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wonwonn/diversifier_generated_adapter

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zero_to_fp32.py761 linesDownload Raw Back to checkpoint-8500
1#!/usr/bin/env python2 3# Copyright (c) Microsoft Corporation.4# SPDX-License-Identifier: Apache-2.05 6# DeepSpeed Team7 8# This script extracts fp32 consolidated weights from a zero 1, 2 and 3 DeepSpeed checkpoints. It gets9# copied into the top level checkpoint dir, so the user can easily do the conversion at any point in10# the future. Once extracted, the weights don't require DeepSpeed and can be used in any11# application.12#13# example:14#   python zero_to_fp32.py . output_dir/15#   or16#   python zero_to_fp32.py . output_dir/ --safe_serialization17 18import argparse19import torch20import glob21import math22import os23import re24import gc25import json26import numpy as np27from tqdm import tqdm28from collections import OrderedDict29from dataclasses import dataclass30 31# while this script doesn't use deepspeed to recover data, since the checkpoints are pickled with32# DeepSpeed data structures it has to be available in the current python environment.33from deepspeed.utils import logger34from deepspeed.checkpoint.constants import (DS_VERSION, OPTIMIZER_STATE_DICT, SINGLE_PARTITION_OF_FP32_GROUPS,35                                            FP32_FLAT_GROUPS, ZERO_STAGE, PARTITION_COUNT, PARAM_SHAPES, BUFFER_NAMES,36                                            FROZEN_PARAM_SHAPES, FROZEN_PARAM_FRAGMENTS)37 38 39@dataclass40class zero_model_state:41    buffers: dict()42    param_shapes: dict()43    shared_params: list44    ds_version: int45    frozen_param_shapes: dict()46    frozen_param_fragments: dict()47 48 49debug = 050 51# load to cpu52device = torch.device('cpu')53 54 55def atoi(text):56    return int(text) if text.isdigit() else text57 58 59def natural_keys(text):60    '''61    alist.sort(key=natural_keys) sorts in human order62    http://nedbatchelder.com/blog/200712/human_sorting.html63    (See Toothy's implementation in the comments)64    '''65    return [atoi(c) for c in re.split(r'(\d+)', text)]66 67 68def get_model_state_file(checkpoint_dir, zero_stage):69    if not os.path.isdir(checkpoint_dir):70        raise FileNotFoundError(f"Directory '{checkpoint_dir}' doesn't exist")71 72    # there should be only one file73    if zero_stage <= 2:74        file = os.path.join(checkpoint_dir, "mp_rank_00_model_states.pt")75    elif zero_stage == 3:76        file = os.path.join(checkpoint_dir, "zero_pp_rank_0_mp_rank_00_model_states.pt")77 78    if not os.path.exists(file):79        raise FileNotFoundError(f"can't find model states file at '{file}'")80 81    return file82 83 84def get_checkpoint_files(checkpoint_dir, glob_pattern):85    # XXX: need to test that this simple glob rule works for multi-node setup too86    ckpt_files = sorted(glob.glob(os.path.join(checkpoint_dir, glob_pattern)), key=natural_keys)87 88    if len(ckpt_files) == 0:89        raise FileNotFoundError(f"can't find {glob_pattern} files in directory '{checkpoint_dir}'")90 91    return ckpt_files92 93 94def get_optim_files(checkpoint_dir):95    return get_checkpoint_files(checkpoint_dir, "*_optim_states.pt")96 97 98def get_model_state_files(checkpoint_dir):99    return get_checkpoint_files(checkpoint_dir, "*_model_states.pt")100 101 102def parse_model_states(files):103    zero_model_states = []104    for file in files:105        state_dict = torch.load(file, map_location=device, weights_only=False)106 107        if BUFFER_NAMES not in state_dict:108            raise ValueError(f"{file} is not a model state checkpoint")109        buffer_names = state_dict[BUFFER_NAMES]110        if debug:111            print("Found buffers:", buffer_names)112 113        # recover just the buffers while restoring them to fp32 if they were saved in fp16114        buffers = {k: v.float() for k, v in state_dict["module"].items() if k in buffer_names}115        param_shapes = state_dict[PARAM_SHAPES]116 117        # collect parameters that are included in param_shapes118        param_names = []119        for s in param_shapes:120            for name in s.keys():121                param_names.append(name)122 123        # update with frozen parameters124        frozen_param_shapes = state_dict.get(FROZEN_PARAM_SHAPES, None)125        if frozen_param_shapes