import os import sys import types from pathlib import Path current_file_path = Path(__file__).resolve() sys.path.insert(0, str(current_file_path.parent.parent)) import argparse import datetime import time import warnings warnings.filterwarnings("ignore") # ignore warning import torch import torch.nn as nn from accelerate import Accelerator, InitProcessGroupKwargs from accelerate.utils import DistributedType from diffusers.models import AutoencoderKL from transformers import T5EncoderModel, T5Tokenizer from torch.utils.data import RandomSampler from mmcv.runner import LogBuffer from copy import deepcopy import numpy as np import torch.nn.functional as F from tqdm import tqdm from PIL import Image import gc from diffusion import IDDPM from diffusion.utils.checkpoint import save_checkpoint, load_checkpoint from diffusion.utils.dist_utils import synchronize, get_world_size, clip_grad_norm_, flush from diffusion.data.builder import build_dataset, build_dataloader, set_data_root from diffusion.model.builder import build_model from diffusion.utils.logger import get_root_logger from diffusion.utils.misc import set_random_seed, read_config, init_random_seed, DebugUnderflowOverflow from diffusion.utils.optimizer import build_optimizer, auto_scale_lr from diffusion.utils.lr_scheduler import build_lr_scheduler from diffusion.utils.data_sampler import AspectRatioBatchSampler, BalancedAspectRatioBatchSampler from diffusion.lcm_scheduler import LCMScheduler from torchvision.utils import save_image def set_fsdp_env(): os.environ["ACCELERATE_USE_FSDP"] = 'true' os.environ["FSDP_AUTO_WRAP_POLICY"] = 'TRANSFORMER_BASED_WRAP' os.environ["FSDP_BACKWARD_PREFETCH"] = 'BACKWARD_PRE' os.environ["FSDP_TRANSFORMER_CLS_TO_WRAP"] = 'PixArtBlock' def ema_update(model_dest: nn.Module, model_src: nn.Module, rate): param_dict_src = dict(model_src.named_parameters()) for p_name, p_dest in model_dest.named_parameters(): p_src = param_dict_src[p_name] assert p_src is not p_dest p_dest.data.mul_(rate).add_((1 - rate) * p_src.data) def append_dims(x, target_dims): """Appends dimensions to the end of a tensor until it has target_dims dimensions.""" dims_to_append = target_dims - x.ndim if dims_to_append < 0: raise ValueError(f"input has {x.ndim} dims but target_dims is {target_dims}, which is less") return x[(...,) + (None,) * dims_to_append] # From LCMScheduler.get_scalings_for_boundary_condition_discrete def scalings_for_boundary_conditions(timestep, sigma_data=0.5, timestep_scaling=10.0): c_skip = sigma_data**2 / ((timestep / 0.1) ** 2 + sigma_data**2) c_out = (timestep / 0.1) / ((timestep / 0.1) ** 2 + sigma_data**2) ** 0.5 return c_skip, c_out def extract_into_tensor(a, t, x_shape): b, *_ = t.shape out = a.gather(-1, t) return out.reshape(b, *((1,) * (len(x_shape) - 1))) class DDIMSolver: def __init__(self, alpha_cumprods, timesteps=1000, ddim_timesteps=50): # DDIM sampling parameters step_ratio = timesteps // ddim_timesteps self.ddim_timesteps = (np.arange(1, ddim_timesteps + 1) * step_ratio).round().astype(np.int64) - 1 self.ddim_alpha_cumprods = alpha_cumprods[self.ddim_timesteps] self.ddim_alpha_cumprods_prev = np.asarray( [alpha_cumprods[0]] + alpha_cumprods[self.ddim_timesteps[:-1]].tolist() ) # convert to torch tensors self.ddim_timesteps = torch.from_numpy(self.ddim_timesteps).long() self.ddim_alpha_cumprods = torch.from_numpy(self.ddim_alpha_cumprods) self.ddim_alpha_cumprods_prev = torch.from_numpy(self.ddim_alpha_cumprods_prev) def to(self, device): self.ddim_timesteps = self.ddim_timesteps.to(device) self.ddim_alpha_cumprods = self.ddim_alpha_cumprods.to(device) self.ddim_alpha_cumprods_prev = self.ddim_alpha_cumprods_prev.to(device) return self def