
                        these modules in 32-bit, you need to set `load_in_8bit_fp32_cpu_offload=True` and pass a custom
                        `device_map` to `from_pretrained`. Check
                        https://huggingface.co/docs/transformers/main/en/main_classes/quantization#offload-between-cpu-and-gpu
                        for more details.
3015
3016
                        """
                    )
3017
3018
                del device_map_without_lm_head

3019
3020
3021
3022
        elif device_map is not None:
            model.tie_weights()
            tied_params = find_tied_parameters(model)
            # check if we don't have tied param in different devices
3023
            check_tied_parameters_on_same_device(tied_params, device_map)
3024

3025
        if from_tf:
3026
            if resolved_archive_file.endswith(".index"):
3027
3028
3029
3030
3031
                # Load from a TensorFlow 1.X checkpoint - provided by original authors
                model = cls.load_tf_weights(model, config, resolved_archive_file[:-6])  # Remove the '.index'
            else:
                # Load from our TensorFlow 2.0 checkpoints
                try:
3032
                    from .modeling_tf_pytorch_utils import load_tf2_checkpoint_in_pytorch_model
3033

Yih-Dar's avatar
Yih-Dar committed
3034
3035
3036
                    model, loading_info = load_tf2_checkpoint_in_pytorch_model(
                        model, resolved_archive_file, allow_missing_keys=True, output_loading_info=True
                    )
3037
                except ImportError:
3038
                    logger.error(
Sylvain Gugger's avatar
Sylvain Gugger committed
3039
3040
3041
                        "Loading a TensorFlow model in PyTorch, requires both PyTorch and TensorFlow to be installed."
                        " Please see https://pytorch.org/ and https://www.tensorflow.org/install/ for installation"
                        " instructions."
3042
                    )
3043
                    raise
3044
3045
3046
3047
3048
3049
3050
        elif from_flax:
            try:
                from .modeling_flax_pytorch_utils import load_flax_checkpoint_in_pytorch_model

                model = load_flax_checkpoint_in_pytorch_model(model, resolved_archive_file)
            except ImportError:
                logger.error(
Sylvain Gugger's avatar
Sylvain Gugger committed
3051
3052
3053
                    "Loading a Flax model in PyTorch, requires both PyTorch and Flax to be installed. Please see"
                    " https://pytorch.org/ and https://flax.readthedocs.io/en/latest/installation.html for"
                    " installation instructions."
3054
3055
                )
                raise
3056
        elif from_pt:
3057
3058
3059
3060
            # restore default dtype
            if dtype_orig is not None:
                torch.set_default_dtype(dtype_orig)

Sylvain Gugger's avatar
Sylvain Gugger committed
3061
3062
3063
3064
3065
3066
3067
3068
            (
                model,
                missing_keys,
                unexpected_keys,
                mismatched_keys,
                offload_index,
                error_msgs,
            ) = cls._load_pretrained_model(
3069
3070
3071
3072
3073
3074
3075
3076
3077
                model,
                state_dict,
                loaded_state_dict_keys,  # XXX: rename?
                resolved_archive_file,
                pretrained_model_name_or_path,
                ignore_mismatched_sizes=ignore_mismatched_sizes,
                sharded_metadata=sharded_metadata,
                _fast_init=_fast_init,
                low_cpu_mem_usage=low_cpu_mem_usage,
3078
3079
3080
3081
                device_map=device_map,
                offload_folder=offload_folder,
                offload_state_dict=offload_state_dict,
                dtype=torch_dtype,
Marc Sun's avatar
Marc Sun committed
3082
                is_quantized=(getattr(model, "quantization_method", None) == QuantizationMethod.BITS_AND_BYTES),
3083
                keep_in_fp32_modules=keep_in_fp32_modules,
3084
            )
3085

3086
        model.is_loaded_in_4bit = load_in_4bit
Younes Belkada's avatar
Younes Belkada committed
3087
        model.is_loaded_in_8bit = load_in_8bit
3088

3089
3090
        # make sure token embedding weights are still tied if needed
        model.tie_weights()
3091

3092
        # Set model in evaluation mode to deactivate DropOut modules by default
3093
3094
        model.eval()

3095
        # If it is a model with generation capabilities, attempt to load the generation config
3096
        if model.can_generate() and pretrained_model_name_or_path is not None:
3097
3098
3099
3100
3101
3102
3103
3104
            try:
                model.generation_config = GenerationConfig.from_pretrained(
                    pretrained_model_name_or_path,
                    cache_dir=cache_dir,
                    force_download=force_download,
                    resume_download=resume_download,
                    proxies=proxies,
                    local_files_only=local_files_only,
3105
                    token=token,
3106
3107
3108
3109
3110
3111
                    revision=revision,
                    subfolder=subfolder,
                    _from_auto=from_auto_class,
                    _from_pipeline=from_pipeline,
                    **kwargs,
                )
3112
            except OSError:
3113
3114
3115
3116
3117
                logger.info(
                    "Generation config file not found, using a generation config created from the model config."
                )
                pass

3118
3119
        # Dispatch model with hooks on all devices if necessary
        if device_map is not None:
3120
3121
3122
3123
3124
            device_map_kwargs = {
                "device_map": device_map,
                "offload_dir": offload_folder,
                "offload_index": offload_index,
            }
3125
            if "skip_keys" in inspect.signature(dispatch_model).parameters:
3126
3127
                device_map_kwargs["skip_keys"] = model._skip_keys_device_placement
            dispatch_model(model, **device_map_kwargs)
3128

Marc Sun's avatar
Marc Sun committed
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
        if quantization_method_from_args == QuantizationMethod.GPTQ:
            if quantization_config.tokenizer is None:
                quantization_config.tokenizer = pretrained_model_name_or_path
            if cls.main_input_name != "input_ids":
                raise RuntimeError("We can only quantize pure text model.")
            quantizer.quantize_model(model, quantization_config.tokenizer)
            model.config.quantization_config = GPTQConfig.from_dict(quantizer.to_dict())
            model._is_quantized_training_enabled = True
        if quantization_method_from_config == QuantizationMethod.GPTQ:
            model = quantizer.post_init_model(model)

thomwolf's avatar
thomwolf committed
3140
        if output_loading_info:
Yih-Dar's avatar
Yih-Dar committed
3141
3142
3143
3144
3145
3146
3147
            if loading_info is None:
                loading_info = {
                    "missing_keys": missing_keys,
                    "unexpected_keys": unexpected_keys,
                    "mismatched_keys": mismatched_keys,
                    "error_msgs": error_msgs,
                }
thomwolf's avatar
thomwolf committed
3148
3149
            return model, loading_info

3150
3151
        return model

3152
    @classmethod
Sylvain Gugger's avatar
Sylvain Gugger committed
3153
3154
3155
3156
    def _load_pretrained_model(
        cls,
        model,
        state_dict,
3157
        loaded_keys,
Sylvain Gugger's avatar
Sylvain Gugger committed
3158
3159
3160
3161
3162
        resolved_archive_file,
        pretrained_model_name_or_path,
        ignore_mismatched_sizes=False,
        sharded_metadata=None,
        _fast_init=True,
3163
        low_cpu_mem_usage=False,
3164
3165
        device_map=None,
        offload_folder=None,
3166
        offload_state_dict=None,
3167
        dtype=None,
3168
        is_quantized=False,
3169
        keep_in_fp32_modules=None,
3170
    ):
Sylvain Gugger's avatar
Sylvain Gugger committed
3171
        is_safetensors = False
3172
3173
        if is_quantized:
            from .utils.bitsandbytes import set_module_quantized_tensor_to_device
3174

