""" Copyright 2023-2024 SGLang Team Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. """ from __future__ import annotations """ Memory pool. SGLang has two levels of memory pool. ReqToTokenPool maps a request to its token locations. TokenToKVPoolAllocator manages the indices to kv cache data. KVCache actually holds the physical kv cache. """ import abc import dataclasses import logging from contextlib import contextmanager, nullcontext from dataclasses import dataclass, fields from typing import TYPE_CHECKING, Any, List, Optional, Tuple, Union import numpy as np import torch import triton import triton.language as tl from sglang.jit_kernel.kvcache import can_use_store_cache, store_cache from sglang.srt.configs.mamba_utils import BaseLinearStateParams from sglang.srt.constants import GPU_MEMORY_TYPE_KV_CACHE from sglang.srt.environ import envs from sglang.srt.layers.attention.nsa import index_buf_accessor from sglang.srt.layers.attention.nsa.quant_k_cache import ( quantize_k_cache, quantize_k_cache_separate, ) from sglang.srt.layers.quantization.fp8_kernel import fp8_dtype, is_fp8_fnuz from sglang.srt.layers.radix_attention import RadixAttention from sglang.srt.mem_cache.utils import ( get_mla_kv_buffer_triton, maybe_init_custom_mem_pool, set_mla_kv_buffer_triton, set_mla_kv_buffer_triton_fp8_quant, set_mla_kv_scale_buffer_triton, ) from sglang.srt.platforms import current_platform from sglang.srt.utils import ( cpu_has_amx_support, is_cpu, is_cuda, is_hip, is_npu, next_power_of_2, ) from sglang.srt.utils.torch_memory_saver_adapter import TorchMemorySaverAdapter if TYPE_CHECKING: from sglang.srt.managers.cache_controller import LayerDoneCounter from sglang.srt.managers.schedule_batch import Req logger = logging.getLogger(__name__) GB = 1024 * 1024 * 1024 _is_cuda = is_cuda() _is_npu = is_npu() _is_cpu = is_cpu() _cpu_has_amx_support = cpu_has_amx_support() _is_hip = is_hip() _is_fp8_fnuz = is_fp8_fnuz() def get_tensor_size_bytes(t: Union[torch.Tensor, List[torch.Tensor]]): if isinstance(t, list): return sum(get_tensor_size_bytes(x) for x in t) return np.prod(t.shape) * t.dtype.itemsize def _set_kv_buffer_impl( k: torch.Tensor, v: torch.Tensor, k_cache: torch.Tensor, v_cache: torch.Tensor, indices: torch.Tensor, row_dim: int, # head_num * head_dim store_dtype: torch.dtype, device_module: Any, alt_stream: Optional[torch.cuda.Stream] = None, same_kv_dim: bool = True, ) -> None: row_bytes = row_dim * store_dtype.itemsize if (_is_cuda or _is_hip) and same_kv_dim and can_use_store_cache(row_bytes): return store_cache( k.view(-1, row_dim), v.view(-1, row_dim), k_cache.view(-1, row_dim), v_cache.view(-1, row_dim), indices, row_bytes=row_bytes, ) from sglang.srt.model_executor.cuda_graph_runner import get_is_capture_mode if get_is_capture_mode() and alt_stream is not None: current_stream = device_module.current_stream() alt_stream.wait_stream(current_stream) k_cache[indices] = k with device_module.stream(alt_stream): v_cache[indices] = v current_stream.wait_stream(alt_stream) else: # fallback to naive implementation k_cache[indices] = k v_cache[indices] = v class ReqToTokenPool: """A memory pool that maps a request to its token locations.""" def __init__( self, size: int, max_context_len: int, device: str, enable_memory_saver: bool, ): memory_saver_adapter = TorchMemorySaverAdapter.create( enable=enable_memory_saver ) self.size = size self.max_context_len = max_context_len self.device = device with memory_saver_adapter.region(GPU_MEMORY_TYPE_KV_CACHE): self.req_to_token = torch.zeros( (size, max_context_len), dtype=torch.int32, device=device ) self.free_slots = list(range(size)) def write(self, indices, values): self.req_to_token[indices] = values def available_size(self): return len(self.free_slots) def alloc(self, reqs: list[Req]) -> Optional[List[int]]: # Indices of reqs that already have a req_pool_idx and will reuse # their existing slot (e.g. chunked prefill continuing across chunks). reusing = [i for i, r in enumerate(reqs) if r.req_pool_idx is not None] # NOTE: this check is relaxed temporarily # https://github.com/sgl-project/sglang/pull/20476 # if not any(r.is_dllm() for r in reqs): # assert ( # sum(1 for i in reusing if reqs[i].is_chunked > 0) <= 1 # ), "only one chunked request may reuse req_pool_idx in a batch" assert all( reqs[i].is_chunked > 0 or reqs[i].kv_committed_len > 0 for i in reusing ), "reusing request must be chunked or have committed KV" need_size = len(reqs) - len(reusing) if need_size > len(self.free_slots): return None select_index = self.free_slots[:need_size] self.free_slots = self.free_slots[need_size:] offset = 0 for r in reqs: if r.req_pool_idx is None: r.req_pool_idx = select_index[offset] offset += 1 return [r.req_pool_idx for r in reqs] def free(self, req: Req): assert req.req_pool_idx is not None, "request must have req_pool_idx" self.free_slots.append(req.req_pool_idx) req.req_pool_idx = None def clear(self): self.free_slots = list(range(self.size)) class MambaPool: @dataclass(frozen=True, kw_only=True) class State: conv: List[torch.Tensor] temporal: torch.Tensor def at_layer_idx(self, layer: int): kwargs = {} # Use fields instead of vars to avoid torch.compile graph break for f in fields(self): name = f.name v = getattr(self, name) if name in ("conv", "intermediate_conv_window"): kwargs[name] = [conv[layer] for conv in v] else: kwargs[name] = v[layer] return type(self)(**kwargs) def mem_usage_bytes(self): return sum( get_tensor_size_bytes(getattr(self, f.name)) for f in dataclasses.fields(self) ) @dataclass(frozen=True, kw_only=True) class SpeculativeState(State): intermediate_ssm: torch.Tensor intermediate_conv_window: List[torch.Tensor] def __init__( self, *, size: int, spec_state_size: int, cache_params: BaseLinearStateParams, mamba_layer_ids: List[int], device: str, enable_memory_saver: bool = False, speculative_num_draft_tokens: Optional[int] = None, ): conv_state_shape = cache_params.shape.conv temporal_state_shape = cache_params.shape.temporal conv_dtype = cache_params.dtype.conv ssm_dtype = cache_params.dtype.temporal self.memory_saver_adapter = TorchMemorySaverAdapter.create( enable=enable_memory_saver ) num_mamba_layers = len(mamba_layer_ids) self.size = size self.device = device # for disagg with nvlink self.enable_custom_mem_pool, self.custom_mem_pool, _ = ( maybe_init_custom_mem_pool(device=self.device) ) with self.memory_saver_adapter.region(GPU_MEMORY_TYPE_KV_CACHE), ( torch.cuda.use_mem_pool(self.custom_mem_pool) if self.enable_custom_mem_pool else nullcontext() ): conv_state = [ torch.zeros( size=(num_mamba_layers, size + 1) + conv_shape, dtype=conv_dtype, device=device, ) for conv_shape in conv_state_shape ] if _is_npu: from