Files
pytorch/test/distributed/test_inductor_collectives.py
2025-10-04 22:06:04 +00:00

2091 lines
82 KiB
Python

# Owner(s): ["module: dynamo"]
import datetime
import functools
import unittest
from collections import Counter
from typing import Optional
from unittest.mock import patch
import torch
import torch._dynamo
import torch._dynamo.logging
import torch._dynamo.test_case
import torch.distributed as c10d
# for some reason importing functional collectives after dynamo breaks collectives handling!
import torch.distributed._functional_collectives as _functional_collectives
from torch._C import FileCheck
from torch._dynamo.testing import CompileCounter
from torch._dynamo.utils import same
from torch._inductor.comms import (
_reorder_communication_preserving_peak_memory_internal,
ReorderInfo,
sink_waits_iterative,
)
from torch._inductor.compile_fx import compile_fx as inductor_compile_fx
from torch._inductor.scheduler import (
_get_mm_like_fn,
BaseSchedulerNode,
get_estimate_runtime_cache,
get_estimate_runtime_cache_key_from_snode,
)
from torch._inductor.utils import fresh_inductor_cache, run_and_get_triton_code
from torch.distributed.distributed_c10d import GroupMember
from torch.fx.experimental.proxy_tensor import make_fx
from torch.testing._internal.common_cuda import SM80OrLater
from torch.testing._internal.common_distributed import (
_dynamo_dist_per_rank_init,
DynamoDistributedMultiProcTestCase,
DynamoDistributedSingleProcTestCase,
MultiProcessTestCase,
requires_accelerator_dist_backend,
skip_if_lt_x_gpu,
)
from torch.testing._internal.common_utils import (
instantiate_parametrized_tests,
parametrize,
skipIfRocm,
skipIfXpu,
TEST_XPU,
xfailIf,
)
from torch.testing._internal.inductor_utils import HAS_GPU
from torch.utils._python_dispatch import TorchDispatchMode
def _tolist(tensor):
lst = tensor.tolist()
return lst
@requires_accelerator_dist_backend(["nccl", "xccl"])
@instantiate_parametrized_tests
class TestCollectivesMultiProc(DynamoDistributedMultiProcTestCase):
"""
Run correctness checks in multi-proc runner, mark with minimum # GPUs to run under
"""
device = acc.type if (acc := torch.accelerator.current_accelerator()) else "cpu"
def get_world_trs(self):
return {
"tag": "",
"ranks": list(range(self.world_size)),
"group_size": self.world_size,
}
@property
def world_size(self) -> int:
# hack: no matter whether we have 2 or 3 or 4 gpus, just run on 2
# works around issue with skipif<2 and workers with unpredictable #s gpu
return 2
@unittest.skipIf(not HAS_GPU, "Inductor+gpu needs triton and recent GPU arch")
@skip_if_lt_x_gpu(2)
def test_broadcast_inductor(self):
"""
Testing if broadcast works correctly when using inductor
"""
def example(tensor, src, *, tag, ranks, group_size):
res = torch.ops.c10d_functional.broadcast(
tensor, src, tag, ranks, group_size
)
res = torch.ops.c10d_functional.wait_tensor(res)
return res
def compile(func, example_inputs):
graph = make_fx(func)(*example_inputs)
return inductor_compile_fx(graph, example_inputs)
with _dynamo_dist_per_rank_init(self.rank, self.world_size):
example = functools.partial(
example,
**self.get_world_trs(),
)
t = torch.randn(4, 4, device=self.device)
inputs = (
t if self.rank == 0 else torch.zeros(4, 4, device=self.device),
0,
)
eager_out = example(*inputs)
self.assertTrue(same(t, eager_out))
compiled_func = compile(example, inputs)
compiled_out = compiled_func(*inputs)
self.assertTrue(same(eager_out, compiled_out))
@unittest.skipIf(not HAS_GPU, "Inductor+gpu needs triton and recent GPU arch")
@skip_if_lt_x_gpu(2)
def test_allreduce_inductor(self):
"""
This is matmul/cat/allreduce is a pattern we aim to optimize.
"""
def matmul_cat_col(a, b, c, d, e, f, *, tag, ranks, group_size):
x = torch.matmul(a, b)
y = torch.matmul(c, d)
z = torch.cat((x, y))
ar = torch.ops.c10d_functional.all_reduce(z, "sum", tag, ranks, group_size)
g = torch.matmul(e, f)
ar = torch.ops.c10d_functional.wait_tensor(ar)
out = torch.add(ar, g.repeat(2, 1))
return (out,)
def compile(func, example_inputs):
graph = make_fx(func)(*example_inputs)
return inductor_compile_fx(graph, example_inputs)
with _dynamo_dist_per_rank_init(self.rank, self.world_size):
matmul_cat_col = functools.partial(
matmul_cat_col,
**self.get_world_trs(),
)
inputs = (torch.ones(4, 4, device=self.device) + self.rank,) * 6
eager_out = matmul_cat_col(*inputs)
compiled_matmul_cat_col = compile(matmul_cat_col, inputs)
inductor_out = compiled_matmul_cat_col(*inputs)
self.assertTrue(same(eager_out, inductor_out, tol=0.001))
@unittest.skipIf(not HAS_GPU, "Inductor+gpu needs triton and recent GPU arch")
@skip_if_lt_x_gpu(2)
def test_allreduce_inductor_cudagraph_trees(self):
"""
Tests whether cudagraph trees support all_reduce from nccl
"""
import torch.distributed as dist
# dist.all_reduce is an inplace op in eager mode but a functionanlized op in compiled mode.
# so we define eager_func and func separately for the same semantic.
def eager_func(x):
y = x * x
dist.all_reduce(y, op=dist.ReduceOp.SUM)
x = torch.nn.functional.silu(x)
return x * y
def func(x):
y = x * x
y = dist.all_reduce(y, op=dist.ReduceOp.SUM)
x = torch.nn.functional.silu(x)
return x * y
options = {
"triton.cudagraphs": True,
"triton.cudagraph_trees": True,
}
with _dynamo_dist_per_rank_init(self.rank, self.world_size):
compiled_func = torch.compile(
func, backend="inductor", fullgraph=True, options=options, dynamic=None
)
for nelem in [1024, 2048, 4096]:
# CI (Tesla T4) does not support bfloat16 compilation natively,
# using float
x = torch.randn(nelem, device=self.device, dtype=torch.float)
golden_out = eager_func(x)
for _ in range(3):
compiled_out = compiled_func(x)
self.assertEqual(golden_out, compiled_out)
def test_c10d_functional_tagged_pt2_compliant(self):
op = torch.ops._c10d_functional.all_reduce.default
self.assertIn(torch.Tag.pt2_compliant_tag, op.tags)
op = torch.ops.c10d_functional.all_reduce.default
self.assertIn(torch.Tag.pt2_compliant_tag, op.tags)
@unittest.skipIf(not HAS_GPU, "Inductor+gpu needs triton and recent GPU arch")
@skip_if_lt_x_gpu(2)
def test_eager_allreduce_inductor_wait(self):
def eager_func(a, b, c, d, *, tag, ranks, group_size):
x = torch.matmul(a, b)
y = torch.matmul(c, d)
z = torch.cat((x, y))
ar = torch.ops.c10d_functional.all_reduce(z, "sum", tag, ranks, group_size)
return ar
def inductor_func(ar, e, f):
g = torch.matmul(e, f)
ar = torch.ops.c10d_functional.wait_tensor(ar)
out = torch.add(ar, g.repeat(2, 1))
return (out,)
def compile(func, example_inputs):
graph = make_fx(func)(*example_inputs)
return inductor_compile_fx(graph, example_inputs)
with _dynamo_dist_per_rank_init(self.rank, self.world_size):
eager_func = functools.partial(
eager_func,
**self.get_world_trs(),
)
eager_inputs = (torch.ones(4, 4, device=self.device) + self.rank,) * 4
inductor_inputs = (torch.ones(4, 4, device=self.device) + self.rank,) * 2
eager_out = inductor_func(eager_func(*eager_inputs), *inductor_inputs)
compiled_inductor_func = compile(
inductor_func, [eager_func(*eager_inputs)] + list(inductor_inputs)
)
inductor_out = compiled_inductor_func(
eager_func(*eager_inputs), *inductor_inputs
)
print(f"eager_out, {eager_out}")
print(f"inductor_out, {inductor_out}")
self.assertTrue(same(eager_out, inductor_out, tol=0.001))
@unittest.skipIf(not HAS_GPU, "Inductor+gpu needs triton and recent GPU arch")
@skip_if_lt_x_gpu(2)
def test_inductor_allreduce_eager_wait(self):
def inductor_func(a, b, c, d, *, tag, ranks, group_size):
x = torch.matmul(a, b)
y = torch.matmul(c, d)
z = torch.cat((x, y))
ar = torch.ops.c10d_functional.all_reduce(z, "sum", tag, ranks, group_size)
return ar
def eager_func(ar, e, f):
g = torch.matmul(e, f)
ar = torch.ops.c10d_functional.wait_tensor(ar)
out = torch.add(ar, g.repeat(2, 1))
return (out,)
def compile(func, example_inputs):
graph = make_fx(func)(*example_inputs)
return inductor_compile_fx(graph, example_inputs)
with _dynamo_dist_per_rank_init(self.rank, self.world_size):
inductor_func = functools.partial(
inductor_func,
**self.get_world_trs(),
)
inductor_inputs = (torch.ones(4, 4, device=self.device) + self.rank,) * 4
eager_inputs = (torch.ones(4, 4, device=self.device) + self.rank,) * 2
eager_out = eager_func(inductor_func(*inductor_inputs), *eager_inputs)
compiled_inductor_func = compile(inductor_func, inductor_inputs)
inductor_out = eager_func(
compiled_inductor_func(*inductor_inputs), *eager_inputs
)
self.assertTrue(same(eager_out, inductor_out, tol=0.001))
@unittest.skipIf(not HAS_GPU, "Inductor+gpu needs triton and recent GPU arch")
@skip_if_lt_x_gpu(2)
@xfailIf(TEST_XPU) # https://github.com/intel/torch-xpu-ops/issues/1728
@skipIfRocm
@xfailIf(TEST_XPU) # https://github.com/intel/torch-xpu-ops/issues/1728
def test_eager_async_allreduce_inductor_wait(self):
import torch.distributed as dist
from torch._inductor.utils import run_and_get_code
def all_reduce_non_functional_eager(x):
y = x * x
work = dist.all_reduce(y, op=dist.ReduceOp.SUM, async_op=True)
assert isinstance(work, torch.distributed.Work)
return work, y
def all_reduce_wait(work, y): # potentially compiled
if torch.compiler.is_dynamo_compiling():
torch.ops.c10d_functional.wait_tensor(y)
else:
work.wait(datetime.timedelta(seconds=10))
