vllm/tests/compile/piecewise/test_toy_llama.py
Russell Bryant e489ad7a21
[Misc] Add SPDX-License-Identifier headers to python source files (#12628)
- **Add SPDX license headers to python source files**
- **Check for SPDX headers using pre-commit**

commit 9d7ef44c3cfb72ca4c32e1c677d99259d10d4745
Author: Russell Bryant <rbryant@redhat.com>
Date:   Fri Jan 31 14:18:24 2025 -0500

    Add SPDX license headers to python source files
    
This commit adds SPDX license headers to python source files as
recommended to
the project by the Linux Foundation. These headers provide a concise way
that is
both human and machine readable for communicating license information
for each
source file. It helps avoid any ambiguity about the license of the code
and can
    also be easily used by tools to help manage license compliance.
    
The Linux Foundation runs license scans against the codebase to help
ensure
    we are in compliance with the licenses of the code we use, including
dependencies. Having these headers in place helps that tool do its job.
    
    More information can be found on the SPDX site:
    
    - https://spdx.dev/learn/handling-license-info/
    
    Signed-off-by: Russell Bryant <rbryant@redhat.com>

commit 5a1cf1cb3b80759131c73f6a9dddebccac039dea
Author: Russell Bryant <rbryant@redhat.com>
Date:   Fri Jan 31 14:36:32 2025 -0500

