Files
nvbench/python/examples/throughput.py
Oleksandr Pavlyk 44ec7de6bd Implement decorators to register benchmarks add axis and options (#347)
* Add decorators for registering benchmarks and adding axis

cuda.bench.register(fn) continues returning Benchmark, and supports
legacy use.

New signature added:
   cuda.bench.register():
      Returns a decorator

```
@bench.register()
@bench.axis.float64("Duration (s)", [7e-5, 1e-4, 5e-4])
@bench.option.min_samples(120)
def single_float64_axis(state: bench.State):
   ...
```

* Remove example/auto_throughput.py

The C++ counterpart's purpose is to demonstrate use of CUPTI
metrics, but these are not supported in Python bindings, so
this example is a duplicate of example/throughput.py

* Add wrong decorator order test for bench.axis.*

* Strengthen type annotation for register function

Acting on code rabbit nit-pick require that function being
registered take cuda.bench.State object as an argument.

Verified the fix as

```
(py313) :~/repos/nvbench/python$ python -m mypy --ignore-missing-import /tmp/t.py
/tmp/t.py:8: error: Argument 1 has incompatible type "Callable[[], None]"; expected "Callable[[State], None]"  [arg-type]
Found 1 error in 1 file (checked 1 source file)
(py313) :~/repos/nvbench/python$ nl -ba /tmp/t.py
     1  # /tmp/check_nvbench_register.py
     2  import cuda.bench as bench
     3
     4  @bench.register()
     5  def good(state: bench.State) -> None:
     6      pass
     7
     8  @bench.register()
     9  def bad() -> None:
    10      pass
```

* Replace use of global variable with thread-safe lru_cache

This improves thread-safety of module initialization.

* Abide by RUF005 linting rule

* Expand docstrings regarding cuda.bench.register() decorator

It explains to the user what the decorator does and provides
a concise usage example.

* Sharpen wording on exception maybe-thrown by decorator
2026-05-14 15:41:30 -05:00

76 lines
2.5 KiB
Python

# Copyright 2025-2026 NVIDIA Corporation
#
# Licensed under the Apache License, Version 2.0 with the LLVM exception
# (the "License"); you may not use this file except in compliance with
# the License.
#
# You may obtain a copy of the License at
#
# http://llvm.org/foundation/relicensing/LICENSE.txt
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import sys
import cuda.bench as bench
import numpy as np
from numba import cuda
def as_cuda_stream(cs: bench.CudaStream) -> cuda.cudadrv.driver.Stream:
return cuda.external_stream(cs.addressof())
def make_throughput_kernel(items_per_thread: int) -> cuda.dispatcher.CUDADispatcher:
@cuda.jit
def kernel(stride: np.uintp, elements: np.uintp, in_arr, out_arr):
tid = cuda.grid(1)
step = cuda.gridDim.x * cuda.blockDim.x
for i in range(stride * tid, stride * elements, stride * step):
for j in range(items_per_thread):
read_id = (items_per_thread * i + j) % elements
write_id = tid + j * elements
out_arr[write_id] = in_arr[read_id]
return kernel
@bench.register()
@bench.axis.int64("Stride", [1, 2, 4])
@bench.axis.int64("ItemsPerThread", [1, 2, 3, 4])
def throughput_bench(state: bench.State) -> None:
stride = state.get_int64("Stride")
ipt = state.get_int64("ItemsPerThread")
nbytes = 128 * 1024 * 1024
elements = nbytes // np.dtype(np.int32).itemsize
alloc_stream = as_cuda_stream(state.get_stream())
inp_arr = cuda.device_array(elements, dtype=np.int32, stream=alloc_stream)
out_arr = cuda.device_array(elements * ipt, dtype=np.int32, stream=alloc_stream)
state.add_element_count(elements, column_name="Elements")
state.add_global_memory_reads(inp_arr.nbytes, column_name="Datasize")
state.add_global_memory_writes(inp_arr.nbytes)
threads_per_block = 256
blocks_in_grid = (elements + threads_per_block - 1) // threads_per_block
krn = make_throughput_kernel(ipt)
def launcher(launch: bench.Launch):
exec_stream = as_cuda_stream(launch.get_stream())
krn[blocks_in_grid, threads_per_block, exec_stream, 0](
stride, elements, inp_arr, out_arr
)
state.exec(launcher)
if __name__ == "__main__":
bench.run_all_benchmarks(sys.argv)