From 5a275f20a3d0ed3c89794a9d6231150718e9a12f Mon Sep 17 00:00:00 2001 From: kghamilton89 <29099829+kghamilton89@users.noreply.github.com> Date: Wed, 9 Apr 2025 09:14:44 +0300 Subject: [PATCH] [train_dreambooth_lora_sdxl.py] Fix the LR Schedulers when num_train_epochs is passed in a distributed training env --- .../dreambooth/train_dreambooth_lora_sdxl.py | 26 ++++++++++++++----- 1 file changed, 19 insertions(+), 7 deletions(-) diff --git a/examples/dreambooth/train_dreambooth_lora_sdxl.py b/examples/dreambooth/train_dreambooth_lora_sdxl.py index 735d48b83400..f5667c8e9420 100644 --- a/examples/dreambooth/train_dreambooth_lora_sdxl.py +++ b/examples/dreambooth/train_dreambooth_lora_sdxl.py @@ -1523,17 +1523,22 @@ def compute_text_embeddings(prompt, text_encoders, tokenizers): tokens_two = torch.cat([tokens_two, class_tokens_two], dim=0) # Scheduler and math around the number of training steps. - overrode_max_train_steps = False - num_update_steps_per_epoch = math.ceil(len(train_dataloader) / args.gradient_accumulation_steps) + # Check the PR https://github.com/huggingface/diffusers/pull/8312 for detailed explanation. + num_warmup_steps_for_scheduler = args.lr_warmup_steps * accelerator.num_processes if args.max_train_steps is None: - args.max_train_steps = args.num_train_epochs * num_update_steps_per_epoch - overrode_max_train_steps = True + len_train_dataloader_after_sharding = math.ceil(len(train_dataloader) / accelerator.num_processes) + num_update_steps_per_epoch = math.ceil(len_train_dataloader_after_sharding / args.gradient_accumulation_steps) + num_training_steps_for_scheduler = ( + args.num_train_epochs * accelerator.num_processes * num_update_steps_per_epoch + ) + else: + num_training_steps_for_scheduler = args.max_train_steps * accelerator.num_processes lr_scheduler = get_scheduler( args.lr_scheduler, optimizer=optimizer, - num_warmup_steps=args.lr_warmup_steps * accelerator.num_processes, - num_training_steps=args.max_train_steps * accelerator.num_processes, + num_warmup_steps=num_warmup_steps_for_scheduler, + num_training_steps=num_training_steps_for_scheduler, num_cycles=args.lr_num_cycles, power=args.lr_power, ) @@ -1550,7 +1555,14 @@ def compute_text_embeddings(prompt, text_encoders, tokenizers): # We need to recalculate our total training steps as the size of the training dataloader may have changed. num_update_steps_per_epoch = math.ceil(len(train_dataloader) / args.gradient_accumulation_steps) - if overrode_max_train_steps: + if args.max_train_steps is None: + args.max_train_steps = args.num_train_epochs * num_update_steps_per_epoch + if num_training_steps_for_scheduler != args.max_train_steps: + logger.warning( + f"The length of the 'train_dataloader' after 'accelerator.prepare' ({len(train_dataloader)}) does not match " + f"the expected length ({len_train_dataloader_after_sharding}) when the learning rate scheduler was created. " + f"This inconsistency may result in the learning rate scheduler not functioning properly." + ) args.max_train_steps = args.num_train_epochs * num_update_steps_per_epoch # Afterwards we recalculate our number of training epochs args.num_train_epochs = math.ceil(args.max_train_steps / num_update_steps_per_epoch)