[example] simplify the GPT2 huggingface example (#1826)

examples/language/gpt/train_gpt_demo.py

@@ -0,0 +1,161 @@
+from functools import partial
+from time import time
+
+import psutil
+import torch
+import torch.nn as nn
+from packaging import version
+
+import colossalai
+from colossalai.logging import disable_existing_loggers, get_dist_logger
+from colossalai.nn.optimizer import HybridAdam
+from colossalai.nn.parallel import ZeroDDP
+from colossalai.tensor import ProcessGroup
+from colossalai.utils import get_current_device
+from colossalai.utils.model.colo_init_context import ColoInitContext
+from colossalai.zero import ZeroOptimizer
+from transformers import GPT2Config, GPT2LMHeadModel
+
+
+class GPTLMModel(nn.Module):
+
+    def __init__(self,
+                 hidden_size=768,
+                 num_layers=12,
+                 num_attention_heads=12,
+                 max_seq_len=1024,
+                 vocab_size=50257,
+                 checkpoint=False):
+        super().__init__()
+        self.checkpoint = checkpoint
+        self.model = GPT2LMHeadModel(
+            GPT2Config(n_embd=hidden_size,
+                       n_layer=num_layers,
+                       n_head=num_attention_heads,
+                       n_positions=max_seq_len,
+                       n_ctx=max_seq_len,
+                       vocab_size=vocab_size))
+        if checkpoint:
+            self.model.gradient_checkpointing_enable()
+
+    def forward(self, input_ids, attention_mask):
+        # Only return lm_logits
+        return self.model(input_ids=input_ids, attention_mask=attention_mask, use_cache=not self.checkpoint)[0]
+
+
+class GPTLMLoss(nn.Module):
+
+    def __init__(self):
+        super().__init__()
+        self.loss_fn = nn.CrossEntropyLoss()
+
+    def forward(self, logits, labels):
+        shift_logits = logits[..., :-1, :].contiguous()
+        shift_labels = labels[..., 1:].contiguous()
+        # Flatten the tokens
+        return self.loss_fn(shift_logits.view(-1, shift_logits.size(-1)), shift_labels.view(-1))
+
+
+def get_data(batch_size, seq_len, vocab_size):
+    input_ids = torch.randint(0, vocab_size, (batch_size, seq_len), device=torch.cuda.current_device())
+    attention_mask = torch.ones_like(input_ids)
+    return input_ids, attention_mask
+
+
+def gpt2_medium(checkpoint=False):
+    return GPTLMModel(hidden_size=1024, num_layers=24, num_attention_heads=16, checkpoint=checkpoint)
+
+
+def gpt2_xl(checkpoint=True):
+    return GPTLMModel(hidden_size=1600, num_layers=48, num_attention_heads=32, checkpoint=checkpoint)
+
+
+def gpt2_10b(checkpoint=True):
+    return GPTLMModel(hidden_size=4096, num_layers=50, num_attention_heads=16, checkpoint=checkpoint)
+
+
+def get_cpu_mem():
+    return psutil.Process().memory_info().rss / 1024**2
+
+
+def get_gpu_mem():
+    return torch.cuda.memory_allocated() / 1024**2
+
+
+def get_mem_info(prefix=''):
+    return f'{prefix}GPU memory usage: {get_gpu_mem():.2f} MB, CPU memory usage: {get_cpu_mem():.2f} MB'
+
+
+def get_tflops(model_numel, batch_size, seq_len, step_time):
+    return model_numel * batch_size * seq_len * 8 / 1e12 / (step_time + 1e-12)
+
+
+def main():
+    BATCH_SIZE = 8
+    SEQ_LEN = 1024
+    VOCAB_SIZE = 50257
+    NUM_STEPS = 10
+    PLACEMENT_POLICY = 'auto'
+    disable_existing_loggers()
+    colossalai.launch_from_torch(config={})
+    pg = ProcessGroup()
+    logger = get_dist_logger()
+
+    logger.info(get_mem_info(), ranks=[0])
+    # build GPT model
+    with ColoInitContext(device=get_current_device()):
+        model = gpt2_medium(checkpoint=True)
+    numel = sum([p.numel() for p in model.parameters()])
+    logger.info(f'Model numel: {numel}', ranks=[0])
+    get_tflops_func = partial(get_tflops, numel, BATCH_SIZE, SEQ_LEN)
+
+    cai_version = colossalai.__version__
+    logger.info(f'using Colossal-AI version {cai_version}')
+    if version.parse(cai_version) > version.parse("0.1.10"):
+        from colossalai.nn.parallel import GeminiDDP
+        model = GeminiDDP(model,
+                          device=get_current_device(),
+                          placement_policy=PLACEMENT_POLICY,
+                          pin_memory=True,
+                          search_range_mb=32)
+    elif version.parse(cai_version) <= version.parse("0.1.10") and version.parse(cai_version) >= version.parse("0.1.9"):
+        from colossalai.gemini import ChunkManager, GeminiManager
+        chunk_size = ChunkManager.search_chunk_size(model, 64 * 1024**2, 32)
+        gemini_manager = GeminiManager(PLACEMENT_POLICY, chunk_manager)
+        chunk_manager = ChunkManager(chunk_size,
+                                     pg,
+                                     enable_distributed_storage=True,
+                                     init_device=GeminiManager.get_default_device(PLACEMENT_POLICY))
+        model = ZeroDDP(model, gemini_manager)
+
+    logger.info(get_mem_info(prefix='After init model, '), ranks=[0])
+
+    # build criterion
+    criterion = GPTLMLoss()
+
+    # optimizer
+    optimizer = HybridAdam(model.parameters(), lr=1e-3)
+    optimizer = ZeroOptimizer(optimizer, model, initial_scale=2**5)
+    logger.info(get_mem_info(prefix='After init optim, '), ranks=[0])
+
+    model.train()
+    for n in range(NUM_STEPS):
+        # we just use randomly generated data here
+        input_ids, attn_mask = get_data(BATCH_SIZE, SEQ_LEN, VOCAB_SIZE)
+        optimizer.zero_grad()
+        start = time()
+        outputs = model(input_ids, attn_mask)
+        loss = criterion(outputs, input_ids)
+        logger.info(get_mem_info(prefix=f'[{n+1}/{NUM_STEPS}] Forward '), ranks=[0])
+        optimizer.backward(loss)
+        logger.info(get_mem_info(prefix=f'[{n+1}/{NUM_STEPS}] Backward '), ranks=[0])
+        optimizer.step()
+        logger.info(get_mem_info(prefix=f'[{n+1}/{NUM_STEPS}] Optimizer step '), ranks=[0])
+        step_time = time() - start
+        logger.info(
+            f'[{n+1}/{NUM_STEPS}] Loss:{loss.item():.3f}, Step time: {step_time:.3f}s, TFLOPS: {get_tflops_func(step_time):.3f}',
+            ranks=[0])
+
+
+if __name__ == '__main__':
+    main()