ddim_step(self, pred_x0, pred_noise, timestep_index): alpha_cumprod_prev = extract_into_tensor(self.ddim_alpha_cumprods_prev, timestep_index, pred_x0.shape) dir_xt = (1.0 - alpha_cumprod_prev).sqrt() * pred_noise x_prev = alpha_cumprod_prev.sqrt() * pred_x0 + dir_xt return x_prev @torch.inference_mode() def log_validation(model, step, device): torch.cuda.empty_cache() model = accelerator.unwrap_model(model).eval() scheduler = LCMScheduler(beta_start=0.0001, beta_end=0.02, beta_schedule="linear", prediction_type="epsilon") scheduler.set_timesteps(4, 50) infer_timesteps = scheduler.timesteps hw = torch.tensor([[1024, 1024]], dtype=torch.float, device=device).repeat(1, 1) ar = torch.tensor([[1.]], device=device).repeat(1, 1) # Create sampling noise: logger.info("Running validation... ") image_logs = [] latents = [] for prompt in validation_prompts: infer_latents = torch.randn(1, 4, latent_size, latent_size, device=device) embed = torch.load(f'output/tmp/{prompt}_{max_length}token.pth', map_location='cpu') caption_embs, emb_masks = embed['caption_embeds'].to(device), embed['emb_mask'].to(device) model_kwargs = dict(data_info={'img_hw': hw, 'aspect_ratio': ar}, mask=emb_masks) # 7. LCM MultiStep Sampling Loop: for i, t in tqdm(list(enumerate(infer_timesteps))): ts = torch.full((1,), t, device=device, dtype=torch.long) # model prediction (v-prediction, eps, x) model_pred = model(infer_latents, ts, caption_embs, **model_kwargs)[:, :4] # compute the previous noisy sample x_t -> x_t-1 infer_latents, denoised = scheduler.step(model_pred, i, t, infer_latents, return_dict=False) latents.append(denoised) torch.cuda.empty_cache() vae = AutoencoderKL.from_pretrained(config.vae_pretrained).cuda() for prompt, latent in zip(validation_prompts, latents): samples = vae.decode(latent.detach() / vae.config.scaling_factor).sample samples = torch.clamp(127.5 * samples + 128.0, 0, 255).permute(0, 2, 3, 1).to("cpu", dtype=torch.uint8).numpy()[0] image = Image.fromarray(samples) image_logs.append({"validation_prompt": prompt, "images": [image]}) for tracker in accelerator.trackers: if tracker.name == "tensorboard": for log in image_logs: images = log["images"] validation_prompt = log["validation_prompt"] formatted_images = [] for image in images: formatted_images.append(np.asarray(image)) formatted_images = np.stack(formatted_images) tracker.writer.add_images(validation_prompt, formatted_images, step, dataformats="NHWC") elif tracker.name == "wandb": import wandb formatted_images = [] for log in image_logs: images = log["images"] validation_prompt = log["validation_prompt"] for image in images: image = wandb.Image(image, caption=validation_prompt) formatted_images.append(image) tracker.log({"validation": formatted_images}) else: logger.warn(f"image logging not implemented for {tracker.name}") gc.collect() torch.cuda.empty_cache() return image_logs def train(): if config.get('debug_nan', False): DebugUnderflowOverflow(model) logger.info('NaN debugger registered. Start to detect overflow during training.') time_start, last_tic = time.time(), time.time() log_buffer = LogBuffer() start_step = start_epoch * len(train_dataloader) global_step = 0 total_steps = len(train_dataloader) * config.num_epochs load_vae_feat = getattr(train_dataloader.dataset, 'load_vae_feat', False) load_t5_feat = getattr(train_dataloader.dataset, 'load_t5_feat', False) # Create uncond embeds for classifier free guidance uncond_prompt_embeds = model.module.y_embedder.y_embedding.repeat(config.train_batch_size, 1, 1, 1) # Now you train the model for epoch in range(start_epoch + 1, config.num_epochs + 1): data_time_start= time.time() data_time_all = 0 for step, batch in enumerate(train_dataloader): data_time_all += time.time() - data_time_start if