Files
sglang/python/sglang/srt/mem_cache/memory_pool_host.py
2026-02-25 00:13:57 -08:00

1239 lines
45 KiB
Python

import abc
import logging
import threading
from collections import defaultdict
from functools import wraps
from typing import Optional
import psutil
import torch
from sglang.jit_kernel.hicache import (
can_use_hicache_jit_kernel,
)
from sglang.jit_kernel.hicache import (
transfer_hicache_all_layer as jit_transfer_hicache_all_layer,
)
from sglang.jit_kernel.hicache import (
transfer_hicache_one_layer as jit_transfer_hicache_one_layer,
)
from sglang.srt.mem_cache.memory_pool import (
KVCache,
MHATokenToKVPool,
MLATokenToKVPool,
NSATokenToKVPool,
)
from sglang.srt.utils import is_cuda, is_npu, is_xpu
_is_cuda = is_cuda()
_is_npu = is_npu()
_is_xpu = is_xpu()
if not (_is_npu or _is_xpu):
from sgl_kernel.kvcacheio import (
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,
)
if _is_npu:
from sgl_kernel_npu.kvcacheio import TransferDirection, transfer_kv_dim_exchange
logger = logging.getLogger(__name__)
def synchronized(func):
@wraps(func)
def wrapper(self, *args, **kwargs):
with self.lock:
return func(self, *args, **kwargs)
return wrapper
class HostTensorAllocator(abc.ABC):
def __init__(self):
"""Initialize the HostTensorAllocator."""
self.dtype = None
self.dims = None
def allocate(self, dims: tuple, dtype: torch.dtype, device: str) -> torch.Tensor:
"""Allocate a tensor of given dims and dtype on the memory."""
self.dtype = dtype
self.dims = dims
tensor = torch.empty(dims, dtype=dtype, device=device)
return tensor
def get_allocator_from_storage(allocator_type):
if allocator_type == "mooncake":
try:
from sglang.srt.mem_cache.storage.mooncake_store.mooncake_store import (
MooncakeHostTensorAllocator,
)
return MooncakeHostTensorAllocator()
except ImportError:
logger.warning(
"Mooncake's tensor allocator requires mooncake >= 0.3.8.post1. "
"Please upgrade Mooncake by 'pip install mooncake-transfer-engine --upgrade'. "
"Fallback to use default allocator."
)
return HostTensorAllocator()
else:
return HostTensorAllocator()
def alloc_with_host_register(
dims,
dtype: torch.dtype,
device: str,
pin_memory: bool,
allocator: HostTensorAllocator,
) -> torch.Tensor:
"""
Allocate tensor and register host memory with cudaHostRegister.
CudaHostRegister only applies when pin_memory=True.
"""
buffer = allocator.allocate(dims, dtype=dtype, device=device)
if pin_memory:
torch.cuda.cudart().cudaHostRegister(
buffer.data_ptr(), buffer.numel() * buffer.element_size(), 0
)
return buffer
def alloc_with_pin_memory(
dims,
dtype: torch.dtype,
device: str,
pin_memory: bool,
allocator: None,
) -> torch.Tensor:
"""
Allocate tensor using PyTorch's built-in pin_memory flag.
"""
buffer = torch.empty(dims, dtype=dtype, device=device, pin_memory=pin_memory)
return buffer
ALLOC_MEMORY_FUNCS = defaultdict(
lambda: alloc_with_host_register,
{
"npu": alloc_with_pin_memory,
},
)
class HostKVCache(abc.ABC):
def __init__(
self,
device_pool: KVCache,
host_to_device_ratio: float,
host_size: int,
page_size: int,
layout: str,
pin_memory: bool,
device: str,
allocator_type: str = "default",
):
self.device_pool = device_pool
self.page_size = page_size
self.layout = layout
self.pin_memory = pin_memory
self.device = device
self.allocator = get_allocator_from_storage(allocator_type)
self.dtype = device_pool.store_dtype
self.size_per_token = self.get_size_per_token()
if host_size > 0:
self.size = int(host_size * 1e9 // self.size_per_token)
else:
self.size = int(device_pool.size * host_to_device_ratio)
# Align up the host memory pool size to the page size
self.page_num = self.size // self.page_size + 1
self.size = self.page_num * self.page_size
self.start_layer = device_pool.start_layer
self.end_layer = device_pool.end_layer
assert (
self.size > device_pool.size
), "The host memory should be larger than the device memory with the current protocol"
# Verify there is enough available host memory.
host_mem = psutil.virtual_memory()
requested_bytes = self.size * self.size_per_token
# preserve at least 10GB for other usage
ten_gb = 10 * (1024**3)
available_bytes = host_mem.available - ten_gb
if requested_bytes > available_bytes:
raise ValueError(
f"Not enough host memory available. Requesting "
f"{requested_bytes / 1e9:.2f} GB but only have "
f"{available_bytes / 1e9:.2f} GB free. Please reduce the "
f"size of the hierarchical cache."