Sylvain Gugger's avatar
Sylvain Gugger committed
3175
        if device_map is not None and "disk" in device_map.values():
Sylvain Gugger's avatar
Sylvain Gugger committed
3176
3177
3178
3179
3180
            archive_file = (
                resolved_archive_file[0] if isinstance(resolved_archive_file, (list, tuple)) else resolved_archive_file
            )
            is_safetensors = archive_file.endswith(".safetensors")
            if offload_folder is None and not is_safetensors:
Sylvain Gugger's avatar
Sylvain Gugger committed
3181
3182
                raise ValueError(
                    "The current `device_map` had weights offloaded to the disk. Please provide an `offload_folder`"
Sylvain Gugger's avatar
Sylvain Gugger committed
3183
3184
                    " for them. Alternatively, make sure you have `safetensors` installed if the model you are using"
                    " offers the weights in this format."
Sylvain Gugger's avatar
Sylvain Gugger committed
3185
                )
Sylvain Gugger's avatar
Sylvain Gugger committed
3186
3187
            if offload_folder is not None:
                os.makedirs(offload_folder, exist_ok=True)
3188
3189
3190
            if offload_state_dict is None:
                offload_state_dict = True

3191
        is_sharded_safetensors = is_safetensors and sharded_metadata is not None
Patrick von Platen's avatar
Patrick von Platen committed
3192
3193
3194
3195

        # tie the model weights before retrieving the state_dict
        model.tie_weights()

3196
        # Retrieve missing & unexpected_keys
3197
3198
        model_state_dict = model.state_dict()
        expected_keys = list(model_state_dict.keys())
3199
3200
        prefix = model.base_model_prefix

Sylvain Gugger's avatar
Sylvain Gugger committed
3201
3202
3203
3204
3205
3206
3207
        def _fix_key(key):
            if "beta" in key:
                return key.replace("beta", "bias")
            if "gamma" in key:
                return key.replace("gamma", "weight")
            return key

3208
        original_loaded_keys = loaded_keys
Sylvain Gugger's avatar
Sylvain Gugger committed
3209
3210
        loaded_keys = [_fix_key(key) for key in loaded_keys]

3211
3212
3213
3214
3215
3216
        if len(prefix) > 0:
            has_prefix_module = any(s.startswith(prefix) for s in loaded_keys)
            expects_prefix_module = any(s.startswith(prefix) for s in expected_keys)
        else:
            has_prefix_module = False
            expects_prefix_module = False
Patrick von Platen's avatar
Patrick von Platen committed
3217
3218
3219

        # key re-naming operations are never done on the keys
        # that are loaded, but always on the keys of the newly initialized model
3220
3221
        remove_prefix_from_model = not has_prefix_module and expects_prefix_module
        add_prefix_to_model = has_prefix_module and not expects_prefix_module
3222

3223
        if remove_prefix_from_model:
3224
3225
3226
            _prefix = f"{prefix}."
            expected_keys_not_prefixed = [s for s in expected_keys if not s.startswith(_prefix)]
            expected_keys = [s[len(_prefix) :] if s.startswith(_prefix) else s for s in expected_keys]
3227
        elif add_prefix_to_model:
3228
3229
3230
            expected_keys = [".".join([prefix, s]) for s in expected_keys]

        missing_keys = list(set(expected_keys) - set(loaded_keys))
Sylvain Gugger's avatar
Sylvain Gugger committed
3231
3232
3233
3234
3235
3236
3237
3238
3239
        unexpected_keys = set(loaded_keys) - set(expected_keys)
        # Remove nonpersistent buffers from unexpected keys: they are not in the state dict but will be in the model
        # buffers
        model_buffers = {n for n, _ in model.named_buffers()}
        if remove_prefix_from_model:
            model_buffers = {key[len(_prefix) :] if key.startswith(_prefix) else key for key in model_buffers}
        elif add_prefix_to_model:
            model_buffers = {".".join([prefix, key]) for key in model_buffers}
        unexpected_keys = list(unexpected_keys - model_buffers)
3240

3241
3242
3243
3244
3245
        if device_map is None:
            ptrs = collections.defaultdict(list)
            for name, tensor in model.state_dict().items():
                id_tensor = id_tensor_storage(tensor)
                ptrs[id_tensor].append(name)
Sylvain Gugger's avatar
Sylvain Gugger committed
3246

3247
3248
3249
3250
3251
            # These are all the pointers of shared tensors.
            tied_params = [names for _, names in ptrs.items() if len(names) > 1]
        else:
            # id function doesn't work for meta tensor so we need this function
            tied_params = find_tied_parameters(model)
Sylvain Gugger's avatar
Sylvain Gugger committed
3252
3253

        for group in tied_params:
Sylvain Gugger's avatar
Sylvain Gugger committed
3254
3255
3256
3257
            if remove_prefix_from_model:
                group = [key[len(_prefix) :] if key.startswith(_prefix) else key for key in group]
            elif add_prefix_to_model:
                group = [".".join([prefix, key]) for key in group]
Sylvain Gugger's avatar
Sylvain Gugger committed
3258
3259
3260
            missing_in_group = [k for k in missing_keys if k in group]
            if len(missing_in_group) > 0 and len(missing_in_group) < len(group):
                missing_keys = [k for k in missing_keys if k not in missing_in_group]
3261

3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
        # Some models may have keys that are not in the state by design, removing them before needlessly warning
        # the user.
        if cls._keys_to_ignore_on_load_missing is not None:
            for pat in cls._keys_to_ignore_on_load_missing:
                missing_keys = [k for k in missing_keys if re.search(pat, k) is None]

        if cls._keys_to_ignore_on_load_unexpected is not None:
            for pat in cls._keys_to_ignore_on_load_unexpected:
                unexpected_keys = [k for k in unexpected_keys if re.search(pat, k) is None]

3272
3273
3274
3275
        # retrieve weights on meta device and put them back on CPU.
        # This is not ideal in terms of memory, but if we don't do that not, we can't initialize them in the next step
        if low_cpu_mem_usage:
            for key in missing_keys:
Susnato Dhar's avatar
Susnato Dhar committed
3276
3277
                if key in list(model_state_dict.keys()):
                    key = key
3278
3279
                elif f"{prefix}.{key}" in list(model_state_dict.keys()):
                    key = f"{prefix}.{key}"
Susnato Dhar's avatar
Susnato Dhar committed
3280
                elif key.startswith(prefix) and ".".join(key.split(".")[1:]) in list(model_state_dict.keys()):
3281
3282
                    key = ".".join(key.split(".")[1:])
                param = model_state_dict[key]
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292

                # upcast in fp32 if any
                target_dtype = dtype
                if (
                    keep_in_fp32_modules is not None
                    and dtype == torch.float16
                    and any(module_to_keep_in_fp32 in key for module_to_keep_in_fp32 in keep_in_fp32_modules)
                ):
                    target_dtype = torch.float32

3293
                if param.device == torch.device("meta"):
3294
                    if not (is_quantized):
3295
                        set_module_tensor_to_device(model, key, "cpu", torch.empty(*param.size(), dtype=target_dtype))
3296
                    else:
3297
                        set_module_quantized_tensor_to_device(
3298
3299
                            model, key, "cpu", torch.empty(*param.size(), dtype=target_dtype)
                        )
3300
3301

        # retrieve unintialized modules and initialize before maybe overriding that with the pretrained weights.
3302
        if _fast_init:
3303
3304
3305
3306
3307
3308
3309
3310
3311
            if remove_prefix_from_model:
                _loaded_keys = [f"{prefix}.{k}" for k in loaded_keys]
            elif add_prefix_to_model:
                _loaded_keys = [k[len(prefix) + 1 :] for k in loaded_keys]
            else:
                _loaded_keys = loaded_keys
            set_initialized_submodules(model, _loaded_keys)
            # This will only initialize submodules that are not marked as initialized by the line above.
            model.apply(model._initialize_weights)
3312

3313
3314
3315
3316
3317
3318
        # Set some modules to fp32 if any
        if keep_in_fp32_modules is not None:
            for name, param in model.named_parameters():
                if any(module_to_keep_in_fp32 in name for module_to_keep_in_fp32 in keep_in_fp32_modules):
                    param = param.to(torch.float32)