    Check for SPDX headers using pre-commit
    
    Signed-off-by: Russell Bryant <rbryant@redhat.com>

---------

Signed-off-by: Russell Bryant <rbryant@redhat.com>
2025-02-02 11:58:18 -08:00

449 lines
16 KiB
Python

# SPDX-License-Identifier: Apache-2.0
"""
Test the piecewise compilation with a simple model, comparing the output
with and without the piecewise compilation.
This is a tractable model, the weights and computation are specially designed
if the config `tractable_init` is set to True. Otherwise, the weights are
initialized randomly with a fixed seed.
"""
from dataclasses import dataclass
from typing import Any, List, Optional, Tuple
import torch
from torch import nn
from torch.library import Library
from vllm.compilation.counter import compilation_counter
from vllm.compilation.decorators import support_torch_compile
from vllm.config import (CompilationConfig, CompilationLevel, VllmConfig,
set_current_vllm_config)
from vllm.utils import direct_register_custom_op
# create a library to hold the custom op
silly_lib = Library("silly", "FRAGMENT") # noqa
def silly_attention(q: torch.Tensor, k: torch.Tensor, v: torch.Tensor,
out: torch.Tensor) -> None:
out.copy_(q)
out += k
out += v
def silly_attention_fake(q: torch.Tensor, k: torch.Tensor, v: torch.Tensor,
out: torch.Tensor) -> None:
return
direct_register_custom_op(
op_name="attention",
op_func=silly_attention,
mutates_args=["out"],
fake_impl=silly_attention_fake,
target_lib=silly_lib,
)
@dataclass
class LlamaConfig:
hidden_size: int = 128
mlp_size: int = 256
vocab_size: int = 128
num_layers: int = 2
init_value: float = 1.0
tractable_init: bool = False
random_seed: int = 0
def compute_hash(self) -> str:
factors: List[Any] = []
for k, v in self.__dict__.items():
if k == "random_seed":
continue
factors.append((k, v))
factors.sort()
import hashlib
return hashlib.md5(str(factors).encode()).hexdigest()
def __post_init__(self):
assert self.mlp_size >= self.hidden_size
class LlamaMLP(nn.Module):
def __init__(self, config: LlamaConfig) -> None:
super().__init__()
self.gate_up_projection = nn.Linear(
in_features=config.hidden_size,
out_features=config.mlp_size * 2,
bias=False,
)
self.down_projection = nn.Linear(
in_features=config.mlp_size,
out_features=config.hidden_size,
bias=False,
)
if config.tractable_init:
nn.init.eye_(self.gate_up_projection.weight.data[:config.mlp_size])
nn.init.eye_(self.gate_up_projection.weight.data[config.mlp_size:])
nn.init.eye_(self.down_projection.weight.data)
else:
nn.init.xavier_normal_(self.gate_up_projection.weight.data,
generator=torch.Generator().manual_seed(
config.random_seed),
gain=0.001)
nn.init.xavier_normal_(self.down_projection.weight.data,
generator=torch.Generator().manual_seed(
config.random_seed),
gain=0.001)
def forward(self, x):
# for tractable_init and positive input, this is
# essentially an elementwise-square
x = self.gate_up_projection(x)
x = x[:, :x.size(1) // 2] * torch.nn.functional.relu(
x[:, x.size(1) // 2:])
x = self.down_projection(x)
return x
class LlamaAttention(nn.Module):
def __init__(self, config: LlamaConfig) -> None:
super().__init__()
self.qkv_projection = nn.Linear(
in_features=config.hidden_size,
out_features=config.hidden_size * 3,
bias=False,
)
self.output_projection = nn.Linear(
in_features=config.hidden_size,
out_features=config.hidden_size,
bias=False,
)
if config.tractable_init:
nn.init.eye_(self.qkv_projection.weight.data[:config.hidden_size])
nn.init.eye_(self.qkv_projection.weight.data[config.hidden_size:2 *
config.hidden_size])
nn.init.eye_(self.qkv_projection.weight.data[2 *
config.hidden_size:])
nn.init.eye_(self.output_projection.weight.data)
else:
nn.init.xavier_normal_(self.qkv_projection.weight.data,
generator=torch.Generator().manual_seed(
config.random_seed),
gain=0.001)
nn.init.xavier_normal_(self.output_projection.weight.data,
generator=torch.Generator().manual_seed(
config.random_seed),
gain=0.001)
def forward(
self,
positions: torch.Tensor,
hidden_states: torch.Tensor,
) -> torch.Tensor:
# for tractable_init, this is:
# output = (hidden_states * 3 + positions * 2)
qkv = self.qkv_projection(hidden_states)