is not None:126            if debug:127                print(f"Found frozen_param_shapes: {frozen_param_shapes}")128            param_names += list(frozen_param_shapes.keys())129 130        # handle shared params131        shared_params = [[k, v] for k, v in state_dict["shared_params"].items()]132 133        ds_version = state_dict.get(DS_VERSION, None)134 135        frozen_param_fragments = state_dict.get(FROZEN_PARAM_FRAGMENTS, None)136 137        z_model_state = zero_model_state(buffers=buffers,138                                         param_shapes=param_shapes,139                                         shared_params=shared_params,140                                         ds_version=ds_version,141                                         frozen_param_shapes=frozen_param_shapes,142                                         frozen_param_fragments=frozen_param_fragments)143        zero_model_states.append(z_model_state)144 145    return zero_model_states146 147 148def parse_optim_states(files, ds_checkpoint_dir):149    total_files = len(files)150    state_dicts = []151    for f in tqdm(files, desc='Loading checkpoint shards'):152        state_dict = torch.load(f, map_location=device, mmap=True, weights_only=False)153        # immediately discard the potentially huge 2 optimizer states as we only care for fp32 master weights154        # and also handle the case where it was already removed by another helper script155        state_dict["optimizer_state_dict"].pop("optimizer_state_dict", None)156        state_dicts.append(state_dict)157 158    if ZERO_STAGE not in state_dicts[0][OPTIMIZER_STATE_DICT]:159        raise ValueError(f"{files[0]} is not a zero checkpoint")160    zero_stage = state_dicts[0][OPTIMIZER_STATE_DICT][ZERO_STAGE]161    world_size = state_dicts[0][OPTIMIZER_STATE_DICT][PARTITION_COUNT]162 163    # For ZeRO-2 each param group can have different partition_count as data parallelism for expert164    # parameters can be different from data parallelism for non-expert parameters. So we can just165    # use the max of the partition_count to get the dp world_size.166 167    if type(world_size) is list:168        world_size = max(world_size)169 170    if world_size != total_files:171        raise ValueError(172            f"Expected {world_size} of '*_optim_states.pt' under '{ds_checkpoint_dir}' but found {total_files} files. "173            "Possibly due to an overwrite of an old checkpoint, or a checkpoint didn't get saved by one or more processes."174        )175 176    # the groups are named differently in each stage177    if zero_stage <= 2:178        fp32_groups_key = SINGLE_PARTITION_OF_FP32_GROUPS179    elif zero_stage == 3:180        fp32_groups_key = FP32_FLAT_GROUPS181    else:182        raise ValueError(f"unknown zero stage {zero_stage}")183 184    fp32_flat_groups = [state_dicts[i][OPTIMIZER_STATE_DICT][fp32_groups_key] for i in range(len(state_dicts))]185    return zero_stage, world_size, fp32_flat_groups186 187 188def _get_fp32_state_dict_from_zero_checkpoint(ds_checkpoint_dir, exclude_frozen_parameters):189    """190    Returns fp32 state_dict reconstructed from ds checkpoint191 192    Args:193        - ``ds_checkpoint_dir``: path to the deepspeed checkpoint folder (where the optimizer files are)194 195    """196    print(f"Processing zero checkpoint '{ds_checkpoint_dir}'")197 198    optim_files = get_optim_files(ds_checkpoint_dir)199    zero_stage, world_size, fp32_flat_groups = parse_optim_states(optim_files, ds_checkpoint_dir)200    print(f"Detected checkpoint of type zero stage {zero_stage}, world_size: {world_size}")201 202    model_files = get_model_state_files(ds_checkpoint_dir)203 204    zero_model_states = parse_model_states(model_files)205    print(f'Parsing checkpoint created by deepspeed=={zero_model_states[0].ds_version}')206 207    if zero_stage <= 2:208        return _get_fp32_state_dict_from_zero2_checkpoint(world_size, fp32_flat_groups, zero_model_states,209                                                          exclude_frozen_parameters)210    elif zero_stage == 3:211        return _get_fp32_state_dict_from_zero3_checkpoint(world_size, fp32_flat_groups, zero_model_states,212                                                          exclude_frozen_parameters)213 214 215def _zero2_merge_frozen_params(state_dict, zero_model_states):216    if