)
else:
logger.info(
f"Allocating {requested_bytes / 1e9:.2f} GB host memory for hierarchical KV cache."
)
self.kv_buffer = self.init_kv_buffer()
# A lock for synchronized operations on memory allocation and state transitions.
self.lock = threading.RLock()
self.clear()
@abc.abstractmethod
def get_size_per_token(self):
raise NotImplementedError()
@abc.abstractmethod
def init_kv_buffer(self):
raise NotImplementedError()
@abc.abstractmethod
def load_to_device_per_layer(
self, device_pool, host_indices, device_indices, layer_id, io_backend
) -> None:
"""
Load KV data from the host memory pool to the device memory pool for a specific layer.
"""
raise NotImplementedError()
@abc.abstractmethod
def backup_from_device_all_layer(
self, device_pool, host_indices, device_indices, io_backend
) -> None:
"""
Backup KV data from the device memory pool to the host memory pool for all layers.
"""
raise NotImplementedError()
@abc.abstractmethod
def get_data_page(self, index, flat: bool = True) -> torch.Tensor:
"""
Get a flat data page from the host memory pool.
"""
raise NotImplementedError()
@abc.abstractmethod
def get_dummy_flat_data_page(self) -> torch.Tensor:
"""
Get a dummy flat data page from the host memory pool.
This is used for prefetching or initializing empty pages.
"""
raise NotImplementedError()
@abc.abstractmethod
def set_from_flat_data_page(self, index: int, data_page: torch.Tensor) -> None:
"""
Set a flat data page to the host memory pool.
"""
raise NotImplementedError()
@synchronized
def clear(self):
# Initialize memory states and tracking structures.
self.mem_state = torch.zeros(
(self.size,), dtype=torch.uint8, device=self.device
)
self.free_slots = torch.arange(self.size, dtype=torch.int64)
def available_size(self):
return len(self.free_slots)
@synchronized
def alloc(self, need_size: int) -> Optional[torch.Tensor]:
assert (
need_size % self.page_size == 0
), "The requested size should be a multiple of the page size."
if need_size > self.available_size():
return None
select_index = self.free_slots[:need_size]
self.free_slots = self.free_slots[need_size:]
return select_index
@synchronized
def free(self, indices: torch.Tensor) -> int:
self.free_slots = torch.cat([self.free_slots, indices])
return len(indices)
class MHATokenToKVPoolHost(HostKVCache):
device_pool: MHATokenToKVPool
def __init__(
self,
device_pool: MHATokenToKVPool,
host_to_device_ratio: float,
host_size: int,
page_size: int,
layout: str,
pin_memory: bool = True,
device: str = "cpu",
allocator_type: str = "default",
):
super().__init__(
device_pool,
host_to_device_ratio,
host_size,
page_size,
layout,
pin_memory,
device,
allocator_type,
)
self.element_dim = self.device_pool.head_num * self.device_pool.head_dim
self.can_use_jit = _is_cuda and can_use_hicache_jit_kernel(
element_size=self.element_dim * self.dtype.itemsize
)
self.k_data_refs = [self.k_buffer[i] for i in range(self.layer_num)]
self.v_data_refs = [self.v_buffer[i] for i in range(self.layer_num)]
self.k_data_ptrs = torch.tensor(
[x.data_ptr() for x in self.k_data_refs],
dtype=torch.uint64,
device=self.device_pool.device,
)
self.v_data_ptrs = torch.tensor(
[x.data_ptr() for x in self.v_data_refs],
dtype=torch.uint64,
device=self.device_pool.device,
)
def get_size_per_token(self):
self.head_num = self.device_pool.head_num
self.head_dim = self.device_pool.head_dim
self.layer_num = self.device_pool.layer_num
return self.head_dim * self.head_num * self.layer_num * self.dtype.itemsize * 2
def get_ksize_per_token(self):
return self.get_size_per_token() // 2
def init_kv_buffer(self):
if self.layout == "layer_first":
dims = (2, self.layer_num, self.size, self.head_num, self.head_dim)
elif self.layout == "page_first":
dims = (2, self.size, self.layer_num, self.head_num, self.head_dim)
elif self.layout == "page_first_direct":
dims = (
2,
self.page_num,
self.layer_num,
self.page_size,
