Files
tinygrad/test/unit/test_allreduce.py
qazalandGitHub 118e812b31 simplify more same device copies (#17766)
* simplify more same device copies

* stack of contigs or copies

* rename
2026-08-27 12:54:12 +09:00

101 lines
4.5 KiB
Python

import unittest
from tinygrad import Tensor, UOp, dtypes
from tinygrad.helpers import Context
from tinygrad.uop.ops import Ops
from test.helpers import KernelCountException
from tinygrad.engine.realize import run_linear
class TestRingAllReduce(unittest.TestCase):
def test_schedule_ring(self):
with Context(RING=2):
N = 4
ds = tuple(f"CPU:{i}" for i in range(N))
t = Tensor.empty(N, N*100).shard(ds, axis=0).realize()
linear = t.sum(0).linear_with_vars()[0]
copies = [si for si in linear.src if si.src[0].op is Ops.COPY]
pairs = [(c.src[1].buffer.device, c.src[2].buffer.device) for c in copies]
# N*(N-1) scatter reduce, and N*(N-1) allgather
if len(pairs) != N*(N-1)*2: raise KernelCountException(N*(N-1)*2, len(pairs))
# copy topology forms a ring
self.assertEqual(len(set(pairs)), N)
def test_schedule_all2all(self):
with Context(ALL2ALL=2):
N = 4
M = N*100
ds = tuple(f"CPU:{i}" for i in range(N))
x = Tensor.arange(N*M, dtype=dtypes.float).reshape(N, M)
t = (x*x).clone().shard(ds, axis=0).realize()
out = t.sum(0).mul(2.).contiguous()
linear, var_vals = out.linear_with_vars()
copies = [si for si in linear.src if si.src[0].op is Ops.COPY]
sinks = [si for si in linear.src if si.src[0].op is Ops.SINK]
# N*(N-1) copies for input and output
copy_count = N*(N-1)*2
if len(copies) != copy_count: raise KernelCountException(copy_count, len(copies))
# N*(N-1) shrinks from other devices becoming contigs, N ALU, N extra contig, reassembly (cat), and mul
sink_count = (N*(N-1))+(N)+(N)+(1)+(1)
if len(sinks) != sink_count: raise KernelCountException(sink_count, len(sinks))
# correctness
run_linear(linear, var_vals)
expected = [2*sum((d*M+i)**2 for d in range(N)) for i in range(M)]
dev_nums = Tensor.arange(1, N+1, dtype=dtypes.float).reshape(N, 1).expand(N, M).shard(ds, axis=0)
shards = out.reshape(1, M).expand(N, M)+dev_nums
self.assertListEqual(shards.tolist(), [[x+d+1 for x in expected] for d in range(N)])
@Context(RING=0, ALL2ALL=0)
def test_schedule_naive(self):
N = 4
ds = tuple(f"NULL:{i}" for i in range(N))
t = Tensor.empty(N, 4096).shard(ds, axis=0).realize()
linear = t.sum(0).linear_with_vars()[0]
copies = [si for si in linear.src if si.src[0].op is Ops.COPY]
sinks = [si for si in linear.src if si.src[0].op is Ops.SINK]
pairs = [(c.src[1].buffer.device, c.src[2].buffer.device) for c in copies]
if len(pairs) != N*(N-1): raise KernelCountException(N*(N-1), len(pairs))
if len(sinks) != 2: raise KernelCountException(2, len(sinks))
self.assertTrue(all(dst != src for dst, src in pairs))
def test_symbolic_shape(self):
rows = UOp.variable("rows", 1, 4).bind(3)
t = Tensor.ones(4, 4).shard(("CPU:0", "CPU:1"), axis=1).realize()
out = t[:rows].sum(1).realize()
self.assertEqual(out.shape, (rows,))
self.assertTrue((out == 4).all().item())
def test_correct_ring(self):
with Context(RING=2):
N = 4
ds = tuple(f"CPU:{i}" for i in range(N))
t = Tensor.ones(N, N*100).contiguous().shard(ds, axis=0).realize()
out = t.sum(0)
self.assertListEqual(out.tolist(), [4]*N*100)
class TestAllreduceCast(unittest.TestCase):
def _get_copy_dtypes(self, dtype, allreduce_cast):
ds = tuple(f"CPU:{i}" for i in range(2))
with Context(ALLREDUCE_CAST=allreduce_cast, RING=0, SCACHE=0):
t = Tensor.empty(4, 4, dtype=dtype).shard(ds, axis=0)
linear = t.sum(0).linear_with_vars()[0]
return {si.src[1].buffer.dtype for si in linear.src if si.src[0].op is Ops.COPY}
def test_allreduce_cast_bf16(self):
# with ALLREDUCE_CAST, allreduce copies stay in bfloat16 instead of promoting to float32
self.assertNotIn(dtypes.float, self._get_copy_dtypes(dtypes.bfloat16, allreduce_cast=1))
self.assertIn(dtypes.float, self._get_copy_dtypes(dtypes.bfloat16, allreduce_cast=0))
def test_allreduce_cast_half(self):
self.assertNotIn(dtypes.float, self._get_copy_dtypes(dtypes.half, allreduce_cast=1))
self.assertIn(dtypes.float, self._get_copy_dtypes(dtypes.half, allreduce_cast=0))
def test_allreduce_cast_float32_noop(self):
# float32 should not be affected by ALLREDUCE_CAST (no promotion happens)
dtypes_on = self._get_copy_dtypes(dtypes.float, allreduce_cast=1)
dtypes_off = self._get_copy_dtypes(dtypes.float, allreduce_cast=0)
self.assertEqual(dtypes_on, dtypes_off)
if __name__ == '__main__':
unittest.main()