zero_model_states[0].frozen_param_shapes is None or len(zero_model_states[0].frozen_param_shapes) == 0:217        return218 219    frozen_param_shapes = zero_model_states[0].frozen_param_shapes220    frozen_param_fragments = zero_model_states[0].frozen_param_fragments221 222    if debug:223        num_elem = sum(s.numel() for s in frozen_param_shapes.values())224        print(f'rank 0: {FROZEN_PARAM_SHAPES}.numel = {num_elem}')225 226        wanted_params = len(frozen_param_shapes)227        wanted_numel = sum(s.numel() for s in frozen_param_shapes.values())228        avail_numel = sum([p.numel() for p in frozen_param_fragments.values()])229        print(f'Frozen params: Have {avail_numel} numels to process.')230        print(f'Frozen params: Need {wanted_numel} numels in {wanted_params} params')231 232    total_params = 0233    total_numel = 0234    for name, shape in frozen_param_shapes.items():235        total_params += 1236        unpartitioned_numel = shape.numel()237        total_numel += unpartitioned_numel238 239        state_dict[name] = frozen_param_fragments[name]240 241        if debug:242            print(f"{name} full shape: {shape} unpartitioned numel {unpartitioned_numel} ")243 244    print(f"Reconstructed Frozen fp32 state dict with {total_params} params {total_numel} elements")245 246 247def _has_callable(obj, fn):248    attr = getattr(obj, fn, None)249    return callable(attr)250 251 252def _zero2_merge_trainable_params(state_dict, world_size, fp32_flat_groups, zero_model_states):253    param_shapes = zero_model_states[0].param_shapes254 255    # Reconstruction protocol:256    #257    # XXX: document this258 259    if debug:260        for i in range(world_size):261            for j in range(len(fp32_flat_groups[0])):262                print(f"{FP32_FLAT_GROUPS}[{i}][{j}].shape={fp32_flat_groups[i][j].shape}")263 264    # XXX: memory usage doubles here (zero2)265    num_param_groups = len(fp32_flat_groups[0])266    merged_single_partition_of_fp32_groups = []267    for i in range(num_param_groups):268        merged_partitions = [sd[i] for sd in fp32_flat_groups]269        full_single_fp32_vector = torch.cat(merged_partitions, 0)270        merged_single_partition_of_fp32_groups.append(full_single_fp32_vector)271    avail_numel = sum(272        [full_single_fp32_vector.numel() for full_single_fp32_vector in merged_single_partition_of_fp32_groups])273 274    if debug:275        wanted_params = sum([len(shapes) for shapes in param_shapes])276        wanted_numel = sum([sum(shape.numel() for shape in shapes.values()) for shapes in param_shapes])277        # not asserting if there is a mismatch due to possible padding278        print(f"Have {avail_numel} numels to process.")279        print(f"Need {wanted_numel} numels in {wanted_params} params.")280 281    # params282    # XXX: for huge models that can't fit into the host's RAM we will have to recode this to support283    # out-of-core computing solution284    total_numel = 0285    total_params = 0286    for shapes, full_single_fp32_vector in zip(param_shapes, merged_single_partition_of_fp32_groups):287        offset = 0288        avail_numel = full_single_fp32_vector.numel()289        for name, shape in shapes.items():290 291            unpartitioned_numel = shape.numel() if _has_callable(shape, 'numel') else math.prod(shape)292            total_numel += unpartitioned_numel293            total_params += 1294 295            if debug:296                print(f"{name} full shape: {shape} unpartitioned numel {unpartitioned_numel} ")297            state_dict[name] = full_single_fp32_vector.narrow(0, offset, unpartitioned_numel).view(shape)298            offset += unpartitioned_numel299 300        # Z2 started to align to 2*world_size to improve nccl performance. Therefore both offset and301        # avail_numel can differ by anywhere between 0..2*world_size. Due to two unrelated complex302        # paddings performed in the code it's almost impossible to predict the exact numbers w/o the303        # live optimizer object, so we are checking that the numbers are within the right range304        align_to = 2 * world_size305 306        def zero2_align(x):307            return align_to * math.ceil(x / align_to)308 309        if debug:310            print(f"original offset={offset}, avail_numel={avail_numel}")311 312        offset = zero2_align(offset)313        