3319
3320
3321
        # Make sure we are able to load base models as well as derived models (with heads)
        start_prefix = ""
        model_to_load = model
3322
        if len(cls.base_model_prefix) > 0 and not hasattr(model, cls.base_model_prefix) and has_prefix_module:
3323
            start_prefix = cls.base_model_prefix + "."
3324
        if len(cls.base_model_prefix) > 0 and hasattr(model, cls.base_model_prefix) and not has_prefix_module:
3325
            model_to_load = getattr(model, cls.base_model_prefix)
Sylvain Gugger's avatar
Sylvain Gugger committed
3326
3327
            base_model_expected_keys = list(model_to_load.state_dict().keys())
            if any(key in expected_keys_not_prefixed and key not in base_model_expected_keys for key in loaded_keys):
3328
                raise ValueError(
3329
                    "The state dictionary of the model you are trying to load is corrupted. Are you sure it was "
3330
3331
                    "properly saved?"
                )
3332
3333
            if device_map is not None:
                device_map = {k.replace(f"{cls.base_model_prefix}.", ""): v for k, v in device_map.items()}
3334

3335
3336
3337
3338
3339
3340
3341
3342
        def _find_mismatched_keys(
            state_dict,
            model_state_dict,
            loaded_keys,
            add_prefix_to_model,
            remove_prefix_from_model,
            ignore_mismatched_sizes,
        ):
Sylvain Gugger's avatar
Sylvain Gugger committed
3343
3344
3345
            mismatched_keys = []
            if ignore_mismatched_sizes:
                for checkpoint_key in loaded_keys:
3346
3347
3348
                    # If the checkpoint is sharded, we may not have the key here.
                    if checkpoint_key not in state_dict:
                        continue
Sylvain Gugger's avatar
Sylvain Gugger committed
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
                    model_key = checkpoint_key
                    if remove_prefix_from_model:
                        # The model key starts with `prefix` but `checkpoint_key` doesn't so we add it.
                        model_key = f"{prefix}.{checkpoint_key}"
                    elif add_prefix_to_model:
                        # The model key doesn't start with `prefix` but `checkpoint_key` does so we remove it.
                        model_key = ".".join(checkpoint_key.split(".")[1:])

                    if (
                        model_key in model_state_dict
                        and state_dict[checkpoint_key].shape != model_state_dict[model_key].shape
                    ):
                        mismatched_keys.append(
                            (checkpoint_key, state_dict[checkpoint_key].shape, model_state_dict[model_key].shape)
                        )
                        del state_dict[checkpoint_key]
3365
3366
            return mismatched_keys

3367
3368
3369
3370
        if resolved_archive_file is not None:
            folder = os.path.sep.join(resolved_archive_file[0].split(os.path.sep)[:-1])
        else:
            folder = None
Sylvain Gugger's avatar
Sylvain Gugger committed
3371
        if device_map is not None and is_safetensors:
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
            param_device_map = expand_device_map(device_map, original_loaded_keys)

            str_dtype = str(dtype).replace("torch.", "") if dtype is not None else "float32"
            if sharded_metadata is None:
                archive_file = (
                    resolved_archive_file[0]
                    if isinstance(resolved_archive_file, (list, tuple))
                    else resolved_archive_file
                )
                weight_map = {p: archive_file for p in original_loaded_keys}
            else:
                weight_map = {p: os.path.join(folder, f) for p, f in sharded_metadata["weight_map"].items()}
Sylvain Gugger's avatar
Sylvain Gugger committed
3384
            offload_index = {
3385
3386
                p: {"safetensors_file": f, "weight_name": p, "dtype": str_dtype}
                for p, f in weight_map.items()
Sylvain Gugger's avatar
Sylvain Gugger committed
3387
3388
3389
                if param_device_map[p] == "disk"
            }

3390
3391
3392
3393
3394
        if state_dict is not None:
            # Whole checkpoint
            mismatched_keys = _find_mismatched_keys(
                state_dict,
                model_state_dict,
3395
                original_loaded_keys,
3396
3397
3398
3399
                add_prefix_to_model,
                remove_prefix_from_model,
                ignore_mismatched_sizes,
            )
Sylvain Gugger's avatar
Sylvain Gugger committed
3400
            error_msgs = _load_state_dict_into_model(model_to_load, state_dict, start_prefix)
Sylvain Gugger's avatar
Sylvain Gugger committed
3401
            offload_index = None
Sylvain Gugger's avatar
Sylvain Gugger committed
3402
        else:
3403
3404
            # Sharded checkpoint or whole but low_cpu_mem_usage==True

Sylvain Gugger's avatar
Sylvain Gugger committed
3405
3406
3407
3408
3409
            # This should always be a list but, just to be sure.
            if not isinstance(resolved_archive_file, list):
                resolved_archive_file = [resolved_archive_file]

            error_msgs = []
3410
            mismatched_keys = []
Sylvain Gugger's avatar
Sylvain Gugger committed
3411
3412
            if not is_safetensors:
                offload_index = {} if device_map is not None and "disk" in device_map.values() else None
3413
3414
3415
3416
3417
3418
3419
            if offload_state_dict:
                state_dict_folder = tempfile.mkdtemp()
                state_dict_index = {}
            else:
                state_dict_folder = None
                state_dict_index = None

3420
            if is_sharded_safetensors:
Sylvain Gugger's avatar
Sylvain Gugger committed
3421
3422
3423
3424
3425
                disk_only_shard_files = get_disk_only_shard_files(device_map, sharded_metadata=sharded_metadata)
                disk_only_shard_files = [os.path.join(folder, f) for f in disk_only_shard_files]
            else:
                disk_only_shard_files = []

3426
3427
            if len(resolved_archive_file) > 1:
                resolved_archive_file = logging.tqdm(resolved_archive_file, desc="Loading checkpoint shards")
Sylvain Gugger's avatar
Sylvain Gugger committed
3428
            for shard_file in resolved_archive_file:
Sylvain Gugger's avatar
Sylvain Gugger committed
3429
3430
3431
                # Skip the load for shards that only contain disk-offloaded weights when using safetensors for the offload.
                if shard_file in disk_only_shard_files:
                    continue
Sylvain Gugger's avatar
Sylvain Gugger committed
3432
                state_dict = load_state_dict(shard_file)
3433

Sylvain Gugger's avatar
Sylvain Gugger committed
3434
3435
                # Mistmatched keys contains tuples key/shape1/shape2 of weights in the checkpoint that have a shape not
                # matching the weights in the model.
3436
3437
3438
                mismatched_keys += _find_mismatched_keys(
                    state_dict,
                    model_state_dict,
3439
                    original_loaded_keys,
3440
3441
3442
3443
                    add_prefix_to_model,
                    remove_prefix_from_model,
                    ignore_mismatched_sizes,
                )
3444
3445

                if low_cpu_mem_usage:
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
                    new_error_msgs, offload_index, state_dict_index = _load_state_dict_into_meta_model(
                        model_to_load,
                        state_dict,
                        loaded_keys,
                        start_prefix,
                        expected_keys,
                        device_map=device_map,
                        offload_folder=offload_folder,
                        offload_index=offload_index,
                        state_dict_folder=state_dict_folder,
                        state_dict_index=state_dict_index,
                        dtype=dtype,
3458
                        is_quantized=is_quantized,
Sylvain Gugger's avatar
Sylvain Gugger committed
3459
                        is_safetensors=is_safetensors,
3460
                        keep_in_fp32_modules=keep_in_fp32_modules,
3461
                    )
3462
                    error_msgs += new_error_msgs
3463
3464
                else:
                    error_msgs += _load_state_dict_into_model(model_to_load, state_dict, start_prefix)
3465

3466
3467
3468
3469
                # force memory release
                del state_dict
                gc.collect()

3470
            if offload_index is not None and len(offload_index) > 0:
Sylvain Gugger's avatar
Sylvain Gugger committed
3471
3472
3473
                if model != model_to_load:
                    # We need to add the prefix of the base model
                    prefix = cls.base_model_prefix
Sylvain Gugger's avatar
Sylvain Gugger committed
3474
3475
3476
3477
3478
3479
                    if not is_safetensors:
                        for weight_name in offload_index:
                            shutil.move(
                                os.path.join(offload_folder, f"{weight_name}.dat"),
                                os.path.join(offload_folder, f"{prefix}.{weight_name}.dat"),
                            )
Sylvain Gugger's avatar
Sylvain Gugger committed
3480
                    offload_index = {f"{prefix}.{key}": value for key, value in offload_index.items()}
Sylvain Gugger's avatar
Sylvain Gugger committed
3481
3482
3483
                if not is_safetensors:
                    save_offload_index(offload_index, offload_folder)
                    offload_index = None
3484
3485
3486

            if offload_state_dict:
                # Load back temporarily offloaded state dict
3487
                load_offloaded_weights(model_to_load, state_dict_index, state_dict_folder)
3488
3489
                shutil.rmtree(state_dict_folder)

