flash-attention/tests/models/test_gpt.py
2023-08-26 13:00:40 -07:00

338 lines
13 KiB
Python

import re
import pytest
import torch
from einops import rearrange
from flash_attn.models.gpt import GPTLMHeadModel, remap_state_dict_hf_gpt2
from flash_attn.utils.pretrained import state_dict_from_pretrained
from transformers import GPT2Config, GPT2Tokenizer
from transformers.models.gpt2.modeling_gpt2 import GPT2LMHeadModel as GPT2LMHeadModelHF
@pytest.mark.parametrize("model_name", ["gpt2", "gpt2-medium"])
# @pytest.mark.parametrize('model_name', ["gpt2"])
def test_gpt2_state_dict(model_name):
config = GPT2Config.from_pretrained(model_name)
pretrained_state_dict = remap_state_dict_hf_gpt2(state_dict_from_pretrained(model_name), config)
model = GPTLMHeadModel(config)
state_dict = model.state_dict()
assert state_dict.keys() == pretrained_state_dict.keys()
for k in state_dict.keys():
assert state_dict[k].shape == pretrained_state_dict[k].shape
@pytest.mark.parametrize("model_name", ["gpt2", "gpt2-medium"])
# @pytest.mark.parametrize('model_name', ["gpt2"])
def test_gpt2_non_optimized(model_name):
"""Check that our implementation of GPT2 (without any optimizations enabled) matches the
HF implementation: the output of our forward pass in fp16 should be around the same as the HF
forward pass in fp16, when compared to the HF forward pass in fp32.
"""
dtype = torch.float16
config = GPT2Config.from_pretrained(model_name)
model = GPTLMHeadModel.from_pretrained(model_name, config)
model = model.cuda().to(dtype=dtype)
model_ref = GPT2LMHeadModelHF.from_pretrained(model_name).cuda()
model_hf = GPT2LMHeadModelHF.from_pretrained(model_name).cuda().to(dtype=dtype)
model.eval()
model_ref.eval()
model_hf.eval()
torch.manual_seed(0)
batch_size = 4
max_seqlen = 512
seqlens = torch.randint(max_seqlen // 2, max_seqlen + 1, (batch_size,), device="cuda")
input_ids = torch.randint(
0, config.vocab_size, (batch_size, max_seqlen), dtype=torch.long, device="cuda"
)
out = model.transformer(input_ids)
out_hf = model_hf.transformer(input_ids).last_hidden_state
out_ref = model_ref.transformer(input_ids).last_hidden_state
print(f"Output max diff: {(out - out_ref).abs().max().item()}")
print(f"Output mean diff: {(out - out_ref).abs().mean().item()}")
print(f"HF fp16 max diff: {(out_hf - out_ref).abs().max().item()}")
print(f"HF fp16 mean diff: {(out_hf - out_ref).abs().mean().item()}")
assert (out - out_ref).abs().max().item() < 3 * (out_hf - out_ref).abs().max().item()
logits = model(input_ids).logits
logits_hf = model_hf(input_ids).logits
logits_ref = model_ref(input_ids).logits
print(f"Logits max diff: {(logits - logits_ref).abs().max().item()}")
print(f"Logits mean diff: {(logits - logits_ref).abs().mean().item()}")
print(f"HF fp16 max diff: {(logits_hf - logits_ref).abs().max().item()}")
print(f"HF fp16 mean diff: {(logits_hf - logits_ref).abs().mean().item()}")
assert (logits - logits_ref).abs().max().item() < 3 * (
logits_hf - logits_ref
).abs().max().item()
@pytest.mark.parametrize("model_name", ["gpt2", "gpt2-medium"])
# @pytest.mark.parametrize('model_name', ["gpt2"])
def test_gpt2_optimized(model_name):
"""Check that our implementation of GPT2 (with all optimizations enabled) matches the
HF implementation: the output of our forward pass in fp16 should be around the same as the HF
forward pass in fp16, when compared to the HF forward pass in fp32.