# Under compile, if `wait_tensor(y)` above is correctly executed,
# `y`'s data is in its final form and the output of this function will match eager;
# otherwise, `y * y` will run in parallel with `all_reduce(y)` and the output of this function
# will not match eager.
return y * y
with _dynamo_dist_per_rank_init(self.rank, self.world_size):
x = torch.ones(12800, 12800, device=self.device) + self.rank
self.assertEqual(torch._C._distributed_c10d._get_work_registry_size(), 0)
# NOTE: We run for 10 iterations each, to ensure that the GPU execution is way behind CPU
# and that `y * y` on CPU side will be issued before `all_reduce(y)` on GPU side is done,
# thus guaranteeing that in the bad case `y * y` on GPU side will run in parallel with `all_reduce(y)`
# thus will produce the wrong result that fails the unit test.
def _run_loop_collective_wait(x, wait_fn, expected_registry_size):
for _ in range(10):
self.assertEqual(
torch._C._distributed_c10d._get_work_registry_size(), 0
)
work, y = all_reduce_non_functional_eager(x)
self.assertEqual(
torch._C._distributed_c10d._get_work_registry_size(),
expected_registry_size,
)
out = wait_fn(work, y)
self.assertEqual(
torch._C._distributed_c10d._get_work_registry_size(), 0
)
return work, y, out
# Test: Pure-eager
all_reduce_wait_eager = all_reduce_wait
work, y, out_ref = _run_loop_collective_wait(
x,
wait_fn=all_reduce_wait_eager,
expected_registry_size=0,
)
all_reduce_wait_compiled = torch.compile(
all_reduce_wait,
backend="inductor",
fullgraph=True,
)
# Test: Issue comm in eager -> wait for comm in compile. Use the context manager.
with _functional_collectives.allow_inflight_collective_as_graph_input_ctx():
work, y, out_compiled = _run_loop_collective_wait(
x, wait_fn=all_reduce_wait_compiled, expected_registry_size=1
)
self.assertEqual(out_ref, out_compiled)
# Check that `wait_tensor()` is in the Inductor generated code
_, triton_codes = run_and_get_code(all_reduce_wait_compiled, work, y)
FileCheck().check("torch.ops._c10d_functional.wait_tensor.default(").run(
triton_codes[0]
)
# Failure Case: Issue comm in eager -> wait for comm in compile. Doesn't use the context manager.
_, _, out_compiled = _run_loop_collective_wait(
x, wait_fn=all_reduce_wait_compiled, expected_registry_size=0
)
# In this case `.wait_tensor(y)` in compiled region will not be able to find the corresponding work object
# to invoke the wait, thus the result will not match eager.
self.assertNotEqual(out_ref, out_compiled)
@unittest.skipIf(not HAS_GPU, "Inductor+gpu needs triton and recent GPU arch")
@skip_if_lt_x_gpu(2)
@patch.object(torch._inductor.config, "allow_buffer_reuse", True)
def test_allreduce_input_buffer_reuse(self):
def func(a, *, tag, ranks, group_size):
ar = _functional_collectives.all_reduce(a, "sum", ranks, tag)
c = torch.relu(a)
d = torch.matmul(c, c)
e = d + ar
return (e,)
with _dynamo_dist_per_rank_init(self.rank, self.world_size):
inputs = torch.ones(4, 4, device=self.device) + self.rank
compiled = torch.compile(func)
out = compiled(inputs, **self.get_world_trs())
correct = func(inputs, **self.get_world_trs())
self.assertTrue(same(out, correct))
@unittest.skipIf(not HAS_GPU, "Inductor+gpu needs triton and recent GPU arch")
@skip_if_lt_x_gpu(2)
def test_permute_tensor(self):
def func(tensor, src_dst_pairs, *, tag, ranks, group_size):
return _functional_collectives.permute_tensor(
tensor, src_dst_pairs, ranks, tag
)
with _dynamo_dist_per_rank_init(self.rank, self.world_size):
inputs = (
# rank0: [0., 1.], rank1: [2., 3.]
torch.arange(2, dtype=torch.float32, device=self.device)
+ 2 * self.rank,
[1, 0],
)
compiled = torch.compile(func)
out = compiled(*inputs, **self.get_world_trs())
correct = func(*inputs, **self.get_world_trs())
self.assertTrue(same(out, correct))
# rank0: [2., 3.], rank1: [0., 1.]
expected = torch.arange(2, dtype=torch.float32, device=self.device) + 2 * (
(self.rank - 1 + self.world_size) % self.world_size
)
self.assertEqual(out, expected)
self.assertEqual(correct, expected)
@unittest.skipIf(not HAS_GPU, "Inductor+gpu needs triton and recent GPU arch")
@skip_if_lt_x_gpu(2)
@patch.object(torch._inductor.config, "allow_buffer_reuse", True)
def test_allgather_output_buffer_reuse(self):
class Model(torch.nn.Module):
def __init__(self, *args, **kwargs) -> None:
super().__init__(*args, **kwargs)
self.emb = torch.nn.Embedding(4, 4)
def forward(self, x, world_size, tag, ranks, group_size):
y = self.emb(x)
last_dim = y.dim() - 1
res = _functional_collectives.all_gather_tensor(y, 0, ranks, tag)
out = torch.cat(torch.chunk(res, world_size, dim=0), dim=last_dim)
return out
with _dynamo_dist_per_rank_init(self.rank, self.world_size):
model = Model().to(self.device)
model_compiled = torch.compile(model)
inp = torch.tensor([[2, 1, 3, 0]], dtype=torch.long, device=self.device)
out = model_compiled(inp, self.world_size, **self.get_world_trs())
correct = model(inp, self.world_size, **self.get_world_trs())
self.assertTrue(same(out, correct))
@unittest.skipIf(not HAS_GPU, "Inductor+gpu needs triton and recent GPU arch")
@skip_if_lt_x_gpu(2)
def test_allgather_scalar_tensor_input(self):
def func(tensor, world_size):
tensor_list = [torch.empty_like(tensor) for _ in range(world_size)]
torch.distributed.all_gather(tensor_list, tensor)
return tensor_list
with _dynamo_dist_per_rank_init(self.rank, self.world_size):
func_compiled = torch.compile(func)
inp = torch.tensor(self.rank, dtype=torch.long, device=self.device)
out = func_compiled(inp, self.world_size)
correct = func(inp, self.world_size)
self.assertTrue(same(out, correct))
@unittest.skipIf(not HAS_GPU, "Inductor+gpu needs triton and recent GPU arch")
@skip_if_lt_x_gpu(2)
def test_allgather_contiguous_input(self):
class Model(torch.nn.Module):
def __init__(self, *args, **kwargs) -> None:
super().__init__(*args, **kwargs)
self.emb = torch.nn.Embedding(4, 4)
def forward(self, x, world_size, tag, ranks, group_size):
y = self.emb(x)
last_dim = y.dim() - 1
y = y.transpose_(0, last_dim).contiguous()
_functional_collectives.all_gather_tensor(y, 0, ranks, tag)
out = y.transpose_(0, last_dim).contiguous()
return out
with _dynamo_dist_per_rank_init(self.rank, self.world_size):
model = Model().to(self.device)
model_compiled = torch.compile(model)
inp = torch.tensor([[2, 1, 3, 0]], dtype=torch.long, device=self.device)
out = model_compiled(inp, self.world_size, **self.get_world_trs())
correct = model(inp, self.world_size, **self.get_world_trs())
self.assertTrue(same(out, correct))
@unittest.skipIf(not HAS_GPU, "Inductor+gpu needs triton and recent GPU arch")
@skip_if_lt_x_gpu(2)
def test_allgather_into_tensor_inductor(self):
"""
This is matmul/cat/allreduce is a pattern we aim to optimize.