3490
3491
        if len(error_msgs) > 0:
            error_msg = "\n\t".join(error_msgs)
3492
3493
3494
3495
            if "size mismatch" in error_msg:
                error_msg += (
                    "\n\tYou may consider adding `ignore_mismatched_sizes=True` in the model `from_pretrained` method."
                )
3496
3497
            raise RuntimeError(f"Error(s) in loading state_dict for {model.__class__.__name__}:\n\t{error_msg}")

3498
        if is_quantized:
3499
3500
3501
            unexpected_keys = [elem for elem in unexpected_keys if "SCB" not in elem]
            missing_keys = [elem for elem in missing_keys if "SCB" not in elem]

3502
        if len(unexpected_keys) > 0:
Sylvain Gugger's avatar
Sylvain Gugger committed
3503
            archs = [] if model.config.architectures is None else model.config.architectures
3504
            warner = logger.warning if model.__class__.__name__ in archs else logger.info
Sylvain Gugger's avatar
Sylvain Gugger committed
3505
            warner(
Sylvain Gugger's avatar
Sylvain Gugger committed
3506
3507
3508
3509
3510
3511
3512
                f"Some weights of the model checkpoint at {pretrained_model_name_or_path} were not used when"
                f" initializing {model.__class__.__name__}: {unexpected_keys}\n- This IS expected if you are"
                f" initializing {model.__class__.__name__} from the checkpoint of a model trained on another task or"
                " with another architecture (e.g. initializing a BertForSequenceClassification model from a"
                " BertForPreTraining model).\n- This IS NOT expected if you are initializing"
                f" {model.__class__.__name__} from the checkpoint of a model that you expect to be exactly identical"
                " (initializing a BertForSequenceClassification model from a BertForSequenceClassification model)."
3513
3514
3515
3516
3517
            )
        else:
            logger.info(f"All model checkpoint weights were used when initializing {model.__class__.__name__}.\n")
        if len(missing_keys) > 0:
            logger.warning(
Sylvain Gugger's avatar
Sylvain Gugger committed
3518
3519
3520
                f"Some weights of {model.__class__.__name__} were not initialized from the model checkpoint at"
                f" {pretrained_model_name_or_path} and are newly initialized: {missing_keys}\nYou should probably"
                " TRAIN this model on a down-stream task to be able to use it for predictions and inference."
3521
            )
3522
        elif len(mismatched_keys) == 0:
3523
            logger.info(
Sylvain Gugger's avatar
Sylvain Gugger committed
3524
3525
3526
3527
                f"All the weights of {model.__class__.__name__} were initialized from the model checkpoint at"
                f" {pretrained_model_name_or_path}.\nIf your task is similar to the task the model of the checkpoint"
                f" was trained on, you can already use {model.__class__.__name__} for predictions without further"
                " training."
3528
            )
3529
3530
3531
3532
3533
3534
3535
3536
        if len(mismatched_keys) > 0:
            mismatched_warning = "\n".join(
                [
                    f"- {key}: found shape {shape1} in the checkpoint and {shape2} in the model instantiated"
                    for key, shape1, shape2 in mismatched_keys
                ]
            )
            logger.warning(
Sylvain Gugger's avatar
Sylvain Gugger committed
3537
3538
3539
3540
                f"Some weights of {model.__class__.__name__} were not initialized from the model checkpoint at"
                f" {pretrained_model_name_or_path} and are newly initialized because the shapes did not"
                f" match:\n{mismatched_warning}\nYou should probably TRAIN this model on a down-stream task to be able"
                " to use it for predictions and inference."
3541
            )
3542

Sylvain Gugger's avatar
Sylvain Gugger committed
3543
        return model, missing_keys, unexpected_keys, mismatched_keys, offload_index, error_msgs
3544
3545

    def retrieve_modules_from_names(self, names, add_prefix=False, remove_prefix=False):
3546
        module_keys = {".".join(key.split(".")[:-1]) for key in names}
3547

Patrick von Platen's avatar
Patrick von Platen committed
3548
3549
        # torch.nn.ParameterList is a special case where two parameter keywords
        # are appended to the module name, *e.g.* bert.special_embeddings.0
3550
        module_keys = module_keys.union(
3551
            {".".join(key.split(".")[:-2]) for key in names if len(key) > 0 and key[-1].isdigit()}
3552
        )
Patrick von Platen's avatar
Patrick von Platen committed
3553

3554
3555
3556
3557
        retrieved_modules = []
        # retrieve all modules that has at least one missing weight name
        for name, module in self.named_modules():
            if remove_prefix:
3558
3559
                _prefix = f"{self.base_model_prefix}."
                name = name[len(_prefix) :] if name.startswith(_prefix) else name
3560
            elif add_prefix:
Patrick von Platen's avatar
Patrick von Platen committed
3561
                name = ".".join([self.base_model_prefix, name]) if len(name) > 0 else self.base_model_prefix
3562
3563
3564
3565
3566
3567

            if name in module_keys:
                retrieved_modules.append(module)

        return retrieved_modules

3568
    @staticmethod
3569
    def _load_pretrained_model_low_mem(model, loaded_state_dict_keys, resolved_archive_file, start_prefix=""):
3570
3571
3572
        """
        This is an experimental function that loads the model using ~1.x model size CPU memory

3573
        Before you call it do:
3574

3575
        1. save which state_dict keys are available
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
        2. drop state_dict before model is created, since the latter takes 1x model size memory

        Here then we continue:

        3. switch to the meta device all params/buffers that are going to be replaced from the loaded state_dict
        4. load state_dict 2nd time
        5. replace the params/buffers from the state_dict

        Currently, it doesn't handle missing_keys, unexpected_keys, mismatched_keys. It can't handle deepspeed.
        """

3587
3588
3589
3590
        _move_model_to_meta(model, loaded_state_dict_keys, start_prefix)
        state_dict = load_state_dict(resolved_archive_file)
        error_msgs = _load_state_dict_into_meta_model(model, state_dict, loaded_state_dict_keys, start_prefix)
        return error_msgs
3591

3592
3593
3594
3595
3596
3597
    @classmethod
    def register_for_auto_class(cls, auto_class="AutoModel"):
        """
        Register this class with a given auto class. This should only be used for custom models as the ones in the
        library are already mapped with an auto class.

3598
3599
3600
3601
3602
3603
        <Tip warning={true}>

        This API is experimental and may have some slight breaking changes in the next releases.

        </Tip>

3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
        Args:
            auto_class (`str` or `type`, *optional*, defaults to `"AutoModel"`):
                The auto class to register this new model with.
        """
        if not isinstance(auto_class, str):
            auto_class = auto_class.__name__

        import transformers.models.auto as auto_module

        if not hasattr(auto_module, auto_class):
            raise ValueError(f"{auto_class} is not a valid auto class.")

        cls._auto_class = auto_class

3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
    def to_bettertransformer(self) -> "PreTrainedModel":
        """
        Converts the model to use [PyTorch's native attention
        implementation](https://pytorch.org/docs/stable/generated/torch.nn.MultiheadAttention.html), integrated to
        Transformers through [Optimum library](https://huggingface.co/docs/optimum/bettertransformer/overview). Only a
        subset of all Transformers models are supported.

        PyTorch's attention fastpath allows to speed up inference through kernel fusions and the use of [nested
        tensors](https://pytorch.org/docs/stable/nested.html). Detailed benchmarks can be found in [this blog
        post](https://medium.com/pytorch/bettertransformer-out-of-the-box-performance-for-huggingface-transformers-3fbe27d50ab2).

