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pytorch/torch/_inductor/runtime/benchmarking.py
PyTorch MergeBot 2928c5c572 Revert "Pyrefly suppressions 2 (#165692)"
This reverts commit 43d78423ac224cce432bf34ed9627035169d5433.

Reverted https://github.com/pytorch/pytorch/pull/165692 on behalf of https://github.com/seemethere due to This is causing merge conflicts when attempting to land internally, see D84890919 for more details ([comment](https://github.com/pytorch/pytorch/pull/165692#issuecomment-3416397240))
2025-10-17 17:13:04 +00:00

386 lines
15 KiB
Python

import functools
import inspect
import time
from functools import cached_property, wraps
from itertools import chain
from statistics import median
from typing import Any, Callable
from typing_extensions import Concatenate, ParamSpec, Self, TypeVar
import torch
from torch._dynamo.utils import counters, dynamo_timed
from torch._inductor.config import use_experimental_benchmarker
logger = torch._logging.getArtifactLogger(__name__, "benchmarking")
use_experimental_benchmarker = (
use_experimental_benchmarker and torch.cuda.is_available()
)
MILLISECONDS_PER_SECOND = 1000
P = ParamSpec("P")
T = TypeVar("T")
def may_distort_benchmarking_result(fn: Callable[..., Any]) -> Callable[..., Any]:
from torch._inductor import config
if config.test_configs.distort_benchmarking_result == "":
return fn
def distort(
ms: list[float] | tuple[float] | float,
) -> list[float] | tuple[float] | float:
if isinstance(ms, (list, tuple)):
return type(ms)(distort(val) for val in ms) # type: ignore[misc]
distort_method = config.test_configs.distort_benchmarking_result
assert isinstance(ms, float)
if distort_method == "inverse":
return 1.0 / ms if ms else 0.0
elif distort_method == "random":
import random
return random.random()
else:
raise RuntimeError(f"Unrecognized distort method {distort_method}")
@functools.wraps(fn)
def wrapper(
*args: list[Any], **kwargs: dict[str, Any]
) -> list[float] | tuple[float] | float:
ms = fn(*args, **kwargs)
return distort(ms)
return wrapper
def may_ban_benchmarking() -> None:
if torch._inductor.config.deterministic:
raise RuntimeError("""In the deterministic mode of Inductor, we will avoid those
benchmarkings that would cause non deterministic results. Only benchmarkings in the vetted
scenarios are allowed. Example include autotuning for triton configs of pointwise kernels.
When you see this exception, you can do one of the following two things:
1. if the benchmarking you are doing does not introduce any non-determinism, you can just
add is_vetted_benchmarking=True to you benchmark_gpu call. That would solve the issue.
2. if the benchmarking you are doing indeed introduces non-determinism, you'll need to disable
such feature in deterministic mode or find an alternative implementation that is deterministic.
""")
def time_and_count(
fn: Callable[Concatenate[Any, P], T],
) -> Callable[Concatenate[Any, P], T]:
"""Wraps `fn` with `dynamo_timed` context, and increments the appropriate dynamo
counters. It is expected that `fn` is a method of `Benchmarker` or one of its
subclasses; typing limitations prevent us from declaring this directly.
"""
@wraps(fn)
def wrapper(self: Any, *args: P.args, **kwargs: P.kwargs) -> T:
fn_qual_name = f"{self.__class__.__name__}.{fn.__name__}"
counters["inductor"][f"benchmarking.{fn_qual_name}"] += 1
with dynamo_timed(fn_qual_name, log_pt2_compile_event=False):
return fn(self, *args, **kwargs)
return wrapper
class Benchmarker:
def __init__(self: Self) -> None:
pass
@time_and_count
def benchmark(
self: Self,
fn: Callable[..., Any],
fn_args: tuple[Any, ...],
fn_kwargs: dict[str, Any],
**kwargs: Any,
) -> float:
"""Benchmark `fn(*fn_args, *fn_kwargs)` and return the runtime, in milliseconds (the
actual runtime calculation is dictated by the benchmarking implementation, but may be
one of [mean, median, minimum, etc.]). Functions as a convenience wrapper around
device-specific implementations, like `benchmark_cpu` and `benchmark_gpu`. Raises
`ValueError(...)` if we can't safely infer the device type of `fn`; for example,
if multiple device types are found in `fn_args` and `fn_kwargs`, or if no device
types are found.
Arguments:
- fn: The function to benchmark.
- fn_args: The function's arguments.
- fn_kwargs: The function's kwargs.
Keyword Arguments:
- **kwargs: The benchmarking implementation's kwargs.
