# Copyright 2020 The HuggingFace Team. 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. """ Integration with Deepspeed """ import importlib.metadata as importlib_metadata import importlib.util import weakref from functools import partialmethod from ..dependency_versions_check import dep_version_check from ..utils import is_accelerate_available, is_torch_available, logging if is_torch_available(): import torch from ..optimization import get_scheduler logger = logging.get_logger(__name__) def is_deepspeed_available(): package_exists = importlib.util.find_spec("deepspeed") is not None # Check we're not importing a "deepspeed" directory somewhere but the actual library by trying to grab the version # AND checking it has an author field in the metadata that is HuggingFace. if package_exists: try: _ = importlib_metadata.metadata("deepspeed") return True except importlib_metadata.PackageNotFoundError: return False if is_accelerate_available() and is_deepspeed_available(): from accelerate.utils.deepspeed import HfDeepSpeedConfig as DeepSpeedConfig else: # Inherits from a dummy `object` if accelerate is not available, so that python succeeds to import this file. # Deepspeed glue code will never inherit this dummy object as it checks if accelerate is available. from builtins import object as DeepSpeedConfig class HfDeepSpeedConfig(DeepSpeedConfig): """ This object contains a DeepSpeed configuration dictionary and can be quickly queried for things like zero stage. A `weakref` of this object is stored in the module's globals to be able to access the config from areas where things like the Trainer object is not available (e.g. `from_pretrained` and `_get_resized_embeddings`). Therefore it's important that this object remains alive while the program is still running. [`Trainer`] uses the `HfTrainerDeepSpeedConfig` subclass instead. That subclass has logic to sync the configuration with values of [`TrainingArguments`] by replacing special placeholder values: `"auto"`. Without this special logic the DeepSpeed configuration is not modified in any way. Args: config_file_or_dict (`Union[str, Dict]`): path to DeepSpeed config file or dict. """ def __init__(self, config_file_or_dict): # set global weakref object set_hf_deepspeed_config(self) dep_version_check("accelerate") dep_version_check("deepspeed") super().__init__(config_file_or_dict) class HfTrainerDeepSpeedConfig(HfDeepSpeedConfig): """ The `HfTrainerDeepSpeedConfig` object is meant to be created during `TrainingArguments` object creation and has the same lifespan as the latter. """ def __init__(self, config_file_or_dict): super().__init__(config_file_or_dict) self._dtype = None self.mismatches = [] def dtype(self): if self._dtype is None: raise ValueError("trainer_config_process() wasn't called yet to tell dtype") return self._dtype def is_auto(self, ds_key_long): val = self.get_value(ds_key_long) if val is None: return False else: return val == "auto" def fill_match(self, ds_key_long, hf_val, hf_key=None, must_match=True): """ A utility method that massages the config file and can optionally verify that the values match. 1. Replace "auto" values with `TrainingArguments` value. 2. If it wasn't "auto" and `must_match` is true, then check that DS config matches Trainer config values and if mismatched add the entry to `self.mismatched` - will assert during `trainer_config_finalize` for one or more mismatches. """ config, ds_key = self.find_config_node(ds_key_long) if config is None: return if config.get(ds_key) == "auto": config[ds_key] = hf_val return if not must_match: return ds_val = config.get(ds_key) if ds_val is not None and ds_val != hf_val: self.mismatches.append(f"- ds {ds_key_long}={ds_val} vs hf {hf_key}={hf_val}") fill_only = partialmethod(fill_match, must_match=False) def trainer_config_process(self, args): """ Adjust the config with `TrainingArguments` values. This stage is run during `TrainingArguments` object creation. """ # DeepSpeed does: # train_batch_size = world_size * train_micro_batch_size_per_gpu * gradient_accumulation_steps train_batch_size = args.world_size * args.per_device_train_batch_size * args.gradient_accumulation_steps self.fill_match( "train_micro_batch_size_per_gpu", args.per_device_train_batch_size, "per_device_train_batch_size" ) self.fill_match("gradient_accumulation_steps", args.gradient_accumulation_steps, "gradient_accumulation_steps") self.fill_match("train_batch_size", train_batch_size, "train_batch_size (calculated)") self.fill_match("gradient_clipping", args.max_grad_norm, "max_grad_norm") self.fill_match("optimizer.params.lr", args.learning_rate, "learning_rate") self.fill_match("optimizer.params.betas", [args.adam_beta1, args.adam_beta2], "adam_beta1+adam_beta2") self.fill_match("optimizer.params.eps", args.adam_epsilon, "adam_epsilon") self.fill_match("optimizer.params.weight_decay", args.weight_decay, "weight_decay") self.fill_only("scheduler.params.warmup_min_lr", 