        Returns:
            [`PreTrainedModel`]: The model converted to BetterTransformer.
        """
        if not is_optimum_available():
            raise ImportError("The package `optimum` is required to use Better Transformer.")

        from optimum.version import __version__ as optimum_version

        if version.parse(optimum_version) < version.parse("1.7.0"):
            raise ImportError(
                f"Please install optimum>=1.7.0 to use Better Transformer. The version {optimum_version} was found."
            )

        from optimum.bettertransformer import BetterTransformer

        return BetterTransformer.transform(self)

    def reverse_bettertransformer(self):
        """
        Reverts the transformation from [`~PreTrainedModel.to_bettertransformer`] so that the original modeling is
        used, for example in order to save the model.

        Returns:
            [`PreTrainedModel`]: The model converted back to the original modeling.
        """
        if not is_optimum_available():
            raise ImportError("The package `optimum` is required to use Better Transformer.")

        from optimum.version import __version__ as optimum_version

        if version.parse(optimum_version) < version.parse("1.7.0"):
            raise ImportError(
                f"Please install optimum>=1.7.0 to use Better Transformer. The version {optimum_version} was found."
            )

        from optimum.bettertransformer import BetterTransformer

        return BetterTransformer.reverse(self)

3668
3669
3670
3671
    def warn_if_padding_and_no_attention_mask(self, input_ids, attention_mask):
        """
        Shows a one-time warning if the input_ids appear to contain padding and no attention mask was given.
        """
3672
3673
3674
3675
3676

        # Skip the check during tracing.
        if is_torch_fx_proxy(input_ids) or torch.jit.is_tracing():
            return

3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
        if (attention_mask is not None) or (self.config.pad_token_id is None):
            return

        # Check only the first and last input IDs to reduce overhead.
        if self.config.pad_token_id in input_ids[:, [-1, 0]]:
            warn_string = (
                "We strongly recommend passing in an `attention_mask` since your input_ids may be padded. See "
                "https://huggingface.co/docs/transformers/troubleshooting"
                "#incorrect-output-when-padding-tokens-arent-masked."
            )

            # If the pad token is equal to either BOS, EOS, or SEP, we do not know whether the user should use an
            # attention_mask or not. In this case, we should still show a warning because this is a rare case.
            if (
                (self.config.bos_token_id is not None and self.config.bos_token_id == self.config.pad_token_id)
                or (self.config.eos_token_id is not None and self.config.eos_token_id == self.config.pad_token_id)
                or (self.config.sep_token_id is not None and self.config.sep_token_id == self.config.pad_token_id)
            ):
                warn_string += (
                    f"\nYou may ignore this warning if your `pad_token_id` ({self.config.pad_token_id}) is identical "
                    f"to the `bos_token_id` ({self.config.bos_token_id}), `eos_token_id` ({self.config.eos_token_id}), "
                    f"or the `sep_token_id` ({self.config.sep_token_id}), and your input is not padded."
                )

            logger.warning_once(warn_string)

thomwolf's avatar
thomwolf committed
3703

3704
PreTrainedModel.push_to_hub = copy_func(PreTrainedModel.push_to_hub)
3705
3706
3707
3708
if PreTrainedModel.push_to_hub.__doc__ is not None:
    PreTrainedModel.push_to_hub.__doc__ = PreTrainedModel.push_to_hub.__doc__.format(
        object="model", object_class="AutoModel", object_files="model file"
    )
3709
3710


thomwolf's avatar
thomwolf committed
3711
class PoolerStartLogits(nn.Module):
Sylvain Gugger's avatar
Sylvain Gugger committed
3712
3713
    """
    Compute SQuAD start logits from sequence hidden states.
3714

Sylvain Gugger's avatar
Sylvain Gugger committed
3715
    Args:
3716
3717
        config ([`PretrainedConfig`]):
            The config used by the model, will be used to grab the `hidden_size` of the model.
Sylvain Gugger's avatar
Sylvain Gugger committed
3718
3719
3720
    """

    def __init__(self, config: PretrainedConfig):
Julien Chaumond's avatar
Julien Chaumond committed
3721
        super().__init__()
thomwolf's avatar
thomwolf committed
3722
3723
        self.dense = nn.Linear(config.hidden_size, 1)

Sylvain Gugger's avatar
Sylvain Gugger committed
3724
3725
3726
3727
3728
    def forward(
        self, hidden_states: torch.FloatTensor, p_mask: Optional[torch.FloatTensor] = None
    ) -> torch.FloatTensor:
        """
        Args:
3729
            hidden_states (`torch.FloatTensor` of shape `(batch_size, seq_len, hidden_size)`):
Sylvain Gugger's avatar
Sylvain Gugger committed
3730
                The final hidden states of the model.
3731
            p_mask (`torch.FloatTensor` of shape `(batch_size, seq_len)`, *optional*):
Sylvain Gugger's avatar
Sylvain Gugger committed
3732
3733
                Mask for tokens at invalid position, such as query and special symbols (PAD, SEP, CLS). 1.0 means token
                should be masked.
Sylvain Gugger's avatar
Sylvain Gugger committed
3734
3735

        Returns:
3736
            `torch.FloatTensor`: The start logits for SQuAD.
thomwolf's avatar
thomwolf committed
3737
        """
thomwolf's avatar
thomwolf committed
3738
3739
3740
        x = self.dense(hidden_states).squeeze(-1)

        if p_mask is not None:
Lysandre Debut's avatar
Lysandre Debut committed
3741
            if get_parameter_dtype(self) == torch.float16:
3742
3743
3744
                x = x * (1 - p_mask) - 65500 * p_mask
            else:
                x = x * (1 - p_mask) - 1e30 * p_mask
thomwolf's avatar
thomwolf committed
3745
3746
3747
3748
3749
3750

        return x


class PoolerEndLogits(nn.Module):
    """
Sylvain Gugger's avatar
Sylvain Gugger committed
3751
    Compute SQuAD end logits from sequence hidden states.
3752

Sylvain Gugger's avatar
Sylvain Gugger committed
3753
    Args:
3754
        config ([`PretrainedConfig`]):
Sylvain Gugger's avatar
Sylvain Gugger committed
3755
3756
            The config used by the model, will be used to grab the `hidden_size` of the model and the `layer_norm_eps`
            to use.
Sylvain Gugger's avatar
Sylvain Gugger committed
3757
3758
3759
    """

    def __init__(self, config: PretrainedConfig):
Julien Chaumond's avatar
Julien Chaumond committed
3760
        super().__init__()
thomwolf's avatar
thomwolf committed
3761
3762
3763
3764
3765
        self.dense_0 = nn.Linear(config.hidden_size * 2, config.hidden_size)
        self.activation = nn.Tanh()
        self.LayerNorm = nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps)
        self.dense_1 = nn.Linear(config.hidden_size, 1)

Sylvain Gugger's avatar
Sylvain Gugger committed
3766
3767
3768
3769
3770
3771
3772
3773
3774
    def forward(
        self,
        hidden_states: torch.FloatTensor,
        start_states: Optional[torch.FloatTensor] = None,
        start_positions: Optional[torch.LongTensor] = None,
        p_mask: Optional[torch.FloatTensor] = None,
    ) -> torch.FloatTensor:
        """
        Args:
3775
            hidden_states (`torch.FloatTensor` of shape `(batch_size, seq_len, hidden_size)`):
Sylvain Gugger's avatar
Sylvain Gugger committed
3776
                The final hidden states of the model.
3777
            start_states (`torch.FloatTensor` of shape `(batch_size, seq_len, hidden_size)`, *optional*):
Sylvain Gugger's avatar
Sylvain Gugger committed
3778
                The hidden states of the first tokens for the labeled span.
3779
            start_positions (`torch.LongTensor` of shape `(batch_size,)`, *optional*):
Sylvain Gugger's avatar
Sylvain Gugger committed
3780
                The position of the first token for the labeled span.
3781
            p_mask (`torch.FloatTensor` of shape `(batch_size, seq_len)`, *optional*):
Sylvain Gugger's avatar
Sylvain Gugger committed
3782
3783
                Mask for tokens at invalid position, such as query and special symbols (PAD, SEP, CLS). 1.0 means token
                should be masked.
Sylvain Gugger's avatar
Sylvain Gugger committed
3784

