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Liger-Kernel/benchmark/scripts/benchmark_fused_linear_cross_entropy.py
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lowdy1 ace042ec55 [Benchmark] Refactor benchmark for linear kernels (#1223)
## Summary
This PR is a descendant of [[PR
#1195](https://github.com/linkedin/Liger-Kernel/pull/1195)] and
continues the benchmark refactor effort by migrating
linear-space-complexity benchmark scripts to the new reusable `setup`
helper infrastructure.



### Benefits

* Significantly reduces benchmark script complexity
* Makes new benchmark additions easier and more consistent
* Centralizes probing and sweep logic
* Improves maintainability of benchmark infrastructure


### Notes

This PR mainly focuses on kernels with approximately linear memory
complexity and migrates them to the new benchmark helper APIs introduced
in the parent refactor.

- [ ] run `make test` to ensure correctness
- [x] run `make checkstyle` to ensure code style
- [ ] run `make test-convergence` to ensure convergence
2026-05-15 18:22:54 +00:00

128 lines
4.5 KiB
Python

import torch
from benchmark_model_configs import MODEL_REGISTRY
from benchmark_model_configs import build_model_config_sweep
from benchmark_model_configs import build_token_length_sweep
from benchmark_model_configs import get_benchmark_model_config
from utils import SingleBenchmarkRunInput
from utils import build_memory_bench_fn
from utils import build_speed_bench_fn
from utils import parse_benchmark_script_args
from utils import run_benchmarks
from liger_kernel.transformers.fused_linear_cross_entropy import LigerFusedLinearCrossEntropyLoss
from liger_kernel.utils import infer_device
device = infer_device()
class TorchLMHeadCE(torch.nn.Module):
"""Ground truth implementation of the linear fused with torch based cross entropy loss.
:param H: hidden size
:param V: vocab size
:param ignore_index: index to ignore
:param reduction: reduction method
"""
def __init__(self, H: int, V: int, dtype: torch.dtype, ignore_index: int = -100):
super().__init__()
self.lin = torch.nn.Linear(in_features=H, out_features=V, bias=False, dtype=dtype)
self.ce_loss = torch.nn.CrossEntropyLoss(ignore_index=ignore_index, reduction="mean")
def forward(self, x, y):
logits = self.lin(x)
return self.ce_loss(logits, y)
class LigerLMHeadCE(torch.nn.Module):
def __init__(self, H: int, V: int, dtype: torch.dtype, ignore_index: int = -100, accum_dtype=None):
super().__init__()
self.lin = torch.nn.Linear(in_features=H, out_features=V, bias=False, dtype=dtype)
self.ce_loss = LigerFusedLinearCrossEntropyLoss(
ignore_index=ignore_index, reduction="mean", accum_dtype=accum_dtype
)
def forward(self, x, y):
return self.ce_loss(self.lin.weight, x, y)
def setup_fused_linear_cross_entropy(input: SingleBenchmarkRunInput):
"""Create input tensor, target, and fused linear CE from benchmark config."""
cfg = input.extra_benchmark_config
if isinstance(input.x, str):
model_cfg = MODEL_REGISTRY[input.x]
BT = cfg["seq_len"] * cfg["bsz"]
V = model_cfg.vocab_size
H = model_cfg.hidden_size
dtype = model_cfg.dtype
else:
BT = input.x
V = cfg["vocab_size"]
H = cfg["hidden_size"]
dtype = cfg["dtype"]
_input = torch.randn(BT, H, requires_grad=True, dtype=dtype, device=device)
target = torch.randint(V, (BT, 1), dtype=torch.long, device=device).squeeze(1)
if input.kernel_provider == "liger":
lm_head_ce = LigerLMHeadCE(H=H, V=V, dtype=dtype).to(device)
elif input.kernel_provider == "liger-fp32-accum":
lm_head_ce = LigerLMHeadCE(H=H, V=V, dtype=dtype, accum_dtype=torch.float32).to(device)
else:
lm_head_ce = TorchLMHeadCE(H=H, V=V, dtype=dtype).to(device)
return _input, lambda _: lm_head_ce(_input, target)
if __name__ == "__main__":
args = parse_benchmark_script_args()
if args.sweep_mode == "model_config":
common_configs = build_model_config_sweep(
kernel_name="fused_linear_cross_entropy",
setup_fn=setup_fused_linear_cross_entropy,
model_keys=["hidden_size", "vocab_size", "dtype"],
probe_provider="torch",
extra_configs={
"eps": 1e-6,
},
probe_dim="BT",
bt=args.bt,
overwrite=args.overwrite,
)
else:
model = get_benchmark_model_config(args.model)
probe_seq_len = 1024
common_configs = build_token_length_sweep(
kernel_name="fused_linear_cross_entropy",
probe_x=probe_seq_len,
model=model,
setup_fn=setup_fused_linear_cross_entropy,
model_keys=["hidden_size", "vocab_size", "dtype"],
extra_configs={
"eps": 1e-6,
},
scale_dim="BT",
x_label="total tokens",
probe_provider="torch",
overwrite=args.overwrite,
)
common_configs["kernel_providers"] = ["torch", "liger", "liger-fp32-accum"]
run_benchmarks(
bench_test_fn=build_speed_bench_fn(setup_fused_linear_cross_entropy),
kernel_operation_modes=["forward", "backward", "full"],
metric_name="speed",
metric_unit="ms",
**common_configs,
)
run_benchmarks(
bench_test_fn=build_memory_bench_fn(setup_fused_linear_cross_entropy),
kernel_operation_modes=["full"],
metric_name="memory",
metric_unit="MB",
**common_configs,
)