"""
def example(a, b, *, tag, ranks, group_size):
c = torch.matmul(a, b)
ag = torch.ops.c10d_functional.all_gather_into_tensor(
c, tag, ranks, group_size
)
ag = torch.ops.c10d_functional.wait_tensor(ag)
return (ag,)
def compile(func, example_inputs):
graph = make_fx(func)(*example_inputs)
return inductor_compile_fx(graph, example_inputs)
with _dynamo_dist_per_rank_init(self.rank, self.world_size):
example = functools.partial(
example,
**self.get_world_trs(),
)
inputs = (torch.ones(4, 4, device=self.device) + self.rank,) * 2
eager_out = example(*inputs)
compiled_matmul_cat_col = compile(example, inputs)
inductor_out = compiled_matmul_cat_col(*inputs)
self.assertTrue(same(eager_out, inductor_out, tol=0.001))
@unittest.skipIf(not HAS_GPU, "Inductor+gpu needs triton and recent GPU arch")
@skip_if_lt_x_gpu(2)
def test_reduce_scatter_tensor_inductor(self):
def example(a, b, *, tag, ranks, group_size):
c = torch.matmul(a, b)
ag = torch.ops.c10d_functional.reduce_scatter_tensor(
c, "sum", tag, ranks, group_size
)
ag = torch.ops.c10d_functional.wait_tensor(ag)
return (ag,)
def compile(func, example_inputs):
graph = make_fx(func)(*example_inputs)
return inductor_compile_fx(graph, example_inputs)
with _dynamo_dist_per_rank_init(self.rank, self.world_size):
example = functools.partial(
example,
**self.get_world_trs(),
)
inputs = (torch.ones(4, 4, device=self.device) + self.rank,) * 2
eager_out = example(*inputs)
compiled_fn = compile(example, inputs)
inductor_out = compiled_fn(*inputs)
self.assertTrue(same(eager_out, inductor_out, tol=0.001))
@unittest.skipIf(not HAS_GPU, "Inductor+gpu needs triton and recent GPU arch")
@skip_if_lt_x_gpu(2)
@patch.object(torch._dynamo.config, "capture_scalar_outputs", True)
def test_all_to_all_single_inductor(self):
def example(
inp,
input_split_sizes_tensor,
output_split_sizes_tensor,
*,
tag,
ranks,
group_size,
):
input_split_sizes = _tolist(input_split_sizes_tensor)
output_split_sizes = _tolist(output_split_sizes_tensor)
a2a = torch.ops.c10d_functional.all_to_all_single(
inp,
output_split_sizes,
input_split_sizes,
tag,
ranks,
group_size,
)
a2a = torch.ops.c10d_functional.wait_tensor(a2a)
out = a2a / a2a.sum(dim=0)
return out
with (
_dynamo_dist_per_rank_init(self.rank, self.world_size),
torch._dynamo.config.patch(
dynamic_shapes=True,
capture_dynamic_output_shape_ops=True,
capture_scalar_outputs=True,
),
):
row = self.world_size * (self.rank + 1) * (self.world_size + 1) / 2
input_split_sizes_tensor = torch.tensor(
[(i + 1) * (self.rank + 1) for i in range(self.world_size)],
dtype=torch.int64,
)
output_split_sizes_tensor = torch.tensor(
[(i + 1) * (self.rank + 1) for i in range(self.world_size)],
dtype=torch.int64,
)
inputs = (
torch.ones(int(row), 5, device=self.device) * (self.rank + 1),
input_split_sizes_tensor,
output_split_sizes_tensor,
)
trs = self.get_world_trs()
compiled_fn = torch.compile(example, fullgraph=True, dynamic=True)
code = run_and_get_triton_code(compiled_fn, *inputs, **trs)
(
FileCheck()
.check_regex(
"torch.ops._c10d_functional.all_to_all_single.default\\("
"arg\\d+_\\d+, "
"\\[u\\d+, u\\d+\\], "
"\\[u\\d+, u\\d+\\]"
)
.run(code)
)
eager_out = example(*inputs, **trs)
inductor_out = compiled_fn(*inputs, **trs)
self.assertTrue(same(eager_out, inductor_out, tol=0.001))
# The goal of this test is that when `unsafe_allow_recompute_of_collectives=False`,
# The partitioner will *never* recompute collectives in the backward, even
# if the activation_memory_budget partitioner is being used,
# unless there is a manual user checkpoint() region (which we know makes it safe
# to recompute the collective, since we assume that the user applied the AC
# region consistently across all ranks)
@unittest.skipIf(not HAS_GPU, "Inductor+gpu needs triton and recent GPU arch")
@skip_if_lt_x_gpu(2)
@patch.object(torch._dynamo.config, "capture_scalar_outputs", True)
@patch.object(torch._functorch.config, "activation_memory_budget", 0.01)
@parametrize("override_with_ac", [False, True])
def test_all_to_all_recompute_is_always_banned(self, override_with_ac):
@torch.library.custom_op("custom_ns::foo", mutates_args=())
def foo(x: torch.Tensor) -> torch.Tensor:
return x + 1
@foo.register_fake
def _(x):
return torch.empty_like(x)
def setup_context(ctx, inputs, output):
ctx.save_for_backward(inputs[0])
return
def backward(ctx, grad):
(x,) = ctx.saved_tensors
return grad * x
foo.register_autograd(backward, setup_context=setup_context)
class AllToAllSingle(torch.autograd.Function):
@staticmethod
def forward(
ctx,
input: torch.Tensor,
output_split_sizes,
input_split_sizes,
tag,
ranks,
group_size: int,
) -> torch.Tensor:
ctx.output_split_sizes = input_split_sizes
ctx.input_split_sizes = output_split_sizes
ctx.group_size = group_size
a2a = torch.ops._c10d_functional.all_to_all_single.default(
input,
output_split_sizes,
input_split_sizes,
"0",
)
a2a = torch.ops.c10d_functional.wait_tensor(a2a)
return a2a
@staticmethod
def backward(ctx, grad):
grad = torch.ops._c10d_functional.all_to_all_single.default(
grad,
ctx.output_split_sizes,
ctx.input_split_sizes,
"0",
)
return (
torch.ops.c10d_functional.wait_tensor(grad),
None,
None,
None,
None,
None,
)
def alltoall_autograd(
inp,
output_split_sizes,
input_split_sizes,
tag,
ranks,
group_size,
):
out = AllToAllSingle.apply(
inp, output_split_sizes, input_split_sizes, tag, ranks, group_size
)
return out
# simple mode to track how many collective ops we saw in the backward
class TrackingMode(TorchDispatchMode):
def __init__(self):
super().__init__()
self.ops_counter = Counter()
def __torch_dispatch__(self, func, types, args=(), kwargs=None):
if kwargs is None:
kwargs = {}
rs = func(*args, **kwargs)
self.ops_counter[func] += 1
return rs
def example(
inp,
input_split_sizes_tensor,
output_split_sizes_tensor,
*,
tag,
ranks,
group_size,
):
input_split_sizes = _tolist(input_split_sizes_tensor)
output_split_sizes = _tolist(output_split_sizes_tensor)
a2a = torch.ops.custom_ns.alltoall_autograd.default(
inp,
output_split_sizes,
input_split_sizes,
tag,
ranks,
group_size,
)
return torch.ops.custom_ns.foo(a2a)
with (
_dynamo_dist_per_rank_init(self.rank, self.world_size),
torch._dynamo.config.patch(
dynamic_shapes=True,
capture_dynamic_output_shape_ops=True,
capture_scalar_outputs=True,
),
torch.library._scoped_library("custom_ns", "FRAGMENT") as lib,
):
lib.define(
"alltoall_autograd(Tensor input, SymInt[]? output_split_sizes, SymInt[]? input_split_sizes, str tag, int[] ranks, int group_size) -> Tensor" # noqa: B950
)
lib.impl("alltoall_autograd", alltoall_autograd, "Autograd")
lib.impl("alltoall_autograd", alltoall_autograd, "Meta")
row = self.world_size * (self.rank + 1) * (self.world_size + 1) / 2
input_split_sizes_tensor = torch.tensor(
[(i + 1) * (self.rank + 1) for i in range(self.world_size)],
dtype=torch.int64,
)
output_split_sizes_tensor = torch.tensor(
[(i + 1) * (self.rank + 1) for i in range(self.world_size)],
dtype=torch.int64,
)
inputs = (
torch.ones(int(row), 5, device=self.device, requires_grad=True)
* (self.rank + 1),
input_split_sizes_tensor,
output_split_sizes_tensor,
)
trs = self.get_world_trs()
compiled_fn = torch.compile(
example,
fullgraph=True,
dynamic=True,
backend="aot_eager_decomp_partition",
)
if override_with_ac:
def compiled_fn_wrapper(*args):
return example(*inputs, **trs)
out = torch.utils.checkpoint.checkpoint(
compiled_fn_wrapper, *inputs, use_reentrant=False
)
else:
out = compiled_fn(*inputs, **trs)
# track how many all_to_alls we saw in the backward
with TrackingMode() as m:
out.sum().backward()
if override_with_ac:
# We wrapped our test in AC, which overrides the partitioner decision
# of never recomputing collectives.
# So we should properly see the all2all be recomputed in the backward
self.assertEqual(
m.ops_counter[torch.ops._c10d_functional.all_to_all_single.default],
2,
)
else:
# there is 1 all2all in the fw, and 1 all2all in the backward.
# notably: even though activation_memory_budget == 0 ("recompute_everything"),
# we are still choosing *not* to recompute the all2all from the fw
self.assertEqual(
m.ops_counter[torch.ops._c10d_functional.all_to_all_single.default],
1,
)
@unittest.skipIf(not HAS_GPU, "Inductor+gpu needs triton and recent GPU arch")
@skip_if_lt_x_gpu(2)
def test_all_to_all_single_inductor_split_sizes_none(self):
def example(inp, *, tag, ranks, group_size):
a2a = torch.ops.c10d_functional.all_to_all_single(
inp,
None,
None,
tag,
ranks,
group_size,
)
a2a = torch.ops.c10d_functional.wait_tensor(a2a)
out = a2a / a2a.sum(dim=0)
return out
with _dynamo_dist_per_rank_init(self.rank, self.world_size):
inputs = (
torch.ones(self.world_size, self.world_size, device=self.device)
* (self.rank + 1),
)
trs = self.get_world_trs()
compiled_fn = torch.compile(example, fullgraph=True, dynamic=True)
code = run_and_get_triton_code(compiled_fn, *inputs, **trs)
(
FileCheck()
.check_regex(
"torch.ops._c10d_functional.all_to_all_single.default\\("
"arg\\d+_\\d+, "
"\\[s\\d+ // \\d, s\\d+ // \\d\\], "
"\\[s\\d+ // \\d, s\\d+ // \\d\\]"
)
.run(code)
)
eager_out = example(*inputs, **trs)
inductor_out = compiled_fn(*inputs, **trs)
self.assertTrue(same(eager_out, inductor_out, tol=0.001))
@instantiate_parametrized_tests
@requires_accelerator_dist_backend(["nccl", "xccl"])
@unittest.skipIf(
not torch.accelerator.is_available(),
"No accelerator is available",
)
class TestCollectivesInductor(DynamoDistributedSingleProcTestCase):
"""
Prefer single-proc test runner for basic tests as it is easier to work with.
"""
def get_world_trs(self, world_size=1):
return {
"tag": "",
"ranks": list(range(world_size)),
"group_size": world_size,
}
@unittest.skipIf(not HAS_GPU, "Inductor+gpu needs triton and recent GPU arch")
@torch._inductor.config.patch(debug=True)
def test_inductor_single_op(self):
def func(inp, *, tag, ranks, group_size):
ar = torch.ops.c10d_functional.all_reduce(
inp, "sum", tag, ranks, group_size
)
ar = torch.ops.c10d_functional.wait_tensor(ar)
return ar
inputs = torch.ones(4, 4, device=self.device)
compiled = torch.compile(func)
out = compiled(inputs, **self.get_world_trs())
code = run_and_get_triton_code(compiled, inputs, **self.get_world_trs())
# NOTE: Make sure we are not unnecessarily copying the outputs of
# wait_tensors before they are returned from the graph.
(
FileCheck()
.check("buf0 = empty_strided")
.check(".run(arg0_1, buf0, 16")
.check("torch.ops._c10d_functional.all_reduce_.default(buf0")
.check("torch.ops._c10d_functional.wait_tensor.default(buf0")
.check("return (buf0")
.run(code)
)
correct = func(inputs, **self.get_world_trs())
self.assertTrue(same(out, correct))
@unittest.skipIf(not HAS_GPU, "Inductor+gpu needs triton and recent GPU arch")
@torch._inductor.config.patch(debug=True)
def test_inductor_steal_buffer(self):
"""
it's ok and optimal if inductor allreduce mutates the buffer of an intermediate
that isn't going to be used again
"""
def func(inp, *, tag, ranks, group_size):
x = inp + 1
ar = torch.ops.c10d_functional.all_reduce(x, "sum", tag, ranks, group_size)
ar = torch.ops.c10d_functional.wait_tensor(ar)
# ensure other is not incorrectly aliasing ar's buffer
other = torch.ones_like(inp) + 22
return ar, other
inputs = torch.ones(4, 4, device=self.device)
compiled = torch.compile(func)
code = run_and_get_triton_code(compiled, inputs, **self.get_world_trs())
(
FileCheck()
.check("buf0 = empty_strided")
.check(".run(arg0_1, buf0")
.check("torch.ops._c10d_functional.all_reduce_.default(buf0")
.check("torch.ops._c10d_functional.wait_tensor.default(buf0")
.check("buf5 = empty_strided")
.check(".run(buf5, 16")
.check("return (buf0, buf5")
.run(code)
)
out = compiled(inputs, **self.get_world_trs())
correct = func(inputs, **self.get_world_trs())
self.assertTrue(same(out, correct))
def _test_inductor_doesnt_mutate_shared(self):
"""
make sure that an intermediate that's going to be reuse isn't mutated unless copied
"""
def func(inp, *, tag, ranks, group_size):
x = inp + 1
ar = torch.ops.c10d_functional.all_reduce(x, "sum", tag, ranks, group_size)
y = x + 2
ar = torch.ops.c10d_functional.wait_tensor(ar)
# ensure other is not incorrectly aliasing ar's buffer
other = torch.ones_like(inp) + 22
return ar, y, other
inputs = torch.ones(4, 4, device=self.device)
compiled = torch.compile(func)
code = run_and_get_triton_code(compiled, inputs, **self.get_world_trs())
# NOTE: Make sure we are not unnecessarily copying the outputs of
# wait_tensors before they are returned from the graph.
(
FileCheck()
.check("buf0 = empty_strided")
.check("buf1 = buf0")
.check("buf6 = empty_strided")
.check(".run(buf1, arg0_1, buf6, 16")
.check("torch.ops._c10d_functional.all_reduce_.default(buf1")
.check("torch.ops._c10d_functional.wait_tensor.default(buf1")
.check("buf7 = empty_strided")
.check(".run(buf7, 16")
.check("return (buf1, buf6, buf7")
.run(code)
)
out = compiled(inputs, **self.get_world_trs())
correct = func(inputs, **self.get_world_trs())
self.assertTrue(same(out, correct))
@unittest.skipIf(not HAS_GPU, "Inductor+gpu needs triton and recent GPU arch")
@torch._inductor.config.patch({"debug": True, "triton.descriptive_names": False})
def test_inductor_doesnt_mutate_shared(self):
self._test_inductor_doesnt_mutate_shared()
@unittest.skipIf(not HAS_GPU, "Inductor+gpu needs triton and recent GPU arch")
@torch._inductor.config.patch({"debug": True, "triton.descriptive_names": False})
@torch._inductor.config.patch("graph_partition", True)
def test_inductor_doesnt_mutate_shared_graph_partition(self):
# checks graph partition reorder does not change relative order of ops
# when all ops are on cuda
self._test_inductor_doesnt_mutate_shared()
def test_dynamo_trace_allreduce(self):
def func(inp):
ar = _functional_collectives.all_reduce(inp, "sum", "0")
return ar
inputs = torch.ones(4, 4, device=self.device)
counter = CompileCounter()
compiled = torch.compile(func, backend=counter)
out = compiled(inputs)
correct = func(inputs)
self.assertEqual(counter.frame_count, 1)
# should test more precisely, but the 2 is supposed to be (all_reduce, wait)
self.assertEqual(counter.op_count, 2)
self.assertTrue(same(out, correct))
@skipIfXpu # https://github.com/intel/torch-xpu-ops/issues/1581
def test_dynamo_trace_all_gather_tensor(self):
def func(inp):
ar = _functional_collectives.all_gather_tensor(inp, 0, "0")
return ar
inputs = torch.ones(4, 4, device=self.device)
counter = CompileCounter()
compiled = torch.compile(func, backend=counter)
out = compiled(inputs)
correct = func(inputs)
self.assertEqual(counter.frame_count, 1)
# should test more precisely, but the 2 is supposed to be (all_gather, wait)
self.assertEqual(counter.op_count, 2)
self.assertTrue(same(out, correct))
@skipIfXpu # https://github.com/intel/torch-xpu-ops/issues/1581
def test_dynamo_trace_all_gather_tensor_pg(self):
def func(inp, *, pg):
ar = _functional_collectives.all_gather_tensor(inp, 0, pg)
return ar
inputs = torch.ones(4, 4, device=self.device)
counter = CompileCounter()
compiled = torch.compile(func, backend=counter, fullgraph=True)
out = compiled(inputs, pg=GroupMember.WORLD)
correct = func(inputs, pg=GroupMember.WORLD)
self.assertEqual(counter.frame_count, 1)
# should test more precisely, but the 2 is supposed to be (all_gather, wait)
self.assertEqual(counter.op_count, 2)
self.assertTrue(same(out, correct))
@skipIfXpu # https://github.com/intel/torch-xpu-ops/issues/1581
def test_dynamo_rewrite_dist_all_gather(self):
def func(inp, out, *, pg):
torch.distributed.all_gather_into_tensor(
out,
inp,
pg,
)
local_size = [4, 4]
# single-proc test
global_size = local_size
inputs = torch.ones(local_size, device=self.device)
outputs = torch.empty(global_size, device=self.device)
correct_outputs = torch.empty(global_size, device=self.device)
counter = CompileCounter()
compiled = torch.compile(func, backend=counter, fullgraph=True)
compiled(inputs, outputs, pg=GroupMember.WORLD)
func(inputs, correct_outputs, pg=GroupMember.WORLD)
assert counter.frame_count == 1
# should test more precisely, but the 3 is supposed to be (all_gather, wait, copy_)
assert counter.op_count == 3
assert same(outputs, correct_outputs)
@skipIfXpu # https://github.com/intel/torch-xpu-ops/issues/1581
def test_dynamo_rewrite_dist_all_gather_list(self):
def func(inp, out, *, pg):
torch.distributed.all_gather(
out,
inp,
pg,
)
local_size = [4, 4]
# single-proc test
global_size = local_size
inputs = torch.ones(local_size, device=self.device)
outputs = [torch.empty(global_size, device=self.device)]
correct_outputs = [torch.empty(global_size, device=self.device)]
counter = CompileCounter()
compiled = torch.compile(func, backend=counter, fullgraph=True)