self.head_num,
self.head_dim,
)
elif self.layout == "page_head":
dims = (
2,
self.page_num,
self.head_num,
self.page_size,
self.layer_num,
self.head_dim,
)
else:
raise ValueError(f"Unsupported layout: {self.layout}")
self.token_stride_size = self.head_num * self.head_dim * self.dtype.itemsize
self.layout_dim = self.token_stride_size * self.layer_num
alloc_func = ALLOC_MEMORY_FUNCS[self.device_pool.device]
buffer = alloc_func(
dims,
dtype=self.dtype,
device=self.device,
pin_memory=self.pin_memory,
allocator=self.allocator,
)
return buffer
@property
def k_buffer(self):
return self.kv_buffer[0]
@property
def v_buffer(self):
return self.kv_buffer[1]
def load_to_device_per_layer(
self,
device_pool,
host_indices,
device_indices,
layer_id,
io_backend,
):
if io_backend == "kernel":
if self.layout == "layer_first":
if self.can_use_jit:
jit_transfer_hicache_one_layer(
k_cache_dst=device_pool.k_buffer[layer_id],
v_cache_dst=device_pool.v_buffer[layer_id],
k_cache_src=self.k_buffer[layer_id],
v_cache_src=self.v_buffer[layer_id],
indices_dst=device_indices,
indices_src=host_indices,
element_dim=self.element_dim,
)
else:
transfer_kv_per_layer(
src_k=self.k_buffer[layer_id],
dst_k=device_pool.k_buffer[layer_id],
src_v=self.v_buffer[layer_id],
dst_v=device_pool.v_buffer[layer_id],
src_indices=host_indices,
dst_indices=device_indices,
item_size=self.token_stride_size,
)
elif self.layout == "page_first":
transfer_kv_per_layer_pf_lf(
src_k=self.k_buffer,
dst_k=device_pool.k_buffer[layer_id],
src_v=self.v_buffer,
dst_v=device_pool.v_buffer[layer_id],
src_indices=host_indices,
dst_indices=device_indices,
layer_id=layer_id,
item_size=self.token_stride_size,
src_layout_dim=self.layout_dim,
)
elif self.layout == "page_head":
transfer_kv_per_layer_ph_lf(
src_k=self.k_buffer,
dst_k=device_pool.k_buffer[layer_id],
src_v=self.v_buffer,
dst_v=device_pool.v_buffer[layer_id],
src_indices=host_indices,
dst_indices=device_indices,
layer_id=layer_id,
item_size=self.token_stride_size,
src_layout_dim=self.layout_dim,
page_size=self.page_size,
head_num=self.head_num,
)
else:
raise ValueError(f"Unsupported layout: {self.layout}")
elif io_backend == "direct":
if self.layout == "layer_first":
transfer_kv_direct(
src_layers=[self.k_buffer[layer_id], self.v_buffer[layer_id]],
dst_layers=[
device_pool.k_buffer[layer_id],
device_pool.v_buffer[layer_id],
],
src_indices=host_indices,
dst_indices=device_indices,
page_size=self.page_size,
)
elif self.layout == "page_first_direct":
transfer_kv_per_layer_direct_pf_lf(
src_ptrs=[self.k_buffer, self.v_buffer],
dst_ptrs=[
device_pool.k_buffer[layer_id],
device_pool.v_buffer[layer_id],
],
src_indices=host_indices,
dst_indices=device_indices,
layer_id=layer_id,
page_size=self.page_size,
)
else:
raise ValueError(f"Unsupported layout: {self.layout}")
elif io_backend == "kernel_ascend":
if self.layout == "page_first_direct":
# Ascend-specific: transfer KV data for all layers when layer_id == 0
if layer_id == 0:
transfer_kv_dim_exchange(
device_indices=device_indices,
host_indices=host_indices,
device_k=device_pool.k_buffer,
host_k=self.k_buffer,
device_v=device_pool.v_buffer,
host_v=self.v_buffer,
page_size=self.page_size,
direction=TransferDirection.H2D,
)
else:
raise ValueError(f"Unsupported layout: {self.layout}")
else:
raise ValueError(f"Unsupported IO backend: {io_backend}")
def backup_from_device_all_layer(
self, device_pool, host_indices, device_indices, io_backend
):
if io_backend == "kernel":
if self.layout == "layer_first":
if self.can_use_jit:
jit_transfer_hicache_all_layer(
k_ptr_dst=self.k_data_ptrs,
v_ptr_dst=self.v_data_ptrs,
indices_dst=host_indices,
k_ptr_src=device_pool.k_data_ptrs,
v_ptr_src=device_pool.v_data_ptrs,
indices_src=device_indices,
kv_cache_dst_stride_bytes=self.token_stride_size,
kv_cache_src_stride_bytes=self.token_stride_size,
element_size=self.element_dim * self.dtype.itemsize,