avail_numel = zero2_align(avail_numel)314 315        if debug:316            print(f"aligned  offset={offset}, avail_numel={avail_numel}")317 318        # Sanity check319        if offset != avail_numel:320            raise ValueError(f"consumed {offset} numels out of {avail_numel} - something is wrong")321 322    print(f"Reconstructed fp32 state dict with {total_params} params {total_numel} elements")323 324 325def _get_fp32_state_dict_from_zero2_checkpoint(world_size, fp32_flat_groups, zero_model_states,326                                               exclude_frozen_parameters):327    state_dict = OrderedDict()328 329    # buffers330    buffers = zero_model_states[0].buffers331    state_dict.update(buffers)332    if debug:333        print(f"added {len(buffers)} buffers")334 335    if not exclude_frozen_parameters:336        _zero2_merge_frozen_params(state_dict, zero_model_states)337 338    _zero2_merge_trainable_params(state_dict, world_size, fp32_flat_groups, zero_model_states)339 340    # recover shared parameters341    for pair in zero_model_states[0].shared_params:342        if pair[1] in state_dict:343            state_dict[pair[0]] = state_dict[pair[1]]344 345    return state_dict346 347 348def zero3_partitioned_param_info(unpartitioned_numel, world_size):349    remainder = unpartitioned_numel % world_size350    padding_numel = (world_size - remainder) if remainder else 0351    partitioned_numel = math.ceil(unpartitioned_numel / world_size)352    return partitioned_numel, padding_numel353 354 355def _zero3_merge_frozen_params(state_dict, world_size, zero_model_states):356    if zero_model_states[0].frozen_param_shapes is None or len(zero_model_states[0].frozen_param_shapes) == 0:357        return358 359    if debug:360        for i in range(world_size):361            num_elem = sum(s.numel() for s in zero_model_states[i].frozen_param_fragments.values())362            print(f'rank {i}: {FROZEN_PARAM_SHAPES}.numel = {num_elem}')363 364        frozen_param_shapes = zero_model_states[0].frozen_param_shapes365        wanted_params = len(frozen_param_shapes)366        wanted_numel = sum(s.numel() for s in frozen_param_shapes.values())367        avail_numel = sum([p.numel() for p in zero_model_states[0].frozen_param_fragments.values()]) * world_size368        print(f'Frozen params: Have {avail_numel} numels to process.')369        print(f'Frozen params: Need {wanted_numel} numels in {wanted_params} params')370 371    total_params = 0372    total_numel = 0373    for name, shape in zero_model_states[0].frozen_param_shapes.items():374        total_params += 1375        unpartitioned_numel = shape.numel()376        total_numel += unpartitioned_numel377 378        param_frags = tuple(model_state.frozen_param_fragments[name] for model_state in zero_model_states)379        state_dict[name] = torch.cat(param_frags, 0).narrow(0, 0, unpartitioned_numel).view(shape)380 381        partitioned_numel, partitioned_padding_numel = zero3_partitioned_param_info(unpartitioned_numel, world_size)382 383        if debug:384            print(385                f"Frozen params: {total_params} {name} full shape: {shape} partition0 numel={partitioned_numel} partitioned_padding_numel={partitioned_padding_numel}"386            )387 388    print(f"Reconstructed Frozen fp32 state dict with {total_params} params {total_numel} elements")389 390 391class GatheredTensor:392    """393    A pseudo tensor that collects partitioned weights.394    It is more memory efficient when there are multiple groups.395    """396 397    def __init__(self, flat_groups, flat_groups_offset, offset, partitioned_numel, shape):398        self.flat_groups = flat_groups399        self.flat_groups_offset = flat_groups_offset400        self.offset = offset401        self.partitioned_numel = partitioned_numel402        self.shape = shape403        self.dtype = self.flat_groups[0][0].dtype404 405    def contiguous(self):406        """407        Merge partitioned weights from flat_groups into a single tensor.408        """409        end_idx = self.offset + self.partitioned_numel410        world_size = len(self.flat_groups)411        pad_flat_param_chunks = []412 413        for rank_i in range(world_size):414            # for each rank, we need to collect weights from related group/groups415            flat_groups_at_rank_i = self.flat_groups[rank_i]416            