compiled(inputs, outputs, pg=GroupMember.WORLD)
func(inputs, correct_outputs, pg=GroupMember.WORLD)
assert counter.frame_count == 1
assert same(outputs, correct_outputs)
@skipIfXpu # https://github.com/intel/torch-xpu-ops/issues/1581
def test_dynamo_rewrite_dist_all_gather_args_match(self):
# Duplicated most of the structure from test_dynamo_rewrite_dist_all_gather
# except uses kwargs to ensure rewrite has matching arg names
def func(inp, out, *, pg):
torch.distributed.all_gather_into_tensor(
output_tensor=out,
input_tensor=inp,
group=pg,
async_op=False,
)
local_size = [4, 4]
# single-proc test
global_size = local_size
inputs = torch.ones(local_size, device=self.device)
outputs = torch.empty(global_size, device=self.device)
correct_outputs = torch.empty(global_size, device=self.device)
counter = CompileCounter()
compiled = torch.compile(func, backend=counter, fullgraph=True)
compiled(inputs, outputs, pg=GroupMember.WORLD)
func(inputs, correct_outputs, pg=GroupMember.WORLD)
assert counter.frame_count == 1
# should test more precisely, but the 3 is supposed to be (all_gather, wait, copy_)
assert counter.op_count == 3
assert same(outputs, correct_outputs)
@skipIfXpu # https://github.com/intel/torch-xpu-ops/issues/1581
def test_dynamo_rewrite_dist_reduce_scatter(self):
def func(inp, out, *, pg):
torch.distributed.reduce_scatter_tensor(
out,
inp,
group=pg,
)
local_size = [4, 4]
# single-proc test
global_size = local_size
inputs = torch.ones(local_size, device=self.device)
outputs = torch.empty(global_size, device=self.device)
correct_outputs = torch.empty(global_size, device=self.device)
counter = CompileCounter()
compiled = torch.compile(func, backend=counter, fullgraph=True)
compiled(inputs, outputs, pg=GroupMember.WORLD)
func(inputs, correct_outputs, pg=GroupMember.WORLD)
assert counter.frame_count == 1
# should test more precisely, but the 3 is supposed to be (reduce_scatter, wait, copy_)
assert counter.op_count == 3
assert same(outputs, correct_outputs)
@parametrize(
"pg_mode",
[
"positional",
"positional_none",
"kwargs",
"kwargs_none",
"unspecified",
],
)
def test_dynamo_rewrite_dist_allreduce(self, pg_mode):
def func(tensor, *args, **kwargs):
torch.distributed.all_reduce(
tensor,
*args,
**kwargs,
)
counter = CompileCounter()
compiled = torch.compile(func, backend=counter, fullgraph=True)
args = []
kwargs = {}
if pg_mode == "positional":
args.append(torch.distributed.ReduceOp.MAX)
args.append(GroupMember.WORLD)
elif pg_mode == "positional_none":
args.append(torch.distributed.ReduceOp.MAX)
args.append(None)
elif pg_mode == "kwargs":
kwargs["group"] = GroupMember.WORLD
elif pg_mode == "kwargs_none":
kwargs["group"] = None
else:
assert pg_mode == "unspecified"
inputs_compiled = torch.ones(2, device=self.device)
inputs_eager = torch.ones(2, device=self.device)
compiled(inputs_compiled, *args, **kwargs)
func(inputs_eager, *args, **kwargs)
assert counter.frame_count == 1
# should test more precisely, but the 3 is supposed to be (all_reduce, wait, copy_)
assert counter.op_count == 3
assert same(inputs_compiled, inputs_eager)
def test_dynamo_rewrite_dist_all_to_all_single(self):
def func(output, input, pg):
torch.distributed.all_to_all_single(output, input, group=pg)
counter = CompileCounter()
compiled = torch.compile(func, backend=counter, fullgraph=True)
input_compiled = torch.ones(2, device=self.device)
input_eager = torch.ones(2, device=self.device)
output_compiled = torch.empty(2, device=self.device)
output_eager = torch.empty(2, device=self.device)
compiled(output_compiled, input_compiled, GroupMember.WORLD)
func(output_eager, input_eager, GroupMember.WORLD)
assert counter.frame_count == 1
assert same(output_compiled, output_eager)
@parametrize(
"reduce_op",
[
torch.distributed.ReduceOp.SUM,
torch.distributed.ReduceOp.AVG,
torch.distributed.ReduceOp.PRODUCT,
torch.distributed.ReduceOp.MIN,
torch.distributed.ReduceOp.MAX,
],
)
def test_dynamo_rewrite_dist_allreduce_reduce_op(self, reduce_op):
from torch.distributed._functional_collectives import REDUCE_OP_TO_STR
def verify_rewrite(gm, _):
ar_nodes = []
for node in gm.graph.nodes:
if node.target in [
torch.ops.c10d_functional.all_reduce,
torch.ops._c10d_functional.all_reduce,
]:
ar_nodes.append(node)
self.assertEqual(len(ar_nodes), 1)
reduce_op_str = ar_nodes[0].args[1]
self.assertEqual(REDUCE_OP_TO_STR[reduce_op], reduce_op_str)
return gm
compiled = torch.compile(
torch.distributed.all_reduce,
backend=verify_rewrite,
fullgraph=True,
)
inputs = (
torch.ones(2, device=self.device),
reduce_op,
GroupMember.WORLD,
)
compiled(*inputs)
@parametrize(
"source",
[
"GroupMember.WORLD",
"group.WORLD",
"_get_default_group",
],
)
def test_dynamo_get_world_group(self, source):
def func(tensor):
if source == "GroupMember.WORLD":
group = torch.distributed.GroupMember.WORLD
elif source == "group.WORLD":
group = torch.distributed.group.WORLD
else:
assert source == "_get_default_group"
group = torch.distributed.distributed_c10d._get_default_group()
torch.distributed.all_reduce(
tensor,
group=group,
)
def verify(gm, _):
ar_nodes = []
for node in gm.graph.nodes:
if node.target in [
torch.ops.c10d_functional.all_reduce,
torch.ops._c10d_functional.all_reduce,
]:
ar_nodes.append(node)
self.assertEqual(len(ar_nodes), 1)
return gm
compiled = torch.compile(func, backend=verify, fullgraph=True)
input = torch.ones(2, device=self.device)
compiled(input)
@skipIfXpu # https://github.com/intel/torch-xpu-ops/issues/1581
def test_dynamo_support_collective_op_with_async_op_False(self):
def func(inp, out, *, pg):
# user explicitly set the attribute `async_op` to False,
# there should be no graph break
torch.distributed.reduce_scatter_tensor(out, inp, group=pg, async_op=False)
local_size = [4, 4]
# single-proc test
global_size = local_size
inputs = torch.ones(local_size, device=self.device)
outputs = torch.empty(global_size, device=self.device)
correct_outputs = torch.empty(global_size, device=self.device)
counter = CompileCounter()
compiled = torch.compile(func, backend=counter)
compiled(inputs, outputs, pg=GroupMember.WORLD)
func(inputs, correct_outputs, pg=GroupMember.WORLD)
assert counter.frame_count == 1
assert counter.op_count == 3
assert same(outputs, correct_outputs)
def test_dynamo_graphbreaks_unsupported_async_op(self):
def func(inp, out, *, pg):
work = torch.distributed.reduce_scatter_tensor(
out, inp, group=pg, async_op=True
)
work.wait()
local_size = [4, 4]
# single-proc test
global_size = local_size
inputs = torch.ones(local_size, device=self.device)
outputs = torch.empty(global_size, device=self.device)
correct_outputs = torch.empty(global_size, device=self.device)
counter = CompileCounter()
compiled = torch.compile(func, backend=counter)
compiled(inputs, outputs, pg=GroupMember.WORLD)
func(inputs, correct_outputs, pg=GroupMember.WORLD)
assert counter.frame_count == 0
assert counter.op_count == 0
assert same(outputs, correct_outputs)
def test_dynamo_pg_var(self):
def func(inp, *, pg):
x = pg.rank() + 1 % pg.size()
return inp + x
local_size = [4, 4]
inputs = torch.ones(local_size, device=self.device)
correct_outputs = torch.empty(local_size, device=self.device)
counter = CompileCounter()
compiled = torch.compile(func, backend=counter, fullgraph=True)
outputs = compiled(inputs, pg=GroupMember.WORLD)
correct_outputs = func(inputs, pg=GroupMember.WORLD)
assert counter.frame_count == 1
assert counter.op_count == 1
assert same(outputs, correct_outputs)
@skipIfXpu # https://github.com/intel/torch-xpu-ops/issues/1581
def test_dynamo_trace_reduce_scatter_tensor(self):
def func(inp):
ar = _functional_collectives.reduce_scatter_tensor(inp, "sum", 0, "0")
return ar
inputs = torch.ones(4, 4, device=self.device)
counter = CompileCounter()
compiled = torch.compile(func, backend=counter)
out = compiled(inputs)
correct = func(inputs)
self.assertEqual(counter.frame_count, 1)
# should test more precisely, but the 2 is supposed to be (reduce_scatter, wait)
self.assertEqual(counter.op_count, 2)
self.assertTrue(same(out, correct))
@skipIfXpu # https://github.com/intel/torch-xpu-ops/issues/1581
def test_dynamo_trace_allgather_coalesced(self):
def func(inp, *, tag, ranks, group_size):
ar = torch.ops.c10d_functional.all_gather_into_tensor_coalesced(
inp, tag, ranks, group_size
)
return ar
inputs = [
torch.ones(4, 4, device=self.device),
torch.ones(6, 6, device=self.device),
]
counter = CompileCounter()
compiled = torch.compile(func, backend=counter)
out = compiled(inputs, **self.get_world_trs())
correct = func(inputs, **self.get_world_trs())
assert counter.frame_count == 1
assert counter.op_count == 3 # It generates 2 getattr to unpack the array
assert same(out, correct)
def test_backwards(self):
"""
It's probably not that common to need backwards support for collectives.