sglang.srt.hardware_backend.npu.memory_pool_npu import ( _init_npu_conv_state, ) conv_state = _init_npu_conv_state( conv_state[0], conv_state_shape, speculative_num_draft_tokens ) if _is_cpu and _cpu_has_amx_support: from sglang.srt.layers.amx_utils import _init_amx_conv_state # CPU uses a different layout of conv_state for kernel optimization conv_state = _init_amx_conv_state(conv_state) temporal_state = torch.zeros( size=(num_mamba_layers, size + 1) + temporal_state_shape, dtype=ssm_dtype, device=device, ) if speculative_num_draft_tokens is not None: # Cache intermediate SSM states per draft token during target verify # Shape: [num_layers, size + 1, speculative_num_draft_tokens, HV, K, V] intermediate_ssm_state_cache = torch.zeros( size=( num_mamba_layers, spec_state_size + 1, speculative_num_draft_tokens, temporal_state_shape[0], temporal_state_shape[1], temporal_state_shape[2], ), dtype=ssm_dtype, device="cuda", ) # Cache intermediate conv windows (last K-1 inputs) per draft token during target verify # Shape: [num_layers, size + 1, speculative_num_draft_tokens, dim, K-1] intermediate_conv_window_cache = [ torch.zeros( size=( num_mamba_layers, spec_state_size + 1, speculative_num_draft_tokens, conv_shape[0], conv_shape[1], ), dtype=conv_dtype, device="cuda", ) for conv_shape in conv_state_shape ] self.mamba_cache = self.SpeculativeState( conv=conv_state, temporal=temporal_state, intermediate_ssm=intermediate_ssm_state_cache, intermediate_conv_window=intermediate_conv_window_cache, ) logger.info( f"Mamba Cache is allocated. " f"max_mamba_cache_size: {size}, " f"conv_state size: {get_tensor_size_bytes(conv_state) / GB:.2f}GB, " f"ssm_state size: {get_tensor_size_bytes(temporal_state) / GB:.2f}GB " f"intermediate_ssm_state_cache size: {get_tensor_size_bytes(intermediate_ssm_state_cache) / GB:.2f}GB " f"intermediate_conv_window_cache size: {get_tensor_size_bytes(intermediate_conv_window_cache) / GB:.2f}GB " ) else: self.mamba_cache = self.State(conv=conv_state, temporal=temporal_state) logger.info( f"Mamba Cache is allocated. " f"max_mamba_cache_size: {size}, " f"conv_state size: {get_tensor_size_bytes(conv_state) / GB:.2f}GB, " f"ssm_state size: {get_tensor_size_bytes(temporal_state) / GB:.2f}GB " ) # The padded slot 0 is used for writing dummy outputs from padded tokens. self.free_slots = torch.arange( 1, self.size + 1, dtype=torch.int64, device=self.device ) self.mem_usage = self.mamba_cache.mem_usage_bytes() / GB self.num_mamba_layers = num_mamba_layers def get_speculative_mamba2_params_all_layers(self) -> SpeculativeState: assert isinstance(self.mamba_cache, self.SpeculativeState) return self.mamba_cache def mamba2_layer_cache(self, layer_id: int): return self.mamba_cache.at_layer_idx(layer_id) def available_size(self): return len(self.free_slots) def alloc(self, need_size: int) -> Optional[torch.Tensor]: if need_size > len(self.free_slots): return None select_index = self.free_slots[:need_size] self.free_slots = self.free_slots[need_size:] # clear at alloc time — expand a scalar GPU zero to the right shape, no CPU-GPU sync for i in range(len(self.mamba_cache.conv)): t = self.mamba_cache.conv[i] z = torch.zeros(1, dtype=t.dtype, device=t.device).expand( t.shape[0], need_size, *t.shape[2:] ) t[:, select_index] = z t = self.mamba_cache.temporal z = torch.zeros(1, dtype=t.dtype, device=t.device).expand( t.shape[0], need_size, *t.shape[2:] ) t[:, select_index] = z return select_index def free(self, free_index: torch.Tensor): if free_index.numel() == 0: return self.free_slots = torch.cat((self.free_slots, free_index)) def clear(self): self.free_slots = torch.arange( 1, self.size + 1, dtype=torch.int64, device=self.device ) def copy_from(self, src_index: torch.Tensor, dst_index: torch.Tensor): for i in range(len(self.mamba_cache.conv)): self.mamba_cache.conv[i][:, dst_index] = self.mamba_cache.conv[i][ :, src_index ] self.mamba_cache.temporal[:, dst_index] = self.mamba_cache.temporal[ :, src_index ] return def fork_from(self, src_index: torch.Tensor) -> Optional[torch.Tensor]: dst_index = self.alloc(1) if dst_index is None: return None self.copy_from(src_index, dst_index) return dst_index def get_cpu_copy(self, indices): torch.cuda.synchronize() conv_cpu = [ conv[:, indices].to("cpu", non_blocking=True) for conv in self.mamba_cache.conv ] temporal_cpu = self.mamba_cache.temporal[:, indices].to( "cpu", non_blocking=True ) torch.cuda.synchronize() return conv_cpu, temporal_cpu def load_cpu_copy(self, mamba_cache_cpu, indices): conv_cpu, temporal_cpu = mamba_cache_cpu torch.cuda.synchronize() for i, conv in enumerate(self.mamba_cache.conv): conv[:, indices] = conv_cpu[i].to(conv.device, non_blocking=True) self.mamba_cache.temporal[:, indices] = temporal_cpu.to( self.mamba_cache.temporal.device, non_blocking=True ) torch.cuda.synchronize() def get_contiguous_buf_infos(self): """ Get buffer info for RDMA registration. Only returns conv and temporal state buffers, excluding intermediate buffers used for speculative decoding (intermediate_ssm, intermediate_conv_window). """ state_tensors = [] for field in vars(self.mamba_cache): # Skip intermediate buffers used only for speculative decoding # These buffers have different size (spec_state_size + 1) and should not be transferred if field in ("intermediate_ssm", "intermediate_conv_window"): continue value = getattr(self.mamba_cache, field) if isinstance(value, list): state_tensors.extend(value) else: state_tensors.append(value) data_ptrs, data_lens, item_lens = [], [], [] for _, state_tensor in enumerate(state_tensors): data_ptrs += [ state_tensor[i].data_ptr() for i in range(self.num_mamba_layers) ] data_lens += [state_tensor[i].nbytes for i in range(self.num_mamba_layers)] item_lens += [ state_tensor[i][0].nbytes for i in range(self.num_mamba_layers) ] return data_ptrs, data_lens, item_lens def get_state_dim_per_tensor(self): """Get the sliceable dimension size for each state tensor. For mamba state, the layout is: - conv_state: [num_layers, size+1, conv_dim/tp, conv_kernel-1] - temporal_state: [num_layers, size+1, num_heads/tp, head_dim, state_size] The 3rd dimension (index 2) is the one that gets sliced by TP. Returns the size of this dimension for each tensor (repeated for each layer). """ state_tensors = [] for field in vars(self.mamba_cache): value = getattr(self.mamba_cache, field) if isinstance(value, list): state_tensors.extend(value) else: state_tensors.append(value) dim_per_tensor = [] for state_tensor in state_tensors: # state_tensor shape: [num_layers, size+1, sliceable_dim, ...] # The sliceable dimension is at index 2 (after num_layers and size) sliceable_dim = state_tensor.shape[2] # Repeat for each layer since we have per-layer data_ptrs dim_per_tensor += [sliceable_dim] * self.num_mamba_layers return dim_per_tensor class HybridReqToTokenPool(ReqToTokenPool): """A memory pool that maps a request to its token locations.""" def __init__( self, *, size: int, mamba_size: int, mamba_spec_state_size: int, max_context_len: int, device: str, enable_memory_saver: bool, cache_params: BaseLinearStateParams, mamba_layer_ids: List[int], enable_mamba_extra_buffer: bool, speculative_num_draft_tokens: int = None, enable_overlap_schedule: bool = True, start_layer: Optional[int] = None, ): super().