#!/usr/bin/env python3 """Trains Karras et al. (2022) diffusion models.""" import argparse from copy import deepcopy from functools import partial import math import json from pathlib import Path import accelerate import torch from torch import nn, optim from torch import multiprocessing as mp from torch.utils import data from torchvision import datasets, transforms, utils from tqdm.auto import trange, tqdm import k_diffusion as K def main(): p = argparse.ArgumentParser(description=__doc__, formatter_class=argparse.ArgumentDefaultsHelpFormatter) p.add_argument('--batch-size', type=int, default=64, help='the batch size') p.add_argument('--config', type=str, required=True, help='the configuration file') p.add_argument('--demo-every', type=int, default=500, help='save a demo grid every this many steps') p.add_argument('--evaluate-every', type=int, default=10000, help='save a demo grid every this many steps') p.add_argument('--evaluate-n', type=int, default=2000, help='the number of samples to draw to evaluate') p.add_argument('--gns', action='store_true', help='measure the gradient noise scale (DDP only)') p.add_argument('--grad-accum-steps', type=int, default=1, help='the number of gradient accumulation steps') p.add_argument('--grow', type=str, help='the checkpoint to grow from') p.add_argument('--grow-config', type=str, help='the configuration file of the model to grow from') p.add_argument('--lr', type=float, help='the learning rate') p.add_argument('--mixed-precision', type=str, help='the mixed precision type') p.add_argument('--name', type=str, default='model', help='the name of the run') p.add_argument('--num-workers', type=int, default=8, help='the number of data loader workers') p.add_argument('--resume', type=str, help='the checkpoint to resume from') p.add_argument('--sample-n', type=int, default=64, help='the number of images to sample for demo grids') p.add_argument('--save-every', type=int, default=10000, help='save every this many steps') p.add_argument('--seed', type=int, help='the random seed') p.add_argument('--start-method', type=str, default='spawn', choices=['fork', 'forkserver', 'spawn'], help='the multiprocessing start method') p.add_argument('--wandb-entity', type=str, help='the wandb entity name') p.add_argument('--wandb-group', type=str, help='the wandb group name') p.add_argument('--wandb-project', type=str, help='the wandb project name (specify this to enable wandb)') p.add_argument('--wandb-save-model', action='store_true', help='save model to wandb') args = p.parse_args() mp.set_start_method(args.start_method) torch.backends.cuda.matmul.allow_tf32 = True config = K.config.load_config(open(args.config)) model_config = config['model'] dataset_config = config['dataset'] opt_config = config['optimizer'] sched_config = config['lr_sched'] ema_sched_config = config['ema_sched'] # TODO: allow non-square input sizes assert len(model_config['input_size']) == 2 and model_config['input_size'][0] == model_config['input_size'][1] size = model_config['input_size'] ddp_kwargs = accelerate.DistributedDataParallelKwargs(find_unused_parameters=model_config['skip_stages'] > 0) accelerator = accelerate.Accelerator(kwargs_handlers=[ddp_kwargs], gradient_accumulation_steps=args.grad_accum_steps, mixed_precision=args.mixed_precision) device = accelerator.device print(f'Process {accelerator.process_index} using device: {device}', flush=True) if args.seed is not None: seeds = torch.randint(-2 ** 63, 2 ** 63 - 1, [accelerator.num_processes], generator=torch.Generator().manual_seed(args.seed)) torch.manual_seed(seeds[accelerator.process_index]) inner_model = K.config.make_model(config) inner_model_ema = deepcopy(inner_model) if accelerator.is_main_process: print('Parameters:', K.utils.n_params(inner_model)) # If logging to wandb, initialize the run use_wandb = accelerator.is_main_process and args.wandb_project if use_wandb: import wandb log_config = vars(args) log_config['config'] = config log_config['parameters'] = K.utils.n_params(inner_model) wandb.init(project=args.wandb_project, entity=args.wandb_entity, group=args.wandb_group, config=log_config, save_code=True) if opt_config['type'] == 'adamw': opt = optim.AdamW(inner_model.parameters(), lr=opt_config['lr'] if args.lr is None else args.lr, betas=tuple(opt_config['betas']), eps=opt_config['eps'], weight_decay=opt_config['weight_decay']) elif