However, I wanted to at least see if it was possible to support it as a design goal.
"""
def func(inp):
ar = _functional_collectives.all_reduce(inp, "sum", "0")
return ar
input = torch.ones(4, 4, device=self.device, requires_grad=True)
compiled = torch.compile(
func, backend="aot_eager"
) # inductor bug with single-op allreduce graph
out = compiled(input)
out.sum().backward()
correct_input = input.detach().clone().requires_grad_()
correct = func(correct_input)
correct.sum().backward()
self.assertTrue(same(out, correct))
self.assertTrue(same(input.grad, correct_input.grad))
def test_meta(self):
x = torch.rand((2, 3, 4), device="meta")
out = torch.ops.c10d_functional.all_reduce(x, "sum", **self.get_world_trs())
self.assertEqual(x.size(), out.size())
@skipIfXpu # https://github.com/intel/torch-xpu-ops/issues/1581
@unittest.skipIf(not HAS_GPU, "Inductor+gpu needs triton and recent GPU arch")
@torch._inductor.config.patch({"debug": True, "triton.descriptive_names": False})
def test_inductor_all_gather_coalesced(self):
"""
make sure that an intermediate that's going to be reuse isn't mutated unless copied
"""
def func(inp, *, tag, ranks, group_size):
x = inp + 1
tensor_list = torch.ops.c10d_functional.all_gather_into_tensor_coalesced(
[x, inp], tag, ranks, group_size
)
y = x + 2
ar0 = torch.ops.c10d_functional.wait_tensor(tensor_list[0])
ar1 = torch.ops.c10d_functional.wait_tensor(tensor_list[1])
# ensure other is not incorrectly aliasing ar's buffer
other = torch.ones_like(inp) + 22
return ar0, y, other, ar1
inputs = torch.ones(4, 4, device=self.device)
compiled = torch.compile(func)
code = run_and_get_triton_code(compiled, inputs, **self.get_world_trs())
# NOTE: Make sure we are not unnecessarily copying the outputs of
# wait_tensors before they are returned from the graph.
(
FileCheck()
.check("buf0 = empty_strided")
.check("buf6 = empty_strided")
.check(".run(arg0_1, buf0, buf6, 16")
.check(
"buf1 = torch.ops._c10d_functional.all_gather_into_tensor_coalesced.default([buf0, arg0_1]"
)
.check("buf2 = buf1[0]")
.check("buf3 = buf1[1]")
.check("torch.ops._c10d_functional.wait_tensor.default(buf2")
.check("buf7 = buf0; del buf0 # reuse")
.check(".run(buf7, 16")
.check("torch.ops._c10d_functional.wait_tensor.default(buf3")
.check("return (buf2, buf6, buf7, buf3")
.run(code)
)
out = compiled(inputs, **self.get_world_trs())
correct = func(inputs, **self.get_world_trs())
assert same(out, correct), f"{out} va {correct}"
@skipIfXpu # https://github.com/intel/torch-xpu-ops/issues/1581
@unittest.skipIf(not HAS_GPU, "Inductor+gpu needs triton and recent GPU arch")
@torch._inductor.config.patch({"debug": True, "triton.descriptive_names": False})
def test_inductor_reduce_scatter_coalesced(self):
"""
make sure that an intermediate that's going to be reuse isn't mutated unless copied
"""
def func(inp, *, tag, ranks, group_size):
x = inp + 1
tensor_list = torch.ops.c10d_functional.reduce_scatter_tensor_coalesced(
[x, inp], "sum", tag, ranks, group_size
)
y = x + 2
ar0 = torch.ops.c10d_functional.wait_tensor(tensor_list[0])
ar1 = torch.ops.c10d_functional.wait_tensor(tensor_list[1])
# ensure other is not incorrectly aliasing ar's buffer
other = torch.ones_like(inp) + 22
return ar0, y, other, ar1
inputs = torch.ones(4, 4, device=self.device)
compiled = torch.compile(func)
code = run_and_get_triton_code(compiled, inputs, **self.get_world_trs())
# NOTE: The first return value should be the output of the first wait_tensor.
# We want to make sure no unnecessary copy is made.
(
FileCheck()
.check("buf0 = empty_strided")
.check("buf6 = empty_strided")
.check(".run(arg0_1, buf0, buf6, 16")
.check(
"buf1 = torch.ops._c10d_functional.reduce_scatter_tensor_coalesced.default([buf0, arg0_1]"
)
.check("buf2 = buf1[0]")
.check("buf3 = buf1[1]")
.check("torch.ops._c10d_functional.wait_tensor.default(buf2")
.check("buf7 = buf0; del buf0 # reuse")
.check(".run(buf7, 16")
.check("torch.ops._c10d_functional.wait_tensor.default(buf3")
.check("return (buf2, buf6, buf7, buf3")
.run(code)
)
out = compiled(inputs, **self.get_world_trs())
correct = func(inputs, **self.get_world_trs())
assert same(out, correct), f"{out} va {correct}"
@skipIfXpu # https://github.com/intel/torch-xpu-ops/issues/1581
@unittest.skipIf(not HAS_GPU, "Inductor+gpu needs triton and recent GPU arch")
def test_reorder_peak_memory(self):
"""
TODO(whc)
- check each of the `limiting_factor` cases
- confirm peak memory is respected in some adversarial case
- check whether it is expected / correct that the "buf7 = buf0; del buf0 # reuse" statement materially changes
"""
def func(inp, *, tag, ranks, group_size):
x = inp + 1
tensor_list = torch.ops.c10d_functional.reduce_scatter_tensor_coalesced(
[x, inp], "sum", tag, ranks, group_size
)
y = x + 2
ar0 = torch.ops.c10d_functional.wait_tensor(tensor_list[0])
ar1 = torch.ops.c10d_functional.wait_tensor(tensor_list[1])
# ensure other is not incorrectly aliasing ar's buffer
other = torch.ones_like(inp) + 22
return ar0, y, other, ar1
inputs = torch.ones(4, 4, device=self.device)
# get stats directly from the internal helper without affecting the real pass's signature
node_stats: Optional[dict[BaseSchedulerNode, ReorderInfo]] = None
def _reorder_communication_preserving_peak_memory(
snodes: list[BaseSchedulerNode],
) -> list[BaseSchedulerNode]:
nonlocal node_stats
(
reordered_snodes,
node_stats,
) = _reorder_communication_preserving_peak_memory_internal(snodes)
return reordered_snodes
with torch._inductor.config.patch(
{
"reorder_for_compute_comm_overlap": True,
"reorder_for_compute_comm_overlap_passes": [
"sink_waits",
# same as reorder_communication_preserving_peak_memory but returns debug info structures directly
_reorder_communication_preserving_peak_memory,
],
}
):
compiled = torch.compile(func)
code = run_and_get_triton_code(compiled, inputs, **self.get_world_trs())
