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sglang/python/sglang/jit_kernel/benchmark/bench_renorm.py

319 lines
11 KiB
Python

import itertools
import sgl_kernel
import torch
import triton
import triton.testing
from sglang.jit_kernel.benchmark.utils import is_in_ci, run_benchmark_no_cudagraph
def torch_top_k_renorm_probs(probs, top_k):
"""Vectorized PyTorch implementation of top-k renormalization."""
batch_size, vocab_size = probs.shape
# Handle scalar or tensor k
if isinstance(top_k, int):
k_val = min(max(top_k, 1), vocab_size)
# Get top-k indices for all batches at once
_, topk_indices = torch.topk(probs, k_val, dim=1, largest=True)
# Create mask: batch_size x vocab_size
mask = torch.zeros_like(probs)
mask.scatter_(1, topk_indices, 1.0)
# Vectorized renormalization
masked_probs = probs * mask
renorm_probs = masked_probs / (masked_probs.sum(dim=1, keepdim=True) + 1e-10)
return renorm_probs
else:
# Variable k per batch - need to handle separately
renorm_probs = torch.zeros_like(probs)
for i in range(batch_size):
k_val = min(max(top_k[i].item(), 1), vocab_size)
_, topk_indices = torch.topk(probs[i], k_val, largest=True)
mask = torch.zeros_like(probs[i])
mask[topk_indices] = 1.0
masked_probs = probs[i] * mask
renorm_probs[i] = masked_probs / (masked_probs.sum() + 1e-10)
return renorm_probs
def torch_top_p_renorm_probs(probs, top_p, eps=1e-5):
"""Vectorized PyTorch implementation of top-p renormalization."""
batch_size, vocab_size = probs.shape
# Handle scalar or tensor p
if isinstance(top_p, float):
p_val = top_p
# Vectorized implementation for uniform top_p
# Sort probs in descending order
sorted_probs, sorted_indices = torch.sort(probs, descending=True, dim=1)
cumsum_probs = torch.cumsum(sorted_probs, dim=1)
# Find cutoff: where cumsum exceeds top_p
cutoff_mask = cumsum_probs <= p_val
# Keep at least one token (the highest prob)
cutoff_mask[:, 0] = True
# Create mask in original order
mask = torch.zeros_like(probs)
mask.scatter_(1, sorted_indices, cutoff_mask.float())
# Vectorized renormalization
masked_probs = probs * mask
renorm_probs = masked_probs / (masked_probs.sum(dim=1, keepdim=True) + eps)
return renorm_probs
else:
# Variable p per batch - need to handle separately
renorm_probs = torch.zeros_like(probs)
for i in range(batch_size):
p_val = top_p[i].item()
sorted_prob, indices = torch.sort(probs[i], descending=False)
cdf = torch.cumsum(sorted_prob, dim=-1)
mask = torch.zeros(vocab_size, dtype=torch.float32, device=probs.device)
mask.scatter_(0, indices, (cdf >= (1 - p_val) - eps).float())
masked_probs = probs[i] * mask
renorm_probs[i] = masked_probs / (masked_probs.sum() + eps)
return renorm_probs
def torch_top_k_mask_logits(logits, top_k):
"""Vectorized PyTorch implementation of top-k logits masking."""
batch_size, vocab_size = logits.shape
# Handle scalar or tensor k
if isinstance(top_k, int):
k_val = min(max(top_k, 1), vocab_size)
# Get top-k indices for all batches at once
_, topk_indices = torch.topk(logits, k_val, dim=1, largest=True)
# Create masked logits: start with -inf everywhere
masked_logits = torch.full_like(logits, float("-inf"))
# Scatter the top-k values back
masked_logits.scatter_(1, topk_indices, logits.gather(1, topk_indices))
else:
# Variable k per batch - need to handle separately
masked_logits = torch.full_like(logits, float("-inf"))
for i in range(batch_size):
k_val = min(max(top_k[i].item(), 1), vocab_size)
_, topk_indices = torch.topk(logits[i], k_val, largest=True)
masked_logits[i, topk_indices] = logits[i, topk_indices]
return masked_logits
def calculate_diff_top_k_renorm(batch_size, vocab_size, k):
"""Compare Torch reference and SGLang kernel for top-k renorm correctness."""
