Files
nanochat/scripts/chat_eval.py

258 lines
12 KiB
Python

"""
Evaluate the Chat model.
All the generic code lives here, and all the evlauation-specific
code lives in nanochat directory and is imported from here.
Example runs:
python -m scripts.chat_eval -a ARC-Easy
torchrun --nproc_per_node=8 -m scripts.chat_eval -- -a ARC-Easy
"""
import argparse
from functools import partial
from contextlib import nullcontext
import torch
import torch.distributed as dist
from nanochat.common import compute_init, compute_cleanup, get_dist_info, print0, autodetect_device_type
from nanochat.checkpoint_manager import load_model
from nanochat.engine import Engine
from tasks.humaneval import HumanEval
from tasks.mmlu import MMLU
from tasks.arc import ARC
from tasks.gsm8k import GSM8K
from tasks.spellingbee import SpellingBee
# -----------------------------------------------------------------------------
# Generative evaluation loop (we go one problem at a time, sample, evaluate)
def run_generative_eval(task_object, tokenizer, model, engine, num_samples, max_new_tokens, temperature, top_k, max_problems=None):
ddp, ddp_rank, ddp_local_rank, ddp_world_size = get_dist_info()
device = model.get_device()
num_problems = len(task_object) if max_problems is None else min(len(task_object), max_problems)
# Run the evaluation
num_passed, total = 0, 0
for i in range(ddp_rank, num_problems, ddp_world_size):
conversation = task_object[i]
# Tokenize the prompt
encoded_prompt = tokenizer.render_for_completion(conversation)
# Get the completions
results, _ = engine.generate_batch(
encoded_prompt,
num_samples=num_samples,
max_tokens=max_new_tokens,
temperature=temperature,
top_k=top_k,
)
# Decode the completions as text
prefix_length = len(encoded_prompt)
completions = [tokenizer.decode(result_tokens[prefix_length:]) for result_tokens in results]
# Evaluate success criteria
outcomes = [task_object.evaluate(conversation, completion) for completion in completions]
passed = any(outcomes)
# Keep stats
total += 1
num_passed += int(passed)
# Logging (overwrite the same line in the console)
print(f"\r\033[KRank {ddp_rank} | {num_passed}/{total} ({100*num_passed/total:.2f}%)", end='', flush=True)
# Finish the in-place progress line with a newline before final summary
print()
# Aggregate results across all ranks
if ddp:
num_passed_tensor = torch.tensor([num_passed], dtype=torch.long, device=device)
total_tensor = torch.tensor([total], dtype=torch.long, device=device)
dist.all_reduce(num_passed_tensor, op=dist.ReduceOp.SUM)
dist.all_reduce(total_tensor, op=dist.ReduceOp.SUM)
num_passed = num_passed_tensor.item()
total = total_tensor.item()
print0("=" * 50)
print0(f"Final: {num_passed}/{total} ({100*num_passed/total:.2f}%)")
# Return the accuracy
return num_passed/total
# -----------------------------------------------------------------------------
# Categorical evaluation loop
# A lot easier because we don't have to sample. Therefore, we can actually go
# batches at a time and just check the logits for correct answer choices.
def run_categorical_eval(task_object, tokenizer, model, batch_size, max_problems=None):
ddp, ddp_rank, ddp_local_rank, ddp_world_size = get_dist_info()
device = model.get_device()
bos = tokenizer.get_bos_token_id() # use BOS as pad token is ok, these positions are ignored
# We'll process batches of independent problems at a time because there is no sampling needed
num_problems = len(task_object) if max_problems is None else min(len(task_object), max_problems)
ceil_div = lambda x, y: -(-x // y)
num_batches = ceil_div(num_problems, batch_size)
# Run the evaluation
letter_to_id_cache = {} # many letters will repeat often, let's save the tokenizer some work
num_passed, total = 0, 0
for i in range(ddp_rank, num_batches, ddp_world_size):
i0, i1 = i * batch_size, min((i + 1) * batch_size, num_problems)
# Prepare the batch of problems. They might all be of different length, so we pad/collate them.
conversations = [task_object[ii] for ii in range(i0, i1)]
prompt_ids = [tokenizer.render_for_completion(conversation) for conversation in conversations] # TODO: remake the way this works
max_length = max(len(ids) for ids in prompt_ids)
answer_time_positions = [len(ids) - 1 for ids in prompt_ids] # where the last token is (and the predicted answer)
padded_prompt_ids = [ids + [bos] * (max_length - len(ids)) for ids in prompt_ids]
prompt_ids = torch.tensor(padded_prompt_ids, dtype=torch.long, device=device)
# Get the logits for the whole batch of conversations in parallel (efficiency win here)
with torch.no_grad():
logits = model(prompt_ids) # (B, T, V)