# NOTE: The first return value should be the output of the first wait_tensor.
# We want to make sure no unnecessary copy is made.
(
FileCheck()
.check("buf0 = empty_strided")
.check("buf6 = empty_strided")
.check(".run(arg0_1, buf0, buf6, 16")
.check(
"buf1 = torch.ops._c10d_functional.reduce_scatter_tensor_coalesced.default([buf0, arg0_1]"
)
# .check("buf2 = buf1[0]")
# .check("buf3 = buf1[1]")
.check("torch.ops._c10d_functional.wait_tensor.default(buf2")
# .check("buf7 = buf0; del buf0 # reuse")
# .check(".run(buf7, 16")
.check("torch.ops._c10d_functional.wait_tensor.default(buf3")
.check("return (buf2, buf6, buf7, buf3")
.run(code)
)
out = compiled(inputs, **self.get_world_trs())
correct = func(inputs, **self.get_world_trs())
assert same(out, correct), f"{out} va {correct}"
# TODO make the test case more interesting and validate the actual desired behavior
assert node_stats is not None
self.assertTrue(isinstance(node_stats, dict))
self.assertEqual(len(node_stats), 1)
for stats in node_stats.values():
self.assertEqual(stats.initial_exposed, 0)
self.assertEqual(stats.limiting_factor, "None")
self.assertEqual(stats.moves, 0)
@unittest.skipIf(not HAS_GPU, "Inductor+gpu needs triton and recent GPU arch")
@unittest.skipIf(not SM80OrLater, "bfloat16")
@parametrize("bucket_mode", ["all", "all_custom_ops"])
def test_all_gather_bucket(self, bucket_mode):
def func(x, w, ag_0, ag_1, ag_2, ag_3, *, tag, ranks, group_size):
# do some unrelated matmuls
y = torch.mm(x, w)
ag_1_cast = ag_1.to(torch.bfloat16)
group_name = (
torch.distributed.distributed_c10d._get_default_group().group_name
)
ag_2_out = torch.ops._c10d_functional.all_gather_into_tensor(
ag_2, group_size, group_name
)
ag_2_out = torch.ops.c10d_functional.wait_tensor(ag_2_out)
ag_0 = ag_2_out + ag_0
ag_0_cast = ag_0.to(torch.bfloat16)
ag_0_out = torch.ops._c10d_functional.all_gather_into_tensor(
ag_0_cast, group_size, group_name
)
ag_0_out = torch.ops.c10d_functional.wait_tensor(ag_0_out)
ag_0_out = ag_0_out * 2
ag_1_out = torch.ops._c10d_functional.all_gather_into_tensor(
ag_1_cast, group_size, group_name
)
ag_1_out = torch.ops.c10d_functional.wait_tensor(ag_1_out)
ag_3_out = torch.ops._c10d_functional.all_gather_into_tensor(
ag_3, group_size, group_name
)
ag_3_out = torch.ops.c10d_functional.wait_tensor(ag_3_out)
return y, ag_0_out, ag_1_out, ag_2_out, ag_3_out
x = torch.ones(4, 384, device="cuda", dtype=torch.float32)
w = torch.ones(384, 512, device="cuda", dtype=torch.float32)
ag_0 = torch.ones(384, 512, device="cuda", dtype=torch.float32)
ag_1 = torch.ones(384, 512, device="cuda", dtype=torch.float32)
ag_2 = torch.ones(384, 512, device="cuda", dtype=torch.float32)
ag_3 = torch.ones(384, 512, device="cuda", dtype=torch.float32)
inputs = [x, w, ag_0, ag_1, ag_2, ag_3]
correct = func(*inputs, **self.get_world_trs())
with (
torch._inductor.config.patch(
{
"bucket_all_gathers_fx": bucket_mode,
"reorder_for_compute_comm_overlap": False,
"runtime_estimations_mms_benchmark": True,
}
),
torch._inductor.config_comms.patch(
{
"runtime_estimations_align_across_all_distributed_ranks": True,
}
),
# Clearing cache to cover runtime_estimations_mms_benchmark that use LocalCache
fresh_inductor_cache(),
):
compiled = torch.compile(func)
code = run_and_get_triton_code(compiled, *inputs, **self.get_world_trs())
# NOTE: The first return value should be the output of the first wait_tensor.
# We want to make sure no unnecessary copy is made.
(
FileCheck()
.check("= torch.ops._c10d_functional.all_gather_into_tensor")
.check("torch.ops._c10d_functional.all_gather_into_tensor_out.default(")
.check("= torch.ops._c10d_functional.all_gather_into_tensor")
.run(code)
)
out = compiled(*inputs, **self.get_world_trs())
assert same(out, correct), f"{out} va {correct}"
@unittest.skipIf(not HAS_GPU, "Inductor+gpu needs triton and recent GPU arch")
@unittest.skipIf(not SM80OrLater, "bfloat16")
def test_all_gather_bucket_path(self):
def func(x, w, ag_0, ag_1, *, tag, ranks, group_size):
# do some unrelated matmuls
y = torch.mm(x, w)
# cast the inputs
ag_0_cast = ag_0.to(torch.bfloat16)
ag_1_cast = ag_1.to(torch.bfloat16)
# first allgather
group_name = (
torch.distributed.distributed_c10d._get_default_group().group_name
)
ag_0_out = torch.ops._c10d_functional.all_gather_into_tensor(
ag_0_cast, group_size, group_name
)
ag_0_out = torch.ops.c10d_functional.wait_tensor(ag_0_out)
ag_0_out = ag_0_out * 2
# Create dependency: second allgather input depends on first allgather output
# This prevents fusion of the two allgather operations
ag_1_modified = (
ag_1_cast + ag_0_out[: ag_1_cast.shape[0]]
) # Use part of ag_0_out
# second allgather (now depends on the first one)
ag_1_out = torch.ops._c10d_functional.all_gather_into_tensor(
ag_1_modified, group_size, group_name
)
ag_1_out = torch.ops.c10d_functional.wait_tensor(ag_1_out)
return y, ag_0_out, ag_1_out
x = torch.ones(4, 384, device=self.device, dtype=torch.float32)
w = torch.ones(384, 512, device=self.device, dtype=torch.float32)
ag_0 = torch.ones(384, 512, device=self.device, dtype=torch.float32)
ag_1 = torch.ones(384, 512, device=self.device, dtype=torch.float32)
inputs = [x, w, ag_0, ag_1]
with torch._inductor.config.patch(
{
"bucket_all_gathers_fx": "all",
"reorder_for_compute_comm_overlap": False,
}
):
compiled = torch.compile(func)
code = run_and_get_triton_code(compiled, *inputs, **self.get_world_trs())
# shouldnt have bucketed
FileCheck().check_count("wait_tensor.default(", 2, exactly=True).run(code)
@unittest.skipIf(not HAS_GPU, "Inductor+gpu needs triton and recent GPU arch")
@unittest.skipIf(not SM80OrLater, "bfloat16")
@parametrize("bucket_mode", ["all", "all_custom_ops"])
def test_reduce_scatter_bucket(self, bucket_mode):
def func(x, w, rs_0, rs_1, tag, ranks, group_size):
# do some unrelated matmuls
y = torch.mm(x, w)
# cast the inputs
rs_0_cast = rs_0.to(torch.bfloat16)
rs_1_cast = rs_1.to(torch.bfloat16)
# reduce_scatter
group_name = (
torch.distributed.distributed_c10d._get_default_group().group_name
)
rs_0_out = torch.ops._c10d_functional.reduce_scatter_tensor(
rs_0_cast, "sum", group_size, group_name
)
rs_1_out = torch.ops._c10d_functional.reduce_scatter_tensor(
rs_1_cast, "sum", group_size, group_name
)
# wait op
rs_0_out = torch.ops.c10d_functional.wait_tensor(rs_0_out)
rs_1_out = torch.ops.c10d_functional.wait_tensor(rs_1_out)
return y, rs_0_out, rs_1_out
# test "fsdp" mode to allow convert_element_type after wait
def func2(x, w, rs_0, rs_1, tag, ranks, group_size):
y, rs_0_out, rs_1_out = func(x, w, rs_0, rs_1, tag, ranks, group_size)
return y, rs_0_out.to(torch.float32), rs_1_out.to(torch.float32)
for f in [func, func2]:
x = torch.ones(4, 384, device="cuda", dtype=torch.float32)
w = torch.ones(384, 512, device="cuda", dtype=torch.float32)
rs_0 = torch.ones(384, 512, device="cuda", dtype=torch.float32)
rs_1 = torch.ones(384, 256, device="cuda", dtype=torch.float32)
inputs = [x, w, rs_0, rs_1]
f(*inputs, **self.get_world_trs())
with torch._inductor.config.patch(
{
"bucket_reduce_scatters_fx": bucket_mode,
"reorder_for_compute_comm_overlap": False,
}
):
compiled = torch.compile(f)
compiled(*inputs, **self.get_world_trs())
code = run_and_get_triton_code(
compiled, *inputs, **self.get_world_trs()
)
# NOTE: The first return value should be the output of the first wait_tensor.
# We want to make sure no unnecessary copy is made.
(
FileCheck()
.check_count(
"torch.ops._c10d_functional.reduce_scatter_tensor.default(",
count=1,
exactly=True,
)
.run(code)
)
out = compiled(*inputs, **self.get_world_trs())
correct = f(*inputs, **self.get_world_trs())
assert same(out, correct), f"{out} va {correct}"
@unittest.skipIf(not HAS_GPU, "Inductor+gpu needs triton and recent GPU arch")
@unittest.skipIf(not SM80OrLater, "bfloat16")
@parametrize("bucket_mode", ["all", "all_custom_ops"])
def test_reorder_peak_memory_bucketed(self, bucket_mode):
"""
Simulate the case where a bucketing pass ran and grouped several inputs into one bucketed allgather.
Ensure the whole bucketed group including copy-ops get moved together rather than the copy ops preventing the
comm from moving due to data dependency.