Returns:
- The runtime of `fn(*fn_args, **fn_kwargs)`, in milliseconds.
"""
inferred_device = None
for arg_or_kwarg in chain(fn_args, fn_kwargs.values()):
if not isinstance(arg_or_kwarg, torch.Tensor):
continue
if inferred_device is None:
inferred_device = arg_or_kwarg.device
elif arg_or_kwarg.device != inferred_device:
raise ValueError(
"Can't safely infer the device type of `fn` with multiple device types in `fn_args` and `fn_kwargs`!"
)
if inferred_device is None:
raise ValueError(
"Can't safely infer the device type of `fn` with no device types in `fn_args` or `fn_kwargs`! You should be calling `.benchmark_cpu` or `.benchmark_gpu` directly." # noqa: B950
)
_callable = lambda: fn(*fn_args, **fn_kwargs) # noqa: E731
if inferred_device == torch.device("cpu"):
return self.benchmark_cpu(_callable, **kwargs)
# TODO(nmacchioni): For non-CPU functions we default to using the GPU-specific benchmarking
# implementation which was written specifically with CUDA devices in mind, we may want to
# explore alternate implementations for other device types.
return self.benchmark_gpu(_callable, **kwargs)
@time_and_count
def benchmark_cpu(
self: Self, _callable: Callable[[], Any], warmup: int = 20, rep: int = 100
) -> float:
"""Benchmark the CPU callable, `_callable`, and return the median runtime,
in milliseconds.
Arguments:
- _callable: The CPU callable to benchmark.
Keyword Arguments:
- warmup: Optionally, the duration, in milliseconds, to run `_callable`
before benchmarking starts.
- rep: Optionally, the duration, in milliseconds, to run `_callable`
during benchmarking.
Returns:
- The median runtime of `_callable`, in milliseconds.
"""
def run_for(ms: int) -> list[float]:
timings = []
run_start_t = time.perf_counter()
while True:
start_t = time.perf_counter()
_callable()
end_t = time.perf_counter()
timings.append((end_t - start_t) * MILLISECONDS_PER_SECOND)
if ((end_t - run_start_t) * MILLISECONDS_PER_SECOND) > ms:
break
return timings
run_for(warmup)
return median(run_for(rep))
@time_and_count
def benchmark_gpu(self: Self, *args: Any, **kwargs: Any) -> float:
raise NotImplementedError
class TritonBenchmarker(Benchmarker):
@cached_property
def triton_do_bench(self: Self) -> Callable[..., Any]:
"""Lazily import Triton's `do_bench`."""
try:
from triton.testing import do_bench
except ImportError as e:
raise NotImplementedError("requires Triton") from e
return do_bench
@may_distort_benchmarking_result
@time_and_count
def benchmark_gpu(
self: Self,
_callable: Callable[[], Any],
is_vetted_benchmarking: bool = False,
**kwargs: Any,
) -> float:
"""Benchmark the GPU callable, `_callable`, and return the runtime, in milliseconds.
Arguments:
- _callable: The GPU callable to benchmark.
Keyword Arguments:
- quantiles: Optionally, a tuple of floats denoting the requested quantiles.
- return_mode: Optionally, the requested return mode. Currently, Triton's
`do_bench` supports min, max, mean, and median return modes.
- **kwargs: Additional kwargs passed to Triton's `do_bench`.
Returns:
- The runtime of `callable`, in milliseconds. If `kwargs["quantiles"]` is specified,
this is the first requested quantile. Else, if `kwargs["return_mode"]` is specified,
this is the requested return mode. Otherwise, this is the median.
"""
if not is_vetted_benchmarking:
may_ban_benchmarking()
do_bench_params = inspect.signature(self.triton_do_bench).parameters
for kwarg in list(kwargs.keys()):
if kwarg not in do_bench_params:
del kwargs[kwarg]
if "quantiles" in kwargs:
return self.triton_do_bench(_callable, **kwargs)[0]
elif "return_mode" in kwargs:
return self.triton_do_bench(_callable, **kwargs)
return self.triton_do_bench(_callable, **kwargs, return_mode="median")
class InductorBenchmarker(TritonBenchmarker): # noqa: docstring_linter
@cached_property
def L2_cache_size(self: Self) -> int:
"""Get the L2 cache size, in bytes, of the current device."""
device = torch.cuda.current_device()
props = torch.cuda.get_device_properties(device)
return props.L2_cache_size
def get_event_pairs(
self: Self, iters: int
) -> list[tuple[torch.cuda.Event, torch.cuda.Event]]:
"""Get `iters` pairs of CUDA events."""