)
else:
transfer_kv_all_layer(
src_k_layers=device_pool.k_data_ptrs,
dst_k_layers=self.k_data_ptrs,
src_v_layers=device_pool.v_data_ptrs,
dst_v_layers=self.v_data_ptrs,
src_indices=device_indices,
dst_indices=host_indices,
item_size=self.token_stride_size,
num_layers=self.layer_num,
)
elif self.layout == "page_first":
transfer_kv_all_layer_lf_pf(
src_k_layers=device_pool.k_data_ptrs,
dst_k=self.k_buffer,
src_v_layers=device_pool.v_data_ptrs,
dst_v=self.v_buffer,
src_indices=device_indices,
dst_indices=host_indices,
item_size=self.token_stride_size,
dst_layout_dim=self.layout_dim,
num_layers=self.layer_num,
)
elif self.layout == "page_head":
transfer_kv_all_layer_lf_ph(
src_k_layers=device_pool.k_data_ptrs,
dst_k=self.k_buffer,
src_v_layers=device_pool.v_data_ptrs,
dst_v=self.v_buffer,
src_indices=device_indices,
dst_indices=host_indices,
item_size=self.token_stride_size,
dst_layout_dim=self.layout_dim,
num_layers=self.layer_num,
page_size=self.page_size,
head_num=self.head_num,
)
else:
raise ValueError(f"Unsupported layout: {self.layout}")
elif io_backend == "direct":
if self.layout == "layer_first":
transfer_kv_direct(
src_layers=device_pool.k_buffer + device_pool.v_buffer,
dst_layers=self.k_data_refs + self.v_data_refs,
src_indices=device_indices,
dst_indices=host_indices,
page_size=self.page_size,
)
elif self.layout == "page_first_direct":
transfer_kv_all_layer_direct_lf_pf(
src_ptrs=device_pool.k_buffer + device_pool.v_buffer,
dst_ptrs=[self.k_buffer, self.v_buffer],
src_indices=device_indices,
dst_indices=host_indices,
page_size=self.page_size,
)
else:
raise ValueError(f"Unsupported layout: {self.layout}")
elif io_backend == "kernel_ascend":
if self.layout == "page_first_direct":
transfer_kv_dim_exchange(
device_indices=device_indices,
host_indices=host_indices,
device_k=device_pool.k_buffer,
host_k=self.k_buffer,
device_v=device_pool.v_buffer,
host_v=self.v_buffer,
page_size=self.page_size,
direction=TransferDirection.D2H,
)
else:
raise ValueError(f"Unsupported layout: {self.layout}")
else:
raise ValueError(f"Unsupported IO backend: {io_backend}")
def get_data_page(self, index, flat: bool = True) -> torch.Tensor:
if self.layout == "layer_first":
data_page = self.kv_buffer[:, :, index : index + self.page_size, :, :]
elif self.layout == "page_first":
data_page = self.kv_buffer[:, index : index + self.page_size, :, :, :]
elif self.layout in ["page_first_direct", "page_head"]:
real_index = index // self.page_size
data_page = self.kv_buffer[:, real_index : real_index + 1, :, :, :, :]
else:
raise ValueError(f"Unsupported layout: {self.layout}")
if flat:
data_page = data_page.flatten()
return data_page
def get_dummy_flat_data_page(self) -> torch.Tensor:
return torch.zeros(
(2, self.layer_num, self.page_size, self.head_num, self.head_dim),
dtype=self.dtype,
device=self.device,
pin_memory=self.pin_memory,
).flatten()
def set_from_flat_data_page(self, index: int, data_page: torch.Tensor) -> None:
if self.layout == "layer_first":
self.kv_buffer[:, :, index : index + self.page_size, :, :] = (
data_page.reshape(
2,
self.layer_num,
self.page_size,
self.head_num,
self.head_dim,
)
)
elif self.layout == "page_first":
self.kv_buffer[:, index : index + self.page_size, :, :, :] = (
data_page.reshape(
2, self.page_size, self.layer_num, self.head_num, self.head_dim
)
)
elif self.layout == "page_first_direct":
real_index = index // self.page_size
self.kv_buffer[:, real_index : real_index + 1, :, :, :, :] = (
data_page.reshape(
2, 1, self.layer_num, self.page_size, self.head_num, self.head_dim
)
)
elif self.layout == "page_head":
real_index = index // self.page_size
self.kv_buffer[:, real_index : real_index + 1, :, :, :, :] = (
data_page.reshape(
2, 1, self.head_num, self.page_size, self.layer_num, self.head_dim
)
)
else:
raise ValueError(f"Unsupported layout: {self.layout}")