0) # not a trainer arg self.fill_match("scheduler.params.warmup_max_lr", args.learning_rate, "learning_rate") # total_num_steps - will get set in trainer_config_finalize # fp16 if args.fp16 or args.fp16_full_eval: fp16_backend = "apex" if args.fp16_backend == "apex" else "amp" else: fp16_backend = None if args.save_on_each_node: # deepspeed uses shared storage by default. Let's override this setting if save_on_each_node == True self.config["checkpoint"] = self.config.get("checkpoint", {}) self.config["checkpoint"]["use_node_local_storage"] = args.save_on_each_node # amp: similar to the pytorch native amp - it has a bunch of optional params but we won't set # any here unless the user did the work self.fill_match( "fp16.enabled", ((args.fp16 or args.fp16_full_eval) and fp16_backend == "amp"), "fp16|fp16_full_eval+fp16_backend(amp)", ) # apex: delegates amp work to apex (which needs to be available), but it cannot be used with any # ZeRO features self.fill_match("amp.enabled", fp16_backend == "apex", "fp16+fp16_backend(apex)") self.fill_match("amp.opt_level", args.fp16_opt_level, "fp16_opt_level") self.fill_match("bf16.enabled", (args.bf16 or args.bf16_full_eval), "bf16|bf16_full_eval") # deepspeed's default mode is fp16 unless there is a config that says differently if self.is_true("bf16.enabled"): self._dtype = torch.bfloat16 elif self.is_false("fp16.enabled"): self._dtype = torch.float32 else: self._dtype = torch.float16 def trainer_config_finalize(self, args, model, num_training_steps): """ This stage is run after we have the model and know num_training_steps. Now we can complete the configuration process. """ # zero # deal with config keys that use `auto` value and rely on model's hidden_size hidden_size_based_keys = [ "zero_optimization.reduce_bucket_size", "zero_optimization.stage3_prefetch_bucket_size", "zero_optimization.stage3_param_persistence_threshold", ] hidden_size_auto_keys = [x for x in hidden_size_based_keys if self.is_auto(x)] if len(hidden_size_auto_keys) > 0: if hasattr(model.config, "hidden_size"): hidden_size = model.config.hidden_size elif hasattr(model.config, "hidden_sizes"): # if there are many hidden sizes pick the largest one hidden_size = max(model.config.hidden_sizes) else: raise ValueError( "The model's config file has neither `hidden_size` nor `hidden_sizes` entry, " "therefore it's not possible to automatically fill out the following `auto` entries " f"in the DeepSpeed config file: {hidden_size_auto_keys}. You can fix that by replacing " "`auto` values for these keys with an integer value of your choice." ) self.fill_only("zero_optimization.reduce_bucket_size", hidden_size * hidden_size) if self.is_zero3(): # automatically assign the optimal config values based on model config self.fill_only("zero_optimization.stage3_prefetch_bucket_size", 0.9 * hidden_size * hidden_size) self.fill_only("zero_optimization.stage3_param_persistence_threshold", 10 * hidden_size) # scheduler self.fill_match("scheduler.params.total_num_steps", num_training_steps, "num_training_steps (calculated)") self.fill_match("scheduler.params.warmup_num_steps", args.get_warmup_steps(num_training_steps), "warmup_steps") if len(self.mismatches) > 0: mismatches = "\n".join(self.mismatches) raise ValueError( "Please correct the following DeepSpeed config values that mismatch TrainingArguments" f" values:\n{mismatches}\nThe easiest method is to set these DeepSpeed config values to 'auto'." ) # keep the config object global to be able to access it anywhere during TrainingArguments life-cycle _hf_deepspeed_config_weak_ref = None def set_hf_deepspeed_config(hf_deepspeed_config_obj): # this is a special weakref global object to allow us to get to Deepspeed config from APIs # that don't have an easy way to get to the Deepspeed config outside of the Trainer domain. global _hf_deepspeed_config_weak_ref # will go away automatically when HfDeepSpeedConfig is destroyed (when TrainingArguments is destroyed) _hf_deepspeed_config_weak_ref = weakref.ref(hf_deepspeed_config_obj) def unset_hf_deepspeed_config(): # useful for unit tests to ensure the global state doesn't leak - call from `tearDown` method global _hf_deepspeed_config_weak_ref _hf_deepspeed_config_weak_ref = None def is_deepspeed_zero3_enabled(): if _hf_deepspeed_config_weak_ref is not None and _hf_deepspeed_config_weak_ref() is not None: return _hf_deepspeed_config_weak_ref().is_zero3() else: return False def deepspeed_config(): if _hf_deepspeed_config_weak_ref is not None and _hf_deepspeed_config_weak_ref() is not None: return _hf_deepspeed_config_weak_ref().config else: return None def deepspeed_optim_sched(trainer, hf_deepspeed_config, args, num_training_steps, model_parameters): """ A convenience wrapper that deals with optimizer and lr scheduler configuration. """ from accelerate.utils import DummyOptim, DummyScheduler config = hf_deepspeed_config.config # Optimizer + Scheduler # Currently supported combos: # 1. DS