import torch import tqdm import numpy as np from pytorch_lightning.root_module.memory import get_gpu_memory_map import traceback from pytorch_lightning.root_module.model_saving import TrainerIO from torch.optim.lr_scheduler import MultiStepLR import pdb try: from apex import amp APEX_AVAILABLE = True except ModuleNotFoundError: APEX_AVAILABLE = False class Trainer(TrainerIO): def __init__(self, experiment, checkpoint_callback, early_stop_callback, cluster=None, process_position=0, current_gpu_name=0, on_gpu=False, enable_tqdm=True, overfit_pct=0.0, track_grad_norm=-1, check_val_every_n_epoch=1, fast_dev_run=False, accumulate_grad_batches=1, enable_early_stop=True, max_nb_epochs=5, min_nb_epochs=1, train_percent_check=1.0, val_percent_check=1.0, test_percent_check=1.0, val_check_interval=0.95, log_save_interval=1, add_log_row_interval=1, lr_scheduler_milestones=None, use_amp=False, nb_sanity_val_steps=5): # Transfer params self.check_val_every_n_epoch = check_val_every_n_epoch self.enable_early_stop = enable_early_stop self.track_grad_norm = track_grad_norm self.fast_dev_run = fast_dev_run self.on_gpu = on_gpu self.enable_tqdm = enable_tqdm self.experiment = experiment self.exp_save_path = experiment.get_data_path(experiment.name, experiment.version) self.cluster = cluster self.process_position = process_position self.current_gpu_name = current_gpu_name self.checkpoint_callback = checkpoint_callback self.checkpoint_callback.save_function = self.save_checkpoint self.early_stop = early_stop_callback self.model = None self.max_nb_epochs = max_nb_epochs self.accumulate_grad_batches = accumulate_grad_batches self.early_stop_callback = early_stop_callback self.min_nb_epochs = min_nb_epochs self.nb_sanity_val_steps = nb_sanity_val_steps self.lr_scheduler_milestones = [] if lr_scheduler_milestones is None else [int(x.strip()) for x in lr_scheduler_milestones.split(',')] self.lr_schedulers = [] # training state self.optimizers = None self.prog_bar = None self.global_step = 0 self.current_epoch = 0 self.total_batches = 0 # logging self.log_save_interval = log_save_interval self.val_check_interval = val_check_interval self.add_log_row_interval = add_log_row_interval # dataloaders self.tng_dataloader = None self.test_dataloader = None self.val_dataloader = None # how much of the data to use self.__determine_data_use_amount(train_percent_check, val_percent_check, test_percent_check, overfit_pct) print('gpu available: {}, used: {}'.format(torch.cuda.is_available(), self.on_gpu)) # apex test self.use_amp = use_amp and APEX_AVAILABLE if self.use_amp: print('using 16bit precision') def __determine_data_use_amount(self, train_percent_check, val_percent_check, test_percent_check, overfit_pct): """ Use less data for debugging purposes """ self.train_percent_check = train_percent_check self.val_percent_check = val_percent_check self.test_percent_check = test_percent_check if overfit_pct > 0: self.train_percent_check = overfit_pct self.val_percent_check = overfit_pct self.test_percent_check = overfit_pct def __is_function_implemented(self, f_name): f_op = getattr(self.model, f_name, None) return callable(f_op) @property def __tng_tqdm_dic(self): tqdm_dic = { 'tng_loss': '{0:.3f}'.format(self.avg_loss), 'gpu': '{}'.format(self.current_gpu_name), 'v_nb': '{}'.format(self.experiment.version), 'epoch': '{}'.format(self.current_epoch), 'batch_nb':'{}'.format(self.batch_nb), } tqdm_dic.update(self.tqdm_metrics) return tqdm_dic def __layout_bookeeping(self): # training bookeeping self.total_batch_nb = 0 self.running_loss = [] self.avg_loss = 0 self.batch_nb = 0 self.tqdm_metrics = {} # determine number of training batches nb_tng_batches = self.model.nb_batches(self.tng_dataloader) self.nb_tng_batches = int(nb_tng_batches * self.train_percent_check) # determine number of validation batches nb_val_batches = self.model.nb_batches(self.val_dataloader) nb_val_batches = int(nb_val_batches * self.val_percent_check) nb_val_batches = max(1, nb_val_batches) self.nb_val_batches = nb_val_batches # determine number of test batches nb_test_batches = self.model.nb_batches(self.test_dataloader) self.nb_test_batches = int(nb_test_batches * self.test_percent_check) # determine when to check validation self.val_check_batch = int(nb_tng_batches * self.val_check_interval) def __add_tqdm_metrics(self, metrics): for k, v in metrics.items(): self.tqdm_metrics[k] = v def validate(self, model, dataloader, max_batches): """ Run validation code :param model: PT model :param dataloader: PT dataloader :param max_batches: Scalar :return: """ print('validating...') # enable eval mode model.zero_grad() model.eval() # disable gradients to save memory torch.set_grad_enabled(False) # bookkeeping outputs = [] # run training for i, data_batch in enumerate(dataloader): if data_batch is None: continue # stop short when on fast dev run if max_batches is not None and i >= max_batches: break # ----------------- # RUN VALIDATION STEP # ----------------- output = model.validation_step(data_batch) outputs.append(output) # batch done if self.enable_tqdm and self.prog_bar is not None: self.prog_bar.update(1) # give model a chance to do something with the outputs val_results = model.validation_end(outputs) # enable train mode again model.train() # enable gradients to save memory torch.set_grad_enabled(True) return val_results def __get_dataloaders(self, model): """ Dataloaders are provided by the model :param model: :return: """ self.tng_dataloader = model.tng_dataloader self.test_dataloader = model.test_dataloader self.val_dataloader = model.val_dataloader # ----------------------------- # MODEL TRAINING # ----------------------------- def fit(self, model): self.model = model model.trainer = self # transfer data loaders from model self.__get_dataloaders(model) # init training constants self.__layout_bookeeping() # CHOOSE OPTIMIZER # filter out the weights that were done on gpu so we can load on good old cpus self.optimizers = model.configure_optimizers() if self.use_amp: # An example self.model, optimizer = amp.initialize( self.model, self.optimizers[0], opt_level="O2", ) self.optimizers[0] = optimizer model.trainer = self # add lr schedulers if self.lr_scheduler_milestones is not None: for optimizer in self.optimizers: scheduler = MultiStepLR(optimizer, self.lr_scheduler_milestones) self.lr_schedulers.append(scheduler) # print model summary model.summarize() # put on gpu if needed if self.on_gpu: model = model.cuda() # run tiny validation to make sure program won't crash during val _ = self.validate(model, self.val_dataloader, max_batches=self.nb_sanity_val_steps) # save exp to get started self.experiment.save() # enable cluster checkpointing if self.cluster is not None: self.enable_auto_hpc_walltime_manager() # --------------------------- # CORE TRAINING LOOP # --------------------------- self.__train() def __train(self): # run all epochs for epoch_nb in range(self.current_epoch, self.max_nb_epochs): # update the lr scheduler for lr_scheduler in self.lr_schedulers: lr_scheduler.step() self.model.current_epoch = epoch_nb # hook if self.__is_function_implemented('on_epoch_start'): self.model.on_epoch_start() self.current_epoch = epoch_nb self.total_batches = self.nb_tng_batches + self.nb_val_batches self.batch_loss_value = 0 # accumulated grads # init progbar when requested if self.enable_tqdm: self.prog_bar = tqdm.tqdm(range(self.total_batches), position=self.process_position) for batch_nb, data_batch in enumerate(self.tng_dataloader): self.batch_nb = batch_nb self.global_step += 1 self.model.global_step = self.global_step # stop when the flag is changed or we've gone past the amount requested in the batches self.total_batch_nb += 1 met_batch_limit = batch_nb > self.nb_tng_batches if met_batch_limit: break # --------------- # RUN TRAIN STEP # --------------- batch_result = self.