def get_split_heads_page_buffer_meta(
self, indices: torch.Tensor, split_factor: int
):
"""
get meta data for zero copy of heterogeneous ranks' KVCache
"""
assert self.layout == "page_head"
assert len(indices) % self.page_size == 0
assert self.head_num % split_factor == 0
ptr_list = []
kv_buffer_data_ptr = self.kv_buffer.data_ptr()
indices = indices.tolist()
v_offset = (
self.layer_num
* self.size
* self.head_num
* self.head_dim
* self.dtype.itemsize
)
for index in range(0, len(indices), self.page_size):
for head_id in range(0, self.head_num, self.head_num // split_factor):
k_ptr = (
kv_buffer_data_ptr
+ indices[index]
* self.layer_num
* self.head_num
* self.head_dim
* self.dtype.itemsize
+ head_id
* self.page_size
* self.layer_num
* self.head_dim
* self.dtype.itemsize
)
v_ptr = k_ptr + v_offset
ptr_list.append(k_ptr)
ptr_list.append(v_ptr)
element_size = (
self.layer_num
* self.dtype.itemsize
* self.page_size
* self.head_num
* self.head_dim
// split_factor
)
element_size_list = [element_size] * len(ptr_list)
return ptr_list, element_size_list
def get_page_buffer_meta(self, indices):
""" "
meta data for zero copy
"""
assert len(indices) % self.page_size == 0
ptr_list = []
kv_buffer_data_ptr = self.kv_buffer.data_ptr()
indices = indices.tolist()
v_offset = (
self.layer_num
* self.size
* self.head_num
* self.head_dim
* self.dtype.itemsize
)
if self.layout == "layer_first":
for index in range(0, len(indices), self.page_size):
for layer_id in range(self.layer_num):
k_ptr = (
kv_buffer_data_ptr
+ indices[index]
* self.head_num
* self.head_dim
* self.dtype.itemsize
+ layer_id
* self.size
* self.head_num
* self.head_dim
* self.dtype.itemsize
)
v_ptr = k_ptr + v_offset
ptr_list.append(k_ptr)
ptr_list.append(v_ptr)
element_size = (
self.dtype.itemsize * self.page_size * self.head_num * self.head_dim
)
element_size_list = [element_size] * len(ptr_list)
elif self.layout in ["page_first", "page_first_direct", "page_head"]:
for index in range(0, len(indices), self.page_size):
k_ptr = (
kv_buffer_data_ptr
+ indices[index]
* self.layer_num
* self.head_num
* self.head_dim
* self.dtype.itemsize
)
v_ptr = k_ptr + v_offset
ptr_list.append(k_ptr)
ptr_list.append(v_ptr)
element_size = (
self.layer_num
* self.dtype.itemsize
* self.page_size
* self.head_num
* self.head_dim
)
element_size_list = [element_size] * len(ptr_list)
else:
raise ValueError(f"Unsupported layout: {self.layout}")
return ptr_list, element_size_list
class MLATokenToKVPoolHost(HostKVCache):
device_pool: MLATokenToKVPool
def __init__(
self,
device_pool: MLATokenToKVPool,
host_to_device_ratio: float,
host_size: int,
page_size: int,
layout: str,
pin_memory: bool = True,
device: str = "cpu",
allocator_type: str = "default",
override_kv_cache_dim: Optional[int] = None,
):
self.override_kv_cache_dim = override_kv_cache_dim
super().__init__(
device_pool,
host_to_device_ratio,
host_size,
page_size,
layout,
pin_memory,
device,
allocator_type,
)
self.data_refs = [self.kv_buffer[i] for i in range(self.layer_num)]
self.data_ptrs = torch.tensor(
[x.data_ptr() for x in self.data_refs],
dtype=torch.uint64,
device=self.device_pool.device,
)
def get_size_per_token(self):
self.kv_lora_rank = self.device_pool.kv_lora_rank
self.qk_rope_head_dim = self.device_pool.qk_rope_head_dim
self.layer_num = self.device_pool.layer_num
self.kv_cache_dim = self.override_kv_cache_dim or (
self.kv_lora_rank + self.qk_rope_head_dim
)
return self.kv_cache_dim * self.dtype.itemsize * self.layer_num
def get_ksize_per_token(self):
return self.get_size_per_token()
def init_kv_buffer(self):
if self.layout == "layer_first":
dims = (
self.layer_num,
self.size,
1,
self.kv_cache_dim,
)
elif self.layout == "page_first":
dims = (
self.size,
self.layer_num,
1,
self.kv_cache_dim,
)
elif self.layout == "page_first_direct":
dims = (
self.page_num,
self.layer_num,
self.page_size,
1,
self.kv_cache_dim,
)