start_group_id = None417            end_group_id = None418            for group_id in range(len(self.flat_groups_offset)):419                if self.flat_groups_offset[group_id] <= self.offset < self.flat_groups_offset[group_id + 1]:420                    start_group_id = group_id421                if self.flat_groups_offset[group_id] < end_idx <= self.flat_groups_offset[group_id + 1]:422                    end_group_id = group_id423                    break424            # collect weights from related group/groups425            for group_id in range(start_group_id, end_group_id + 1):426                flat_tensor = flat_groups_at_rank_i[group_id]427                start_offset = self.offset - self.flat_groups_offset[group_id]428                end_offset = min(end_idx, self.flat_groups_offset[group_id + 1]) - self.flat_groups_offset[group_id]429                pad_flat_param_chunks.append(flat_tensor[start_offset:end_offset])430 431        # collect weights from all ranks432        pad_flat_param = torch.cat(pad_flat_param_chunks, dim=0)433        param = pad_flat_param[:self.shape.numel()].view(self.shape).contiguous()434        return param435 436 437def _zero3_merge_trainable_params(state_dict, world_size, fp32_flat_groups, zero_model_states):438    param_shapes = zero_model_states[0].param_shapes439    avail_numel = sum([flat_group.numel() for flat_group in fp32_flat_groups[0]]) * world_size440 441    # Reconstruction protocol: For zero3 we need to zip the partitions together at boundary of each442    # param, re-consolidating each param, while dealing with padding if any443 444    # merge list of dicts, preserving order445    param_shapes = {k: v for d in param_shapes for k, v in d.items()}446 447    if debug:448        for i in range(world_size):449            print(f"{FP32_FLAT_GROUPS}[{i}].shape={fp32_flat_groups[i].shape}")450 451        wanted_params = len(param_shapes)452        wanted_numel = sum(shape.numel() for shape in param_shapes.values())453        # not asserting if there is a mismatch due to possible padding454        avail_numel = fp32_flat_groups[0].numel() * world_size455        print(f"Trainable params: Have {avail_numel} numels to process.")456        print(f"Trainable params: Need {wanted_numel} numels in {wanted_params} params.")457 458    # params459    # XXX: for huge models that can't fit into the host's RAM we will have to recode this to support460    # out-of-core computing solution461    offset = 0462    total_numel = 0463    total_params = 0464    flat_groups_offset = [0] + list(np.cumsum([flat_tensor.numel() for flat_tensor in fp32_flat_groups[0]]))465    for name, shape in tqdm(param_shapes.items(), desc='Gathering sharded weights'):466        unpartitioned_numel = shape.numel()467        total_numel += unpartitioned_numel468        total_params += 1469        partitioned_numel, partitioned_padding_numel = zero3_partitioned_param_info(unpartitioned_numel, world_size)470 471        if debug:472            print(473                f"Trainable params: {total_params} {name} full shape: {shape} partition0 numel={partitioned_numel} partitioned_padding_numel={partitioned_padding_numel}"474            )475 476        # memory efficient tensor477        tensor = GatheredTensor(fp32_flat_groups, flat_groups_offset, offset, partitioned_numel, shape)478        state_dict[name] = tensor479        offset += partitioned_numel480 481    offset *= world_size482 483    # Sanity check484    if offset != avail_numel:485        raise ValueError(f"consumed {offset} numels out of {avail_numel} - something is wrong")486 487    print(f"Reconstructed Trainable fp32 state dict with {total_params} params {total_numel} elements")488 489 490def _get_fp32_state_dict_from_zero3_checkpoint(world_size, fp32_flat_groups, zero_model_states,491                                               exclude_frozen_parameters):492    state_dict = OrderedDict()493 494    # buffers495    buffers = zero_model_states[0].buffers496    state_dict.update(buffers)497    if debug:498        print(f"added {len(buffers)} buffers")499 500    if not exclude_frozen_parameters:501        _zero3_merge_frozen_params(state_dict, world_size, zero_model_states)502 503    _zero3_merge_trainable_params(state_dict, world_size, fp32_flat_groups, zero_model_states)504 505    # recover shared parameters506    for pair in