# Focus on the available answer on just the letters corresponding to choices
# Note that this helps the evaluation a lot because it specifically narrows the focus to only the avilable letters
# The much harder alternative would be to just generate from the Assistant and check if it responded with the correct
# letter (e.g. A, B, C, D), but evaluations typically make the task easier in this way.
for idx, conversation in enumerate(conversations):
# get the token ids of all the available letters of this problem
letters = conversation['letters']
letter_ids = []
for letter in letters:
if not letter in letter_to_id_cache:
encoded_letter = tokenizer.encode(letter)
assert len(encoded_letter) == 1, "Each letter must be a single token"
letter_to_id_cache[letter] = encoded_letter[0]
letter_ids.append(letter_to_id_cache[letter])
# focus logits just down to the answer position and the available letters of the answer
answer_pos = answer_time_positions[idx]
focus_logits = logits[idx, answer_pos, letter_ids]
# get the argmax letter (the predicted answer)
argmax_letter_id = focus_logits.argmax(dim=-1).item()
predicted_letter = letters[argmax_letter_id]
# evaluate the outcome
outcome = task_object.evaluate(conversation, predicted_letter)
num_passed += int(outcome)
total += 1
# Aggregate results across all ranks
if ddp:
num_passed_tensor = torch.tensor([num_passed], dtype=torch.long, device=device)
total_tensor = torch.tensor([total], dtype=torch.long, device=device)
dist.all_reduce(num_passed_tensor, op=dist.ReduceOp.SUM)
dist.all_reduce(total_tensor, op=dist.ReduceOp.SUM)
num_passed = num_passed_tensor.item()
total = total_tensor.item()
average = num_passed/total
print0(f"Final: {num_passed}/{total} ({100*average:.2f}%)")
return average
# -----------------------------------------------------------------------------
def run_chat_eval(task_name, model, tokenizer, engine,
batch_size=1, num_samples=1, max_new_tokens=512, temperature=0.0, top_k=50,
max_problems=None):
# Create the evaluation object
task_module = {
'HumanEval': HumanEval,
'MMLU': partial(MMLU, subset="all", split="test"),
'ARC-Easy': partial(ARC, subset="ARC-Easy", split="test"),
'ARC-Challenge': partial(ARC, subset="ARC-Challenge", split="test"),
'GSM8K': partial(GSM8K, subset="main", split="test"),
'SpellingBee': partial(SpellingBee, size=256, split="test"),
}[task_name]
task_object = task_module()
# Run the evaluation
if task_object.eval_type == 'generative':
acc = run_generative_eval(task_object, tokenizer, model, engine, num_samples, max_new_tokens, temperature, top_k, max_problems=max_problems)
elif task_object.eval_type == 'categorical':
acc = run_categorical_eval(task_object, tokenizer, model, batch_size, max_problems=max_problems)
else:
raise ValueError(f"Unsupported task evaluation type: {task_object.eval_type}")
return acc
# -----------------------------------------------------------------------------
if __name__ == "__main__":
# Parse command-line arguments
parser = argparse.ArgumentParser()
parser.add_argument('-i', '--source', type=str, required=True, help="Source of the model: sft|mid|rl")
parser.add_argument('-a', '--task-name', type=str, default=None, help="Task name. Default = all tasks. Use | to split multiple tasks.")
parser.add_argument('-d', '--dtype', type=str, default='bfloat16', choices=['float32', 'bfloat16'])
parser.add_argument('-t', '--temperature', type=float, default=0.0)
parser.add_argument('-m', '--max-new-tokens', type=int, default=512)
parser.add_argument('-n', '--num-samples', type=int, default=1)
parser.add_argument('-k', '--top-k', type=int, default=50)
parser.add_argument('-b', '--batch-size', type=int, default=8, help='Batch size for categorical evaluation')
parser.add_argument('-g', '--model-tag', type=str, default=None, help='Model tag to load')
parser.add_argument('-s', '--step', type=int, default=None, help='Step to load')
parser.add_argument('-x', '--max-problems', type=int, default=None, help='Max problems to evaluate')
parser.add_argument('--device-type', type=str, default='', choices=['cuda', 'cpu', 'mps'], help='Device type for evaluation: cuda|cpu|mps. empty => autodetect')
args = parser.parse_args()
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)
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()
model, tokenizer, meta = load_model(args.source, device, phase="eval", model_tag=args.model_tag, step=args.step)
engine = Engine(model, tokenizer)
# Get the tasks to evaluate on
all_tasks = ['ARC-Easy', 'ARC-Challenge', 'MMLU', 'GSM8K', 'HumanEval', 'SpellingBee']
baseline_accuracies = {
'ARC-Easy': 0.25, # multiple choice 1 of 4 => 25%
'ARC-Challenge': 0.25, # multiple choice 1 of 4 => 25%
'MMLU': 0.25, # multiple choice 1 of 4 => 25%
'GSM8K': 0.0, # open-ended => 0%
'HumanEval': 0.0, # open-ended => 0%
'SpellingBee': 0.0, # open-ended => 0%
}
task_names = all_tasks if args.task_name is None else args.task_name.split('|')
# Run all the task evaluations sequentially
results = {}
for task_name in task_names:
with autocast_ctx:
acc = run_chat_eval(
task_name,
model, tokenizer, engine,
batch_size=args.batch_size,
num_samples=args.num_samples,
max_new_tokens=args.max_new_tokens,
temperature=args.temperature,
top_k=args.top_k,
max_problems=args.max_problems,
)
results[task_name] = acc
print0(f"{task_name} accuracy: {100 * acc:.2f}%")
# Log to report
from nanochat.report import get_report
all_tasks_were_evaluated = all(task_name in results for task_name in all_tasks)
# calculate the ChatCORE metric if we can (similar to CORE, it's the mean centered accuracy)
# this way, ChatCORE ranges from 0 (at random baseline) to 1 (peak performance)
chatcore_metric_dict = {}
if all_tasks_were_evaluated:
centered_mean = 0
for task_name, acc in results.items():
baseline_acc = baseline_accuracies.get(task_name, 0.0)
centered_acc = (acc - baseline_acc) / (1.0 - baseline_acc)
centered_mean += centered_acc
chatcore_metric = centered_mean / len(results)
chatcore_metric_dict = {"ChatCORE metric": chatcore_metric}
get_report().log(section="Chat evaluation " + args.source, data=[
vars(args), # CLI args
results,
chatcore_metric_dict,
])
compute_cleanup()