load_vae_feat: z = batch[0] else: with torch.no_grad(): with torch.cuda.amp.autocast(enabled=config.mixed_precision == 'fp16'): posterior = vae.encode(batch[0]).latent_dist if config.sample_posterior: z = posterior.sample() else: z = posterior.mode() latents = z * config.scale_factor data_info = {'img_hw': batch[3]['img_hw'].to(latents.dtype), 'aspect_ratio': batch[3]['aspect_ratio'].to(latents.dtype),} if load_t5_feat: y = batch[1] y_mask = batch[2] else: with torch.no_grad(): txt_tokens = tokenizer( batch[1], max_length=max_length, padding="max_length", truncation=True, return_tensors="pt" ).to(accelerator.device) y = text_encoder( txt_tokens.input_ids, attention_mask=txt_tokens.attention_mask)[0][:, None] y_mask = txt_tokens.attention_mask[:, None, None] # Sample a random timestep for each image grad_norm = None with accelerator.accumulate(model): # Predict the noise residual optimizer.zero_grad() # Sample noise that we'll add to the latents noise = torch.randn_like(latents) bsz = latents.shape[0] # Sample a random timestep for each image t_n ~ U[0, N - k - 1] without bias. topk = config.train_sampling_steps // config.num_ddim_timesteps index = torch.randint(0, config.num_ddim_timesteps, (bsz,), device=latents.device).long() start_timesteps = solver.ddim_timesteps[index] timesteps = start_timesteps - topk timesteps = torch.where(timesteps < 0, torch.zeros_like(timesteps), timesteps) # Get boundary scalings for start_timesteps and (end) timesteps. c_skip_start, c_out_start = scalings_for_boundary_conditions(start_timesteps) c_skip_start, c_out_start = [append_dims(x, latents.ndim) for x in [c_skip_start, c_out_start]] c_skip, c_out = scalings_for_boundary_conditions(timesteps) c_skip, c_out = [append_dims(x, latents.ndim) for x in [c_skip, c_out]] # Sample a random guidance scale w from U[w_min, w_max] and embed it # w = (config.w_max - config.w_min) * torch.rand((bsz,)) + config.w_min w = config.cfg_scale * torch.ones((bsz,)) w = w.reshape(bsz, 1, 1, 1) w = w.to(device=latents.device, dtype=latents.dtype) # Get online LCM prediction on z_{t_{n + k}}, w, c, t_{n + k} _, pred_x_0, noisy_model_input = train_diffusion.training_losses( model, latents, start_timesteps, model_kwargs=dict(y=y, mask=y_mask, data_info=data_info), noise=noise ) model_pred = c_skip_start * noisy_model_input + c_out_start * pred_x_0 # Use the ODE solver to predict the kth step in the augmented PF-ODE trajectory after # noisy_latents with both the conditioning embedding c and unconditional embedding 0 # Get teacher model prediction on noisy_latents and conditional embedding with torch.no_grad(): with torch.autocast("cuda"): cond_teacher_output, cond_pred_x0, _ = train_diffusion.training_losses( model_teacher, latents, start_timesteps, model_kwargs=dict(y=y, mask=y_mask, data_info=data_info), noise=noise ) # Get teacher model prediction on noisy_latents and unconditional embedding uncond_teacher_output, uncond_pred_x0, _ = train_diffusion.training_losses( model_teacher, latents, start_timesteps, model_kwargs=dict(y=uncond_prompt_embeds, mask=y_mask, data_info=data_info), noise=noise ) # Perform "CFG" to get x_prev estimate (using the LCM paper's CFG formulation) pred_x0 = cond_pred_x0 + w * (cond_pred_x0 - uncond_pred_x0) pred_noise = cond_teacher_output + w * (cond_teacher_output - uncond_teacher_output) x_prev = solver.ddim_step(pred_x0, pred_noise, index) # Get target LCM prediction on x_prev, w, c, t_n with torch.no_grad(): with torch.autocast("cuda", enabled=True): _, pred_x_0, _ = train_diffusion.training_losses( model_ema, x_prev.float(), timesteps, model_kwargs=dict(y=y, mask=y_mask, data_info=data_info), skip_noise=True ) target = c_skip * x_prev + c_out * pred_x_0 # Calculate loss if