"""
dtype = torch.float16
config = GPT2Config.from_pretrained(model_name)
vocab_size_og = config.vocab_size
config.use_flash_attn = True
config.fused_bias_fc = True
config.fused_mlp = True
config.fused_dropout_add_ln = True
config.residual_in_fp32 = True
config.pad_vocab_size_multiple = 8
model = GPTLMHeadModel.from_pretrained(model_name, config)
model = model.cuda().to(dtype=dtype)
model_ref = GPT2LMHeadModelHF.from_pretrained(model_name).cuda()
model_hf = GPT2LMHeadModelHF.from_pretrained(model_name).cuda().to(dtype=dtype)
model.eval()
model_ref.eval()
model_hf.eval()
torch.manual_seed(0)
batch_size = 4
max_seqlen = 512
seqlens = torch.randint(max_seqlen // 2, max_seqlen + 1, (batch_size,), device="cuda")
input_ids = torch.randint(
0, vocab_size_og, (batch_size, max_seqlen), dtype=torch.long, device="cuda"
)
out = model.transformer(input_ids)
out_hf = model_hf.transformer(input_ids).last_hidden_state
out_ref = model_ref.transformer(input_ids).last_hidden_state
print(f"Output max diff: {(out - out_ref).abs().max().item()}")
print(f"Output mean diff: {(out - out_ref).abs().mean().item()}")
print(f"HF fp16 max diff: {(out_hf - out_ref).abs().max().item()}")
print(f"HF fp16 mean diff: {(out_hf - out_ref).abs().mean().item()}")
assert (out - out_ref).abs().max().item() < 3 * (out_hf - out_ref).abs().max().item()
logits = model(input_ids).logits[..., :vocab_size_og]
logits_hf = model_hf(input_ids).logits
logits_ref = model_ref(input_ids).logits
print(f"Logits max diff: {(logits - logits_ref).abs().max().item()}")
print(f"Logits mean diff: {(logits - logits_ref).abs().mean().item()}")
print(f"HF fp16 max diff: {(logits_hf - logits_ref).abs().max().item()}")
print(f"HF fp16 mean diff: {(logits_hf - logits_ref).abs().mean().item()}")
assert (logits - logits_ref).abs().max().item() < 3 * (
logits_hf - logits_ref
).abs().max().item()
@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_gpt2_generation(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()
def get_logits(model, input_ids, max_length, teacher_outputs=None, **kwargs):
out = model.generate(
input_ids=input_ids,
max_length=max_length,
fused_ft_kernel=True,
teacher_outputs=teacher_outputs,
return_dict_in_generate=True,
output_scores=True,
timing=True,
**kwargs,
)
return torch.stack(out.scores, dim=1)
@pytest.mark.parametrize("seqlen,maxlen", [(10, 20), (30, 150), (3000, 3400), (14000, 15000)])
# @pytest.mark.parametrize('seqlen,maxlen', [(10, 20)])
@pytest.mark.parametrize("rotary", [None, "interleaved", "block"])
# @pytest.mark.parametrize('rotary', [None])
@pytest.mark.parametrize("model_name", ["gpt2"])
def test_gpt2_generation_cg(model_name, rotary, seqlen, maxlen):
"""Check that decoding with CUDA graph is the same as decoding without CUDA graph."""
dtype = torch.float16
device = "cuda"
rtol, atol = 3e-3, 3e-1
config = GPT2Config.from_pretrained(model_name)
config.n_positions = 16 * 1024
assert seqlen <= maxlen <= config.n_positions
if rotary is not None:
config.n_positions = 0
config.rotary_emb_dim = 32
config.rotary_emb_interleaved = rotary == "interleaved"
config.residual_in_fp32 = True
config.use_flash_attn = True
config.fused_bias_fc = True
config.fused_mlp = True
config.fused_dropout_add_ln = True
model = GPTLMHeadModel(config, device=device, dtype=dtype)
model.eval()
torch.manual_seed(0)
batch_size = 1
input_ids = torch.randint(
0, config.vocab_size, (batch_size, seqlen), dtype=torch.long, device=device
)
teacher_outputs = torch.randint(
0, config.vocab_size, (batch_size, maxlen), dtype=torch.long, device=device
)
logits = get_logits(model, input_ids, maxlen, teacher_outputs=teacher_outputs)
logits_cg = get_logits(model, input_ids, maxlen, teacher_outputs=teacher_outputs, cg=True)
assert torch.equal(logits, logits_cg)
# Try increasing batch size and seqlen, then decrease them to see if it's still correct
batch_size = 3
maxlen += 30
input_ids = torch.randint(
0, config.vocab_size, (batch_size, seqlen), dtype=torch.long, device=device
)
teacher_outputs = torch.randint(
0, config.vocab_size, (batch_size, maxlen), dtype=torch.long, device=device
)
logits = get_logits(model, input_ids, maxlen, teacher_outputs=teacher_outputs)
logits_cg = get_logits(model, input_ids, maxlen, teacher_outputs=teacher_outputs, cg=True)
assert torch.equal(logits, logits_cg)
batch_size = 2
maxlen -= 35
input_ids = torch.randint(
0, config.vocab_size, (batch_size, seqlen), dtype=torch.long, device=device
)
teacher_outputs = torch.randint(
0, config.vocab_size, (batch_size, maxlen), dtype=torch.long, device=device
)
logits = get_logits(model, input_ids, maxlen, teacher_outputs=teacher_outputs)
logits_cg = get_logits(model, input_ids, maxlen, teacher_outputs=teacher_outputs, cg=True)
assert torch.equal(logits, logits_cg)