delete the configurator in favor of argparse and clean up a lot of kwarg details to make them more consistent across all scripts

This commit is contained in:
Andrej Karpathy
2026-01-04 19:14:23 +00:00
parent 507d54224a
commit eb7bbc1b66
9 changed files with 546 additions and 450 deletions
+59 -54
View File
@@ -9,6 +9,7 @@ Or torchrun for training:
torchrun --standalone --nproc_per_node=8 -m scripts.chat_sft
"""
import argparse
import os
os.environ["PYTORCH_ALLOC_CONF"] = "expandable_segments:True"
@@ -31,49 +32,51 @@ from tasks.customjson import CustomJSON
from tasks.spellingbee import SimpleSpelling, SpellingBee
# -----------------------------------------------------------------------------
# SFT Hyperparameters
run = "dummy" # wandb run name default ("dummy" is special - we won't log to wandb)
# input model options
source = "mid" # base|mid , which checkpoint to load the model from (base model or midtrained model)
model_tag = None # model tag to load the model from (base model or midtrained model)
step = None # step to load the model from (base model or midtrained model)
# compute/precision
device_type = "" # cuda|cpu|mps (empty => autodetect)
dtype = "bfloat16"
device_batch_size = 4 # max to avoid OOM
# optimization
num_epochs = 1
num_iterations = -1 # override number of iterations (-1 = disable, use num_epochs to derive it)
target_examples_per_step = 32
unembedding_lr = 0.004
embedding_lr = 0.2
matrix_lr = 0.02
weight_decay = 0.0
init_lr_frac = 0.02
# evaluation and logging there of
eval_every = 100
eval_steps = 100
eval_metrics_every = 200
eval_metrics_max_problems = 1024
# now allow CLI to override the settings via the configurator lol
config_keys = [k for k,v in globals().items() if not k.startswith('_') and isinstance(v, (int, float, bool, str))]
exec(open(os.path.join('nanochat', 'configurator.py')).read()) # overrides from command line or config file
user_config = {k: globals()[k] for k in config_keys} # possibly useful for logging
# CLI arguments
parser = argparse.ArgumentParser(description="Supervised finetuning for chat")
# Logging
parser.add_argument("--run", type=str, default="dummy", help="wandb run name ('dummy' disables wandb logging)")
# Runtime
parser.add_argument("--device_type", type=str, default="", help="cuda|cpu|mps (empty = autodetect)")
parser.add_argument("--dtype", type=str, default="bfloat16", help="float32|bfloat16")
# Model loading
parser.add_argument("--source", type=str, default="mid", help="base|mid - which checkpoint to load from")
parser.add_argument("--model_tag", type=str, default=None, help="model tag to load from")
parser.add_argument("--model_step", type=int, default=None, help="model step to load from")
# Training horizon
parser.add_argument("--num_epochs", type=int, default=1, help="number of epochs")
parser.add_argument("--num_iterations", type=int, default=-1, help="override number of iterations (-1 = use num_epochs)")
# Batch sizes
parser.add_argument("--device_batch_size", type=int, default=4, help="per-device batch size")
parser.add_argument("--target_examples_per_step", type=int, default=32, help="target examples per optimization step")
# Optimization
parser.add_argument("--embedding_lr", type=float, default=0.2, help="learning rate for embedding parameters (Adam)")
parser.add_argument("--unembedding_lr", type=float, default=0.004, help="learning rate for unembedding parameters (Adam)")
parser.add_argument("--matrix_lr", type=float, default=0.02, help="learning rate for matrix parameters (Muon)")
parser.add_argument("--weight_decay", type=float, default=0.0, help="weight decay for embedding/unembedding parameters (Adam)")
parser.add_argument("--init_lr_frac", type=float, default=0.02, help="initial LR as fraction of base LR")
# Evaluation
parser.add_argument("--eval_every", type=int, default=100, help="evaluate val loss every N steps")
parser.add_argument("--eval_steps", type=int, default=100, help="number of batches for val loss evaluation")
parser.add_argument("--eval_metrics_every", type=int, default=200, help="evaluate accuracy metrics every N steps")
parser.add_argument("--eval_metrics_max_problems", type=int, default=1024, help="max problems per metric evaluation")
args = parser.parse_args()
user_config = vars(args).copy()
# -----------------------------------------------------------------------------
# Compute init
device_type = autodetect_device_type() if device_type == "" else device_type
device_type = autodetect_device_type() if args.device_type == "" else args.device_type
ddp, ddp_rank, ddp_local_rank, ddp_world_size, device = compute_init(device_type)
master_process = ddp_rank == 0
ptdtype = torch.float32 if dtype == 'float32' else torch.bfloat16
ptdtype = torch.float32 if args.dtype == 'float32' else torch.bfloat16
autocast_ctx = torch.amp.autocast(device_type=device_type, dtype=ptdtype) if device_type == "cuda" else nullcontext()
# wandb logging init
use_dummy_wandb = run == "dummy" or not master_process
wandb_run = DummyWandb() if use_dummy_wandb else wandb.init(project="nanochat-sft", name=run, config=user_config, save_code=True)
use_dummy_wandb = args.run == "dummy" or not master_process
wandb_run = DummyWandb() if use_dummy_wandb else wandb.init(project="nanochat-sft", name=args.run, config=user_config, save_code=True)