3785
        <Tip>
Sylvain Gugger's avatar
Sylvain Gugger committed
3786

Stas Bekman's avatar
Stas Bekman committed
3787
3788
        One of `start_states` or `start_positions` should be not `None`. If both are set, `start_positions` overrides
        `start_states`.
3789
3790

        </Tip>
Sylvain Gugger's avatar
Sylvain Gugger committed
3791
3792

        Returns:
3793
            `torch.FloatTensor`: The end logits for SQuAD.
thomwolf's avatar
thomwolf committed
3794
        """
3795
3796
3797
        assert (
            start_states is not None or start_positions is not None
        ), "One of start_states, start_positions should be not None"
thomwolf's avatar
thomwolf committed
3798
        if start_positions is not None:
3799
            slen, hsz = hidden_states.shape[-2:]
3800
3801
3802
            start_positions = start_positions[:, None, None].expand(-1, -1, hsz)  # shape (bsz, 1, hsz)
            start_states = hidden_states.gather(-2, start_positions)  # shape (bsz, 1, hsz)
            start_states = start_states.expand(-1, slen, -1)  # shape (bsz, slen, hsz)
thomwolf's avatar
thomwolf committed
3803
3804
3805
3806
3807
3808
3809

        x = self.dense_0(torch.cat([hidden_states, start_states], dim=-1))
        x = self.activation(x)
        x = self.LayerNorm(x)
        x = self.dense_1(x).squeeze(-1)

        if p_mask is not None:
Lysandre Debut's avatar
Lysandre Debut committed
3810
            if get_parameter_dtype(self) == torch.float16:
3811
3812
3813
                x = x * (1 - p_mask) - 65500 * p_mask
            else:
                x = x * (1 - p_mask) - 1e30 * p_mask
thomwolf's avatar
thomwolf committed
3814
3815
3816
3817
3818

        return x


class PoolerAnswerClass(nn.Module):
Sylvain Gugger's avatar
Sylvain Gugger committed
3819
3820
3821
3822
    """
    Compute SQuAD 2.0 answer class from classification and start tokens hidden states.

    Args:
3823
3824
        config ([`PretrainedConfig`]):
            The config used by the model, will be used to grab the `hidden_size` of the model.
Sylvain Gugger's avatar
Sylvain Gugger committed
3825
    """
3826

thomwolf's avatar
thomwolf committed
3827
    def __init__(self, config):
Julien Chaumond's avatar
Julien Chaumond committed
3828
        super().__init__()
thomwolf's avatar
thomwolf committed
3829
3830
3831
3832
        self.dense_0 = nn.Linear(config.hidden_size * 2, config.hidden_size)
        self.activation = nn.Tanh()
        self.dense_1 = nn.Linear(config.hidden_size, 1, bias=False)

Sylvain Gugger's avatar
Sylvain Gugger committed
3833
3834
3835
3836
3837
3838
3839
    def forward(
        self,
        hidden_states: torch.FloatTensor,
        start_states: Optional[torch.FloatTensor] = None,
        start_positions: Optional[torch.LongTensor] = None,
        cls_index: Optional[torch.LongTensor] = None,
    ) -> torch.FloatTensor:
3840
3841
        """
        Args:
3842
            hidden_states (`torch.FloatTensor` of shape `(batch_size, seq_len, hidden_size)`):
Sylvain Gugger's avatar
Sylvain Gugger committed
3843
                The final hidden states of the model.
3844
            start_states (`torch.FloatTensor` of shape `(batch_size, seq_len, hidden_size)`, *optional*):
Sylvain Gugger's avatar
Sylvain Gugger committed
3845
                The hidden states of the first tokens for the labeled span.
3846
            start_positions (`torch.LongTensor` of shape `(batch_size,)`, *optional*):
Sylvain Gugger's avatar
Sylvain Gugger committed
3847
                The position of the first token for the labeled span.
3848
3849
3850
3851
            cls_index (`torch.LongTensor` of shape `(batch_size,)`, *optional*):
                Position of the CLS token for each sentence in the batch. If `None`, takes the last token.

        <Tip>
Sylvain Gugger's avatar
Sylvain Gugger committed
3852

Stas Bekman's avatar
Stas Bekman committed
3853
3854
        One of `start_states` or `start_positions` should be not `None`. If both are set, `start_positions` overrides
        `start_states`.
Sylvain Gugger's avatar
Sylvain Gugger committed
3855

3856
        </Tip>
Sylvain Gugger's avatar
Sylvain Gugger committed
3857
3858

        Returns:
3859
            `torch.FloatTensor`: The SQuAD 2.0 answer class.
thomwolf's avatar
thomwolf committed
3860
        """
Sylvain Gugger's avatar
Sylvain Gugger committed
3861
        # No dependency on end_feature so that we can obtain one single `cls_logits` for each sample.
3862
        hsz = hidden_states.shape[-1]
3863
3864
3865
        assert (
            start_states is not None or start_positions is not None
        ), "One of start_states, start_positions should be not None"
thomwolf's avatar
thomwolf committed
3866
        if start_positions is not None:
3867
3868
            start_positions = start_positions[:, None, None].expand(-1, -1, hsz)  # shape (bsz, 1, hsz)
            start_states = hidden_states.gather(-2, start_positions).squeeze(-2)  # shape (bsz, hsz)
thomwolf's avatar
thomwolf committed
3869
3870

        if cls_index is not None:
3871
3872
            cls_index = cls_index[:, None, None].expand(-1, -1, hsz)  # shape (bsz, 1, hsz)
            cls_token_state = hidden_states.gather(-2, cls_index).squeeze(-2)  # shape (bsz, hsz)
thomwolf's avatar
thomwolf committed
3873
        else:
3874
            cls_token_state = hidden_states[:, -1, :]  # shape (bsz, hsz)
thomwolf's avatar
thomwolf committed
3875
3876
3877
3878
3879
3880
3881
3882

        x = self.dense_0(torch.cat([start_states, cls_token_state], dim=-1))
        x = self.activation(x)
        x = self.dense_1(x).squeeze(-1)

        return x


3883
3884
3885
@dataclass
class SquadHeadOutput(ModelOutput):
    """
3886
    Base class for outputs of question answering models using a [`~modeling_utils.SQuADHead`].
3887
3888

    Args:
3889
        loss (`torch.FloatTensor` of shape `(1,)`, *optional*, returned if both `start_positions` and `end_positions` are provided):
Sylvain Gugger's avatar
Sylvain Gugger committed
3890
3891
            Classification loss as the sum of start token, end token (and is_impossible if provided) classification
            losses.
3892
        start_top_log_probs (`torch.FloatTensor` of shape `(batch_size, config.start_n_top)`, *optional*, returned if `start_positions` or `end_positions` is not provided):
3893
            Log probabilities for the top config.start_n_top start token possibilities (beam-search).
3894
        start_top_index (`torch.LongTensor` of shape `(batch_size, config.start_n_top)`, *optional*, returned if `start_positions` or `end_positions` is not provided):
3895
            Indices for the top config.start_n_top start token possibilities (beam-search).
3896
3897
        end_top_log_probs (`torch.FloatTensor` of shape `(batch_size, config.start_n_top * config.end_n_top)`, *optional*, returned if `start_positions` or `end_positions` is not provided):
            Log probabilities for the top `config.start_n_top * config.end_n_top` end token possibilities
Sylvain Gugger's avatar
Sylvain Gugger committed
3898
            (beam-search).
3899
3900
3901
3902
        end_top_index (`torch.LongTensor` of shape `(batch_size, config.start_n_top * config.end_n_top)`, *optional*, returned if `start_positions` or `end_positions` is not provided):
            Indices for the top `config.start_n_top * config.end_n_top` end token possibilities (beam-search).
        cls_logits (`torch.FloatTensor` of shape `(batch_size,)`, *optional*, returned if `start_positions` or `end_positions` is not provided):
            Log probabilities for the `is_impossible` label of the answers.
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913