zero_model_states[0].shared_params:507        if pair[1] in state_dict:508            state_dict[pair[0]] = state_dict[pair[1]]509 510    return state_dict511 512 513def to_torch_tensor(state_dict, return_empty_tensor=False):514    """515    Convert state_dict of GatheredTensor to torch tensor516    """517    torch_state_dict = {}518    converted_tensors = {}519    for name, tensor in state_dict.items():520        tensor_id = id(tensor)521        if tensor_id in converted_tensors:  # shared tensors522            shared_tensor = torch_state_dict[converted_tensors[tensor_id]]523            torch_state_dict[name] = shared_tensor524        else:525            converted_tensors[tensor_id] = name526            if return_empty_tensor:527                torch_state_dict[name] = torch.empty(tensor.shape, dtype=tensor.dtype)528            else:529                torch_state_dict[name] = tensor.contiguous()530    return torch_state_dict531 532 533def get_fp32_state_dict_from_zero_checkpoint(checkpoint_dir,534                                             tag=None,535                                             exclude_frozen_parameters=False,536                                             lazy_mode=False):537    """538    Convert ZeRO 2 or 3 checkpoint into a single fp32 consolidated state_dict that can be loaded with539    ``load_state_dict()`` and used for training without DeepSpeed or shared with others, for example540    via a model hub.541 542    Args:543        - ``checkpoint_dir``: path to the desired checkpoint folder544        - ``tag``: checkpoint tag used as a unique identifier for checkpoint. If not provided will attempt to load tag in 'latest' file. e.g., ``global_step14``545        - ``exclude_frozen_parameters``: exclude frozen parameters546        - ``lazy_mode``: get state_dict in lazy mode. It returns a dict of pesduo tensor instead of torch tensor, which is more memory efficient.547          Convert the pesduo tensor to torch tensor by ``.contiguous()``548 549    Returns:550        - pytorch ``state_dict``551 552    A typical usage might be ::553 554        from deepspeed.utils.zero_to_fp32 import get_fp32_state_dict_from_zero_checkpoint555        # do the training and checkpoint saving556        state_dict = get_fp32_state_dict_from_zero_checkpoint(checkpoint_dir) # already on cpu557        model = model.cpu() # move to cpu558        model.load_state_dict(state_dict)559        # submit to model hub or save the model to share with others560 561    In this example the ``model`` will no longer be usable in the deepspeed context of the same562    application. i.e. you will need to re-initialize the deepspeed engine, since563    ``model.load_state_dict(state_dict)`` will remove all the deepspeed magic from it.564 565    If you want it all done for you, use ``load_state_dict_from_zero_checkpoint`` instead.566 567    Note: the above usage may not work if your application doesn't have sufficient free CPU memory.568    You may need to use the offline approach using the ``zero_to_fp32.py`` script that is saved with569    the checkpoint. Or you can load state_dict in lazy mode ::570 571        from deepspeed.utils.zero_to_fp32 import get_fp32_state_dict_from_zero_checkpoint572        state_dict = get_fp32_state_dict_from_zero_checkpoint(checkpoint_dir, lazy_mode=True) # not on cpu573        for name, lazy_tensor in state_dict.item():574            tensor = lazy_tensor.contiguous()  # to cpu575            print(name, tensor)576            # del tensor to release memory if it no longer in use577    """578    if tag is None:579        latest_path = os.path.join(checkpoint_dir, 'latest')580        if os.path.isfile(latest_path):581            with open(latest_path, 'r') as fd:582                tag = fd.read().strip()583        else:584            raise ValueError(f"Unable to find 'latest' file at {latest_path}")585 586    ds_checkpoint_dir = os.path.join(checkpoint_dir, tag)587 588    if not os.path.isdir(ds_checkpoint_dir):589        raise FileNotFoundError(f"Directory '{ds_checkpoint_dir}' doesn't exist")590 591    state_dict = _get_fp32_state_dict_from_zero_checkpoint(ds_checkpoint_dir, exclude_frozen_parameters)592    if lazy_mode:593        return state_dict594    else:595        return to_torch_tensor(state_dict)596 597 598def convert_zero_checkpoint_to_fp32_state_dict(checkpoint_dir,599                                               