torch.manual_seed(42)
device = torch.device("cuda")
pre_norm_prob = torch.rand(batch_size, vocab_size, device=device)
probs = pre_norm_prob / pre_norm_prob.sum(dim=-1, keepdim=True)
top_k_tensor = torch.full((batch_size,), k, device=device, dtype=torch.int32)
torch_output = torch_top_k_renorm_probs(probs, top_k_tensor)
sglang_output = sgl_kernel.top_k_renorm_prob(probs, top_k_tensor)
torch.testing.assert_close(torch_output, sglang_output, rtol=1e-3, atol=1e-3)
def calculate_diff_top_p_renorm(batch_size, vocab_size, p):
"""Compare Torch reference and SGLang kernel for top-p renorm correctness."""
torch.manual_seed(42)
device = torch.device("cuda")
pre_norm_prob = torch.rand(batch_size, vocab_size, device=device)
probs = pre_norm_prob / pre_norm_prob.sum(dim=-1, keepdim=True)
top_p_tensor = torch.full((batch_size,), p, device=device, dtype=torch.float32)
torch_output = torch_top_p_renorm_probs(probs, top_p_tensor)
sglang_output = sgl_kernel.top_p_renorm_prob(probs, top_p_tensor)
torch.testing.assert_close(torch_output, sglang_output, rtol=1e-3, atol=1e-3)
def calculate_diff_top_k_mask(batch_size, vocab_size, k):
"""Compare Torch reference and SGLang kernel for top-k mask correctness."""
torch.manual_seed(42)
device = torch.device("cuda")
logits = torch.randn(batch_size, vocab_size, device=device) * 5
top_k_tensor = torch.full((batch_size,), k, device=device, dtype=torch.int32)
torch_output = torch_top_k_mask_logits(logits, top_k_tensor)
sglang_output = sgl_kernel.top_k_mask_logits(logits, top_k_tensor)
torch.testing.assert_close(torch_output, sglang_output, rtol=1e-3, atol=1e-3)
# Parameter space - simplified for CI
if is_in_ci():
batch_size_range = [16]
vocab_size_range = [111]
k_range = [10]
p_range = [0.5]
else:
batch_size_range = [16, 64, 128]
vocab_size_range = [111, 32000, 128256]
k_range = [10, 100, 500]
p_range = [0.1, 0.5, 0.9]
configs_k = list(itertools.product(batch_size_range, vocab_size_range, k_range))
configs_p = list(itertools.product(batch_size_range, vocab_size_range, p_range))
@triton.testing.perf_report(
triton.testing.Benchmark(
x_names=["batch_size", "vocab_size", "k"],
x_vals=configs_k,
line_arg="provider",
line_vals=["torch", "sglang"],
line_names=["Torch Reference", "SGL Kernel"],
styles=[("red", "-"), ("green", "-")],
ylabel="us",
plot_name="top-k-renorm-probs-performance",
args={},
)
)
def benchmark_top_k_renorm(batch_size, vocab_size, k, provider):
# Skip invalid configurations
if k >= vocab_size:
return float("nan"), float("nan"), float("nan")
torch.manual_seed(42)
device = torch.device("cuda")
pre_norm_prob = torch.rand(batch_size, vocab_size, device=device)
probs = pre_norm_prob / pre_norm_prob.sum(dim=-1, keepdim=True)
top_k_tensor = torch.full((batch_size,), k, device=device, dtype=torch.int32)
if provider == "torch":
fn = lambda: torch_top_k_renorm_probs(probs.clone(), top_k_tensor)
elif provider == "sglang":
fn = lambda: sgl_kernel.top_k_renorm_prob(probs.clone(), top_k_tensor)
return run_benchmark_no_cudagraph(fn)
@triton.testing.perf_report(
triton.testing.Benchmark(
x_names=["batch_size", "vocab_size", "p"],
x_vals=configs_p,
line_arg="provider",
line_vals=["torch", "sglang"],
line_names=["Torch Reference", "SGL Kernel"],