    """

    loss: Optional[torch.FloatTensor] = None
    start_top_log_probs: Optional[torch.FloatTensor] = None
    start_top_index: Optional[torch.LongTensor] = None
    end_top_log_probs: Optional[torch.FloatTensor] = None
    end_top_index: Optional[torch.LongTensor] = None
    cls_logits: Optional[torch.FloatTensor] = None


thomwolf's avatar
thomwolf committed
3914
class SQuADHead(nn.Module):
Sylvain Gugger's avatar
Sylvain Gugger committed
3915
3916
    r"""
    A SQuAD head inspired by XLNet.
3917

Sylvain Gugger's avatar
Sylvain Gugger committed
3918
    Args:
3919
        config ([`PretrainedConfig`]):
Sylvain Gugger's avatar
Sylvain Gugger committed
3920
3921
            The config used by the model, will be used to grab the `hidden_size` of the model and the `layer_norm_eps`
            to use.
thomwolf's avatar
thomwolf committed
3922
    """
3923

thomwolf's avatar
thomwolf committed
3924
    def __init__(self, config):
Julien Chaumond's avatar
Julien Chaumond committed
3925
        super().__init__()
thomwolf's avatar
thomwolf committed
3926
3927
3928
3929
3930
3931
3932
        self.start_n_top = config.start_n_top
        self.end_n_top = config.end_n_top

        self.start_logits = PoolerStartLogits(config)
        self.end_logits = PoolerEndLogits(config)
        self.answer_class = PoolerAnswerClass(config)

Sylvain Gugger's avatar
Sylvain Gugger committed
3933
    @replace_return_docstrings(output_type=SquadHeadOutput, config_class=PretrainedConfig)
3934
    def forward(
3935
        self,
Sylvain Gugger's avatar
Sylvain Gugger committed
3936
3937
3938
3939
3940
3941
        hidden_states: torch.FloatTensor,
        start_positions: Optional[torch.LongTensor] = None,
        end_positions: Optional[torch.LongTensor] = None,
        cls_index: Optional[torch.LongTensor] = None,
        is_impossible: Optional[torch.LongTensor] = None,
        p_mask: Optional[torch.FloatTensor] = None,
3942
        return_dict: bool = False,
Sylvain Gugger's avatar
Sylvain Gugger committed
3943
3944
    ) -> Union[SquadHeadOutput, Tuple[torch.FloatTensor]]:
        """
Lysandre's avatar
Lysandre committed
3945
        Args:
3946
            hidden_states (`torch.FloatTensor` of shape `(batch_size, seq_len, hidden_size)`):
Lysandre's avatar
Lysandre committed
3947
                Final hidden states of the model on the sequence tokens.
3948
            start_positions (`torch.LongTensor` of shape `(batch_size,)`, *optional*):
Lysandre's avatar
Lysandre committed
3949
                Positions of the first token for the labeled span.
3950
            end_positions (`torch.LongTensor` of shape `(batch_size,)`, *optional*):
Lysandre's avatar
Lysandre committed
3951
                Positions of the last token for the labeled span.
3952
3953
3954
            cls_index (`torch.LongTensor` of shape `(batch_size,)`, *optional*):
                Position of the CLS token for each sentence in the batch. If `None`, takes the last token.
            is_impossible (`torch.LongTensor` of shape `(batch_size,)`, *optional*):
Lysandre's avatar
Lysandre committed
3955
                Whether the question has a possible answer in the paragraph or not.
3956
            p_mask (`torch.FloatTensor` of shape `(batch_size, seq_len)`, *optional*):
Sylvain Gugger's avatar
Sylvain Gugger committed
3957
3958
                Mask for tokens at invalid position, such as query and special symbols (PAD, SEP, CLS). 1.0 means token
                should be masked.
3959
            return_dict (`bool`, *optional*, defaults to `False`):
3960
                Whether or not to return a [`~utils.ModelOutput`] instead of a plain tuple.
Sylvain Gugger's avatar
Sylvain Gugger committed
3961

Lysandre's avatar
Lysandre committed
3962
        Returns:
Sylvain Gugger's avatar
Sylvain Gugger committed
3963
        """
thomwolf's avatar
thomwolf committed
3964
        start_logits = self.start_logits(hidden_states, p_mask=p_mask)
thomwolf's avatar
thomwolf committed
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987

        if start_positions is not None and end_positions is not None:
            # If we are on multi-GPU, let's remove the dimension added by batch splitting
            for x in (start_positions, end_positions, cls_index, is_impossible):
                if x is not None and x.dim() > 1:
                    x.squeeze_(-1)

            # during training, compute the end logits based on the ground truth of the start position
            end_logits = self.end_logits(hidden_states, start_positions=start_positions, p_mask=p_mask)

            loss_fct = CrossEntropyLoss()
            start_loss = loss_fct(start_logits, start_positions)
            end_loss = loss_fct(end_logits, end_positions)
            total_loss = (start_loss + end_loss) / 2

            if cls_index is not None and is_impossible is not None:
                # Predict answerability from the representation of CLS and START
                cls_logits = self.answer_class(hidden_states, start_positions=start_positions, cls_index=cls_index)
                loss_fct_cls = nn.BCEWithLogitsLoss()
                cls_loss = loss_fct_cls(cls_logits, is_impossible)

                # note(zhiliny): by default multiply the loss by 0.5 so that the scale is comparable to start_loss and end_loss
                total_loss += cls_loss * 0.5
3988

3989
            return SquadHeadOutput(loss=total_loss) if return_dict else (total_loss,)
thomwolf's avatar
thomwolf committed
3990
3991
3992
3993

        else:
            # during inference, compute the end logits based on beam search
            bsz, slen, hsz = hidden_states.size()
3994
            start_log_probs = nn.functional.softmax(start_logits, dim=-1)  # shape (bsz, slen)
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005

            start_top_log_probs, start_top_index = torch.topk(
                start_log_probs, self.start_n_top, dim=-1
            )  # shape (bsz, start_n_top)
            start_top_index_exp = start_top_index.unsqueeze(-1).expand(-1, -1, hsz)  # shape (bsz, start_n_top, hsz)
            start_states = torch.gather(hidden_states, -2, start_top_index_exp)  # shape (bsz, start_n_top, hsz)
            start_states = start_states.unsqueeze(1).expand(-1, slen, -1, -1)  # shape (bsz, slen, start_n_top, hsz)

            hidden_states_expanded = hidden_states.unsqueeze(2).expand_as(
                start_states
            )  # shape (bsz, slen, start_n_top, hsz)
thomwolf's avatar
thomwolf committed
4006
4007
            p_mask = p_mask.unsqueeze(-1) if p_mask is not None else None
            end_logits = self.end_logits(hidden_states_expanded, start_states=start_states, p_mask=p_mask)
4008
            end_log_probs = nn.functional.softmax(end_logits, dim=1)  # shape (bsz, slen, start_n_top)
thomwolf's avatar
thomwolf committed
4009

4010
4011
4012
            end_top_log_probs, end_top_index = torch.topk(
                end_log_probs, self.end_n_top, dim=1
            )  # shape (bsz, end_n_top, start_n_top)
thomwolf's avatar
thomwolf committed
4013
4014
4015
4016
4017
4018
            end_top_log_probs = end_top_log_probs.view(-1, self.start_n_top * self.end_n_top)
            end_top_index = end_top_index.view(-1, self.start_n_top * self.end_n_top)

            start_states = torch.einsum("blh,bl->bh", hidden_states, start_log_probs)
            cls_logits = self.answer_class(hidden_states, start_states=start_states, cls_index=cls_index)

4019
            if not return_dict:
4020
4021
4022
4023
4024
4025
4026
4027
4028
                return (start_top_log_probs, start_top_index, end_top_log_probs, end_top_index, cls_logits)
            else:
                return SquadHeadOutput(
                    start_top_log_probs=start_top_log_probs,
                    start_top_index=start_top_index,
                    end_top_log_probs=end_top_log_probs,
                    end_top_index=end_top_index,
                    cls_logits=cls_logits,
                )
thomwolf's avatar
thomwolf committed
4029
4030
4031


class SequenceSummary(nn.Module):
Sylvain Gugger's avatar
Sylvain Gugger committed
4032
4033
4034
4035
    r"""
    Compute a single vector summary of a sequence hidden states.