# Ascend-specific: Aligns with NPUMLATokenToKVPool layout
# Separately allocate k_buffer and v_buffer for easier data transfer.
elif self.layout == "page_first_kv_split":
base_dims = (
self.page_num,
self.layer_num,
self.page_size,
1,
)
alloc_func = ALLOC_MEMORY_FUNCS[self.device_pool.device]
self.k_buffer = alloc_func(
(*base_dims, self.kv_lora_rank),
dtype=self.dtype,
device=self.device,
pin_memory=self.pin_memory,
allocator=self.allocator,
)
self.v_buffer = alloc_func(
(*base_dims, self.qk_rope_head_dim),
dtype=self.dtype,
device=self.device,
pin_memory=self.pin_memory,
allocator=self.allocator,
)
self.index_k_buffer = None
if self.device_pool.index_head_dim is not None:
self.index_k_buffer = alloc_func(
(*base_dims, self.device_pool.index_head_dim),
dtype=self.dtype,
device=self.device,
pin_memory=self.pin_memory,
allocator=self.allocator,
)
# Return k_buffer to preserve original kv_buffer and data_refs init logic,
# though Ascend doesn't use these parameters.
return self.k_buffer
else:
raise ValueError(f"Unsupported layout: {self.layout}")
self.token_stride_size = self.kv_cache_dim * self.dtype.itemsize
self.layout_dim = self.token_stride_size * self.layer_num
alloc_func = ALLOC_MEMORY_FUNCS[self.device_pool.device]
buffer = alloc_func(
dims,
dtype=self.dtype,
device=self.device,
pin_memory=self.pin_memory,
allocator=self.allocator,
)
return buffer
def load_to_device_per_layer(
self, device_pool, host_indices, device_indices, layer_id, io_backend
):
if io_backend == "kernel":
if self.layout == "layer_first":
transfer_kv_per_layer_mla(
src=self.kv_buffer[layer_id],
dst=device_pool.kv_buffer[layer_id],
src_indices=host_indices,
dst_indices=device_indices,
item_size=self.token_stride_size,
)
elif self.layout == "page_first":
transfer_kv_per_layer_mla_pf_lf(
src=self.kv_buffer,
dst=device_pool.kv_buffer[layer_id],
src_indices=host_indices,
dst_indices=device_indices,
layer_id=layer_id,
item_size=self.token_stride_size,
src_layout_dim=self.layout_dim,
)
else:
raise ValueError(f"Unsupported layout: {self.layout}")
elif io_backend == "direct":
if self.layout == "layer_first":
transfer_kv_direct(
src_layers=[self.kv_buffer[layer_id]],
dst_layers=[device_pool.kv_buffer[layer_id]],
src_indices=host_indices,
dst_indices=device_indices,
page_size=self.page_size,
)
elif self.layout == "page_first_direct":
transfer_kv_per_layer_direct_pf_lf(
src_ptrs=[self.kv_buffer],
dst_ptrs=[device_pool.kv_buffer[layer_id]],
src_indices=host_indices,
dst_indices=device_indices,
layer_id=layer_id,
page_size=self.page_size,
)
else:
raise ValueError(f"Unsupported layout: {self.layout}")
elif io_backend == "kernel_ascend":
if self.layout == "page_first_kv_split":
# Ascend-specific: transfer KV data for all layers when layer_id == 0
if layer_id == 0:
transfer_kv_dim_exchange(
device_indices=device_indices,
host_indices=host_indices,
device_k=device_pool.k_buffer,
host_k=self.k_buffer,
device_v=device_pool.v_buffer,
host_v=self.v_buffer,
device_index_k=device_pool.index_k_buffer,
host_index_k=self.index_k_buffer,
page_size=self.page_size,
direction=TransferDirection.H2D,
)
else:
raise ValueError(f"Unsupported layout: {self.layout}")
else:
raise ValueError(f"Unsupported IO backend: {io_backend}")
def backup_from_device_all_layer(
self, device_pool, host_indices, device_indices, io_backend
):
if io_backend == "kernel":
if self.layout == "layer_first":
transfer_kv_all_layer_mla(
src_layers=device_pool.data_ptrs,
dst_layers=self.data_ptrs,
src_indices=device_indices,
dst_indices=host_indices,
item_size=self.token_stride_size,
num_layers=self.layer_num,
)
elif self.layout == "page_first":
transfer_kv_all_layer_mla_lf_pf(
src_layers=device_pool.data_ptrs,
dst=self.kv_buffer,
src_indices=device_indices,
dst_indices=host_indices,
item_size=self.token_stride_size,
dst_layout_dim=self.layout_dim,
num_layers=self.layer_num,
)
else:
raise ValueError(f"Unsupported layout: {self.layout}")
elif io_backend == "direct":
if self.layout == "layer_first":
transfer_kv_direct(
src_layers=device_pool.kv_buffer,
dst_layers=self.data_refs,
src_indices=device_indices,
dst_indices=host_indices,
page_size=self.page_size,
)
elif self.layout == "page_first_direct":
transfer_kv_all_layer_direct_lf_pf(
src_ptrs=device_pool.kv_buffer,
dst_ptrs=[self.kv_buffer],
src_indices=device_indices,
dst_indices=host_indices,
page_size=self.page_size,
)
else:
raise ValueError(f"Unsupported layout: {self.layout}")
elif io_backend == "kernel_ascend":
if self.layout == "page_first_kv_split":
transfer_kv_dim_exchange(
device_indices=device_indices,
host_indices=host_indices,
device_k=device_pool.k_buffer,
host_k=self.k_buffer,
device_v=device_pool.v_buffer,
host_v=self.v_buffer,
device_index_k=device_pool.index_k_buffer,
host_index_k=self.index_k_buffer,
page_size=self.page_size,
direction=TransferDirection.D2H,
)
else:
raise ValueError(f"Unsupported layout: {self.layout}")
else:
raise ValueError(f"Unsupported IO backend: {io_backend}")
def get_data_page(self, index, flat: bool = True) -> torch.Tensor:
if self.layout == "layer_first":
data_page = self.kv_buffer[:, index : index + self.page_size, :, :]
elif self.layout == "page_first":
data_page = self.kv_buffer[index : index + self.page_size, :, :, :]
elif self.layout == "page_first_direct":
real_index = index // self.page_size
data_page = self.kv_buffer[real_index : real_index + 1, :, :, :, :]
else:
raise ValueError(f"Unsupported layout: {self.layout}")
if flat:
data_page = data_page.flatten()
return data_page
def get_dummy_flat_data_page(self) -> torch.Tensor:
return torch.zeros(
(
self.layer_num,
self.page_size,
1,
self.kv_cache_dim,
),
dtype=self.dtype,
device=self.device,
pin_memory=self.pin_memory,
).flatten()
def set_from_flat_data_page(self, index: int, data_page: torch.Tensor) -> None:
if self.layout == "layer_first":
self.kv_buffer[:, index : index + self.page_size, :, :] = data_page.reshape(
self.layer_num,
self.page_size,
1,
self.kv_cache_dim,
)
elif self.layout == "page_first":
self.kv_buffer[index : index + self.page_size, :, :, :] = data_page.reshape(
self.page_size,
self.layer_num,
1,
self.kv_cache_dim,
)
elif self.layout == "page_first_direct":
real_index = index // self.page_size
self.kv_buffer[real_index : real_index + 1, :, :, :, :] = data_page.reshape(
1,
self.layer_num,
self.page_size,
1,
self.kv_cache_dim,
)
else:
raise ValueError(f"Unsupported layout: {self.layout}")
def get_page_buffer_meta(self, indices):
""" "
meta data for zero copy
"""
assert len(indices) % self.page_size == 0
ptr_list = []
kv_buffer_data_ptr = self.kv_buffer.data_ptr()
indices = indices.tolist()
if self.layout == "layer_first":
for index in range(0, len(indices), self.page_size):
for layer_id in range(self.layer_num):
k_ptr = (
kv_buffer_data_ptr
+ indices[index] * self.kv_cache_dim * self.dtype.itemsize
+ layer_id * self.size * self.kv_cache_dim * self.dtype.itemsize
)
ptr_list.append(k_ptr)
element_size = self.dtype.itemsize * self.page_size * self.kv_cache_dim
element_size_list = [element_size] * len(ptr_list)
elif self.layout in ["page_first", "page_first_direct"]:
for index in range(0, len(indices), self.page_size):
k_ptr = (
kv_buffer_data_ptr
+ indices[index]
* self.layer_num
* self.kv_cache_dim
* self.dtype.itemsize
)
ptr_list.append(k_ptr)
element_size = (
self.layer_num
* self.dtype.itemsize
* self.page_size
* self.kv_cache_dim
)
element_size_list = [element_size] * len(ptr_list)
else:
raise ValueError(f"Unsupported layout: {self.layout}")
return ptr_list, element_size_list
class NSATokenToKVPoolHost(MLATokenToKVPoolHost):
device_pool: NSATokenToKVPool
def __init__(
self,
device_pool: NSATokenToKVPool,
host_to_device_ratio: float,
host_size: int,
page_size: int,
layout: str,
pin_memory: bool = True,
device: str = "cpu",
allocator_type: str = "default",
):