styles=[("red", "-"), ("blue", "-")],
ylabel="us",
plot_name="top-p-renorm-probs-performance",
args={},
)
)
def benchmark_top_p_renorm(batch_size, vocab_size, p, provider):
torch.manual_seed(42)
device = torch.device("cuda")
pre_norm_prob = torch.rand(batch_size, vocab_size, device=device)
probs = pre_norm_prob / pre_norm_prob.sum(dim=-1, keepdim=True)
top_p_tensor = torch.full((batch_size,), p, device=device, dtype=torch.float32)
if provider == "torch":
fn = lambda: torch_top_p_renorm_probs(probs.clone(), top_p_tensor)
elif provider == "sglang":
fn = lambda: sgl_kernel.top_p_renorm_prob(probs.clone(), top_p_tensor)
return run_benchmark_no_cudagraph(fn)
@triton.testing.perf_report(
triton.testing.Benchmark(
x_names=["batch_size", "vocab_size", "k"],
x_vals=configs_k,
line_arg="provider",
line_vals=["torch", "sglang"],
line_names=["Torch Reference", "SGL Kernel"],
styles=[("red", "-"), ("orange", "-")],
ylabel="us",
plot_name="top-k-mask-logits-performance",
args={},
)
)
def benchmark_top_k_mask(batch_size, vocab_size, k, provider):
# Skip invalid configurations
if k >= vocab_size:
return float("nan"), float("nan"), float("nan")
torch.manual_seed(42)
device = torch.device("cuda")
logits = torch.randn(batch_size, vocab_size, device=device) * 5
top_k_tensor = torch.full((batch_size,), k, device=device, dtype=torch.int32)
if provider == "torch":
fn = lambda: torch_top_k_mask_logits(logits.clone(), top_k_tensor)
elif provider == "sglang":
fn = lambda: sgl_kernel.top_k_mask_logits(logits.clone(), top_k_tensor)
return run_benchmark_no_cudagraph(fn)
if __name__ == "__main__":
print("=" * 60)
print("Running correctness checks...")
print("=" * 60)
# Correctness checks - simplified for CI
if is_in_ci():
test_configs_k = [configs_k[0]] if configs_k else [(16, 111, 10)]
test_configs_p = [configs_p[0]] if configs_p else [(16, 111, 0.5)]
else:
test_configs_k = configs_k[:3] # Test first 3 configs
test_configs_p = configs_p[:3]
print("\n1. Testing top_k_renorm_probs...")
for cfg in test_configs_k:
batch_size, vocab_size, k = cfg
if k < vocab_size: # Skip invalid configs
calculate_diff_top_k_renorm(batch_size, vocab_size, k)
print(
f" ✓ Passed: batch_size={batch_size}, vocab_size={vocab_size}, k={k}"
)
print("\n2. Testing top_p_renorm_probs...")
for cfg in test_configs_p:
calculate_diff_top_p_renorm(*cfg)
batch_size, vocab_size, p = cfg
print(f" ✓ Passed: batch_size={batch_size}, vocab_size={vocab_size}, p={p}")
print("\n3. Testing top_k_mask_logits...")
for cfg in test_configs_k:
batch_size, vocab_size, k = cfg
if k < vocab_size: # Skip invalid configs
calculate_diff_top_k_mask(batch_size, vocab_size, k)
print(
f" ✓ Passed: batch_size={batch_size}, vocab_size={vocab_size}, k={k}"
)
print("\n" + "=" * 60)
print("All correctness checks passed!")
print("=" * 60)
print("\n" + "=" * 60)
print("Starting performance benchmarks...")
print("=" * 60)
print("\n1. Benchmarking top_k_renorm_probs...")
benchmark_top_k_renorm.run(print_data=True)
print("\n2. Benchmarking top_p_renorm_probs...")
benchmark_top_p_renorm.run(print_data=True)
print("\n3. Benchmarking top_k_mask_logits...")
benchmark_top_k_mask.run(print_data=True)
print("\n" + "=" * 60)
print("Benchmarking complete!")
print("=" * 60)