Synchronize ranks for DDP

trainer/diffusers_trainer.py

@@ -78,7 +78,7 @@ parser.add_argument('--shuffle', dest='shuffle', type=bool_t, default='True', he
 parser.add_argument('--hf_token', type=str, default=None, required=False, help='A HuggingFace token is needed to download private models for training.')
 parser.add_argument('--project_id', type=str, default='diffusers', help='Project ID for reporting to WandB')
 parser.add_argument('--fp16', dest='fp16', type=bool_t, default='False', help='Train in mixed precision')
-parser.add_argument('--image_log_steps', type=int, default=100, help='Number of steps to log images at.')
+parser.add_argument('--image_log_steps', type=int, default=500, help='Number of steps to log images at.')
 parser.add_argument('--image_log_amount', type=int, default=4, help='Number of images to log every image_log_steps')
 parser.add_argument('--image_log_inference_steps', type=int, default=50, help='Number of inference steps to use to log images.')
 parser.add_argument('--image_log_scheduler', type=str, default="PNDMScheduler", help='Number of inference steps to use to log images.')
@@ -691,6 +691,13 @@ def main():
     unet = unet.to(device, dtype=torch.float32)
     text_encoder = text_encoder.to(device, dtype=weight_dtype)
 
+    unet = torch.nn.parallel.DistributedDataParallel(
+        unet,
+        device_ids=[rank],
+        output_device=rank,
+        gradient_as_bucket_view=True
+    )
+        
     if args.use_8bit_adam: # Bits and bytes is only supported on certain CUDA setups, so default to regular adam if it fails.
         try:
             import bitsandbytes as bnb
@@ -701,6 +708,7 @@ def main():
     else:
         optimizer_cls = torch.optim.AdamW
 
+    """
     optimizer = optimizer_cls(
         unet.parameters(),
         lr=args.lr,
@@ -708,13 +716,25 @@ def main():
         eps=args.adam_epsilon,
         weight_decay=args.adam_weight_decay,
     )
+    """
 
-    noise_scheduler = DDPMScheduler(
-        beta_start=0.00085,
-        beta_end=0.012,
-        beta_schedule='scaled_linear',
-        num_train_timesteps=1000,
-        clip_sample=False
+    # Create distributed optimizer
+    from torch.distributed.optim import ZeroRedundancyOptimizer
+    optimizer = ZeroRedundancyOptimizer(
+        unet.parameters(),
+        optimizer_class=optimizer_cls,
+        parameters_as_bucket_view=True,
+        lr=args.lr,
+        betas=(args.adam_beta1, args.adam_beta2),
+        eps=args.adam_epsilon,
+        weight_decay=args.adam_weight_decay,
+    )
+
+
+    noise_scheduler = DDPMScheduler.from_pretrained(
+        args.model,
+        subfolder='scheduler',
+        use_auth_token=args.hf_token,
     )
 
     # load dataset
@@ -743,8 +763,6 @@ def main():
         print(f"Completed resize and migration to '{args.dataset}_cropped' please relaunch the trainer without the --resize argument and train on the migrated dataset.")
         exit(0)
 
-    unet = torch.nn.parallel.DistributedDataParallel(unet, device_ids=[rank], output_device=rank, gradient_as_bucket_view=True)
-
     # create ema
     if args.use_ema:
         ema_unet = EMAModel(unet.parameters())
@@ -786,8 +804,6 @@ def main():
 
             if args.use_ema:
                 ema_unet.restore(unet.parameters())
-        # barrier
-        torch.distributed.barrier()
 
     # train!
     try:
@@ -823,10 +839,6 @@ def main():
                 else:
                     encoder_hidden_states = encoder_hidden_states.last_hidden_state
 
-                # Predict the noise residual and compute loss
-                with torch.autocast('cuda', enabled=args.fp16):
-                    noise_pred = unet.module(noisy_latents, timesteps, encoder_hidden_states).sample
-
                 if noise_scheduler.config.prediction_type == "epsilon":
                     target = noise
                 elif noise_scheduler.config.prediction_type == "v_prediction":
@@ -834,6 +846,11 @@ def main():
                 else:
                     raise ValueError(f"Unknown prediction type: {noise_scheduler.config.prediction_type}")
 
+                with unet.join():
+                    # Predict the noise residual and compute loss
+                    with torch.autocast('cuda', enabled=args.fp16):
+                        noise_pred = unet(noisy_latents, timesteps, encoder_hidden_states).sample
+                        
                     loss = torch.nn.functional.mse_loss(noise_pred.float(), target.float(), reduction="mean")
 
                     # backprop and update
@@ -875,11 +892,10 @@ def main():
                     progress_bar.set_postfix(logs)
                     run.log(logs, step=global_step)
 
-                if global_step % args.save_steps == 0:
+                if global_step % args.save_steps == 0 and global_step > 0:
                     save_checkpoint(global_step)
-
                 if args.enableinference:
-                    if global_step % args.image_log_steps == 0:
+                    if global_step % args.image_log_steps == 0 and global_step > 0:
                         if rank == 0:
                             # get prompt from random batch
                             prompt = tokenizer.decode(batch['input_ids'][random.randint(0, len(batch['input_ids'])-1)].tolist())
@@ -935,7 +951,6 @@ def main():
                             # cleanup so we don't run out of memory
                             del pipeline
                             gc.collect()
-                        torch.distributed.barrier()
     except Exception as e:
         print(f'Exception caught on rank {rank} at step {global_step}, saving checkpoint...\n{e}\n{traceback.format_exc()}')
         pass