output_dir,600                                               max_shard_size="5GB",601                                               safe_serialization=False,602                                               tag=None,603                                               exclude_frozen_parameters=False):604    """605    Convert ZeRO 2 or 3 checkpoint into a single fp32 consolidated ``state_dict`` file that can be606    loaded with ``torch.load(file)`` + ``load_state_dict()`` and used for training without DeepSpeed.607 608    Args:609        - ``checkpoint_dir``: path to the desired checkpoint folder. (one that contains the tag-folder, like ``global_step14``)610        - ``output_dir``: directory to the pytorch fp32 state_dict output files611        - ``max_shard_size``: the maximum size for a checkpoint before being sharded, default value is 5GB612        - ``safe_serialization``:  whether to save the model using `safetensors` or the traditional PyTorch way (that uses `pickle`).613        - ``tag``: checkpoint tag used as a unique identifier for checkpoint. If not provided will attempt to load tag in the file named ``latest`` in the checkpoint folder, e.g., ``global_step14``614        - ``exclude_frozen_parameters``: exclude frozen parameters615    """616 617    # Dependency pre-check618    if safe_serialization:619        try:620            from safetensors.torch import save_file621        except ImportError:622            print('If you want to use `safe_serialization`, please `pip install safetensors`')623            raise624    if max_shard_size is not None:625        try:626            from huggingface_hub import split_torch_state_dict_into_shards627        except ImportError:628            print('If you want to use `max_shard_size`, please `pip install huggingface_hub`')629            raise630 631    # Convert zero checkpoint to state_dict632    state_dict = get_fp32_state_dict_from_zero_checkpoint(checkpoint_dir,633                                                          tag,634                                                          exclude_frozen_parameters,635                                                          lazy_mode=True)636 637    # Shard the model if it is too big.638    weights_name = "model.safetensors" if safe_serialization else "pytorch_model.bin"639    if max_shard_size is not None:640        filename_pattern = weights_name.replace(".bin", "{suffix}.bin").replace(".safetensors", "{suffix}.safetensors")641        # an memory-efficient approach for sharding642        empty_state_dict = to_torch_tensor(state_dict, return_empty_tensor=True)643        state_dict_split = split_torch_state_dict_into_shards(empty_state_dict,644                                                              filename_pattern=filename_pattern,645                                                              max_shard_size=max_shard_size)646    else:647        from collections import namedtuple648        StateDictSplit = namedtuple("StateDictSplit", ["is_sharded", "filename_to_tensors"])649        state_dict_split = StateDictSplit(is_sharded=False,650                                          filename_to_tensors={weights_name: list(state_dict.keys())})651 652    # Save the model by shard653    os.makedirs(output_dir, exist_ok=True)654    filename_to_tensors = state_dict_split.filename_to_tensors.items()655    for shard_file, tensors in tqdm(filename_to_tensors, desc="Saving checkpoint shards"):656        shard_state_dict = {tensor_name: state_dict[tensor_name] for tensor_name in tensors}657        shard_state_dict = to_torch_tensor(shard_state_dict)658        output_path = os.path.join(output_dir, shard_file)659        if safe_serialization:660            save_file(shard_state_dict, output_path, metadata={"format": "pt"})661        else:662            torch.save(shard_state_dict, output_path)663        # release the memory of current shard664        for tensor_name in list(shard_state_dict.keys()):665            del state_dict[tensor_name]666            del shard_state_dict[tensor_name]667        del shard_state_dict668        gc.collect()669 670    # Save index if sharded671    if state_dict_split.is_sharded:672        index = {673            "metadata": state_dict_split.metadata,674            "weight_map": state_dict_split.tensor_to_filename,675        }676        save_index_file = "model.safetensors.index.json" if safe_serialization else "pytorch_model.bin.index.json"677        save_index_file = os.path.join(output_dir, save_index_file)678        with open(save_index_file, "w", encoding="utf-8") as f:679            content = json.dumps(index, indent=2, sort_keys=True) + "\n"680            f.write(content)681 682 683def load_state_dict_from_zero_checkpoint(model, checkpoint_dir, tag=None):684    """685    1. Put the provided model to cpu686    2. Convert ZeRO 2 or 3 checkpoint into a single fp32 consolidated ``state_dict``687    3. Load it into the provided model688 689    Args:690        - ``model``: the model object to update691        - ``checkpoint_dir``: path to the desired checkpoint folder. (one that contains the tag-folder, like ``global_step14``)692        - ``tag``: checkpoint tag used as a unique identifier for checkpoint. If not provided will attempt to load tag in the file named ``latest`` in the checkpoint folder, e.g., ``global_step14``693 694    Returns:695        - ``model`: modified model696 697    Make sure you have plenty of CPU memory available before you call this function. If you don't698    have enough use the ``zero_to_fp32.py`` utility to do the conversion. You will find it699    conveniently placed for you in the checkpoint folder.700 701    A typical usage might be ::702 703        from deepspeed.utils.zero_to_fp32 import load_state_dict_from_zero_checkpoint704        model = load_state_dict_from_zero_checkpoint(trainer.model, checkpoint_dir)705        # submit to model hub or save the model to share with others706 707    Note, that once this was run, the ``model`` will no longer be usable in the deepspeed context708    of the same application. i.e. you will need to re-initialize the deepspeed engine, since709    ``model.load_state_dict(state_dict)`` will remove all the deepspeed magic from it.710 711    """712    logger.info("Extracting fp32 weights")713    state_dict = get_fp32_state_dict_from_zero_checkpoint(checkpoint_dir, tag)714 715    logger.info("Overwriting model with fp32 weights")716    model = model.cpu()717    model.load_state_dict(state_dict, strict=False)718 719    return model720 721 722if __name__ == "__main__":723    parser = argparse.ArgumentParser()724    parser.add_argument("checkpoint_dir",725                        type=str,726                        help="path to the desired checkpoint folder, e.g., path/checkpoint-12")727    parser.add_argument("output_dir",728                        type=str,729                        help="directory to the pytorch fp32 state_dict output files"730                        "(e.g. path/checkpoint-12-output/)")731    parser.add_argument(732        "--max_shard_size",733        type=str,734        default="5GB",735        help="The maximum size for a checkpoint before being sharded. Checkpoints shard will then be each of size"736        "lower than this size. If expressed as a string, needs to be digits followed by a unit (like `5MB`"737        "We default it to 5GB in order for models to be able to run easily on free-tier google colab instances"738        "without CPU OOM issues.")739    parser.add_argument(740        "--safe_serialization",741        default=False,742        action='store_true',743        help="Whether to save the model using `safetensors` or the traditional PyTorch way (that uses `pickle`).")744    parser.add_argument("-t",745                        "--tag",746                        type=str,747                        default=None,748                        help="checkpoint tag used as a unique identifier for checkpoint. e.g., global_step1")749    parser.add_argument("--exclude_frozen_parameters", action='store_true', help="exclude frozen parameters")750    parser.add_argument("-d", "--debug", action='store_true', help="enable debug")751    args = parser.parse_args()752 753    debug = args.debug754 755    convert_zero_checkpoint_to_fp32_state_dict(args.checkpoint_dir,756                                               args.output_dir,757                                               max_shard_size=args.max_shard_size,758                                               safe_serialization=args.safe_serialization,759                                               tag=args.tag,760                                               exclude_frozen_parameters=args.exclude_frozen_parameters)761