config.loss_type == "l2": loss = F.mse_loss(model_pred.float(), target.float(), reduction="mean") elif config.loss_type == "huber": loss = torch.mean(torch.sqrt((model_pred.float() - target.float()) ** 2 + config.huber_c**2) - config.huber_c) # Backpropagation on the online student model (`model`) accelerator.backward(loss) if accelerator.sync_gradients: grad_norm = accelerator.clip_grad_norm_(model.parameters(), config.gradient_clip) optimizer.step() lr_scheduler.step() optimizer.zero_grad(set_to_none=True) if accelerator.sync_gradients: ema_update(model_ema, model, config.ema_decay) lr = lr_scheduler.get_last_lr()[0] logs = {"loss": accelerator.gather(loss).mean().item()} if grad_norm is not None: logs.update(grad_norm=accelerator.gather(grad_norm).mean().item()) log_buffer.update(logs) if (step + 1) % config.log_interval == 0 or (step + 1) == 1: t = (time.time() - last_tic) / config.log_interval t_d = data_time_all / config.log_interval avg_time = (time.time() - time_start) / (global_step + 1) eta = str(datetime.timedelta(seconds=int(avg_time * (total_steps - start_step - global_step - 1)))) eta_epoch = str(datetime.timedelta(seconds=int(avg_time * (len(train_dataloader) - step - 1)))) # avg_loss = sum(loss_buffer) / len(loss_buffer) log_buffer.average() info = f"Step/Epoch [{(epoch-1)*len(train_dataloader)+step+1}/{epoch}][{step + 1}/{len(train_dataloader)}]:total_eta: {eta}, " \ f"epoch_eta:{eta_epoch}, time_all:{t:.3f}, time_data:{t_d:.3f}, lr:{lr:.3e}, s:({data_info['img_hw'][0][0].item()}, {data_info['img_hw'][0][1].item()}), " info += ', '.join([f"{k}:{v:.4f}" for k, v in log_buffer.output.items()]) logger.info(info) last_tic = time.time() log_buffer.clear() data_time_all = 0 logs.update(lr=lr) accelerator.log(logs, step=global_step + start_step) global_step += 1 data_time_start= time.time() accelerator.wait_for_everyone() if accelerator.is_main_process: if ((epoch - 1) * len(train_dataloader) + step + 1) % config.save_model_steps == 0: os.umask(0o000) save_checkpoint(os.path.join(config.work_dir, 'checkpoints'), epoch=epoch, step=(epoch - 1) * len(train_dataloader) + step + 1, model=accelerator.unwrap_model(model), model_ema=accelerator.unwrap_model(model_ema), optimizer=optimizer, lr_scheduler=lr_scheduler ) if ((epoch - 1) * len(train_dataloader) + step + 1) % config.eval_sampling_steps == 0: log_validation(model, global_step, device=accelerator.device) accelerator.wait_for_everyone() if accelerator.is_main_process: if epoch % config.save_model_epochs == 0 or epoch == config.num_epochs: os.umask(0o000) save_checkpoint(os.path.join(config.work_dir, 'checkpoints'), epoch=epoch, step=(epoch - 1) * len(train_dataloader) + step + 1, model=accelerator.unwrap_model(model), model_ema=accelerator.unwrap_model(model_ema), optimizer=optimizer, lr_scheduler=lr_scheduler ) synchronize() def parse_args(): parser = argparse.ArgumentParser(description="Process some integers.") parser.add_argument("config", type=str, help="config") parser.add_argument("--cloud", action='store_true', default=False, help="cloud or local machine") parser.add_argument('--work-dir', help='the dir to save logs and models') parser.add_argument('--resume-from', help='the dir to resume the training') parser.add_argument('--load-from', default=None, help='the dir to load a ckpt for training') parser.add_argument('--local-rank', type=int, default=-1) parser.add_argument('--local_rank', type=int, default=-1) parser.add_argument('--debug', action='store_true') parser.add_argument( "--pipeline_load_from", default='output/pretrained_models/pixart_sigma_sdxlvae_T5_diffusers', type=str, help="Download for loading text_encoder, " "tokenizer and vae from https://huggingface.co/PixArt-alpha/pixart_sigma_sdxlvae_T5_diffusers" ) args = parser.parse_args() return args if __name__ == '__main__': args = parse_args() config = read_config(args.config) if args.work_dir is not None: # update configs according to CLI args if args.work_dir is not None config.work_dir = args.work_dir if args.cloud: config.data_root = '/data/data' if args.resume_from is not None: config.load_from = None config.resume_from = dict( checkpoint=args.resume_from, load_ema=False, resume_optimizer=True, resume_lr_scheduler=True) if args.debug: config.log_interval = 1 config.train_batch_size = 2 os.umask(0o000) os.makedirs(config.work_dir, exist_ok=True) init_handler = InitProcessGroupKwargs() init_handler.timeout = datetime.timedelta(seconds=5400) # change timeout to avoid a strange NCCL bug # Initialize accelerator and tensorboard logging if config.use_fsdp: init_train = 'FSDP' from accelerate import FullyShardedDataParallelPlugin from torch.distributed.fsdp.fully_sharded_data_parallel import FullStateDictConfig set_fsdp_env() fsdp_plugin = FullyShardedDataParallelPlugin(state_dict_config=FullStateDictConfig(offload_to_cpu=False, rank0_only=False),) else: init_train = 'DDP' fsdp_plugin = None even_batches = True if config.multi_scale: even_batches=False, accelerator = Accelerator( mixed_precision=config.mixed_precision, gradient_accumulation_steps=config.gradient_accumulation_steps, log_with="tensorboard", project_dir=os.path.join(config.work_dir, "logs"), fsdp_plugin=fsdp_plugin, even_batches=even_batches, kwargs_handlers=[init_handler] ) logger = get_root_logger(os.path.join(config.work_dir, 'train_log.log')) config.seed = init_random_seed(config.get('seed', None)) set_random_seed(config.seed) if accelerator.is_main_process: config.dump(os.path.join(config.work_dir, 'config.py')) logger.info(f"Config: \n{config.pretty_text}") logger.info(f"World_size: {get_world_size()}, seed: {config.seed}") logger.info(f"Initializing: {init_train} for training") image_size = config.image_size # @param [256, 512] latent_size = int(image_size) // 8 pred_sigma = getattr(config, 'pred_sigma', True) learn_sigma = getattr(config, 'learn_sigma', True) and pred_sigma max_length = config.model_max_length model_kwargs={"pe_interpolation": config.pe_interpolation, 'config':config, 'model_max_length': max_length} # build models train_diffusion = IDDPM(str(config.train_sampling_steps), learn_sigma=learn_sigma, pred_sigma=pred_sigma, snr=config.snr_loss, return_startx=True) model = build_model(config.model, config.grad_checkpointing, config.get('fp32_attention', False), input_size=latent_size, learn_sigma=learn_sigma, pred_sigma=pred_sigma, **model_kwargs).train() logger.info(f"{model.__class__.__name__} Model Parameters: {sum(p.numel() for p in model.parameters()):,}") if config.load_from is not None: if args.load_from is not None: config.load_from = args.load_from missing, unexpected = load_checkpoint( config.load_from, model, load_ema=config.get('load_ema', False), max_length=max_length) logger.warning(f'Missing keys: {missing}') logger.warning(f'Unexpected keys: {unexpected}') model_ema = deepcopy(model).eval() model_teacher = deepcopy(model).eval() if not config.data.load_vae_feat: vae = AutoencoderKL.from_pretrained(config.vae_pretrained).cuda() # prepare for FSDP clip grad norm calculation if accelerator.distributed_type == DistributedType.FSDP: for m in accelerator._models: m.clip_grad_norm_ = types.MethodType(clip_grad_norm_, m) tokenizer = text_encoder = None if not config.data.load_t5_feat: tokenizer = T5Tokenizer.from_pretrained(args.pipeline_load_from, subfolder="tokenizer") text_encoder = T5EncoderModel.from_pretrained( args.pipeline_load_from, subfolder="text_encoder", torch_dtype=torch.float16).to(accelerator.device) logger.info(f"vae