[2/N] [Kernel] Fuse padding-preserving HiSparse slot translation (#39837)

This commit is contained in:
Sasha Sidorov
2026-09-20 12:04:03 +08:00
committed by GitHub
parent df0dc44931
commit 59dd2fc734
7 changed files with 455 additions and 2 deletions
@@ -0,0 +1,136 @@
"""Model-free AITER KV-write regression for MI35x, including graph replay."""
import unittest
from types import SimpleNamespace
from unittest.mock import patch
import torch
from sglang.test.ci.ci_register import register_amd_ci
from sglang.test.test_utils import CustomTestCase
register_amd_ci(est_time=20, suite="stage-b-test-1-gpu-small-amd-mi35x")
class TestRocmHiSparseFusedKVKernel(CustomTestCase):
@classmethod
def setUpClass(cls):
super().setUpClass()
if not torch.version.hip or not torch.cuda.is_available():
raise AssertionError("The MI35x regression requires ROCm and an AMD GPU")
arch = torch.cuda.get_device_properties(0).gcnArchName
if not arch.startswith("gfx95"):
raise AssertionError("The MI35x regression requires gfx95 hardware")
from sglang.srt.mem_cache.hisparse_memory_pool import HiSparseDSATokenToKVPool
from sglang.srt.models.deepseek_common.attention_forward_methods import (
forward_mla_rocm,
)
if not forward_mla_rocm._use_aiter_gfx95:
raise AssertionError(
"This gfx95 regression must run with the fused MLA path; "
"set SGLANG_USE_AITER=1 before starting Python"
)
cls.forward = forward_mla_rocm
cls.pool_type = HiSparseDSATokenToKVPool
def setUp(self):
super().setUp()
# The owned guard catches out-of-range writes without corrupting other tensors.
self.backing = torch.full(
(24, 1, 576), -99.0, dtype=torch.bfloat16, device="cuda"
)
mapping = torch.zeros(65, dtype=torch.int64, device="cuda")
mapping[17], mapping[18] = 3, 5
mapping[-1] = -1
self.pool = self.pool_type.__new__(self.pool_type)
self.pool.register_mapping(mapping)
self.pool.kv_buffer = [self.backing[:8]]
self.pool.start_layer = 7
self.pool.layer_transfer_counter = None
self.pool.dtype = self.pool.store_dtype = torch.bfloat16
self.attn = SimpleNamespace(
kv_cache_dtype="bfloat16",
current_attention_backend="dsa",
attn_mqa=SimpleNamespace(layer_id=7, k_scale=torch.ones(1, device="cuda")),
rotary_emb=SimpleNamespace(
cos_cache=torch.ones((8, 64), dtype=torch.bfloat16, device="cuda"),
sin_cache=torch.zeros((8, 64), dtype=torch.bfloat16, device="cuda"),
is_neox_style=False,
),
)
self.qn = torch.ones((3, 8, 512), dtype=torch.bfloat16, device="cuda")
self.qr = torch.ones((3, 8, 64), dtype=torch.bfloat16, device="cuda")
self.kn = (
torch.arange(1, 4, dtype=torch.bfloat16, device="cuda")[:, None, None]
.expand(3, 1, 512)
.contiguous()
)
self.kr = torch.full((3, 1, 64), 2.5, dtype=torch.bfloat16, device="cuda")
self.positions = torch.zeros(3, dtype=torch.int64, device="cuda")
self.locations = torch.tensor([17, 18, -1], device="cuda")
self.expected_rows = torch.cat((self.kn, self.kr), dim=-1)
def write(self):
return self.forward._fused_rope_cat_and_cache(
self.attn,
self.qn,
self.qr,
self.kn,
self.kr,
self.positions,
self.locations,
)
def check_cache(self, row_to_slot):
torch.cuda.synchronize()
expected = torch.full_like(self.backing, -99.0)
for row, slot in row_to_slot.items():
expected[slot] = self.expected_rows[row]
torch.testing.assert_close(self.backing, expected, rtol=0, atol=0)
def test_eager_and_graph_writes_use_physical_slots(self):
with patch.object(self.forward, "get_token_to_kv_pool", return_value=self.pool):
# The helper calls the real AITER kernel with the pool's device buffer.
self.write()
with self.subTest(mode="eager"):
self.check_cache({0: 3, 1: 5})
graph = torch.cuda.CUDAGraph()
with torch.cuda.graph(graph):
self.write()
self.backing.fill_(-99.0)
graph.replay()
with self.subTest(mode="graph"):
self.check_cache({0: 3, 1: 5})
# Inputs are mutable between graph replays, including padding.
self.locations.copy_(torch.tensor([18, -1, 17], device="cuda"))
self.backing.fill_(-99.0)
graph.replay()
with self.subTest(mode="graph-updated-inputs"):
self.check_cache({0: 5, 2: 3})
self.locations.copy_(torch.tensor([19, -1, 17], device="cuda"))
self.backing.fill_(-99.0)
graph.replay()
with self.subTest(mode="graph-unmapped-dummy-slot"):
self.check_cache({0: 0, 2: 3})
def test_resident_strided_locations(self):
"""AITER must write selected slots rather than interleaved storage values."""
