flash-attention/tests/models/test_gpt_generation.py
2023-08-18 20:59:35 -07:00

299 lines
11 KiB
Python

import os
import re
import time
import pytest
import torch
from einops import rearrange
from flash_attn.models.gpt import GPTLMHeadModel, remap_state_dict_hf_gpt2
from flash_attn.models.opt import opt_config_to_gpt2_config, remap_state_dict_hf_opt
from flash_attn.utils.generation import update_graph_cache
from flash_attn.utils.pretrained import state_dict_from_pretrained
from transformers import AutoTokenizer, GPT2Config, GPT2Tokenizer, OPTConfig
from transformers.models.gpt2.modeling_gpt2 import GPT2LMHeadModel as GPT2LMHeadModelHF
from transformers.models.opt.modeling_opt import OPTForCausalLM
@pytest.mark.parametrize("fused_ft_kernel", [False, True])
# @pytest.mark.parametrize('fused_ft_kernel', [True])
@pytest.mark.parametrize("optimized", [False, True])
# @pytest.mark.parametrize('optimized', [False])
@pytest.mark.parametrize("rotary", [False, True])
# @pytest.mark.parametrize('rotary', [False])
@pytest.mark.parametrize("model_name", ["gpt2"])
def test_greedy_decode_gpt2(model_name, rotary, optimized, fused_ft_kernel):
"""Check that our implementation of GPT2 generation matches the HF implementation:
the scores in fp16 should be around the same as the HF scores in fp16, when compared to
the HF scores in fp32.
"""
dtype = torch.float16
device = "cuda"
rtol, atol = 3e-3, 3e-1
config = GPT2Config.from_pretrained(model_name)
if rotary:
config.n_positions = 0
config.rotary_emb_fraction = 0.5
config.rotary_emb_base = 24000
config.residual_in_fp32 = True
if optimized:
config.use_flash_attn = True
config.fused_bias_fc = True
config.fused_mlp = True
config.fused_dropout_add_ln = True
# if not rotary, we load the weight from HF but ignore the position embeddings.
# The model would be nonsense but it doesn't matter for the test.
model = GPTLMHeadModel.from_pretrained(
model_name, config, strict=not rotary, device=device, dtype=dtype
)
model.eval()
if not rotary:
model_ref = GPT2LMHeadModelHF.from_pretrained(model_name).to(device=device)
model_hf = GPT2LMHeadModelHF.from_pretrained(model_name, torch_dtype=dtype).to(
device=device
)
model_ref.eval()
model_hf.eval()
torch.manual_seed(0)
tokenizer = GPT2Tokenizer.from_pretrained("gpt2")
input_ids = tokenizer("Hello, my dog is cute and he", return_tensors="pt").input_ids.to(
device=device
)
max_length = 25
# input_ids = torch.randint(0, 100, (2, 10), dtype=torch.long, device='cuda')
# max_length = input_ids.shape[1] + 40
# Slow generation for reference
sequences = []
scores = []
cur_input_ids = input_ids
with torch.inference_mode():
scores.append(model(cur_input_ids).logits[:, -1])
sequences.append(scores[-1].argmax(dim=-1))
for _ in range(input_ids.shape[1] + 1, max_length):
cur_input_ids = torch.cat([cur_input_ids, rearrange(sequences[-1], "b -> b 1")], dim=-1)
scores.append(model(cur_input_ids).logits[:, -1])
sequences.append(scores[-1].argmax(dim=-1))
sequences = torch.cat([input_ids, torch.stack(sequences, dim=1)], dim=1)
scores = tuple(scores)
out = model.generate(
input_ids=input_ids,
max_length=max_length,
fused_ft_kernel=fused_ft_kernel,
return_dict_in_generate=True,
output_scores=True,
timing=True,
)
print(out.sequences)