__init__( size=size, max_context_len=max_context_len, device=device, enable_memory_saver=enable_memory_saver, ) self.mamba_ping_pong_track_buffer_size = 2 if enable_overlap_schedule else 1 self.enable_mamba_extra_buffer = enable_mamba_extra_buffer self.enable_memory_saver = enable_memory_saver self.start_layer = start_layer if start_layer is not None else 0 self.layer_transfer_counter = None self._init_mamba_pool( size=mamba_size, mamba_spec_state_size=mamba_spec_state_size, cache_params=cache_params, mamba_layer_ids=mamba_layer_ids, device=device, enable_mamba_extra_buffer=enable_mamba_extra_buffer, speculative_num_draft_tokens=speculative_num_draft_tokens, ) def _init_mamba_pool( self, size: int, mamba_spec_state_size: int, cache_params: BaseLinearStateParams, mamba_layer_ids: List[int], device: str, enable_mamba_extra_buffer: bool, speculative_num_draft_tokens: int = None, ): self.mamba_pool = MambaPool( size=size, spec_state_size=mamba_spec_state_size, cache_params=cache_params, mamba_layer_ids=mamba_layer_ids, device=device, enable_memory_saver=self.enable_memory_saver, speculative_num_draft_tokens=speculative_num_draft_tokens, ) self.mamba_map = {layer_id: i for i, layer_id in enumerate(mamba_layer_ids)} self.device = device self.req_index_to_mamba_index_mapping: torch.Tensor = torch.zeros( size, dtype=torch.int32, device=self.device ) if enable_mamba_extra_buffer: self.req_index_to_mamba_ping_pong_track_buffer_mapping: torch.Tensor = ( torch.zeros( (size, self.mamba_ping_pong_track_buffer_size), dtype=torch.int32, device=self.device, ) ) def register_layer_transfer_counter( self, layer_transfer_counter: "LayerDoneCounter" ): self.layer_transfer_counter = layer_transfer_counter # For chunk prefill req, we do not need to allocate mamba cache, # We could use allocated mamba cache instead. def alloc(self, reqs: List["Req"]) -> Optional[List[int]]: select_index = super().alloc(reqs) if select_index is None: return None mamba_indices: list[torch.Tensor] = [] mamba_ping_pong_track_buffers: list[torch.Tensor] = [] for req in reqs: mid = None if req.mamba_pool_idx is not None: # for radix cache mid = req.mamba_pool_idx else: mid = self.mamba_pool.alloc(1) assert ( mid is not None ), f"Not enough space for mamba cache, try to increase --mamba-full-memory-ratio or --max-mamba-cache-size. {mid=}, {self.mamba_pool.size=}, {self.mamba_pool.available_size()=}, {len(reqs)=}" mid = mid[0] req.mamba_pool_idx = mid mamba_indices.append(mid) if self.enable_mamba_extra_buffer: if req.mamba_ping_pong_track_buffer is None: req.mamba_ping_pong_track_buffer = self.mamba_pool.alloc( self.mamba_ping_pong_track_buffer_size ) assert ( req.mamba_ping_pong_track_buffer is not None ), "Not enough space for mamba ping pong idx, try to increase --mamba-full-memory-ratio." req.mamba_next_track_idx = 0 mamba_ping_pong_track_buffers.append(req.mamba_ping_pong_track_buffer) assert len(select_index) == len( mamba_indices ), f"Not enough space for mamba cache, try to increase --mamba-full-memory-ratio or --max-mamba-cache-size." if self.enable_mamba_extra_buffer: assert len(select_index) == len( mamba_ping_pong_track_buffers ), f"Not enough space for mamba ping pong idx, try to increase --mamba-full-memory-ratio." mamba_index_tensor = torch.stack(mamba_indices).to(dtype=torch.int32) self.req_index_to_mamba_index_mapping[select_index] = mamba_index_tensor if self.enable_mamba_extra_buffer: ping_pong_tensor = torch.stack(mamba_ping_pong_track_buffers).to( dtype=torch.int32 ) self.req_index_to_mamba_ping_pong_track_buffer_mapping[select_index] = ( ping_pong_tensor ) return select_index def get_mamba_indices(self, req_indices: torch.Tensor) -> torch.Tensor: return self.req_index_to_mamba_index_mapping[req_indices] def mamba2_layer_cache(self, layer_id: int): assert layer_id in self.mamba_map if self.layer_transfer_counter is not None: self.layer_transfer_counter.wait_until(layer_id - self.start_layer) return self.mamba_pool.mamba2_layer_cache(self.mamba_map[layer_id]) def get_speculative_mamba2_params_all_layers(self) -> MambaPool.SpeculativeState: return self.mamba_pool.get_speculative_mamba2_params_all_layers() def get_mamba_ping_pong_other_idx(self, mamba_next_track_idx: int) -> int: if self.mamba_ping_pong_track_buffer_size == 2: return 1 - mamba_next_track_idx else: return mamba_next_track_idx def free_mamba_cache( self, req: "Req", mamba_ping_pong_track_buffer_to_keep: Optional[int] = None ): mamba_index = req.mamba_pool_idx assert mamba_index is not None, "double free? mamba_index is None" self.mamba_pool.free(mamba_index.unsqueeze(0)) req.mamba_pool_idx = None if self.enable_mamba_extra_buffer: mamba_ping_pong_track_buffer_to_free = ( self.req_index_to_mamba_ping_pong_track_buffer_mapping[req.req_pool_idx] ) if mamba_ping_pong_track_buffer_to_keep is not None: assert mamba_ping_pong_track_buffer_to_keep in [ 0, 1, ], f"mamba_ping_pong_track_buffer_to_keep must be 0 or 1, {mamba_ping_pong_track_buffer_to_keep=}" # Avoid Python-list advanced indexing on a device tensor. # The ping-pong buffer size is either 2 (normal) or 1 (spec decode). if self.mamba_ping_pong_track_buffer_size == 2: idx_to_free = 1 - mamba_ping_pong_track_buffer_to_keep mamba_ping_pong_track_buffer_to_free = ( mamba_ping_pong_track_buffer_to_free[ idx_to_free : idx_to_free + 1 ] ) else: assert self.mamba_ping_pong_track_buffer_size == 1, ( f"Unexpected mamba_ping_pong_track_buffer_size=" f"{self.mamba_ping_pong_track_buffer_size}" ) assert mamba_ping_pong_track_buffer_to_keep == 0, ( "mamba_ping_pong_track_buffer_to_keep must be 0 when " "mamba_ping_pong_track_buffer_size is 1" ) # Keep the only slot, so free nothing. mamba_ping_pong_track_buffer_to_free = ( mamba_ping_pong_track_buffer_to_free[0:0] ) self.mamba_pool.free(mamba_ping_pong_track_buffer_to_free) def clear(self): logger.info("Reset HybridReqToTokenPool") super().clear() self.mamba_pool.clear() self.req_index_to_mamba_index_mapping.zero_() if self.enable_mamba_extra_buffer: self.req_index_to_mamba_ping_pong_track_buffer_mapping.zero_() class KVCache(abc.ABC): @abc.abstractmethod def __init__( self, size: int, page_size: int, dtype: torch.dtype, layer_num: int, device: str, enable_memory_saver: bool, start_layer: Optional[int] = None, end_layer: Optional[int] = None, ): self.size = size self.page_size = page_size self.dtype = dtype self.device = device if dtype in (torch.float8_e5m2, torch.float8_e4m3fn): # NOTE: Store as torch.uint8 because Tensor.index_put is not implemented for torch.float8_e5m2 self.store_dtype = torch.uint8 else: self.store_dtype = dtype self.layer_num = layer_num self.start_layer = start_layer or 0 self.end_layer = end_layer or layer_num - 1 self.memory_saver_adapter = TorchMemorySaverAdapter.create( enable=enable_memory_saver ) self.mem_usage = 0 # used for chunked cpu-offloading self.cpu_offloading_chunk_size = 8192 # default state for optional layer-wise transfer control self.layer_transfer_counter = None # for disagg with nvlink self.enable_custom_mem_pool, self.custom_mem_pool, _ = ( maybe_init_custom_mem_pool(device=self.device) ) def _finalize_allocation_log(self, num_tokens: int): """Common logging and mem_usage computation for KV cache allocation. Supports both tuple (K, V) size returns and single KV size returns. """ kv_size_bytes = self.get_kv_size_bytes() if isinstance(kv_size_bytes, tuple): k_size, v_size = kv_size_bytes k_size_GB = k_size / GB v_size_GB = v_size / GB logger.info( f"KV Cache is allocated. #tokens: {num_tokens}, K size: {k_size_GB:.2f} GB, V size: {v_size_GB:.2f} GB" ) self.mem_usage = k_size_GB + v_size_GB else: kv_size_GB = kv_size_bytes / GB logger.info( f"KV Cache is allocated. #tokens: {num_tokens}, KV size: {kv_size_GB:.2f} GB" ) self.mem_usage = kv_size_GB @abc.abstractmethod def get_key_buffer(self, layer_id: int) -> torch.Tensor: raise NotImplementedError() @abc.abstractmethod def get_value_buffer(self, layer_id: int) -> torch.Tensor: raise NotImplementedError() @abc.abstractmethod def get_kv_buffer(self, layer_id: int) -> Tuple[torch.Tensor, torch.Tensor]: raise NotImplementedError() @abc.abstractmethod def set_kv_buffer( self, layer: RadixAttention, loc: torch.Tensor, cache_k: torch.Tensor, cache_v: torch.Tensor, ) -> None: raise NotImplementedError() def register_layer_transfer_counter(self, layer_transfer_counter: LayerDoneCounter): self.layer_transfer_counter = layer_transfer_counter def get_cpu_copy(self, indices, mamba_indices=None): raise NotImplementedError() def load_cpu_copy(self, kv_cache_cpu, indices, mamba_indices=None): raise NotImplementedError() def maybe_get_custom_mem_pool(self): return self.custom_mem_pool class MHATokenToKVPool(KVCache): def __init__( self, size: int, page_size: int, dtype: torch.dtype, head_num: int, head_dim: int, layer_num: int, device: str, enable_memory_saver: bool, v_head_dim: Optional[int] = None, swa_head_num: Optional[int] = None, swa_head_dim: Optional[int] = None, swa_v_head_dim: Optional[int] = None, start_layer: Optional[int] = None, end_layer: Optional[int] = None, enable_alt_stream: bool = True, enable_kv_cache_copy: bool = False, ): super().__init__( size, page_size, dtype, layer_num, device, enable_memory_saver, start_layer, end_layer, ) self.head_num = swa_head_num if swa_head_num is not None else head_num self.head_dim = swa_head_dim if swa_head_dim is not None else head_dim self.v_head_dim = ( swa_v_head_dim if swa_v_head_dim is not None else v_head_dim if v_head_dim is not None else head_dim ) self._create_buffers() self.device_module = torch.get_device_module(self.device) _use_alt_stream = _is_cuda or current_platform.is_cuda_alike() self.alt_stream = ( self.device_module.Stream() if _use_alt_stream and enable_alt_stream else None ) if enable_kv_cache_copy: self._init_kv_copy_and_warmup() else: self._kv_copy_config = None self._finalize_allocation_log(size) # for store_cache JIT kernel self.row_dim = self.head_num * self.head_dim self.same_kv_dim = self.head_dim == self.v_head_dim def _init_kv_copy_and_warmup(self): # Heuristics for KV copy tiling _KV_COPY_STRIDE_THRESHOLD_LARGE = 8192 _KV_COPY_STRIDE_THRESHOLD_MEDIUM = 4096 _KV_COPY_TILE_SIZE_LARGE = 512 _KV_COPY_TILE_SIZE_MEDIUM = 256 _KV_COPY_TILE_SIZE_SMALL = 128 _KV_COPY_NUM_WARPS_LARGE_TILE = 8 _KV_COPY_NUM_WARPS_SMALL_TILE = 4 stride_bytes = int(self.data_strides[0].item()) if stride_bytes >= _KV_COPY_STRIDE_THRESHOLD_LARGE: bytes_per_tile = _KV_COPY_TILE_SIZE_LARGE elif stride_bytes >= _KV_COPY_STRIDE_THRESHOLD_MEDIUM: bytes_per_tile = _KV_COPY_TILE_SIZE_MEDIUM else: bytes_per_tile = _KV_COPY_TILE_SIZE_SMALL # Calculate num_locs_upper to avoid large Triton specialization (e.g. 8192) chunk_upper = 128 if bytes_per_tile >= _KV_COPY_TILE_SIZE_LARGE else 256 self._kv_copy_config = { "bytes_per_tile": bytes_per_tile, "byte_tiles": (stride_bytes + bytes_per_tile - 1) // bytes_per_tile, "num_warps": ( _KV_COPY_NUM_WARPS_SMALL_TILE if bytes_per_tile <= _KV_COPY_TILE_SIZE_MEDIUM else _KV_COPY_NUM_WARPS_LARGE_TILE ), "num_locs_upper": chunk_upper, } dummy_loc = torch.zeros(chunk_upper, dtype=torch.int64, device=self.device) grid = (self.data_ptrs.numel(), self._kv_copy_config["byte_tiles"]) copy_all_layer_kv_cache_tiled[grid]( self.data_ptrs, self.data_strides, dummy_loc, dummy_loc, 1, chunk_upper, BYTES_PER_TILE=self._kv_copy_config["bytes_per_tile"], num_warps=self._kv_copy_config["num_warps"], num_stages=2, ) def _create_buffers(self): with self.memory_saver_adapter.region(GPU_MEMORY_TYPE_KV_CACHE): with ( torch.cuda.use_mem_pool(self.custom_mem_pool) if self.enable_custom_mem_pool else nullcontext() ): # [size, head_num, head_dim] for each layer # The padded slot 0 is used for writing dummy outputs from padded tokens. self.k_buffer = [ torch.zeros( (self.size + self.page_size, self.head_num, self.head_dim), dtype=self.store_dtype, device=self.device, ) for _ in range(self.layer_num) ] self.v_buffer = [ torch.zeros( (self.size + self.page_size, self.head_num, self.v_head_dim), dtype=self.store_dtype, device=self.device, ) for _ in range(self.layer_num) ] self.k_data_ptrs = torch.tensor( [x.data_ptr() for x in self.k_buffer], dtype=torch.uint64, device=self.device, ) self.v_data_ptrs = torch.tensor( [x.data_ptr() for x in self.v_buffer], dtype=torch.uint64, device=self.device, ) self.data_ptrs = torch.cat([self.k_data_ptrs, self.v_data_ptrs], dim=0) self.data_strides = torch.tensor( [ np.prod(x.shape[1:]) * x.dtype.itemsize for x in self.k_buffer + self.v_buffer ], device=self.device, ) def _clear_buffers(self): del self.k_buffer del self.v_buffer def get_kv_size_bytes(self): assert hasattr(self, "k_buffer") assert hasattr(self, "v_buffer") k_size_bytes = 0 for k_cache in self.k_buffer: k_size_bytes += get_tensor_size_bytes(k_cache) v_size_bytes = 0 for v_cache in self.v_buffer: v_size_bytes += get_tensor_size_bytes(v_cache) return