from sglang.srt.mem_cache.memory_pool import DSATokenToKVPool
resident = DSATokenToKVPool.__new__(DSATokenToKVPool)
resident.__dict__.update(self.pool.__dict__)
self.pool = resident
self.locations = torch.tensor([3, 21, 5, 22, -1, 23], device="cuda")[::2]
with patch.object(self.forward, "get_token_to_kv_pool", return_value=self.pool):
self.write()
with self.subTest(layout="strided"):
self.check_cache({0: 3, 1: 5})
if __name__ == "__main__":
unittest.main()
@@ -0,0 +1,72 @@
"""Portable HiSparse logical-to-physical slot translation kernel checks."""
import unittest
import weakref
import torch
from sglang.test.ci.ci_register import register_amd_ci, register_cuda_ci
from sglang.test.test_utils import CustomTestCase
register_cuda_ci(est_time=20, stage="base-b-kernel-unit", runner_config="1-gpu-large")
register_amd_ci(est_time=20, stage="jit-kernel-unit", runner_config="amd")
class TestHiSparseSlotMapping(CustomTestCase):
def test_accepts_weak_mapping_used_by_pool(self):
from sglang.kernels.ops.kvcache.hisparse_slot_mapping import (
translate_padded_hisparse_locations as translate,
)
mapping = torch.arange(32, dtype=torch.int64, device="cuda") + 100
locations = torch.tensor([17, -1, 18], device="cuda")
actual = translate(weakref.proxy(mapping), locations)
torch.testing.assert_close(actual, torch.tensor([117, -1, 118], device="cuda"))
def test_fused_slot_mapping_matches_padded_gather(self):
from sglang.kernels.ops.kvcache.hisparse_slot_mapping import (
translate_padded_hisparse_locations as translate,
)
for map_dtype in (torch.int32, torch.int64):
mapping = torch.arange(257, dtype=map_dtype, device="cuda") * 3 + 1
for loc_dtype in (torch.int32, torch.int64):
for count in (0, 1, 3, 127, 129, 1024):
for stride in (1, 2):
with self.subTest(
map_dtype=map_dtype,
loc_dtype=loc_dtype,
count=count,
stride=stride,
):
locations = (
torch.arange(
count * stride, dtype=loc_dtype, device="cuda"
)[::stride]
% 257
)
if stride == 2:
storage = torch.zeros(
count * 2, dtype=loc_dtype, device="cuda"
)
storage[::2] = locations
locations = storage[::2]
locations[::3] = -1
locations[1::7] = -2
original = locations.clone()
expected = torch.where(
locations >= 0,
mapping[locations.clamp_min(0)],
locations,
)
actual = translate(mapping, locations)
torch.testing.assert_close(actual, expected, rtol=0, atol=0)
torch.testing.assert_close(
locations, original, rtol=0, atol=0
)
if __name__ == "__main__":
unittest.main()
@@ -0,0 +1,68 @@
"""Check portable HiSparse pool translation dispatch and gather fallbacks."""
import unittest
from unittest.mock import PropertyMock, patch
import torch
from sglang.srt.mem_cache import hisparse_memory_pool
from sglang.srt.mem_cache.hisparse_memory_pool import HiSparseDSATokenToKVPool
from sglang.test.ci.ci_register import register_cpu_ci
from sglang.test.test_utils import CustomTestCase
register_cpu_ci(est_time=5, stage="base-a", runner_config="cpu")
class TestHiSparseSlotTranslation(CustomTestCase):
def make_pool(self, pool_type):
return pool_type.__new__(pool_type)
def test_pool_translation_selects_fused_kernel_for_gpu_slot_lists(self):
pool = self.make_pool(HiSparseDSATokenToKVPool)
mapping = torch.arange(32, dtype=torch.int64) + 100
pool.register_mapping(mapping)
storage = torch.tensor([17, 0, -1, 0, 18, 0])
locations = storage[::2]
expected = torch.tensor([117, -1, 118])
with (
patch.object(
torch.Tensor, "is_cuda", new_callable=PropertyMock, return_value=True
),
patch.object(
hisparse_memory_pool,
"translate_padded_hisparse_locations",
return_value=expected,
) as fused,
):
self.assertIs(pool.translate_loc_to_hisparse_device(locations), expected)
self.assertIs(fused.call_args.args[0], mapping)
self.assertIs(fused.call_args.args[1], locations)
fused.assert_called_once()
torch.testing.assert_close(storage, torch.tensor([17, 0, -1, 0, 18, 0]))
def test_pool_translation_keeps_gather_for_page_tables_and_other_devices(self):
pool = self.make_pool(HiSparseDSATokenToKVPool)
mapping = torch.arange(32, dtype=torch.int64) + 100
pool.register_mapping(mapping)
for gpu, locations in (
(False, torch.tensor([17, -1, 18])),
(True, torch.tensor([[17, -1], [18, 0]])),
(True, torch.tensor(17)),
):
with (
self.subTest(gpu=gpu, shape=locations.shape),
patch.object(
torch.Tensor, "is_cuda", new_callable=PropertyMock, return_value=gpu
),
patch.object(
hisparse_memory_pool, "translate_padded_hisparse_locations"
) as fused,
):
actual = pool.translate_loc_to_hisparse_device(locations)
torch.testing.assert_close(actual, mapping[locations])
self.assertEqual(actual.shape, locations.shape)
fused.assert_not_called()
if __name__ == "__main__":
unittest.main()
@@ -0,0 +1,97 @@
"""Exercise the ROCm writer's slot contract with a CPU kernel boundary."""