hidden_size = qkv.size(-1) // 3
q, k, v = qkv.split([hidden_size, hidden_size, hidden_size], dim=-1)
q = q + positions.unsqueeze(1)
k = k + positions.unsqueeze(1)
attn_output = torch.empty_like(q)
torch.ops.silly.attention(q, k, v, attn_output)
output = self.output_projection(attn_output)
return output
class LlamaDecoderLayer(nn.Module):
def __init__(self, config: LlamaConfig) -> None:
super().__init__()
self.self_attention = LlamaAttention(config)
self.mlp = LlamaMLP(config)
def forward(
self,
positions: torch.Tensor,
hidden_states: torch.Tensor,
residual: Optional[torch.Tensor],
) -> Tuple[torch.Tensor, torch.Tensor]:
"""
For tractable computation:
- if residual is None, the outputs are:
- residual = (hidden_states + 1) * 3 + positions * 2 + hidden_states = hidden_states * 4 + positions * 2 + 3
- hidden_states = (residual + 1) ** 2
- if residual is not None, the outputs are:
- residual = (hidden_states + residual + 1) * 3 + positions * 2 + hidden_states + residual = (hidden_states + residual) * 4 + positions * 2 + 3
- hidden_states = (residual + 1) ** 2
""" # noqa
if residual is None:
residual = hidden_states
hidden_states = hidden_states + 1
else:
hidden_states = hidden_states + residual
residual = hidden_states
hidden_states = hidden_states + 1
hidden_states = self.self_attention(positions=positions,
hidden_states=hidden_states)
hidden_states = hidden_states + residual
residual = hidden_states
hidden_states = hidden_states + 1
hidden_states = self.mlp(hidden_states)
return hidden_states, residual
@support_torch_compile
class LlamaModel(nn.Module):
def __init__(self,
*,
vllm_config: VllmConfig,
config: LlamaConfig,
prefix: str = '',
**kwargs) -> None:
super().__init__()
self.embedding_tokens = nn.Embedding(
num_embeddings=config.vocab_size,
embedding_dim=config.hidden_size,
)
self.layers = nn.ModuleList(
[LlamaDecoderLayer(config) for _ in range(config.num_layers)])
# this is the initial value of the hidden states
self.embedding_tokens.weight.data.fill_(config.init_value)
def forward(
self,
input_ids: Optional[torch.Tensor],
positions: torch.Tensor,
) -> torch.Tensor:
hidden_states = self.embedding_tokens(input_ids)
residual = None
for layer in self.layers:
hidden_states, residual = layer(positions, hidden_states, residual)
return hidden_states
def tractable_computation(input_ids: torch.Tensor,
positions: torch.Tensor,
config: LlamaConfig,
init_value: float = 1.0) -> torch.Tensor:
hidden_states = torch.ones(input_ids.size(0),
config.hidden_size,
device=input_ids.device,
dtype=input_ids.dtype) * init_value
# first layer
residual = hidden_states * 4 + positions.unsqueeze(1) * 2 + 3
hidden_states = (residual + 1)**2
# following layers
for _ in range(config.num_layers - 1):
hidden_states = hidden_states + residual
residual = hidden_states * 4 + positions.unsqueeze(1) * 2 + 3
hidden_states = (residual + 1)**2
return hidden_states
@torch.inference_mode
def run_model(llama_config,
use_compile: bool,
split_attn: bool = False) -> torch.Tensor:
if use_compile:
compilation_config = CompilationConfig(
level=CompilationLevel.PIECEWISE,
use_cudagraph=True,
cudagraph_capture_sizes=[1, 2],
)
if split_attn:
compilation_config.splitting_ops = ["silly.attention"]
else:
compilation_config = CompilationConfig(
level=CompilationLevel.NO_COMPILATION, )
vllm_config = VllmConfig(compilation_config=compilation_config,
additional_config=llama_config)
with set_current_vllm_config(vllm_config):
model = LlamaModel(config=llama_config,
vllm_config=vllm_config,
prefix="").eval().cuda()
B = 16 # max batch size
input_ids = torch.randint(0, llama_config.vocab_size, (B, )).cuda()
positions = torch.arange(B).cuda()
model(input_ids, positions)
model(input_ids[:2], positions[:2])
model(input_ids[:1], positions[:1])
input_ids[:2].zero_()
output = model(input_ids[:2], positions[:2])
output = output.cpu()
if llama_config.tractable_init:
expected_output = tractable_computation(input_ids[:2], positions[:2],
llama_config).cpu()
assert torch.allclose(output, expected_output)
else:
return output.cpu()
def test_toy_llama():
