feat: map CP HiCache writes to owned physical slots

This commit is contained in:
2026-05-08 01:14:58 +08:00
parent eb0ec4299d
commit 301420f976
2 changed files with 288 additions and 2 deletions

View File

@@ -16,6 +16,7 @@ limitations under the License.
import logging
import threading
import time
from dataclasses import dataclass
from queue import Empty, Full, Queue
from typing import TYPE_CHECKING, List, NamedTuple, Optional
@@ -40,7 +41,8 @@ from sglang.srt.layers.dp_attention import (
get_attention_tp_size,
is_dp_attention_enabled,
)
from sglang.srt.mem_cache.memory_pool import MLATokenToKVPool
from sglang.srt.mem_cache.cp_shared_kv_layout import CpSharedKVLayout
from sglang.srt.mem_cache.memory_pool import MLATokenToKVPool, NSATokenToKVPool
from sglang.srt.utils import get_device_module
logger = logging.getLogger(__name__)
@@ -244,6 +246,18 @@ class PrefetchOperation(StorageOperation):
return self._terminated_flag
@dataclass
class HiCacheWriteResult:
metadata: object
required_host_slots: int = 0
@dataclass
class HiCacheWriteFailure:
required_host_slots: int
metadata: object = None
class HiCacheController:
def __init__(
@@ -262,6 +276,7 @@ class HiCacheController:
pp_rank: int = 0,
pp_size: int = 1,
enable_storage_metrics: bool = False,
cp_shared_kv_layout: Optional[CpSharedKVLayout] = None,
):
self.tp_group = tp_group
self.mem_pool_device_allocator = token_to_kv_pool_allocator
@@ -271,6 +286,14 @@ class HiCacheController:
if isinstance(mem_pool_device, HybridLinearKVPool):
mem_pool_device = mem_pool_device.full_kv_pool
self.mem_pool_device = mem_pool_device
self.cp_shared_kv_layout = cp_shared_kv_layout
self.uses_cp_hicache = cp_shared_kv_layout is not None
if self.uses_cp_hicache and not isinstance(
self.mem_pool_device, NSATokenToKVPool
):
raise ValueError(
"CP shared KV HiCache host integration requires NSATokenToKVPool."
)
self.mem_pool_host = mem_pool_host
self.write_policy = write_policy
self.page_size = page_size
@@ -656,10 +679,13 @@ class HiCacheController:
device_indices: torch.Tensor,
priority: Optional[int] = None,
node_id: int = -1,
) -> Optional[torch.Tensor]:
) -> Optional[torch.Tensor | HiCacheWriteResult | HiCacheWriteFailure]:
"""
Back up KV caches from device memory to host memory.
"""
if self.uses_cp_hicache:
return self._write_cp(device_indices, priority, node_id)
host_indices = self.mem_pool_host.alloc(len(device_indices))
if host_indices is None:
return None
@@ -697,6 +723,56 @@ class HiCacheController:
self.ack_write_queue.append(HiCacheAck(start_event, finish_event, op.node_ids))
def _append_completed_write_ack(self, node_id: int) -> None:
event = device_module.Event()
event.record()
self.ack_write_queue.append(HiCacheAck(event, event, [node_id]))
def _append_completed_load_ack(self, node_id: int) -> None:
event = device_module.Event()
event.record()
self.ack_load_queue.append(HiCacheAck(event, event, [node_id]))
def _write_cp(
self,
device_indices: torch.Tensor,
priority: Optional[int] = None,
node_id: int = -1,
) -> HiCacheWriteResult | HiCacheWriteFailure:
from sglang.srt.mem_cache.hiradix_cache import CpHiCacheNodeMetadata
layout = self.cp_shared_kv_layout
owned_mask = layout.owned_by_this_rank(device_indices)
owned_positions = owned_mask.nonzero(as_tuple=True)[0].cpu()
logical_len = len(device_indices)
if owned_positions.numel() == 0:
self._append_completed_write_ack(node_id)
return HiCacheWriteResult(
metadata=CpHiCacheNodeMetadata(
logical_len=logical_len,
owned_positions=owned_positions,
host_indices=torch.empty((0,), dtype=torch.int64),
)
)
owned_logical_indices = device_indices[owned_mask]
physical_device_indices = layout.logical_locs_to_physical(owned_logical_indices)
host_indices = self.mem_pool_host.alloc(len(physical_device_indices))
if host_indices is None:
return HiCacheWriteFailure(required_host_slots=len(physical_device_indices))
self.write_queue.append(
CacheOperation(host_indices, physical_device_indices, node_id, priority)
)
self.start_writing()
return HiCacheWriteResult(
metadata=CpHiCacheNodeMetadata(
logical_len=logical_len,
owned_positions=owned_positions,
host_indices=host_indices.cpu(),
)
)
def load(
self,
host_indices: torch.Tensor,