sacle factor: {config.scale_factor}") # build dataloader set_data_root(config.data_root) dataset = build_dataset(config.data, resolution=image_size, aspect_ratio_type=config.aspect_ratio_type) if config.multi_scale: batch_sampler = AspectRatioBatchSampler(sampler=RandomSampler(dataset), dataset=dataset, batch_size=config.train_batch_size, aspect_ratios=dataset.aspect_ratio, drop_last=True, ratio_nums=dataset.ratio_nums, config=config, valid_num=config.valid_num) train_dataloader = build_dataloader(dataset, batch_sampler=batch_sampler, num_workers=config.num_workers) else: train_dataloader = build_dataloader(dataset, num_workers=config.num_workers, batch_size=config.train_batch_size, shuffle=True) # preparing embeddings for visualization. We put it here for saving GPU memory validation_prompts = [ "dog", "portrait photo of a girl, photograph, highly detailed face, depth of field", "Self-portrait oil painting, a beautiful cyborg with golden hair, 8k", "Astronaut in a jungle, cold color palette, muted colors, detailed, 8k", "A photo of beautiful mountain with realistic sunset and blue lake, highly detailed, masterpiece", ] logger.info("Preparing Visulalization prompt embeddings...") skip = True for prompt in validation_prompts: if not os.path.exists(f'output/tmp/{prompt}_{max_length}token.pth'): skip = False break logger.info("Preparing Visualization prompt embeddings...") if accelerator.is_main_process and not skip: if config.data.load_t5_feat and (tokenizer is None or text_encoder is None): logger.info(f"Loading text encoder and tokenizer from {args.pipeline_load_from} ...") tokenizer = T5Tokenizer.from_pretrained(args.pipeline_load_from, subfolder="tokenizer") text_encoder = T5EncoderModel.from_pretrained( args.pipeline_load_from, subfolder="text_encoder", torch_dtype=torch.float16).to(accelerator.device) for prompt in validation_prompts: txt_tokens = tokenizer( prompt, max_length=max_length, padding="max_length", truncation=True, return_tensors="pt" ).to(accelerator.device) caption_emb = text_encoder(txt_tokens.input_ids, attention_mask=txt_tokens.attention_mask)[0] torch.save( {'caption_embeds': caption_emb, 'emb_mask': txt_tokens.attention_mask}, f'output/tmp/{prompt}_{max_length}token.pth') if config.data.load_t5_feat: del tokenizer del txt_tokens flush() time.sleep(5) # build optimizer and lr scheduler lr_scale_ratio = 1 if config.get('auto_lr', None): lr_scale_ratio = auto_scale_lr(config.train_batch_size * get_world_size() * config.gradient_accumulation_steps, config.optimizer, **config.auto_lr) optimizer = build_optimizer(model, config.optimizer) lr_scheduler = build_lr_scheduler(config, optimizer, train_dataloader, lr_scale_ratio) timestamp = time.strftime("%Y-%m-%d_%H:%M:%S", time.localtime()) if accelerator.is_main_process: accelerator.init_trackers(f"tb_{timestamp}") start_epoch = 0 if config.resume_from is not None and config.resume_from['checkpoint'] is not None: start_epoch, missing, unexpected = load_checkpoint(**config.resume_from, model=model, model_ema=model_ema, optimizer=optimizer, lr_scheduler=lr_scheduler, ) logger.warning(f'Missing keys: {missing}') logger.warning(f'Unexpected keys: {unexpected}') solver = DDIMSolver(train_diffusion.alphas_cumprod, timesteps=config.train_sampling_steps, ddim_timesteps=config.num_ddim_timesteps) solver.to(accelerator.device) # Prepare everything # There is no specific order to remember, you just need to unpack the # objects in the same order you gave them to the prepare method. model, model_ema, model_teacher = accelerator.prepare(model, model_ema, model_teacher) optimizer, train_dataloader, lr_scheduler = accelerator.prepare(optimizer, train_dataloader, lr_scheduler) train()