    Args:
4036
        config ([`PretrainedConfig`]):
Sylvain Gugger's avatar
Sylvain Gugger committed
4037
4038
            The config used by the model. Relevant arguments in the config class of the model are (refer to the actual
            config class of your model for the default values it uses):
Sylvain Gugger's avatar
Sylvain Gugger committed
4039

4040
            - **summary_type** (`str`) -- The method to use to make this summary. Accepted values are:
Sylvain Gugger's avatar
Sylvain Gugger committed
4041

4042
4043
4044
4045
4046
                - `"last"` -- Take the last token hidden state (like XLNet)
                - `"first"` -- Take the first token hidden state (like Bert)
                - `"mean"` -- Take the mean of all tokens hidden states
                - `"cls_index"` -- Supply a Tensor of classification token position (GPT/GPT-2)
                - `"attn"` -- Not implemented now, use multi-head attention
Sylvain Gugger's avatar
Sylvain Gugger committed
4047

4048
            - **summary_use_proj** (`bool`) -- Add a projection after the vector extraction.
Sylvain Gugger's avatar
Sylvain Gugger committed
4049
4050
4051
4052
4053
4054
            - **summary_proj_to_labels** (`bool`) -- If `True`, the projection outputs to `config.num_labels` classes
              (otherwise to `config.hidden_size`).
            - **summary_activation** (`Optional[str]`) -- Set to `"tanh"` to add a tanh activation to the output,
              another string or `None` will add no activation.
            - **summary_first_dropout** (`float`) -- Optional dropout probability before the projection and activation.
            - **summary_last_dropout** (`float`)-- Optional dropout probability after the projection and activation.
thomwolf's avatar
thomwolf committed
4055
    """
4056

4057
    def __init__(self, config: PretrainedConfig):
Julien Chaumond's avatar
Julien Chaumond committed
4058
        super().__init__()
thomwolf's avatar
thomwolf committed
4059

4060
        self.summary_type = getattr(config, "summary_type", "last")
4061
        if self.summary_type == "attn":
thomwolf's avatar
thomwolf committed
4062
4063
4064
4065
4066
            # We should use a standard multi-head attention module with absolute positional embedding for that.
            # Cf. https://github.com/zihangdai/xlnet/blob/master/modeling.py#L253-L276
            # We can probably just use the multi-head attention module of PyTorch >=1.1.0
            raise NotImplementedError

thomwolf's avatar
thomwolf committed
4067
        self.summary = Identity()
4068
4069
        if hasattr(config, "summary_use_proj") and config.summary_use_proj:
            if hasattr(config, "summary_proj_to_labels") and config.summary_proj_to_labels and config.num_labels > 0:
4070
                num_classes = config.num_labels
thomwolf's avatar
thomwolf committed
4071
4072
4073
4074
            else:
                num_classes = config.hidden_size
            self.summary = nn.Linear(config.hidden_size, num_classes)

4075
        activation_string = getattr(config, "summary_activation", None)
Lysandre's avatar
Lysandre committed
4076
        self.activation: Callable = get_activation(activation_string) if activation_string else Identity()
thomwolf's avatar
thomwolf committed
4077

thomwolf's avatar
thomwolf committed
4078
        self.first_dropout = Identity()
4079
        if hasattr(config, "summary_first_dropout") and config.summary_first_dropout > 0:
4080
4081
            self.first_dropout = nn.Dropout(config.summary_first_dropout)

thomwolf's avatar
thomwolf committed
4082
        self.last_dropout = Identity()
4083
        if hasattr(config, "summary_last_dropout") and config.summary_last_dropout > 0:
4084
            self.last_dropout = nn.Dropout(config.summary_last_dropout)
thomwolf's avatar
thomwolf committed
4085

Sylvain Gugger's avatar
Sylvain Gugger committed
4086
4087
4088
4089
4090
4091
4092
    def forward(
        self, hidden_states: torch.FloatTensor, cls_index: Optional[torch.LongTensor] = None
    ) -> torch.FloatTensor:
        """
        Compute a single vector summary of a sequence hidden states.

        Args:
4093
            hidden_states (`torch.FloatTensor` of shape `[batch_size, seq_len, hidden_size]`):
Sylvain Gugger's avatar
Sylvain Gugger committed
4094
                The hidden states of the last layer.
4095
            cls_index (`torch.LongTensor` of shape `[batch_size]` or `[batch_size, ...]` where ... are optional leading dimensions of `hidden_states`, *optional*):
Sylvain Gugger's avatar
Sylvain Gugger committed
4096
                Used if `summary_type == "cls_index"` and takes the last token of the sequence as classification token.
Sylvain Gugger's avatar
Sylvain Gugger committed
4097
4098

        Returns:
4099
            `torch.FloatTensor`: The summary of the sequence hidden states.
thomwolf's avatar
thomwolf committed
4100
        """
4101
        if self.summary_type == "last":
thomwolf's avatar
thomwolf committed
4102
            output = hidden_states[:, -1]
4103
        elif self.summary_type == "first":
thomwolf's avatar
thomwolf committed
4104
            output = hidden_states[:, 0]
4105
        elif self.summary_type == "mean":
thomwolf's avatar
thomwolf committed
4106
            output = hidden_states.mean(dim=1)
4107
        elif self.summary_type == "cls_index":
thomwolf's avatar
thomwolf committed
4108
            if cls_index is None:
Lysandre's avatar
Lysandre committed
4109
4110
4111
4112
4113
                cls_index = torch.full_like(
                    hidden_states[..., :1, :],
                    hidden_states.shape[-2] - 1,
                    dtype=torch.long,
                )
thomwolf's avatar
thomwolf committed
4114
            else:
thomwolf's avatar
thomwolf committed
4115
                cls_index = cls_index.unsqueeze(-1).unsqueeze(-1)
4116
                cls_index = cls_index.expand((-1,) * (cls_index.dim() - 1) + (hidden_states.size(-1),))
thomwolf's avatar
thomwolf committed
4117
            # shape of cls_index: (bsz, XX, 1, hidden_size) where XX are optional leading dim of hidden_states
4118
4119
            output = hidden_states.gather(-2, cls_index).squeeze(-2)  # shape (bsz, XX, hidden_size)
        elif self.summary_type == "attn":
thomwolf's avatar
thomwolf committed
4120
4121
            raise NotImplementedError

4122
        output = self.first_dropout(output)
thomwolf's avatar
thomwolf committed
4123
4124
        output = self.summary(output)
        output = self.activation(output)
4125
        output = self.last_dropout(output)
thomwolf's avatar
thomwolf committed
4126
4127
4128
4129

        return output


4130
def unwrap_model(model: nn.Module) -> nn.Module:
4131
4132
4133
4134
    """
    Recursively unwraps a model from potential containers (as used in distributed training).

    Args:
4135
        model (`torch.nn.Module`): The model to unwrap.
4136
4137
4138
4139
4140
4141
    """
    # since there could be multiple levels of wrapping, unwrap recursively
    if hasattr(model, "module"):
        return unwrap_model(model.module)
    else:
        return model
Sylvain Gugger's avatar
Sylvain Gugger committed
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164


def expand_device_map(device_map, param_names):
    """
    Expand a device map to return the correspondance parameter name to device.
    """
    new_device_map = {}
    for module, device in device_map.items():
        new_device_map.update({p: device for p in param_names if p == module or p.startswith(f"{module}.")})
    return new_device_map


def get_disk_only_shard_files(device_map, sharded_metadata):
    """
    Returns the list of shard files containing only weights offloaded to disk.
    """
    files_content = collections.defaultdict(list)
    for weight_name, filename in sharded_metadata["weight_map"].items():
        while len(weight_name) > 0 and weight_name not in device_map:
            weight_name = ".".join(weight_name.split(".")[:-1])
        files_content[filename].append(device_map[weight_name])

    return [fname for fname, devices in files_content.items() if set(devices) == {"disk"}]