__run_tng_batch(data_batch) early_stop_epoch = batch_result == -1 # --------------- # RUN VAL STEP # --------------- is_val_check_batch = (batch_nb + 1) % self.val_check_batch == 0 if self.fast_dev_run or is_val_check_batch or early_stop_epoch: self.__run_validation() # when batch should be saved if (batch_nb + 1) % self.log_save_interval == 0 or early_stop_epoch: self.experiment.save() # when metrics should be logged if batch_nb % self.add_log_row_interval == 0 or early_stop_epoch: # count items in memory # nb_params, nb_tensors = count_mem_items() metrics = self.model.update_tng_log_metrics(self.__tng_tqdm_dic) # add gpu memory if self.on_gpu: mem_map = get_gpu_memory_map() metrics.update(mem_map) # add norms if self.track_grad_norm > 0: grad_norm_dic = self.model.grad_norm(self.track_grad_norm) metrics.update(grad_norm_dic) # log metrics self.experiment.log(metrics) self.experiment.save() # hook if self.__is_function_implemented('on_batch_end'): self.model.on_batch_end() # end epoch early if early_stop_epoch: break # hook if self.__is_function_implemented('on_epoch_end'): self.model.on_epoch_end() # early stopping if self.enable_early_stop: should_stop = self.early_stop_callback.on_epoch_end(epoch=epoch_nb, logs=self.__tng_tqdm_dic) met_min_epochs = epoch_nb > self.min_nb_epochs # stop training stop = should_stop and met_min_epochs if stop: return def __run_tng_batch(self, data_batch): if data_batch is None: return 0 # hook if self.__is_function_implemented('on_batch_start'): response = self.model.on_batch_start(data_batch) if response == -1: return -1 if self.enable_tqdm: self.prog_bar.update(1) # forward pass # return a scalar value and a dic with tqdm metrics loss, model_specific_tqdm_metrics_dic = self.model.training_step(data_batch) self.__add_tqdm_metrics(model_specific_tqdm_metrics_dic) # backward pass if self.use_amp: for optimizer in self.optimizers: with amp.scale_loss(loss, optimizer) as scaled_loss: scaled_loss.backward() else: loss.backward() self.batch_loss_value += loss.item() # gradient update with accumulated gradients if (self.batch_nb + 1) % self.accumulate_grad_batches == 0: # update gradients across all optimizers for optimizer in self.optimizers: optimizer.step() # clear gradients optimizer.zero_grad() # queuing loss across batches blows it up proportionally... divide out the number accumulated self.batch_loss_value = self.batch_loss_value / self.accumulate_grad_batches # track loss self.running_loss.append(self.batch_loss_value) self.batch_loss_value = 0 self.avg_loss = np.mean(self.running_loss[-100:]) # update progbar if self.enable_tqdm: # add model specific metrics tqdm_metrics = self.__tng_tqdm_dic self.prog_bar.set_postfix(**tqdm_metrics) # activate batch end hook if self.__is_function_implemented('on_batch_end'): self.model.on_batch_end() return 0 def __run_validation(self): # decide if can check epochs can_check_epoch = (self.current_epoch + 1) % self.check_val_every_n_epoch == 0 if self.fast_dev_run: print('skipping to check performance bc of --fast_dev_run') elif not can_check_epoch: return try: # hook if self.__is_function_implemented('on_pre_performance_check'): self.model.on_pre_performance_check() # use full val set on end of epoch # use a small portion otherwise max_batches = None if not self.fast_dev_run else 1 model_specific_tqdm_metrics_dic = self.validate( self.model, self.val_dataloader, max_batches ) self.__add_tqdm_metrics(model_specific_tqdm_metrics_dic) # hook if self.__is_function_implemented('on_post_performance_check'): self.model.on_post_performance_check() except Exception as e: print(e) print(traceback.print_exc()) if self.enable_tqdm: # add model specific metrics tqdm_metrics = self.__tng_tqdm_dic self.prog_bar.set_postfix(**tqdm_metrics) # model checkpointing print('save callback...') self.checkpoint_callback.on_epoch_end(epoch=self.current_epoch, logs=self.__tng_tqdm_dic)