# Initialize indexer metadata before HostKVCache.__init__ calls get_size_per_token.
self.index_head_dim = device_pool.index_head_dim
self.indexer_quant_block_size = device_pool.quant_block_size
self.indexer_dtype = NSATokenToKVPool.index_k_with_scale_buffer_dtype
self.indexer_size_per_token = (
self.index_head_dim
+ self.index_head_dim // self.indexer_quant_block_size * 4
)
super().__init__(
device_pool,
host_to_device_ratio,
host_size,
page_size,
layout,
pin_memory,
device,
allocator_type,
override_kv_cache_dim=device_pool.kv_cache_dim,
)
self.indexer_page_stride_size = (
self.indexer_size_per_token * self.page_size * self.indexer_dtype.itemsize
)
self.indexer_page_num = (self.size + self.page_size + 1) // self.page_size
self._init_indexer_buffers()
logger.info(
f"NSATokenToKVPoolHost initialized with indexer page stride size: {self.indexer_page_stride_size}, page num: {self.indexer_page_num}"
)
def get_size_per_token(self):
base = super().get_size_per_token()
return (
base
+ self.indexer_size_per_token * self.layer_num * self.indexer_dtype.itemsize
)
def _init_indexer_buffers(self):
alloc_func = ALLOC_MEMORY_FUNCS[self.device_pool.device]
self.index_k_with_scale_buffer = [
alloc_func(
(self.indexer_page_num, self.indexer_page_stride_size),
dtype=self.indexer_dtype,
device=self.device,
pin_memory=self.pin_memory,
allocator=self.allocator,
)
for _ in range(self.layer_num)
]
self.index_k_data_refs = [
self.index_k_with_scale_buffer[i] for i in range(self.layer_num)
]
self.index_k_data_ptrs = torch.tensor(
[x.data_ptr() for x in self.index_k_data_refs],
dtype=torch.uint64,
device=self.device_pool.device,
)
self.index_k_device_ptrs = torch.tensor(
[x.data_ptr() for x in self.device_pool.index_k_with_scale_buffer],
dtype=torch.uint64,
device=self.device_pool.device,
)
def _get_indexer_page_indices(self, host_indices, device_indices):
if host_indices.numel() == 0:
return host_indices, device_indices
if host_indices.numel() % self.page_size != 0:
raise ValueError(
"Index buffer transfer expects page-aligned indices for NSA."
)
host_page_indices = (
host_indices.reshape(-1, self.page_size)[:, 0] // self.page_size
)
device_page_indices = (
device_indices.reshape(-1, self.page_size)[:, 0] // self.page_size
)
return host_page_indices, device_page_indices
def _load_indexer_to_device_per_layer(
self, device_pool, host_indices, device_indices, layer_id, io_backend
):
host_page_indices, device_page_indices = self._get_indexer_page_indices(
host_indices, device_indices
)
use_kernel = io_backend == "kernel" and self.indexer_page_stride_size % 8 == 0
if use_kernel:
transfer_kv_per_layer_mla(
src=self.index_k_with_scale_buffer[layer_id],
dst=device_pool.index_k_with_scale_buffer[layer_id],
src_indices=host_page_indices,
dst_indices=device_page_indices,
item_size=self.indexer_page_stride_size,
)
else:
transfer_kv_direct(
src_layers=[self.index_k_with_scale_buffer[layer_id]],
dst_layers=[device_pool.index_k_with_scale_buffer[layer_id]],
src_indices=host_page_indices,
dst_indices=device_page_indices,
page_size=1,
)
def _backup_indexer_from_device_all_layer(
self, device_pool, host_indices, device_indices, io_backend
):
host_page_indices, device_page_indices = self._get_indexer_page_indices(
host_indices, device_indices
)
use_kernel = io_backend == "kernel" and self.indexer_page_stride_size % 8 == 0
if use_kernel:
transfer_kv_all_layer_mla(
src_layers=self.index_k_device_ptrs,
dst_layers=self.index_k_data_ptrs,
src_indices=device_page_indices,
dst_indices=host_page_indices,
item_size=self.indexer_page_stride_size,
num_layers=self.layer_num,
)
else:
transfer_kv_direct(
src_layers=device_pool.index_k_with_scale_buffer,
dst_layers=self.index_k_with_scale_buffer,
src_indices=device_page_indices,
dst_indices=host_page_indices,
page_size=1,
)
def load_to_device_per_layer(
self,
device_pool,
host_indices,
device_indices,
layer_id,
io_backend,
):
super().load_to_device_per_layer(
device_pool, host_indices, device_indices, layer_id, io_backend
)
self._load_indexer_to_device_per_layer(
device_pool, host_indices, device_indices, layer_id, io_backend
)
def backup_from_device_all_layer(
self, device_pool, host_indices, device_indices, io_backend
):
super().backup_from_device_all_layer(
device_pool, host_indices, device_indices, io_backend
)
self._backup_indexer_from_device_all_layer(
device_pool, host_indices, device_indices, io_backend
)