lora restart saving gradient changes

This commit is contained in:
Jai Suphavadeeprasit 2026-02-12 10:43:24 -05:00
parent 1127083b5f
commit 90281f5993
7 changed files with 805 additions and 19 deletions

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@ -5,9 +5,11 @@ Contains the four main training modes:
- train_legacy: Checkpoint-based training with vLLM restarts
- train_shared_vllm: Single-copy mode with CUDA IPC
- train_lora: LoRA adapter training with HTTP hot-swap
- train_lora_restart: LoRA training with vLLM restarts (FAST mode)
"""
import os
import subprocess
import time
from typing import Optional
@ -658,3 +660,279 @@ def _hotswap_lora_adapter(
return False
def train_lora_restart(config: TrainingConfig):
"""
GRPO training with LoRA adapters using vLLM restarts (FAST mode).
This mode:
1. Freezes base model, trains only LoRA adapter weights
2. Runs vLLM WITH CUDA graphs enabled (no --enforce-eager)
3. Restarts vLLM every N steps with the new adapter pre-loaded
Performance comparison:
- lora_only (--enforce-eager): ~13 TPS (SLOW)
- lora_restart (CUDA graphs): ~170 TPS (FAST)
The restart overhead (~45s) is much less than the 12x inference slowdown.
Requirements:
- No external vLLM needed - this mode manages vLLM internally
- Requires PEFT library for LoRA
"""
if not PEFT_AVAILABLE:
raise RuntimeError(
"PEFT library required for LoRA mode. Install with: pip install peft"
)
training_start_time = time.time()
# === Setup ===
use_wandb = setup_wandb(config)
print("\n" + "=" * 60)
print("LORA RESTART MODE (fast inference with CUDA graphs)")
print("=" * 60)
print(f"Base model: {config.model_name}")
print(f"LoRA config: r={config.lora_r}, alpha={config.lora_alpha}")
print(f"Save path: {config.save_path}")
print(f"vLLM port: {config.vllm_port}")
print(f"Restart interval: every {config.vllm_restart_interval} steps")
print("=" * 60)
print("NOTE: This mode restarts vLLM to keep CUDA graphs enabled.")
print(" Expected inference speed: ~170 TPS (vs ~13 TPS with --enforce-eager)")
print("=" * 60 + "\n")
# Load model with LoRA adapters for training
print("[1/4] Loading model with LoRA adapters...")
model, tokenizer = load_model_and_tokenizer(config)
# Only optimize LoRA parameters
trainable_params = [p for p in model.parameters() if p.requires_grad]
optimizer = AdamW(trainable_params, lr=config.lr)
os.makedirs(config.save_path, exist_ok=True)
# Save initial adapter
print("[2/4] Saving initial LoRA adapter...")
initial_adapter_path = save_lora_checkpoint(model, config.save_path, 0)
current_adapter_path = initial_adapter_path
# Launch vLLM with the initial adapter
print("[3/4] Launching vLLM with CUDA graphs (no --enforce-eager)...")
vllm_proc = _launch_vllm_with_lora(config, current_adapter_path)
if vllm_proc is None:
raise RuntimeError("Failed to launch vLLM")
print(f"[4/4] Starting training for {config.training_steps} steps")
print("-" * 60)
# Check Atropos API
if not check_atropos_api(url=config.atropos_url, timeout=30):
_terminate_vllm(vllm_proc)
raise RuntimeError(f"Atropos API not reachable at {config.atropos_url}")
register_trainer(config)
# === Benchmark tracking ===
benchmark_stats = {
"step_times": [],
"sync_times": [],
"data_fetch_times": [],
"gpu_memories": [],
"restart_times": [],
}
# === Training Loop ===
batches = []
for step in range(config.training_steps):
print(f"\nStep {step+1}/{config.training_steps}")
# Fetch data (with inference logprobs for proper GRPO)
data_fetch_start = time.time()
if len(batches) == 0:
batches, _ = get_data(
config.batch_size,
config.seq_len,
config.atropos_url,
extract_inference_logprobs=True,
)
batch_data = batches.pop(0)
token_batches, label_batches, advantage_batches, temperature_batches = (
batch_data[:4]
)
inference_logprob_batches = batch_data[4] if len(batch_data) > 4 else None
data_fetch_time = time.time() - data_fetch_start
benchmark_stats["data_fetch_times"].append(data_fetch_time)
# Training step with proper GRPO
step_start = time.time()
metrics = run_training_step(
model,
optimizer,
token_batches,
label_batches,
advantage_batches,
temperature_batches,
config,
inference_logprob_batches=inference_logprob_batches,
)
step_time = time.time() - step_start
benchmark_stats["step_times"].append(step_time)
# GPU memory tracking
gpu_mem_gb = (
torch.cuda.memory_allocated() / 1e9 if torch.cuda.is_available() else 0
)
gpu_mem_reserved_gb = (
torch.cuda.memory_reserved() / 1e9 if torch.cuda.is_available() else 0
)
benchmark_stats["gpu_memories"].append(gpu_mem_gb)
# Periodic adapter save + vLLM restart
sync_time = 0
should_sync = (step + 1) % config.vllm_restart_interval == 0
if should_sync and (step + 1) < config.training_steps: # Don't restart on last step
sync_start = time.time()
# Save new adapter
current_adapter_path = save_lora_checkpoint(model, config.save_path, step + 1)
# Restart vLLM with new adapter
print(f" [RESTART] Restarting vLLM with new adapter...")