"""
def func(x, w, ag_0, ag_1, ag_2, ag_3, *, tag, ranks, group_size):
# do some unrelated matmuls
y = torch.mm(x, w)
# cast the inputs
ag_0_cast = ag_0.to(torch.bfloat16)
ag_1_cast = ag_1.to(torch.bfloat16)
# allgather
group_name = (
torch.distributed.distributed_c10d._get_default_group().group_name
)
ag_0_out = torch.ops._c10d_functional.all_gather_into_tensor(
ag_0_cast, group_size, group_name
)
ag_1_out = torch.ops._c10d_functional.all_gather_into_tensor(
ag_1_cast, group_size, group_name
)
# wait op
ag_0_out = torch.ops.c10d_functional.wait_tensor(ag_0_out)
ag_1_out = torch.ops.c10d_functional.wait_tensor(ag_1_out)
rs_0_out = torch.ops._c10d_functional.reduce_scatter_tensor(
ag_0_cast, "sum", group_size, group_name
)
rs_1_out = torch.ops._c10d_functional.reduce_scatter_tensor(
ag_1_cast, "sum", group_size, group_name
)
# wait op
rs_0_out = torch.ops.c10d_functional.wait_tensor(rs_0_out)
rs_1_out = torch.ops.c10d_functional.wait_tensor(rs_1_out)
y += torch.mm(2 * x, 2 * w)
# cast the inputs
ag_2_cast = ag_2.to(torch.bfloat16)
ag_3_cast = ag_3.to(torch.bfloat16)
ag_2_out = torch.ops._c10d_functional.all_gather_into_tensor(
ag_2_cast, group_size, group_name
)
ag_3_out = torch.ops._c10d_functional.all_gather_into_tensor(
ag_3_cast, group_size, group_name
)
# wait op
ag_2_out = torch.ops.c10d_functional.wait_tensor(ag_2_out)
ag_3_out = torch.ops.c10d_functional.wait_tensor(ag_3_out)
#
rs_2_out = torch.ops._c10d_functional.reduce_scatter_tensor(
ag_2_cast, "sum", group_size, group_name
)
rs_3_out = torch.ops._c10d_functional.reduce_scatter_tensor(
ag_3_cast, "sum", group_size, group_name
)
# wait op
rs_2_out = torch.ops.c10d_functional.wait_tensor(rs_2_out)
rs_3_out = torch.ops.c10d_functional.wait_tensor(rs_3_out)
return (
y,
ag_0_out,
ag_1_out,
ag_2_out,
ag_3_out,
rs_0_out,
rs_1_out,
rs_2_out,
rs_3_out,
)
x = torch.ones(4, 384, device=self.device, dtype=torch.float32)
w = torch.ones(384, 512, device=self.device, dtype=torch.float32)
ag_0 = torch.ones(1024, 512, device=self.device, dtype=torch.float32)
ag_1 = torch.ones(512, 1024, device=self.device, dtype=torch.float32)
ag_2 = torch.ones(1024, 512, device=self.device, dtype=torch.float32)
ag_3 = torch.ones(512, 1024, device=self.device, dtype=torch.float32)
inputs = [x, w, ag_0, ag_1, ag_2, ag_3]
# get stats directly from the internal helper without affecting the real pass's signature
node_stats: Optional[dict[BaseSchedulerNode, ReorderInfo]] = None
def _reorder_communication_preserving_peak_memory(
snodes: list[BaseSchedulerNode],
) -> list[BaseSchedulerNode]:
if torch._inductor.config.runtime_estimations_mms_benchmark:
cache = get_estimate_runtime_cache()
for snode in snodes:
if _get_mm_like_fn(snode) is None:
continue
cache_key = get_estimate_runtime_cache_key_from_snode(snode)
assert cache.lookup(cache_key) is not None
if torch._inductor.config_comms.runtime_estimations_align_across_all_distributed_ranks:
for snode in snodes:
assert snode.override_estimated_runtime is not None
nonlocal node_stats
(
reordered_snodes,
node_stats,
) = _reorder_communication_preserving_peak_memory_internal(snodes)
return reordered_snodes
with (
torch._inductor.config.patch(
{
"bucket_all_gathers_fx": bucket_mode,
"bucket_all_gathers_fx_bucket_size_determinator": lambda _: 2,
"bucket_reduce_scatters_fx": bucket_mode,
"bucket_reduce_scatters_fx_bucket_size_determinator": lambda _: 2,
"reorder_for_compute_comm_overlap": True,
"reorder_for_compute_comm_overlap_passes": [
sink_waits_iterative,
_reorder_communication_preserving_peak_memory,
],
"allow_buffer_reuse": False,
"test_configs.track_memory_lifecycle": "error",
"runtime_estimations_mms_benchmark": True,
}
),
torch._inductor.config_comms.patch(
{
"runtime_estimations_align_across_all_distributed_ranks": True,
}
),
# Clearing cache to cover runtime_estimations_mms_benchmark that use LocalCache
fresh_inductor_cache(),
):
compiled = torch.compile(func, fullgraph=True)
code = run_and_get_triton_code(compiled, *inputs, **self.get_world_trs())
# make sure memory tracking is codegen. the ops will then do runtime checking with assertion.
FileCheck().check("check_memory_step").check("tracked_empty_strided").run(code)
# NOTE: The first return value should be the output of the first wait_tensor.
# We want to make sure no unnecessary copy is made.
(
FileCheck()
.check_count(
"torch.ops._c10d_functional.all_gather_into_tensor_out.default(",
count=2,
exactly=True,
)
.check(
"extern_kernels.mm",
)
.check(
"extern_kernels.addmm",
)
.run(code)
)
(
FileCheck()
.check_count(
"torch.ops._c10d_functional.reduce_scatter_tensor.default(",
count=2,
exactly=True,
)
.check(
"extern_kernels.mm",
)
.check(
"extern_kernels.addmm",
)
.run(code)
)
out = compiled(*inputs, **self.get_world_trs())
correct = func(*inputs, **self.get_world_trs())
assert same(out, correct), f"{out} va {correct}"
assert node_stats is not None
self.assertTrue(isinstance(node_stats, dict))
self.assertEqual(len(node_stats), 4)
it = iter(node_stats.values())
node_stat0 = next(it)
self.assertTrue(node_stat0.limiting_factor == "None")
node_stat1 = next(it)
self.assertTrue("collective ordering" in node_stat1.limiting_factor)
@skipIfXpu # https://github.com/intel/torch-xpu-ops/issues/1581
@unittest.skipIf(not HAS_GPU, "Inductor+gpu needs triton and recent GPU arch")
def test_reorder_respects_wait_dep(self):
"""
Covers the case where the output of one collective feeds the input of another collective.
e.g. TP + FSDP - all_gather(tp+dp sharded param on TP dim) -> allgather dp_sharded buffer on DP dim
"""
def func(inp, *, tag, ranks, group_size):
group_name = (
torch.distributed.distributed_c10d._get_default_group().group_name
)
ag_0_out = torch.ops._c10d_functional.all_gather_into_tensor(
inp, group_size, group_name
)
ag_0_wait = torch.ops.c10d_functional.wait_tensor(ag_0_out)
ag_1_out = torch.ops._c10d_functional.all_gather_into_tensor(
ag_0_wait, group_size, group_name
)
ag_1_wait = torch.ops.c10d_functional.wait_tensor(ag_1_out)
# ensure other is not incorrectly aliasing ar's buffer
return ag_1_wait
inputs = torch.ones(4, 4, device=self.device)
# get stats directly from the internal helper without affecting the real pass's signature
node_stats: Optional[dict[BaseSchedulerNode, ReorderInfo]] = None
def _reorder_communication_preserving_peak_memory(
snodes: list[BaseSchedulerNode],
) -> list[BaseSchedulerNode]:
nonlocal node_stats
(
reordered_snodes,
node_stats,
) = _reorder_communication_preserving_peak_memory_internal(snodes)
return reordered_snodes
with torch._inductor.config.patch(
{
"reorder_for_compute_comm_overlap": True,
"reorder_for_compute_comm_overlap_passes": [
"sink_waits",
# same as reorder_communication_preserving_peak_memory but returns debug info structures directly
_reorder_communication_preserving_peak_memory,
],
}
):
compiled = torch.compile(func)
code = run_and_get_triton_code(compiled, inputs, **self.get_world_trs())
# NOTE: The first return value should be the output of the first wait_tensor.
# We want to make sure no unnecessary copy is made.
(
FileCheck()
.check("all_gather")
.check("wait")
.check("all_gather")
.check("wait")
.run(code)
)
out = compiled(inputs, **self.get_world_trs())
correct = func(inputs, **self.get_world_trs())
assert same(out, correct), f"{out} va {correct}"
# TODO make the test case more interesting and validate the actual desired behavior
assert node_stats is not None
self.assertTrue(isinstance(node_stats, dict))
self.assertEqual(len(node_stats), 2)
for stats in node_stats.values():
self.assertEqual(stats.moves, 0)
@requires_accelerator_dist_backend(["nccl", "xccl"])
class TestSyncDecisionCrossRanks(MultiProcessTestCase):
def setUp(self) -> None:
super().setUp()
self._spawn_processes()
@property
def world_size(self) -> int:
return 2
@property
def ranks(self) -> list[int]:
return list(range(self.world_size))
@property
def device(self) -> torch.device:
device_type = torch.accelerator.current_accelerator().type
return torch.device(f"{device_type}:{self.rank}")
def _init_process_group(self) -> None:
torch._inductor.config.triton.store_cubin = True
torch._inductor.config.debug = True
torch.get_device_module(self.device).set_device(self.device)
store = torch.distributed.FileStore(self.file_name, self.world_size)
backend = c10d.get_default_backend_for_device(
torch.accelerator.current_accelerator().type
)
torch.distributed.init_process_group(
backend=backend,
world_size=self.world_size,
rank=self.rank,
store=store,
)
torch._C._distributed_c10d._register_process_group(
"default", torch.distributed.group.WORLD
)
@skip_if_lt_x_gpu(2)
def test_sync_decision_cross_ranks(self):
from torch._functorch.partitioners import _sync_decision_cross_ranks
test_graph = torch.fx.Graph()
node1 = test_graph.placeholder("x")
ag1 = test_graph.create_node(
"call_function",
torch.ops._c10d_functional.all_gather_into_tensor.default,
(node1,),
)
wt1 = test_graph.create_node(
"call_function", torch.ops._c10d_functional.wait_tensor.default, (ag1,)
)
wt1.meta["val"] = torch.randn(10, 10)
ag2 = test_graph.create_node(
"call_function",
torch.ops._c10d_functional.all_gather_into_tensor.default,
(node1,),
)
wt2 = test_graph.create_node(
"call_function", torch.ops._c10d_functional.wait_tensor.default, (ag2,)
)
wt2.meta["val"] = torch.randn(10, 20)
if self.rank == 0:
saved_values = [wt1]
else:
saved_values = [wt2]
self._init_process_group()
saved_values = _sync_decision_cross_ranks(test_graph, saved_values)
self.assertEqual(saved_values, [wt1])
if __name__ == "__main__":
from torch._dynamo.test_case import run_tests
run_tests()