# Load the model and tokenizer
model, tokenizer, meta = load_model(source, device, phase="train", model_tag=model_tag, step=step)
model, tokenizer, meta = load_model(args.source, device, phase="train", model_tag=args.model_tag, step=args.model_step)
orig_model = model # original, uncompiled model
# model = torch.compile(model, dynamic=True) # doesn't work super well because of variable lengths of inputs
engine = Engine(model, tokenizer) # will be used for inline model evaluation only
@@ -127,34 +130,36 @@ def sft_data_generator(dataset, batch_size):
yield collate_and_yield(batch)
batch = []
examples_per_step = device_batch_size * ddp_world_size
print0(f"Target examples per step: {target_examples_per_step}")
print0(f"Device batch size: {device_batch_size}")
examples_per_step = args.device_batch_size * ddp_world_size
print0(f"Target examples per step: {args.target_examples_per_step}")
print0(f"Device batch size: {args.device_batch_size}")
print0(f"Examples per step is device_batch_size * ddp_world_size: {examples_per_step}")
assert target_examples_per_step % examples_per_step == 0, "Target examples per step must be divisible by examples per step"
grad_accum_steps = target_examples_per_step // examples_per_step
assert args.target_examples_per_step % examples_per_step == 0, "Target examples per step must be divisible by examples per step"
grad_accum_steps = args.target_examples_per_step // examples_per_step
print0(f"=> Setting grad accum steps: {grad_accum_steps}")
if num_iterations == -1:
if args.num_iterations == -1:
# derive num_iterations from num_epochs and the size of the dataset
assert num_epochs > 0, "num_epochs must be positive if num_iterations is -1"
num_iterations = (len(train_ds) // target_examples_per_step) * num_epochs
train_loader = sft_data_generator(train_ds, batch_size=device_batch_size)
build_val_loader = lambda: sft_data_generator(val_ds, batch_size=device_batch_size)
assert args.num_epochs > 0, "num_epochs must be positive if num_iterations is -1"
num_iterations = (len(train_ds) // args.target_examples_per_step) * args.num_epochs
else:
num_iterations = args.num_iterations
train_loader = sft_data_generator(train_ds, batch_size=args.device_batch_size)
build_val_loader = lambda: sft_data_generator(val_ds, batch_size=args.device_batch_size)
# -----------------------------------------------------------------------------
# Initialize the Optimizer
optimizers = model.setup_optimizers(
unembedding_lr=unembedding_lr,
embedding_lr=embedding_lr,
matrix_lr=matrix_lr,
weight_decay=weight_decay,
unembedding_lr=args.unembedding_lr,
embedding_lr=args.embedding_lr,
matrix_lr=args.matrix_lr,
weight_decay=args.weight_decay,
)
# Set the initial learning rate as a fraction of the base learning rate
for opt in optimizers:
for group in opt.param_groups:
group["lr"] = group["lr"] * init_lr_frac
group["lr"] = group["lr"] * args.init_lr_frac
group["initial_lr"] = group["lr"] # save the initial learning so we can decay easily later
# -----------------------------------------------------------------------------
@@ -171,11 +176,11 @@ for step in range(num_iterations):
last_step = step == num_iterations - 1
# evaluate the validation loss
if last_step or step % eval_every == 0:
if last_step or step % args.eval_every == 0:
model.eval()
val_loader = build_val_loader()
losses = []
for _ in range(eval_steps):
for _ in range(args.eval_steps):
val_inputs, val_targets = next(val_loader)
with torch.no_grad(), autocast_ctx:
loss = model(val_inputs, val_targets)
@@ -192,13 +197,13 @@ for step in range(num_iterations):
model.train()
# evaluate accuracy of the multiple choice tasks (which are quick to run)
if last_step or (step > 0 and step % eval_metrics_every == 0):
if last_step or (step > 0 and step % args.eval_metrics_every == 0):
model.eval()
metrics = {}
with torch.no_grad(), autocast_ctx:
# note that because these are inside no_grad, we can usually afford to at least ~2X the batch size
metrics["mmlu_acc"] = run_chat_eval("MMLU", model, tokenizer, engine, batch_size=device_batch_size*2, max_problems=eval_metrics_max_problems)
metrics["arc_easy_acc"] = run_chat_eval("ARC-Easy", model, tokenizer, engine, batch_size=device_batch_size*2, max_problems=eval_metrics_max_problems)
metrics["mmlu_acc"] = run_chat_eval("MMLU", model, tokenizer, engine, batch_size=args.device_batch_size*2, max_problems=args.eval_metrics_max_problems)
metrics["arc_easy_acc"] = run_chat_eval("ARC-Easy", model, tokenizer, engine, batch_size=args.device_batch_size*2, max_problems=args.eval_metrics_max_problems)
metrics_str = ', '.join(f'{k}: {v:.6f}' for k, v in metrics.items())
print0(f"Step {step:05d} | {metrics_str}")
wandb_run.log({
@@ -250,7 +255,7 @@ for step in range(num_iterations):
if master_process:
base_dir = get_base_dir()
depth = model.config.n_layer
output_dirname = model_tag if model_tag else f"d{depth}" # e.g. d12
output_dirname = args.model_tag if args.model_tag else f"d{depth}" # e.g. d12
checkpoint_dir = os.path.join(base_dir, "chatsft_checkpoints", output_dirname)
model_config_kwargs = model.config.__dict__ # slightly naughty, abusing the simplicity of GPTConfig, TODO nicer
save_checkpoint(