import unittest
from types import SimpleNamespace
from unittest.mock import patch
import torch
from sglang.srt.mem_cache.hisparse_memory_pool import HiSparseDSATokenToKVPool
from sglang.srt.mem_cache.memory_pool import DSATokenToKVPool
from sglang.srt.models.deepseek_common.attention_forward_methods import forward_mla_rocm
from sglang.test.ci.ci_register import register_cpu_ci
from sglang.test.test_utils import CustomTestCase
register_cpu_ci(est_time=5, suite="base-a-test-cpu")
class TestRocmHiSparseFusedKV(CustomTestCase):
def setUp(self):
super().setUp()
self.cache = object()
self.pool = self.make_pool(DSATokenToKVPool)
self.attn = SimpleNamespace(
kv_cache_dtype="bfloat16",
current_attention_backend="dsa",
attn_mqa=SimpleNamespace(layer_id=7, k_scale=1.0),
rotary_emb=SimpleNamespace(
cos_cache=None, sin_cache=None, is_neox_style=False
),
)
def make_pool(self, pool_type):
# Supply storage without allocating a model's cache; keep real accessors.
pool = pool_type.__new__(pool_type)
pool.kv_buffer = [self.cache]
pool.start_layer = 7
pool.layer_transfer_counter = None
pool.dtype = pool.store_dtype = torch.bfloat16
return pool
def use_hisparse(self):
self.pool = self.make_pool(HiSparseDSATokenToKVPool)
mapping = torch.zeros(65, dtype=torch.int64)
mapping[17], mapping[18], mapping[-1] = 3, 5, -1
self.pool.register_mapping(mapping)
return mapping
def invoke(self, locations):
with (
patch.object(forward_mla_rocm, "get_token_to_kv_pool", lambda: self.pool),
patch.object(
forward_mla_rocm,
"fused_qk_rope_cat_and_cache_mla",
lambda *args, **kwargs: args,
create=True,
),
):
args = forward_mla_rocm._fused_rope_cat_and_cache(
self.attn, torch.empty(0), None, None, None, None, locations
)
self.assertIs(args[4], self.cache)
return args[5]
def test_resident_locations_are_unchanged(self):
locations = torch.tensor([17, 0, -1], dtype=torch.int64)
self.assertIs(self.invoke(locations), locations)
def test_resident_strided_locations(self):
"""Strided locations must not send interleaved storage values to AITER."""
storage = torch.tensor([3, 21, 5, 22, -1, 23])
locations = storage[::2]
actual = self.invoke(locations)
with self.subTest(layout="strided"):
self.assertTrue(actual.is_contiguous())
torch.testing.assert_close(actual, torch.tensor([3, 5, -1]))
torch.testing.assert_close(storage, torch.tensor([3, 21, 5, 22, -1, 23]))
def test_hisparse_maps_logical_slots(self):
"""Logical slots beyond device capacity must write their physical rows."""
self.use_hisparse()
locations = torch.tensor([17, 18], dtype=torch.int64)
with self.subTest(logical_slots=[17, 18]):
torch.testing.assert_close(self.invoke(locations), torch.tensor([3, 5]))
torch.testing.assert_close(locations, torch.tensor([17, 18]))
def test_hisparse_padding_and_unmapped_slots(self):
self.use_hisparse()
locations = torch.tensor([17, -1, 19, 0])
with self.subTest(padding=-1, unmapped=19):
torch.testing.assert_close(
self.invoke(locations), torch.tensor([3, -1, 0, 0])
)
torch.testing.assert_close(locations, torch.tensor([17, -1, 19, 0]))
if __name__ == "__main__":
unittest.main()