_terminate_vllm(vllm_proc)
vllm_proc = _launch_vllm_with_lora(config, current_adapter_path)
if vllm_proc is None:
raise RuntimeError("Failed to restart vLLM")
sync_time = time.time() - sync_start
benchmark_stats["sync_times"].append(sync_time)
benchmark_stats["restart_times"].append(sync_time)
print(f" [RESTART] vLLM restarted in {sync_time:.1f}s")
# Update metrics
metrics.update(
{
"step_time": step_time,
"sync_time": sync_time,
"data_fetch_time": data_fetch_time,
"gpu_memory_gb": gpu_mem_gb,
"gpu_memory_reserved_gb": gpu_mem_reserved_gb,
}
)
log_metrics(metrics, step + 1, use_wandb, benchmark=config.benchmark)
# === Cleanup ===
print("\nSaving final adapter...")
final_sync_start = time.time()
final_adapter_path = save_lora_checkpoint(
model, config.save_path, config.training_steps, is_final=True
)
final_sync_time = time.time() - final_sync_start
benchmark_stats["sync_times"].append(final_sync_time)
# Terminate vLLM
_terminate_vllm(vllm_proc)
finalize_training(
use_wandb,
training_start_time,
"lora_restart",
config.training_steps,
benchmark_stats,
config.benchmark,
)
# Save tokenizer
tokenizer_path = os.path.join(config.save_path, "tokenizer")
tokenizer.save_pretrained(tokenizer_path)
print(f"Tokenizer saved to {tokenizer_path}")
print(f"Final adapter saved to {final_adapter_path}")
def _launch_vllm_with_lora(config: TrainingConfig, adapter_path: str) -> Optional[subprocess.Popen]:
"""
Launch vLLM with a LoRA adapter pre-loaded (CUDA graphs enabled).
Unlike lora_only mode, this does NOT use --enforce-eager, so we get
full CUDA graph speed (~170 TPS instead of ~13 TPS).
"""
from .vllm_manager import kill_process_on_port, wait_for_vllm_ready
# Kill any existing process on the port
kill_process_on_port(config.vllm_port)
# Find the vllm_api_server.py script
script_dir = os.path.dirname(os.path.abspath(__file__))
server_script = os.path.join(script_dir, "vllm_api_server.py")
# Build command - NO --enforce-eager for full speed
cmd = [
"python", server_script,
"--model", config.model_name,
"--port", str(config.vllm_port),
"--gpu-memory-utilization", str(config.vllm_gpu_memory_utilization),
"--enable-lora",
"--max-lora-rank", str(max(config.lora_r * 2, 32)),
# Note: NOT adding --enforce-eager - this is the key difference!
# LoRA adapter will be loaded at startup, CUDA graphs compiled with it
]
# Set environment for GPU selection
env = os.environ.copy()
if config.vllm_gpu is not None:
env["CUDA_VISIBLE_DEVICES"] = str(config.vllm_gpu)
print(f" GPU: {config.vllm_gpu} (via CUDA_VISIBLE_DEVICES)")
else:
print(f" GPU: Same as trainer (inherited CUDA_VISIBLE_DEVICES)")
print(f" Launching: {' '.join(cmd)}")
print(f" Adapter: {adapter_path}")
try:
proc = subprocess.Popen(cmd, env=env)
print(f" vLLM PID: {proc.pid}")
# Wait for server to be ready
if not wait_for_vllm_ready(config.vllm_port, timeout=180):
print(" ERROR: vLLM failed to start")
proc.terminate()
return None
# Load the LoRA adapter
print(f" Loading LoRA adapter...")
try:
resp = requests.post(
f"http://localhost:{config.vllm_port}/lora/load",
json={"adapter_path": adapter_path, "adapter_name": "training_adapter"},
timeout=60,
)
if resp.status_code == 200:
print(f" ✓ Adapter loaded successfully")
else:
print(f" WARNING: Adapter load returned {resp.status_code}: {resp.text}")
except Exception as e:
print(f" WARNING: Could not load adapter: {e}")
# Continue anyway - base model inference still works
return proc
except Exception as e:
print(f" ERROR: {e}")
return None
def _terminate_vllm(proc: Optional[subprocess.Popen]) -> None:
"""Terminate a vLLM process."""
if proc is None:
return
try:
proc.terminate()
proc.wait(timeout=10)
except subprocess.TimeoutExpired:
proc.kill()
proc.wait()
except Exception:
pass