View File

@@ -0,0 +1,210 @@
import sys
import types
import unittest
from unittest.mock import patch
import torch
if "sgl_kernel" not in sys.modules:
sys.modules["sgl_kernel"] = types.ModuleType("sgl_kernel")
if "sgl_kernel.kvcacheio" not in sys.modules:
kvcacheio_stub = types.ModuleType("sgl_kernel.kvcacheio")
for name in (
"transfer_kv_all_layer",
"transfer_kv_all_layer_direct_lf_pf",
"transfer_kv_all_layer_lf_pf",
"transfer_kv_all_layer_lf_ph",
"transfer_kv_all_layer_mla",
"transfer_kv_all_layer_mla_lf_pf",
"transfer_kv_direct",
"transfer_kv_per_layer",
"transfer_kv_per_layer_direct_pf_lf",
"transfer_kv_per_layer_mla",
"transfer_kv_per_layer_mla_pf_lf",
"transfer_kv_per_layer_pf_lf",
"transfer_kv_per_layer_ph_lf",
):
setattr(kvcacheio_stub, name, lambda *args, **kwargs: None)
sys.modules["sgl_kernel.kvcacheio"] = kvcacheio_stub
from sglang.srt.managers.cache_controller import HiCacheController
from sglang.srt.mem_cache.cp_shared_kv_layout import CpSharedKVLayout
from sglang.test.ci.ci_register import register_cpu_ci
from sglang.test.test_utils import CustomTestCase
register_cpu_ci(est_time=2, suite="stage-a-test-cpu")
class FakeHostPool:
def __init__(self, alloc_result):
self.alloc_result = alloc_result
self.alloc_calls = []
self.backups = []
self.loads = []
self.frees = []
self.page_size = 4
self.layout = "page_first_direct"
def alloc(self, need_size):
self.alloc_calls.append(need_size)
if self.alloc_result is None:
return None
return self.alloc_result[:need_size].clone()
def backup_from_device_all_layer(
self, device_pool, host_indices, device_indices, io_backend
):
self.backups.append((host_indices.clone(), device_indices.clone()))
def load_to_device_per_layer(
self, device_pool, host_indices, device_indices, layer_id, io_backend
):
self.loads.append((host_indices.clone(), device_indices.clone(), layer_id))
def free(self, indices):
self.frees.append(indices.clone())
return len(indices)
class FakeDevicePool:
device = "cpu"
layer_num = 1
def register_layer_transfer_counter(self, counter):
self.counter = counter
class FakeAllocator:
def __init__(self, alloc_result=None):
self.alloc_result = alloc_result
self.alloc_calls = []
self.cp_size = 4
self.cp_rank = 1
def get_kvcache(self):
return FakeDevicePool()
def alloc(self, need_size):
self.alloc_calls.append(need_size)
if self.alloc_result is None:
return None
return self.alloc_result[:need_size].clone()
class DummyEvent:
def record(self):
pass
def wait(self, stream):
pass
def query(self):
return True
def synchronize(self):
pass
class DummyStream:
def __enter__(self):
return self
def __exit__(self, exc_type, exc, tb):
return False
class DummyDeviceModule:
Event = DummyEvent
Stream = DummyStream
@staticmethod
def stream(stream):
return stream
class DummyLayerDoneCounter:
def __init__(self):
self.events = [
type(
"ProducerEvent",
(),
{
"start_event": DummyEvent(),
"finish_event": DummyEvent(),
"complete": lambda self, layer_id: None,
},
)()
]
def update_producer(self):
return 0
class TestHiCacheControllerCPWrite(CustomTestCase):
def setUp(self):
self.device_module_patcher = patch(
"sglang.srt.managers.cache_controller.device_module",
DummyDeviceModule,
)
self.nsa_pool_patcher = patch(
"sglang.srt.managers.cache_controller.NSATokenToKVPool",
FakeDevicePool,
)
self.device_module_patcher.start()
self.nsa_pool_patcher.start()
self.addCleanup(self.device_module_patcher.stop)
self.addCleanup(self.nsa_pool_patcher.stop)
def make_controller(self, host_pool, allocator=None, cp_rank=1):
allocator = allocator or FakeAllocator()
controller = HiCacheController(
token_to_kv_pool_allocator=allocator,
mem_pool_host=host_pool,
page_size=4,
tp_group=None,
load_cache_event=__import__("threading").Event(),
io_backend="direct",
cp_shared_kv_layout=CpSharedKVLayout(
page_size=4, cp_size=4, cp_rank=cp_rank
),
)
controller.layer_done_counter = DummyLayerDoneCounter()
return controller
def test_cp_write_filters_to_owned_physical_locs(self):
host_pool = FakeHostPool(torch.tensor([100, 101, 102, 103], dtype=torch.int64))
controller = self.make_controller(host_pool, cp_rank=1)
logical_locs = torch.arange(4, 20, dtype=torch.int64)
result = controller.write(logical_locs, node_id=7)
self.assertEqual(result.metadata.logical_len, 16)
self.assertEqual(result.metadata.owned_positions.tolist(), [4, 5, 6, 7])
self.assertEqual(result.metadata.host_indices.tolist(), [100, 101, 102, 103])
self.assertEqual(host_pool.alloc_calls, [4])
self.assertEqual(host_pool.backups[0][1].tolist(), [4, 5, 6, 7])
def test_cp_write_zero_owned_returns_metadata_and_noop_ack(self):
host_pool = FakeHostPool(torch.tensor([], dtype=torch.int64))
controller = self.make_controller(host_pool, cp_rank=3)
logical_locs = torch.arange(4, 8, dtype=torch.int64)
result = controller.write(logical_locs, node_id=8)
self.assertEqual(result.metadata.logical_len, 4)
self.assertEqual(result.metadata.host_indices.tolist(), [])
self.assertEqual(host_pool.alloc_calls, [])
self.assertEqual(len(controller.ack_write_queue), 1)
def test_cp_write_allocation_failure_reports_required_host_slots(self):
host_pool = FakeHostPool(None)
controller = self.make_controller(host_pool, cp_rank=1)
logical_locs = torch.arange(4, 20, dtype=torch.int64)
result = controller.write(logical_locs, node_id=9)
self.assertEqual(result.required_host_slots, 4)
if __name__ == "__main__":
unittest.main()