return [
(
torch.cuda.Event(enable_timing=True),
torch.cuda.Event(enable_timing=True),
)
for _ in range(iters)
]
def get_event_pairs_min_timing(
self: Self, event_pairs: list[tuple[torch.cuda.Event, torch.cuda.Event]]
) -> float:
"""Get the minimum timing, in milliseconds, for a group of CUDA event pairs."""
return min(
[
start_event.elapsed_time(end_event)
for start_event, end_event in event_pairs
]
)
@may_distort_benchmarking_result
@time_and_count
def benchmark_gpu( # type: ignore[override]
self: Self,
_callable: Callable[[], Any],
estimation_iters: int = 5,
memory_warmup_iters: int = 100,
benchmark_iters: int = 100,
max_benchmark_duration: int = 25,
return_mode: str = "min",
grad_to_none: list[torch.Tensor] | None = None,
is_vetted_benchmarking: bool = False,
**kwargs: Any,
) -> float | list[float]:
"""Benchmark a GPU callable using a custom benchmarking implementation.
Arguments:
- _callable: The callable to benchmark.
Keyword Arguments:
- estimation_iters: Optionally, the number of iterations to run `_callable`
during runtime estimation.
- memory_warmup_iters: Optionally, the number of iterations to flush the L2
cache before starting benchmarking.
- benchmark_iters: Optionally, the number of iterations to run `_callable`
during the benchmarking.
- max_benchmark_duration: Optionally, the maximum duration of the benchmarking,
in milliseconds. An estimated duration is calculated based on the values
of `memory_warmup_iters` and `benchmark_iters`, along with the estimated
runtime of `_callable` and various other factors, and we then shrink
`benchmark_iters` to fit in the allotted maximum duration.
- return_mode: Return mode for benchmark results. Options are "min" (default),
"all" (returns all measurements).
- grad_to_none: Optionally, a list of tensors whose gradients should be cleared
before each benchmark iteration.
- is_vetted_benchmarking: in deterministic mode, we only allow
benchmarking in vetted cases.
- **kwargs: Additional kwargs that may be passed to the fallback.
Returns:
- If return_mode="min": The minimum runtime of `_callable`, in milliseconds.
- If return_mode="all": List of all runtime measurements, in milliseconds.
"""
if not is_vetted_benchmarking:
may_ban_benchmarking()
# we don't want any outside errors propagating into benchmarking
torch.cuda.synchronize()
# warmup `_callable` (and catches any failures in the process)
_callable()
torch.cuda.synchronize()
# see https://github.com/triton-lang/triton/pull/840 for why `dtype=torch.int`
buffer = torch.empty(self.L2_cache_size // 4, dtype=torch.int, device="cuda")
buffer.zero_()
# estimate the runtime of `_callable`
event_pairs = self.get_event_pairs(estimation_iters)
for start_event, end_event in event_pairs:
# Clear gradients before timing (matches triton.testing.do_bench)
if grad_to_none is not None:
for x in grad_to_none:
x.grad = None
buffer.zero_()
start_event.record()
_callable()
end_event.record()
torch.cuda.synchronize()
estimated_timing = self.get_event_pairs_min_timing(event_pairs)
# adjust `benchmark_iters` to fit in the maximum benchmarking duration
benchmark_iters = max(
min(benchmark_iters, int(max_benchmark_duration // estimated_timing)), 1
)
# do the memory warmup
for _ in range(memory_warmup_iters):
buffer.zero_()
# benchmark `_callable`
event_pairs = self.get_event_pairs(benchmark_iters)
for start_event, end_event in event_pairs:
# Clear gradients before timing (matches triton.testing.do_bench)
if grad_to_none is not None:
for x in grad_to_none:
x.grad = None
buffer.zero_()
start_event.record()
_callable()
end_event.record()
torch.cuda.synchronize()
# explicitly delete the buffer, sometimes helps memory
# footprint metrics in OSS Inductor performance benchmarks
del buffer
# Return based on the requested mode
if return_mode == "all":
# Get all timings from event pairs
all_timings = [
start_event.elapsed_time(end_event)
for start_event, end_event in event_pairs
]
return all_timings
elif return_mode == "min":
benchmarked_timing = self.get_event_pairs_min_timing(event_pairs)
# return the minimum of `estimated_timing` and `benchmarked_timing`,
# we just want the minimum timing overall so we might as well check both
return min(estimated_timing, benchmarked_timing)
else:
raise ValueError(
f"Unsupported return_mode: {return_mode}. Use 'min' or 'all'."
)
benchmarker = (
InductorBenchmarker() if use_experimental_benchmarker else TritonBenchmarker()
)