opt_config['type'] == 'sgd': opt = optim.SGD(inner_model.parameters(), lr=opt_config['lr'] if args.lr is None else args.lr, momentum=opt_config.get('momentum', 0.), nesterov=opt_config.get('nesterov', False), weight_decay=opt_config.get('weight_decay', 0.)) else: raise ValueError('Invalid optimizer type') if sched_config['type'] == 'inverse': sched = K.utils.InverseLR(opt, inv_gamma=sched_config['inv_gamma'], power=sched_config['power'], warmup=sched_config['warmup']) elif sched_config['type'] == 'exponential': sched = K.utils.ExponentialLR(opt, num_steps=sched_config['num_steps'], decay=sched_config['decay'], warmup=sched_config['warmup']) elif sched_config['type'] == 'constant': sched = optim.lr_scheduler.LambdaLR(opt, lambda _: 1.0) else: raise ValueError('Invalid schedule type') assert ema_sched_config['type'] == 'inverse' ema_sched = K.utils.EMAWarmup(power=ema_sched_config['power'], max_value=ema_sched_config['max_value']) tf = transforms.Compose([ transforms.Resize(size[0], interpolation=transforms.InterpolationMode.LANCZOS), transforms.CenterCrop(size[0]), K.augmentation.KarrasAugmentationPipeline(model_config['augment_prob']), ]) if dataset_config['type'] == 'imagefolder': train_set = K.utils.FolderOfImages(dataset_config['location'], transform=tf) elif dataset_config['type'] == 'cifar10': train_set = datasets.CIFAR10(dataset_config['location'], train=True, download=True, transform=tf) elif dataset_config['type'] == 'mnist': train_set = datasets.MNIST(dataset_config['location'], train=True, download=True, transform=tf) elif dataset_config['type'] == 'huggingface': from datasets import load_dataset train_set = load_dataset(dataset_config['location']) train_set.set_transform(partial(K.utils.hf_datasets_augs_helper, transform=tf, image_key=dataset_config['image_key'])) train_set = train_set['train'] else: raise ValueError('Invalid dataset type') if accelerator.is_main_process: try: print('Number of items in dataset:', len(train_set)) except TypeError: pass image_key = dataset_config.get('image_key', 0) train_dl = data.DataLoader(train_set, args.batch_size, shuffle=True, drop_last=True, num_workers=args.num_workers, persistent_workers=True) if args.grow: if not args.grow_config: raise ValueError('--grow requires --grow-config') ckpt = torch.load(args.grow, map_location='cpu') old_config = K.config.load_config(open(args.grow_config)) old_inner_model = K.config.make_model(old_config) old_inner_model.load_state_dict(ckpt['model_ema']) if old_config['model']['skip_stages'] != model_config['skip_stages']: old_inner_model.set_skip_stages(model_config['skip_stages']) if old_config['model']['patch_size'] != model_config['patch_size']: old_inner_model.set_patch_size(model_config['patch_size']) inner_model.load_state_dict(old_inner_model.state_dict()) del ckpt, old_inner_model inner_model, inner_model_ema, opt, train_dl = accelerator.prepare(inner_model, inner_model_ema, opt, train_dl) if use_wandb: wandb.watch(inner_model) if args.gns: gns_stats_hook = K.gns.DDPGradientStatsHook(inner_model) gns_stats = K.gns.GradientNoiseScale() else: gns_stats = None sigma_min = model_config['sigma_min'] sigma_max = model_config['sigma_max'] sample_density = K.config.make_sample_density(model_config) model = K.config.make_denoiser_wrapper(config)(inner_model) model_ema = K.config.make_denoiser_wrapper(config)(inner_model_ema) state_path = Path(f'{args.name}_state.json') if state_path.exists() or args.resume: if args.resume: ckpt_path = args.resume if not args.resume: state = json.load(open(state_path)) ckpt_path = state['latest_checkpoint'] if accelerator.is_main_process: print(f'Resuming from {ckpt_path}...') ckpt = torch.load(ckpt_path, map_location='cpu') accelerator.unwrap_model(model.inner_model).load_state_dict(ckpt['model']) accelerator.unwrap_model(model_ema.inner_model).load_state_dict(ckpt['model_ema']) opt.load_state_dict(ckpt['opt']) sched.load_state_dict(ckpt['sched']) ema_sched.load_state_dict(ckpt['ema_sched']) epoch = ckpt['epoch'] + 1 step = ckpt['step'] + 1 if args.gns and ckpt.get('gns_stats', None) is not None: gns_stats.load_state_dict(ckpt['gns_stats']) del ckpt else: epoch = 0 step = 0 evaluate_enabled = args.evaluate_every > 0 and args.evaluate_n > 0 if evaluate_enabled: extractor = K.evaluation.InceptionV3FeatureExtractor(device=device) train_iter = iter(train_dl) if accelerator.is_main_process: print('Computing features for reals...') reals_features = K.evaluation.compute_features(accelerator, lambda x: next(train_iter)[image_key][1], extractor, args.evaluate_n, args.batch_size) if accelerator.is_main_process: metrics_log = K.utils.CSVLogger(f'{args.name}_metrics.csv', ['step', 'fid', 'kid']) del train_iter @torch.no_grad() @K.utils.eval_mode(model_ema) def demo(): if accelerator.is_main_process: tqdm.write('Sampling...') filename = f'{args.name}_demo_{step:08}.png' n_per_proc = math.ceil(args.sample_n / accelerator.num_processes) x = torch.randn([n_per_proc, model_config['input_channels'], size[0], size[1]], device=device) * sigma_max sigmas = K.sampling.get_sigmas_karras(50, sigma_min, sigma_max, rho=7., device=device) x_0 = K.sampling.sample_dpmpp_2m(model_ema, x, sigmas, disable=not accelerator.is_main_process) x_0 = accelerator.gather(x_0)[:args.sample_n] if accelerator.is_main_process: grid = utils.make_grid(x_0, nrow=math.ceil(args.sample_n ** 0.5), padding=0) K.utils.to_pil_image(grid).save(filename) if use_wandb: wandb.log({'demo_grid': wandb.Image(filename)}, step=step) @torch.no_grad() @K.utils.eval_mode(model_ema) def evaluate(): if not evaluate_enabled: return if accelerator.is_main_process: tqdm.write('Evaluating...') sigmas = K.sampling.get_sigmas_karras(50, sigma_min, sigma_max, rho=7., device=device) def sample_fn(n): x = torch.randn([n, model_config['input_channels'], size[0], size[1]], device=device) * sigma_max x_0 = K.sampling.sample_dpmpp_2m(model_ema, x, sigmas, disable=True) return x_0 fakes_features = K.evaluation.compute_features(accelerator, sample_fn, extractor, args.evaluate_n, args.batch_size) if accelerator.is_main_process: fid = K.evaluation.fid(fakes_features, reals_features) kid = K.evaluation.kid(fakes_features, reals_features) print(f'FID: {fid.item():g}, KID: {kid.item():g}') if accelerator.is_main_process: metrics_log.write(step, fid.item(), kid.item()) if use_wandb: wandb.log({'FID': fid.item(), 'KID': kid.item()}, step=step) def save(): accelerator.wait_for_everyone() filename = f'{args.name}_{step:08}.pth' if accelerator.is_main_process: tqdm.write(f'Saving to {filename}...') obj = { 'model': accelerator.unwrap_model(model.inner_model).state_dict(), 'model_ema': accelerator.unwrap_model(model_ema.inner_model).state_dict(), 'opt': opt.state_dict(), 'sched': sched.state_dict(), 'ema_sched': ema_sched.state_dict(), 'epoch': epoch, 'step': step, 'gns_stats': gns_stats.state_dict() if gns_stats is not None else None, } accelerator.save(obj, filename) if accelerator.is_main_process: state_obj = {'latest_checkpoint': filename} json.dump(state_obj, open(state_path, 'w')) if args.wandb_save_model and use_wandb: wandb.save(filename) try: while True: for batch in tqdm(train_dl, disable=not accelerator.is_main_process): with accelerator.accumulate(model): reals, _, aug_cond = batch[image_key] noise = torch.randn_like(reals) sigma = sample_density([reals.shape[0]], device=device) losses = model.loss(reals, noise, sigma, aug_cond=aug_cond) losses_all = accelerator.gather(losses) loss = losses_all.mean() accelerator.backward(losses.mean()) if args.gns: sq_norm_small_batch, sq_norm_large_batch = gns_stats_hook.get_stats() gns_stats.update(sq_norm_small_batch, sq_norm_large_batch, reals.shape[0], reals.shape[0] * accelerator.num_processes) opt.step() sched.step() opt.zero_grad() if accelerator.sync_gradients: ema_decay = ema_sched.get_value() K.utils.ema_update(model, model_ema, ema_decay) ema_sched.step() if accelerator.is_main_process: if step % 25 == 0: if args.gns: tqdm.write(f'Epoch: {epoch}, step: {step}, loss: {loss.item():g}, gns: {gns_stats.get_gns():g}') else: tqdm.write(f'Epoch: {epoch}, step: {step}, loss: {loss.item():g}') if use_wandb: log_dict = { 'epoch': epoch, 'loss': loss.item(), 'lr': sched.get_last_lr()[0], 'ema_decay': ema_decay, } if args.gns: log_dict['gradient_noise_scale'] = gns_stats.get_gns() wandb.log(log_dict, step=step) if step % args.demo_every == 0: demo() if evaluate_enabled and step > 0 and step % args.evaluate_every == 0: evaluate() if step > 0 and step % args.save_every == 0: save() step += 1 epoch += 1 except KeyboardInterrupt: pass if __name__ == '__main__': main()