# compare output with and without piecewise compilation
llama_config = LlamaConfig(hidden_size=128,
mlp_size=256,
vocab_size=128,
num_layers=12)
tractable_config = LlamaConfig(hidden_size=128,
mlp_size=256,
vocab_size=128,
num_layers=2,
tractable_init=True)
outputs = []
with compilation_counter.expect(
num_graphs_seen=0,
num_piecewise_graphs_seen=0,
num_piecewise_capturable_graphs_seen=0,
num_inductor_compilations=0,
num_cudagraph_caputured=0,
):
outputs.append(run_model(llama_config, use_compile=False))
run_model(tractable_config, use_compile=False)
with compilation_counter.expect(
num_graphs_seen=1, # one graph for the model
num_piecewise_graphs_seen=1,
num_piecewise_capturable_graphs_seen=1,
num_inductor_compilations=1, # num_piecewise_capturable_graphs_seen
num_cudagraph_caputured=
2, # num_cudagraph_sizes * num_piecewise_capturable_graphs_seen
):
outputs.append(run_model(llama_config, use_compile=True))
run_model(tractable_config, use_compile=True)
with compilation_counter.expect(
num_graphs_seen=1, # one graph for the model
num_piecewise_graphs_seen=2 * llama_config.num_layers +
1, # 2 * num_layers + 1
num_piecewise_capturable_graphs_seen=1 +
llama_config.num_layers, # 1 + num_layers
num_inductor_compilations=1 +
llama_config.num_layers, # num_piecewise_capturable_graphs_seen
num_cudagraph_caputured=2 *
(1 + llama_config.num_layers
), # num_cudagraph_sizes * num_piecewise_capturable_graphs_seen
):
outputs.append(
run_model(llama_config, use_compile=True, split_attn=True))
run_model(tractable_config, use_compile=True, split_attn=True)
for i in range(1, len(outputs)):
assert torch.allclose(outputs[0], outputs[i])
@torch.inference_mode
def benchmark():
from triton.testing import do_bench
# similar to llama 3.1-8B
llama_config = LlamaConfig(hidden_size=4096,
mlp_size=14336,
vocab_size=128 * 1024,
num_layers=32)
# a tiny model to measure the overhead
# of piecewise cudagraph
llama_config = LlamaConfig(hidden_size=40,
mlp_size=80,
vocab_size=128,
num_layers=2)
cudagraph_sizes = [1, 2, 4] + [i * 8 for i in range(1, 33)]
eager_time = {}
full_cudagraph_time = {}
piecewise_cudagraph_time = {}
pool = torch.cuda.graph_pool_handle()
for piecewise in [False, True]:
if piecewise:
compilation_config = CompilationConfig(
level=CompilationLevel.PIECEWISE,
use_cudagraph=True,
splitting_ops=["silly.attention"],
cudagraph_capture_sizes=cudagraph_sizes,
)
else:
compilation_config = CompilationConfig(
level=CompilationLevel.PIECEWISE,
cudagraph_capture_sizes=cudagraph_sizes,
)
vllm_config = VllmConfig(compilation_config=compilation_config)
with set_current_vllm_config(vllm_config):
model = LlamaModel(config=llama_config,
vllm_config=vllm_config,
prefix="").eval().cuda().to(torch.bfloat16)
B = 256 # max batch size
input_ids = torch.randint(0, llama_config.vocab_size, (B, )).cuda()
positions = torch.arange(B).cuda().to(torch.bfloat16)
graphs = {}
model(input_ids, positions)
for b in cudagraph_sizes[::-1]:
if not piecewise:
graph = torch.cuda.CUDAGraph()
with torch.cuda.graph(graph, pool=pool):
output = model(input_ids[:b], positions[:b])
graphs[b] = (graph, output)
else:
output = model(input_ids[:b], positions[:b])
graphs[b] = (model, output)
for b in cudagraph_sizes:
if piecewise:
# noqa is for `Function definition does not bind loop variable`
# it will be problematic if we save the created lambda function
# and use it later, because it will look up the name `b` in the
# enclosing scope, and the value of `b` will always be 256.
# it is fine here, because we only use the lambda function once.
runtime = do_bench(lambda: graphs[b][0] # noqa
(input_ids[:b], positions[:b])) # noqa
piecewise_cudagraph_time[b] = runtime
else:
runtime = do_bench(lambda: graphs[b][0].replay()) # noqa
eager_runtime = do_bench(
lambda: model(input_ids[:b], positions[:b])) # noqa
full_cudagraph_time[b] = runtime
eager_time[b] = eager_runtime
# print in tabular format
print("batch size\teager mode\tfull cudagraph\tpiecewise cudagraph")
for b in cudagraph_sizes:
print(f"{b}\t{eager_time[b]:.3f}\t{full_cudagraph_time[b]:.3f}"
f"\t{piecewise_cudagraph_time[b]:.3f}")
if __name__ == "__main__":
benchmark()