scheduler + DS optimizer: Yes # 2. HF scheduler + HF optimizer: Yes # 3. DS scheduler + HF optimizer: Yes # 4. HF scheduler + DS optimizer: No # # Unless Offload is enabled in which case it's: # 1. DS scheduler + DS optimizer: Yes # 2. HF scheduler + HF optimizer: Mostly* # 3. DS scheduler + HF optimizer: Mostly* # 4. HF scheduler + DS optimizer: Yes # # Mostly*: All non-native DeepSpeed optimizers that have both CPU and GPU implementation should work (except LAMB) optimizer = None if "optimizer" in config: if args.adafactor: raise ValueError( "--adafactor was passed, but also found `optimizer` configured in the DeepSpeed config. " "Only one optimizer can be configured." ) optimizer = DummyOptim(params=model_parameters) else: if hf_deepspeed_config.is_offload(): logger.info( "Detected ZeRO Offload and non-DeepSpeed optimizers: This combination should work as long as the" " custom optimizer has both CPU and GPU implementation (except LAMB)" ) # ds supports Adam, OneBitAdam, and Lamb optimizers and can import other optimizers from torch. # But trainer uses AdamW by default. optimizer = trainer.create_optimizer() # To use other optimizers requires voiding warranty with: `zero_allow_untested_optimizer` config["zero_allow_untested_optimizer"] = True lr_scheduler = None if "scheduler" in config: lr_scheduler = DummyScheduler(optimizer) else: if isinstance(optimizer, DummyOptim): def _lr_scheduler_callable(optimizer): return get_scheduler( trainer.args.lr_scheduler_type, optimizer=optimizer, num_warmup_steps=trainer.args.get_warmup_steps(num_training_steps), num_training_steps=num_training_steps, ) lr_scheduler = DummyScheduler(optimizer, lr_scheduler_callable=_lr_scheduler_callable) else: lr_scheduler = trainer.create_scheduler(num_training_steps=num_training_steps, optimizer=optimizer) return optimizer, lr_scheduler def deepspeed_init(trainer, num_training_steps, inference=False): """ Init DeepSpeed, after updating the DeepSpeed configuration with any relevant Trainer's args. If `resume_from_checkpoint` was passed then an attempt to resume from a previously saved checkpoint will be made. Args: trainer: Trainer object num_training_steps: per single gpu resume_from_checkpoint: path to a checkpoint if to resume from after normal DeepSpeedEngine load inference: launch in inference mode (no optimizer and no lr scheduler) Returns: optimizer, lr_scheduler We may use `deepspeed_init` more than once during the life of Trainer, when we do - it's a temp hack based on: https://github.com/microsoft/DeepSpeed/issues/1394#issuecomment-937405374 until Deepspeed fixes a bug where it can't resume from a checkpoint after it did some stepping https://github.com/microsoft/DeepSpeed/issues/1612 """ from deepspeed.utils import logger as ds_logger model = trainer.model args = trainer.args hf_deepspeed_config = trainer.accelerator.state.deepspeed_plugin.hf_ds_config # resume config update - some bits like `model` and `num_training_steps` only become available during train hf_deepspeed_config.trainer_config_finalize(args, model, num_training_steps) # set the Deepspeed log level consistent with the Trainer ds_logger.setLevel(args.get_process_log_level()) if inference: # only Z3 makes sense for the inference if not hf_deepspeed_config.is_zero3(): raise ValueError("ZeRO inference only makes sense with ZeRO Stage 3 - please adjust your config") # in case the training config is re-used for inference hf_deepspeed_config.del_config_sub_tree("optimizer") hf_deepspeed_config.del_config_sub_tree("lr_scheduler") optimizer, lr_scheduler = None, None model_parameters = None else: trainer.optimizer = None # important for when deepspeed_init is used as re-init model_parameters = list(filter(lambda p: p.requires_grad, model.parameters())) optimizer, lr_scheduler = deepspeed_optim_sched( trainer, hf_deepspeed_config, args, num_training_steps, model_parameters ) # keep for quick debug: # from pprint import pprint; pprint(config) return optimizer, lr_scheduler def deepspeed_load_checkpoint(deepspeed_engine, checkpoint_path): # it's possible that the user is trying to resume from model_path, which doesn't necessarily # contain a deepspeed checkpoint. e.g. examples just check if the dir exists and assume it's # a resume from a checkpoint and not just a local pretrained weight. So we check here if the # path contains what looks like a deepspeed checkpoint import glob deepspeed_checkpoint_dirs = sorted(glob.glob(f"{checkpoint_path}/global_step*")) if len(deepspeed_checkpoint_dirs) > 0: logger.info(f"Attempting to resume from {checkpoint_path}") # this magically updates self.optimizer and self.lr_scheduler load_path, _ = deepspeed_engine.load_checkpoint( checkpoint_path, load_optimizer_states=True, load_lr_scheduler_states=True ) if load_path is None: raise ValueError(f"[deepspeed] failed to resume from checkpoint {checkpoint_path}") else: raise ValueError(f"Can't find a valid checkpoint at {checkpoint_path}")