print(tokenizer.batch_decode(out.sequences.tolist()))
if fused_ft_kernel:
out_cg = model.generate(
input_ids=input_ids,
max_length=max_length,
fused_ft_kernel=fused_ft_kernel,
cg=True,
return_dict_in_generate=True,
output_scores=True,
timing=True,
)
print(out_cg.sequences)
if not rotary:
out_hf = model_hf.generate(
input_ids=input_ids,
max_length=max_length,
return_dict_in_generate=True,
output_scores=True,
)
out_ref = model_ref.generate(
input_ids=input_ids,
max_length=max_length,
return_dict_in_generate=True,
output_scores=True,
)
print(
f"Scores max diff: {(torch.stack(out.scores, 1) - torch.stack(out_ref.scores, 1)).abs().max().item()}"
)
print(
f"Scores mean diff: {(torch.stack(out.scores, 1) - torch.stack(out_ref.scores, 1)).abs().mean().item()}"
)
print(
f"HF fp16 max diff: {(torch.stack(out_hf.scores, 1) - torch.stack(out_ref.scores, 1)).abs().max().item()}"
)
print(
f"HF fp16 mean diff: {(torch.stack(out_hf.scores, 1) - torch.stack(out_ref.scores, 1)).abs().mean().item()}"
)
print(tokenizer.batch_decode(out_ref.sequences.tolist()))
assert torch.all(out.sequences == sequences)
assert torch.allclose(
torch.stack(out.scores, dim=1), torch.stack(scores, dim=1), rtol=rtol, atol=atol
)
if not rotary:
assert torch.all(out.sequences == out_ref.sequences)
assert torch.all(out.sequences == out_hf.sequences)
assert (
torch.stack(out.scores, 1) - torch.stack(out_ref.scores, 1)
).abs().max().item() < 3 * (
torch.stack(out_hf.scores, 1) - torch.stack(out_ref.scores, 1)
).abs().max().item()
@pytest.mark.parametrize(
"model_name",
[
"facebook/opt-125m",
"facebook/opt-350m",
"facebook/opt-1.3b",
"facebook/opt-2.7b",
"facebook/opt-6.7b",
],
)
# @pytest.mark.parametrize('model_name', ["facebook/opt-125m"])
def test_greedy_decode_opt(model_name):
"""Check that our implementation of OPT generation matches the HF implementation:
the scores in fp16 should be around the same as the HF scores in fp16, when compared to
the HF scores in fp32.
"""
print(f"\nMODEL: {model_name}")
verbose = False
dtype = torch.float16
device = "cuda"
rtol, atol = 3e-3, 3e-1
fused_ft_kernel = True
config = opt_config_to_gpt2_config(OPTConfig.from_pretrained(model_name))
# Only prenorm supports residual_in_fp32
config.residual_in_fp32 = getattr(config, "prenorm", True)
config.use_flash_attn = True
config.fused_bias_fc = True
config.fused_mlp = True
config.fused_dropout_add_ln = True
model = GPTLMHeadModel.from_pretrained(model_name, config, device=device, dtype=dtype)
model.eval()
torch.manual_seed(0)
# OPT tokenizer requires use_fast=False
# https://huggingface.co/docs/transformers/model_doc/opt
tokenizer = AutoTokenizer.from_pretrained(model_name, use_fast=False)
eos_token_id = tokenizer.eos_token_id
input_ids = tokenizer("Hello, my dog is cute and he", return_tensors="pt").input_ids.to(
device=device
)
max_length = 25
# input_ids = torch.randint(0, 100, (2, 10), dtype=torch.long, device='cuda')
# max_length = input_ids.shape[1] + 40
# Slow generation for reference
sequences = []
scores = []
cur_input_ids = input_ids
with torch.inference_mode():
scores.append(model(cur_input_ids).logits[:, -1])
sequences.append(scores[-1].argmax(dim=-1))
for _ in range(input_ids.shape[1] + 1, max_length):
cur_input_ids = torch.cat([cur_input_ids, rearrange(sequences[-1], "b -> b 1")], dim=-1)
scores.append(model(cur_input_ids).logits[:, -1])
sequences.append(scores[-1].argmax(dim=-1))
if eos_token_id is not None and (sequences[-1] == eos_token_id).all():
break
sequences = torch.cat([input_ids, torch.stack(sequences, dim=1)], dim=1)
scores = tuple(scores)
print("Without CUDA graph")
torch.cuda.synchronize()
start = time.time()
out = model.generate(
input_ids=input_ids,
max_length=max_length,
eos_token_id=eos_token_id,
fused_ft_kernel=fused_ft_kernel,
return_dict_in_generate=True,
output_scores=True,
timing=True,
)
torch.cuda.synchronize()
print(f"Prompt processing + decoding time: {(time.time() - start) * 1000:.0f}ms")
if verbose:
print(out.sequences)
print(tokenizer.batch_decode(out.sequences.tolist()))
if fused_ft_kernel:
# Capture graph outside the timing loop
batch_size, seqlen_og = input_ids.shape
model._decoding_cache = update_graph_cache(model, None, batch_size, seqlen_og, max_length)
print("With CUDA graph")
torch.cuda.synchronize()
start = time.time()
out_cg = model.generate(
input_ids=input_ids,
max_length=max_length,
fused_ft_kernel=fused_ft_kernel,
cg=True,
return_dict_in_generate=True,
output_scores=True,
timing=True,
)
torch.cuda.synchronize()
print(f"Prompt processing + decoding time: {(time.time() - start) * 1000:.0f}ms")
if verbose:
print(out_cg.sequences)
print(tokenizer.batch_decode(out_cg.sequences.tolist()))
del model
model_hf = OPTForCausalLM.from_pretrained(model_name, torch_dtype=dtype).to(device=device)
model_hf.eval()
print("HF fp16")
torch.cuda.synchronize()
start = time.time()
out_hf = model_hf.generate(
input_ids=input_ids, max_length=max_length, return_dict_in_generate=True, output_scores=True
)
torch.cuda.synchronize()
print(f"Prompt processing + decoding time: {(time.time() - start) * 1000:.0f}ms")
del model_hf
model_ref = OPTForCausalLM.from_pretrained(model_name).to(device=device)
model_ref.eval()
print("HF fp32")
torch.cuda.synchronize()
start = time.time()
out_ref = model_ref.generate(
input_ids=input_ids, max_length=max_length, return_dict_in_generate=True, output_scores=True
)
torch.cuda.synchronize()
print(f"Prompt processing + decoding time: {(time.time() - start) * 1000:.0f}ms")
del model_ref
print(tokenizer.batch_decode(out_ref.sequences.tolist()))
if verbose:
print(
f"Scores max diff: {(torch.stack(out.scores, 1) - torch.stack(out_ref.scores, 1)).abs().max().item()}"
)
print(
f"Scores mean diff: {(torch.stack(out.scores, 1) - torch.stack(out_ref.scores, 1)).abs().mean().item()}"
)
print(
f"HF fp16 max diff: {(torch.stack(out_hf.scores, 1) - torch.stack(out_ref.scores, 1)).abs().max().item()}"
)
print(
f"HF fp16 mean diff: {(torch.stack(out_hf.scores, 1) - torch.stack(out_ref.scores, 1)).abs().mean().item()}"
)
assert torch.all(out.sequences == sequences)
assert torch.allclose(
torch.stack(out.scores, dim=1), torch.stack(scores, dim=1), rtol=rtol, atol=atol
)
assert torch.all(out.sequences == out_ref.sequences)
assert torch.all(out.sequences == out_hf.sequences)
assert (torch.stack(out.scores, 1) - torch.stack(out_ref.scores, 1)).abs().max().item() < 3 * (
torch.stack(out_hf.scores, 1) - torch.stack(out_ref.scores, 1)
).abs().max().item()