k_size_bytes, v_size_bytes # for disagg def get_contiguous_buf_infos(self): # layer_num x [seq_len, head_num, head_dim] # layer_num x [page_num, page_size, head_num, head_dim] kv_data_ptrs = [ self._get_key_buffer(i).data_ptr() for i in range(self.start_layer, self.start_layer + self.layer_num) ] + [ self._get_value_buffer(i).data_ptr() for i in range(self.start_layer, self.start_layer + self.layer_num) ] kv_data_lens = [ self._get_key_buffer(i).nbytes for i in range(self.start_layer, self.start_layer + self.layer_num) ] + [ self._get_value_buffer(i).nbytes for i in range(self.start_layer, self.start_layer + self.layer_num) ] kv_item_lens = [ self._get_key_buffer(i)[0].nbytes * self.page_size for i in range(self.start_layer, self.start_layer + self.layer_num) ] + [ self._get_value_buffer(i)[0].nbytes * self.page_size for i in range(self.start_layer, self.start_layer + self.layer_num) ] return kv_data_ptrs, kv_data_lens, kv_item_lens def get_cpu_copy(self, indices, mamba_indices=None): torch.cuda.synchronize() kv_cache_cpu = [] chunk_size = self.cpu_offloading_chunk_size for layer_id in range(self.layer_num): kv_cache_cpu.append([]) for i in range(0, len(indices), chunk_size): chunk_indices = indices[i : i + chunk_size] k_cpu = self.k_buffer[layer_id][chunk_indices].to( "cpu", non_blocking=True ) v_cpu = self.v_buffer[layer_id][chunk_indices].to( "cpu", non_blocking=True ) kv_cache_cpu[-1].append([k_cpu, v_cpu]) torch.cuda.synchronize() return kv_cache_cpu def load_cpu_copy(self, kv_cache_cpu, indices, mamba_indices=None): torch.cuda.synchronize() chunk_size = self.cpu_offloading_chunk_size for layer_id in range(self.layer_num): for i in range(0, len(indices), chunk_size): chunk_indices = indices[i : i + chunk_size] k_cpu, v_cpu = ( kv_cache_cpu[layer_id][i // chunk_size][0], kv_cache_cpu[layer_id][i // chunk_size][1], ) assert k_cpu.shape[0] == v_cpu.shape[0] == len(chunk_indices) k_chunk = k_cpu.to(self.k_buffer[0].device, non_blocking=True) v_chunk = v_cpu.to(self.v_buffer[0].device, non_blocking=True) self.k_buffer[layer_id][chunk_indices] = k_chunk self.v_buffer[layer_id][chunk_indices] = v_chunk torch.cuda.synchronize() def _get_key_buffer(self, layer_id: int): # for internal use of referencing if self.store_dtype != self.dtype: return self.k_buffer[layer_id - self.start_layer].view(self.dtype) return self.k_buffer[layer_id - self.start_layer] def get_key_buffer(self, layer_id: int): # note: get_key_buffer is hooked with synchronization for layer-wise KV cache loading # it is supposed to be used only by attention backend not for information purpose # same applies to get_value_buffer and get_kv_buffer if self.layer_transfer_counter is not None: self.layer_transfer_counter.wait_until(layer_id - self.start_layer) return self._get_key_buffer(layer_id) def _get_value_buffer(self, layer_id: int): # for internal use of referencing if self.store_dtype != self.dtype: return self.v_buffer[layer_id - self.start_layer].view(self.dtype) return self.v_buffer[layer_id - self.start_layer] def get_value_buffer(self, layer_id: int): if self.layer_transfer_counter is not None: self.layer_transfer_counter.wait_until(layer_id - self.start_layer) return self._get_value_buffer(layer_id) def get_kv_buffer(self, layer_id: int): return self.get_key_buffer(layer_id), self.get_value_buffer(layer_id) def set_kv_buffer( self, layer: RadixAttention, loc: torch.Tensor, cache_k: torch.Tensor, cache_v: torch.Tensor, k_scale: Optional[float] = None, v_scale: Optional[float] = None, layer_id_override: Optional[int] = None, ): if layer_id_override is not None: layer_id = layer_id_override else: layer_id = layer.layer_id if cache_k.dtype != self.dtype: if k_scale is not None: cache_k.div_(k_scale) if v_scale is not None: cache_v.div_(v_scale) cache_k = cache_k.to(self.dtype) cache_v = cache_v.to(self.dtype) if self.store_dtype != self.dtype: cache_k = cache_k.view(self.store_dtype) cache_v = cache_v.view(self.store_dtype) _set_kv_buffer_impl( cache_k, cache_v, self.k_buffer[layer_id - self.start_layer], self.v_buffer[layer_id - self.start_layer], loc, row_dim=self.row_dim, store_dtype=self.store_dtype, device_module=self.device_module, alt_stream=self.alt_stream, same_kv_dim=self.same_kv_dim, ) def move_kv_cache(self, tgt_loc: torch.Tensor, src_loc: torch.Tensor): if envs.SGLANG_NATIVE_MOVE_KV_CACHE.get(): move_kv_cache_native(self.k_buffer, self.v_buffer, tgt_loc, src_loc) return N = tgt_loc.numel() if N == 0: return assert ( self._kv_copy_config is not None ), "KV copy not initialized. Set enable_kv_cache_copy=True in __init__" cfg = self._kv_copy_config cap = int(cfg.get("num_locs_upper", 256)) grid = (self.data_ptrs.numel(), cfg["byte_tiles"]) if N <= cap: upper = next_power_of_2(N) copy_all_layer_kv_cache_tiled[grid]( self.data_ptrs, self.data_strides, tgt_loc, src_loc, N, upper, BYTES_PER_TILE=cfg["bytes_per_tile"], num_warps=cfg["num_warps"], num_stages=2, ) return # Huge N: chunk, but each chunk's upper is still pow2(<= cap) for start in range(0, N, cap): end = min(start + cap, N) chunk_len = end - start upper = next_power_of_2(chunk_len) copy_all_layer_kv_cache_tiled[grid]( self.data_ptrs, self.data_strides, tgt_loc[start:end], src_loc[start:end], chunk_len, upper, BYTES_PER_TILE=cfg["bytes_per_tile"], num_warps=cfg["num_warps"], num_stages=2, ) class MHATokenToKVPoolFP4(MHATokenToKVPool): def _create_buffers(self): with self.memory_saver_adapter.region(GPU_MEMORY_TYPE_KV_CACHE): with ( torch.cuda.use_mem_pool(self.custom_mem_pool) if self.enable_custom_mem_pool else nullcontext() ): # [size, head_num, head_dim] for each layer # The padded slot 0 is used for writing dummy outputs from padded tokens. m = self.size + self.page_size n = self.head_num k = self.head_dim scale_block_size = 16 self.store_dtype = torch.uint8 self.k_buffer = [ torch.zeros( (m, n, k // 2), dtype=self.store_dtype, device=self.device, ) for _ in range(self.layer_num) ] self.v_buffer = [ torch.zeros( (m, n, k // 2), dtype=self.store_dtype, device=self.device, ) for _ in range(self.layer_num) ] self.k_scale_buffer = [ torch.zeros( (m, (n * k) // scale_block_size), dtype=self.store_dtype, device=self.device, ) for _ in range(self.layer_num) ] self.v_scale_buffer = [ torch.zeros( (m, (n * k) // scale_block_size), dtype=self.store_dtype, device=self.device, ) for _ in range(self.layer_num) ] def _clear_buffers(self): del self.k_buffer del self.v_buffer del self.k_scale_buffer del self.v_scale_buffer def _get_key_buffer(self, layer_id: int): # for internal use of referencing if self.store_dtype != self.dtype: cache_k_nope_fp4 = self.k_buffer[layer_id - self.start_layer].view( torch.uint8 ) cache_k_nope_fp4_sf = self.k_scale_buffer[layer_id - self.start_layer] from sglang.srt.layers.quantization.kvfp4_tensor import KVFP4QuantizeUtil cache_k_nope_fp4_dequant = KVFP4QuantizeUtil.batched_dequantize( cache_k_nope_fp4, cache_k_nope_fp4_sf ) return cache_k_nope_fp4_dequant return self.k_buffer[layer_id - self.start_layer] def _get_value_buffer(self, layer_id: int): # for internal use of referencing if self.store_dtype != self.dtype: cache_v_nope_fp4 = self.v_buffer[layer_id - self.start_layer].view( torch.uint8 ) cache_v_nope_fp4_sf = self.v_scale_buffer[layer_id - self.start_layer] from sglang.srt.layers.quantization.kvfp4_tensor import KVFP4QuantizeUtil cache_v_nope_fp4_dequant = KVFP4QuantizeUtil.batched_dequantize( cache_v_nope_fp4, cache_v_nope_fp4_sf ) return cache_v_nope_fp4_dequant return self.v_buffer[layer_id - self.start_layer] def set_kv_buffer( self, layer: RadixAttention, loc: torch.Tensor, cache_k: torch.Tensor, cache_v: torch.Tensor, k_scale: Optional[float] = None, v_scale: Optional[float] = None, layer_id_override: Optional[int] = None, ): from sglang.srt.model_executor.cuda_graph_runner import get_is_capture_mode if layer_id_override is not None: layer_id = layer_id_override else: layer_id = layer.layer_id if cache_k.dtype != self.dtype: if k_scale is not None: cache_k.div_(k_scale) if v_scale is not None: cache_v.div_(v_scale) from sglang.srt.layers.quantization.kvfp4_tensor import KVFP4QuantizeUtil cache_k, cache_k_fp4_sf = KVFP4QuantizeUtil.batched_quantize(cache_k) cache_v, cache_v_fp4_sf = KVFP4QuantizeUtil.batched_quantize(cache_v) if self.store_dtype != self.dtype: cache_k = cache_k.view(self.store_dtype) cache_v = cache_v.view(self.store_dtype) cache_k_fp4_sf = cache_k_fp4_sf.view(self.store_dtype) cache_v_fp4_sf = cache_v_fp4_sf.view(self.store_dtype) if get_is_capture_mode() and self.alt_stream is not None: # Overlap the copy of K and V cache for small batch size current_stream = self.device_module.current_stream() self.alt_stream.wait_stream(current_stream) self.k_buffer[layer_id - self.start_layer][loc] = cache_k self.k_scale_buffer[layer_id - self.start_layer][loc] = cache_k_fp4_sf with self.device_module.stream(self.alt_stream): self.v_buffer[layer_id - self.start_layer][loc] = cache_v self.v_scale_buffer[layer_id - self.start_layer][loc] = cache_v_fp4_sf current_stream.wait_stream(self.alt_stream) else: self.k_buffer[layer_id - self.start_layer][loc] = cache_k self.v_buffer[layer_id - self.start_layer][loc] = cache_v self.k_scale_buffer[layer_id - self.start_layer][loc] = cache_k_fp4_sf self.v_scale_buffer[layer_id - self.start_layer][loc] = cache_v_fp4_sf class HybridLinearKVPool(KVCache): """KV cache with separate pools for full and linear attention layers.""" def __init__( self, size: int, dtype: torch.dtype, page_size: int, head_num: int, head_dim: int, full_attention_layer_ids: List[int], enable_kvcache_transpose: bool, device: str, mamba_pool: MambaPool, enable_memory_saver: bool = False, # TODO: refactor mla related args use_mla: bool = False, kv_lora_rank: int = None, qk_rope_head_dim: int = None, start_layer: Optional[int] = None, ): self.size = size self.dtype = dtype self.device = device self.full_layer_nums = len(full_attention_layer_ids) self.page_size = page_size self.start_layer = start_layer if start_layer is not None else 0 self.layer_transfer_counter = None self.head_num = head_num self.head_dim = head_dim self.mamba_pool = mamba_pool # TODO MHATransposedTokenToKVPool if enable_kvcache_transpose is True assert not enable_kvcache_transpose self.use_mla = use_mla if not use_mla: TokenToKVPoolClass = MHATokenToKVPool if current_platform.is_out_of_tree(): TokenToKVPoolClass = current_platform.get_mha_kv_pool_cls() elif _is_npu: from sglang.srt.hardware_backend.npu.memory_pool_npu import ( NPUMHATokenToKVPool, ) TokenToKVPoolClass = NPUMHATokenToKVPool self.full_kv_pool = TokenToKVPoolClass( size=size, page_size=self.page_size, dtype=dtype, head_num=head_num, head_dim=head_dim, layer_num=self.full_layer_nums, device=device, enable_memory_saver=enable_memory_saver, ) else: TokenToKVPoolClass = MLATokenToKVPool if current_platform.is_out_of_tree(): TokenToKVPoolClass = current_platform.get_mla_kv_pool_cls() elif _is_npu: from sglang.srt.hardware_backend.npu.memory_pool_npu import ( NPUMLATokenToKVPool, ) TokenToKVPoolClass = NPUMLATokenToKVPool self.full_kv_pool = TokenToKVPoolClass( size=size, page_size=self.page_size, dtype=dtype, layer_num=self.full_layer_nums, device=device, kv_lora_rank=kv_lora_rank, qk_rope_head_dim=qk_rope_head_dim, enable_memory_saver=enable_memory_saver, ) self.full_attention_layer_id_mapping = { id: i for i, id in enumerate(full_attention_layer_ids) } if use_mla: self.mem_usage = self.get_kv_size_bytes() / GB else: k_size, v_size = self.get_kv_size_bytes() self.mem_usage = (k_size + v_size) / GB def get_kv_size_bytes(self): return self.full_kv_pool.get_kv_size_bytes() def get_contiguous_buf_infos(self): return self.full_kv_pool.get_contiguous_buf_infos() def get_state_buf_infos(self): mamba_data_ptrs, mamba_data_lens, mamba_item_lens = ( self.mamba_pool.get_contiguous_buf_infos() ) return mamba_data_ptrs, mamba_data_lens, mamba_item_lens def get_state_dim_per_tensor(self): """Get the sliceable dimension size for each mamba state tensor.""" return self.mamba_pool.get_state_dim_per_tensor() def maybe_get_custom_mem_pool(self): return self.full_kv_pool.maybe_get_custom_mem_pool() def _transfer_full_attention_id(self, layer_id: int): if layer_id not in self.full_attention_layer_id_mapping: raise ValueError( f"{layer_id=} not in full attention layers: {self.full_attention_layer_id_mapping.keys()}" ) return self.full_attention_layer_id_mapping[layer_id] def register_layer_transfer_counter( self, layer_transfer_counter: "LayerDoneCounter" ): self.layer_transfer_counter = layer_transfer_counter # The layer-wise wait logic is executed at the Hybrid LinearPool level; # no additional wait is needed in the full_kv_pool self.full_kv_pool.register_layer_transfer_counter(None) def _wait_for_layer(self, layer_id: int): if self.layer_transfer_counter is not None: self.layer_transfer_counter.wait_until(layer_id - self.start_layer) def get_key_buffer(self, layer_id: int): self._wait_for_layer(layer_id) layer_id = self._transfer_full_attention_id(layer_id) return self.full_kv_pool.get_key_buffer(layer_id) def get_value_buffer(self, layer_id: int): self._wait_for_layer(layer_id) layer_id = self._transfer_full_attention_id(layer_id) return self.full_kv_pool.get_value_buffer(layer_id) def get_kv_buffer(self, layer_id: int): self._wait_for_layer(layer_id) layer_id = self._transfer_full_attention_id(layer_id) return self.full_kv_pool.get_kv_buffer(layer_id) @contextmanager def _transfer_id_context(self, layer: RadixAttention): @contextmanager def _patch_layer_id(layer): original_layer_id = layer.layer_id layer.layer_id = self._transfer_full_attention_id(layer.layer_id) try: yield finally: layer.layer_id = original_layer_id with _patch_layer_id(layer): yield def set_kv_buffer( self, layer: RadixAttention, loc: torch.Tensor, cache_k: torch.Tensor, cache_v: torch.Tensor, k_scale: float = 1.0, v_scale: float = 1.0, ): layer_id = self._transfer_full_attention_id(layer.layer_id) if not self.use_mla: self.full_kv_pool.set_kv_buffer( None, loc, cache_k, cache_v, k_scale, v_scale, layer_id_override=layer_id, ) else: with self._transfer_id_context(layer): self.full_kv_pool.set_kv_buffer( layer, loc, cache_k, cache_v, ) def move_kv_cache(self, tgt_loc: torch.Tensor, src_loc: torch.Tensor): self.full_kv_pool.move_kv_cache(tgt_loc, src_loc) def get_cpu_copy(self, indices, mamba_indices=None): kv_cpu = self.full_kv_pool.get_cpu_copy(indices) mamba_cpu = ( self.mamba_pool.get_cpu_copy(mamba_indices) if mamba_indices is not None else None ) return kv_cpu, mamba_cpu def load_cpu_copy(self, cache_cpu, indices, mamba_indices=None): kv_cpu, mamba_cpu = cache_cpu self.full_kv_pool.load_cpu_copy(kv_cpu, indices) if mamba_cpu is not None and mamba_indices is not None: self.mamba_pool.load_cpu_copy(mamba_cpu, mamba_indices) def get_v_head_dim(self): return self.full_kv_pool.get_value_buffer(0).shape[-1] def set_mla_kv_buffer( self, layer: RadixAttention, loc: torch.Tensor, cache_k_nope: torch.Tensor, cache_k_rope: torch.Tensor, ): assert self.use_mla, "set_mla_kv_buffer called when use_mla is False" with self._transfer_id_context(layer): self.full_kv_pool.set_mla_kv_buffer(layer, loc, cache_k_nope, cache_k_rope) def get_mla_kv_buffer( self, layer: RadixAttention, loc: torch.Tensor, dst_dtype: Optional[torch.dtype] = None, ): assert self.use_mla, "get_mla_kv_buffer called when use_mla is False" with self._transfer_id_context(layer): return self.full_kv_pool.get_mla_kv_buffer(layer, loc, dst_dtype) class MLATokenToKVPool(KVCache): def __init__( self, size: int, page_size: int, dtype: torch.dtype, kv_lora_rank: int, qk_rope_head_dim: int, layer_num: int, device: str, enable_memory_saver: bool, start_layer: Optional[int] = None, end_layer: Optional[int] = None, use_nsa: bool = False, override_kv_cache_dim: Optional[int] = None, ): super().__init__( size, page_size, dtype, layer_num, device, enable_memory_saver, start_layer, end_layer, ) self.kv_lora_rank = kv_lora_rank self.qk_rope_head_dim = qk_rope_head_dim self.use_nsa = use_nsa self.nsa_kv_cache_store_fp8 = ( use_nsa and dtype == torch.float8_e4m3fn and override_kv_cache_dim is not None ) # When override_kv_cache_dim is provided with nsa model, we assume the # override kv cache dim is correct and use it directly. self.kv_cache_dim = ( override_kv_cache_dim if self.nsa_kv_cache_store_fp8 else (kv_lora_rank + qk_rope_head_dim) ) self._create_buffers() self.data_ptrs = torch.tensor( [x.data_ptr() for x in self.kv_buffer], dtype=torch.uint64, device=self.device, ) if not use_nsa: # NSA will allocate indexer KV cache later and then log the total size self._finalize_allocation_log(size) def _create_buffers(self): with self.memory_saver_adapter.region(GPU_MEMORY_TYPE_KV_CACHE): with ( torch.cuda.use_mem_pool(self.custom_mem_pool) if self.custom_mem_pool else nullcontext() ): # The padded slot 0 is used for writing dummy outputs from padded tokens. self.kv_buffer = [ torch.zeros( (self.size + self.page_size, 1, self.kv_cache_dim), dtype=self.store_dtype, device=self.device, ) for _ in range(self.layer_num) ] def _clear_buffers(self): del self.kv_buffer def get_kv_size_bytes(self): assert hasattr(self, "kv_buffer") kv_size_bytes = 0 for kv_cache in self.kv_buffer: kv_size_bytes += get_tensor_size_bytes(kv_cache) return kv_size_bytes # for disagg def get_contiguous_buf_infos(self): # MLA has only one kv_buffer, so only the information of this buffer needs to be returned. kv_data_ptrs = [self.kv_buffer[i].data_ptr() for i in range(self.layer_num)] kv_data_lens = [self.kv_buffer[i].nbytes for i in range(self.layer_num)] kv_item_lens = [ self.kv_buffer[i][0].nbytes * self.page_size for i in range(self.layer_num) ] return kv_data_ptrs, kv_data_lens, kv_item_lens def get_key_buffer(self, layer_id: int): if self.layer_transfer_counter is not None: self.layer_transfer_counter.wait_until(layer_id - self.start_layer) if self.store_dtype != self.dtype: return self.kv_buffer[layer_id - self.start_layer].view(self.dtype) return self.kv_buffer[layer_id - self.start_layer] def get_value_buffer(self, layer_id: int): if self.layer_transfer_counter is not None: self.layer_transfer_counter.wait_until(layer_id - self.start_layer) if self.store_dtype != self.dtype: return self.kv_buffer[layer_id - self.start_layer][ ..., : self.kv_lora_rank ].view(self.dtype) return self.kv_buffer[layer_id - self.start_layer][..., : self.kv_lora_rank] def get_kv_buffer(self, layer_id: int): return self.get_key_buffer(layer_id), self.get_value_buffer(layer_id) def set_kv_buffer( self, layer: RadixAttention, loc: torch.Tensor, cache_k: torch.Tensor, cache_v: torch.Tensor, ): layer_id = layer.layer_id assert not self.nsa_kv_cache_store_fp8 if cache_k.dtype != self.dtype: cache_k = cache_k.to(self.dtype) if self.store_dtype != self.dtype: self.kv_buffer[layer_id - self.start_layer][loc] = cache_k.view( self.store_dtype ) else: self.kv_buffer[layer_id - self.start_layer][loc] = cache_k def set_mla_kv_buffer( self, layer: RadixAttention, loc: torch.Tensor, cache_k_nope: torch.Tensor, cache_k_rope: torch.Tensor, ): layer_id = layer.layer_id if _is_hip and self.use_nsa and self.dtype == fp8_dtype: # HIP FP8 path uses raw MLA KV layout (nope + rope) without per-block scales. # Fuse BF16/FP16 -> FP8 cast with paged KV write. set_mla_kv_buffer_triton_fp8_quant( self.kv_buffer[layer_id - self.start_layer], loc, cache_k_nope, cache_k_rope, fp8_dtype, ) elif self.nsa_kv_cache_store_fp8: # OPTIMIZATION: Quantize k_nope and k_rope separately to avoid concat overhead # This also enables reuse of set_mla_kv_buffer_triton two-tensor write path # quantize_k_cache_separate returns (nope_part, rope_part) as uint8 bytes cache_k_nope_fp8, cache_k_rope_fp8 = quantize_k_cache_separate( cache_k_nope, cache_k_rope ) # Reuse existing two-tensor write kernel (works with FP8 byte layout) # cache_k_nope_fp8: (num_tokens, 1, 528) uint8 [nope_fp8(512) | scales(16)] # cache_k_rope_fp8: (num_tokens, 1, 128) uint8 [rope_bf16_bytes(128)] set_mla_kv_buffer_triton( self.kv_buffer[layer_id - self.start_layer], loc, cache_k_nope_fp8, cache_k_rope_fp8, ) else: if cache_k_nope.dtype != self.dtype: cache_k_nope = cache_k_nope.to(self.dtype) cache_k_rope = cache_k_rope.to(self.dtype) if self.store_dtype != self.dtype: cache_k_nope = cache_k_nope.view(self.store_dtype) cache_k_rope = cache_k_rope.view(self.store_dtype) set_mla_kv_buffer_triton( self.kv_buffer[layer_id - self.start_layer], loc, cache_k_nope, cache_k_rope, ) def get_mla_kv_buffer( self, layer: RadixAttention, loc: torch.Tensor, dst_dtype: Optional[torch.dtype] = None, ): # get k nope and k rope from the kv buffer, and optionally cast them to dst_dtype. layer_id = layer.layer_id kv_buffer = self.get_key_buffer(layer_id) dst_dtype = dst_dtype or self.dtype cache_k_nope = torch.empty( (loc.shape[0], 1, self.kv_lora_rank), dtype=dst_dtype, device=kv_buffer.device, ) cache_k_rope = torch.empty( (loc.shape[0], 1, self.qk_rope_head_dim), dtype=dst_dtype, device=kv_buffer.device, ) get_mla_kv_buffer_triton(kv_buffer, loc, cache_k_nope, cache_k_rope) return cache_k_nope, cache_k_rope def get_cpu_copy(self, indices, mamba_indices=None): torch.cuda.synchronize() kv_cache_cpu = [] chunk_size = self.cpu_offloading_chunk_size for layer_id in range(self.layer_num): kv_cache_cpu.append([]) for i in range(0, len(indices), chunk_size): chunk_indices = indices[i : i + chunk_size] kv_cpu = self.kv_buffer[layer_id][chunk_indices].to( "cpu", non_blocking=True ) kv_cache_cpu[-1].append(kv_cpu) torch.cuda.synchronize() return kv_cache_cpu def load_cpu_copy(self, kv_cache_cpu, indices, mamba_indices=None): torch.cuda.synchronize() chunk_size = self.cpu_offloading_chunk_size for layer_id in range(self.layer_num): for i in range(0, len(indices), chunk_size): chunk_indices = indices[i : i + chunk_size] kv_cpu = kv_cache_cpu[layer_id][i // chunk_size] assert kv_cpu.shape[0] == len(chunk_indices) kv_chunk = kv_cpu.to(self.kv_buffer[0].device, non_blocking=True) self.kv_buffer[layer_id][chunk_indices] = kv_chunk torch.cuda.synchronize() class MLATokenToKVPoolFP4(MLATokenToKVPool): def _create_buffers(self): with self.memory_saver_adapter.region(GPU_MEMORY_TYPE_KV_CACHE): with ( torch.cuda.use_mem_pool(self.custom_mem_pool) if self.custom_mem_pool else nullcontext() ): # The padded slot 0 is used for writing dummy outputs from padded tokens. m = self.size + self.page_size n = 1 # head_num k = self.kv_cache_dim # head_dim scale_block_size = 16 self.store_dtype = torch.uint8 self.kv_buffer = [ torch.zeros( (m, n, k // 2), dtype=self.store_dtype, device=self.device, ) for _ in range(self.layer_num) ] self.kv_scale_buffer = [ torch.zeros( (m, k // scale_block_size), dtype=self.store_dtype, device=self.device, ) for _ in range(self.layer_num) ] def _clear_buffers(self): del self.kv_buffer del self.kv_scale_buffer def get_key_buffer(self, layer_id: int): if self.layer_transfer_counter is not None: self.layer_transfer_counter.wait_until(layer_id - self.start_layer) if self.store_dtype != self.dtype: cache_k_nope_fp4 = self.kv_buffer[layer_id - self.start_layer].view( torch.uint8 ) cache_k_nope_fp4_sf = self.kv_scale_buffer[layer_id - self.start_layer] from sglang.srt.layers.quantization.kvfp4_tensor import KVFP4QuantizeUtil cache_k_nope_fp4_dequant = KVFP4QuantizeUtil.batched_dequantize( cache_k_nope_fp4, cache_k_nope_fp4_sf ) return cache_k_nope_fp4_dequant return self.kv_buffer[layer_id - self.start_layer] def set_kv_buffer( self, layer: RadixAttention, loc: torch.Tensor, cache_k: torch.Tensor, cache_v: torch.Tensor, ): layer_id = layer.layer_id assert not self.nsa_kv_cache_store_fp8 if cache_k.dtype != self.dtype: from sglang.srt.layers.quantization.kvfp4_tensor import KVFP4QuantizeUtil cache_k_fp4, cache_k_fp4_sf = KVFP4QuantizeUtil.batched_quantize(cache_k) if self.store_dtype != self.dtype: self.kv_buffer[layer_id - self.start_layer][loc] = cache_k_fp4.view( self.store_dtype ) self.kv_scale_buffer[layer_id - self.start_layer][loc] = ( cache_k_fp4_sf.view(self.store_dtype) ) else: self.kv_buffer[layer_id - self.start_layer][loc] = cache_k def set_mla_kv_buffer( self, layer: RadixAttention, loc: torch.Tensor, cache_k_nope: torch.Tensor, cache_k_rope: torch.Tensor, ): layer_id = layer.layer_id if self.nsa_kv_cache_store_fp8: # original cache_k: (num_tokens, num_heads 1, hidden 576); we unsqueeze the page_size=1 dim here # TODO no need to cat cache_k = torch.cat([cache_k_nope, cache_k_rope], dim=-1) cache_k = quantize_k_cache(cache_k.unsqueeze(1)).squeeze(1) cache_k = cache_k.view(self.store_dtype) self.kv_buffer[layer_id - self.start_layer][loc] = cache_k else: if cache_k_nope.dtype != self.dtype: from sglang.srt.layers.quantization.kvfp4_tensor import ( KVFP4QuantizeUtil, ) cache_k_nope_fp4, cache_k_nope_fp4_sf = ( KVFP4QuantizeUtil.batched_quantize(cache_k_nope) ) cache_k_rope_fp4, cache_k_rope_fp4_sf = ( KVFP4QuantizeUtil.batched_quantize(cache_k_rope) ) if self.store_dtype != self.dtype: cache_k_nope = cache_k_nope.view(self.store_dtype) cache_k_rope = cache_k_rope.view(self.store_dtype) set_mla_kv_buffer_triton( self.kv_buffer[layer_id - self.start_layer], loc, cache_k_nope_fp4, cache_k_rope_fp4, ) set_mla_kv_scale_buffer_triton( self.kv_scale_buffer[layer_id - self.start_layer], loc, cache_k_nope_fp4_sf, cache_k_rope_fp4_sf, ) class NSATokenToKVPool(MLATokenToKVPool): quant_block_size = 128 index_k_with_scale_buffer_dtype = torch.uint8 rope_storage_dtype = torch.bfloat16 # rope is always stored in bf16 def __init__( self, size: int, page_size: int, kv_lora_rank: int, dtype: torch.dtype, qk_rope_head_dim: int, layer_num: int, device: str, index_head_dim: int, enable_memory_saver: bool, kv_cache_dim: int, start_layer: Optional[int] = None, end_layer: Optional[int] = None, index_buf_size: Optional[int] = None, ): override_dim = ( kv_cache_dim if kv_cache_dim != kv_lora_rank + qk_rope_head_dim else None ) super().__init__( size, page_size, dtype, kv_lora_rank, qk_rope_head_dim, layer_num, device, enable_memory_saver, start_layer, end_layer, use_nsa=True, override_kv_cache_dim=override_dim, ) # self.index_k_dtype = torch.float8_e4m3fn # self.index_k_scale_dtype = torch.float32 self.index_head_dim = index_head_dim if index_buf_size is None: index_buf_size = size # num head == 1 and head dim == 128 for index_k in NSA assert index_head_dim == 128 if _is_hip: assert self.page_size == 1 else: assert self.page_size == 64 with ( torch.cuda.use_mem_pool(self.custom_mem_pool) if self.custom_mem_pool else nullcontext() ): self.index_k_with_scale_buffer = [ torch.zeros( # Layout: # ref: test_attention.py :: kv_cache_cast_to_fp8 # shape: (num_pages, page_size 64 * head_dim 128 + page_size 64 * fp32_nbytes 4) # data: for page i, # * buf[i, :page_size * head_dim] for fp8 data # * buf[i, page_size * head_dim:].view(float32) for scale ( (index_buf_size + page_size + 1) // self.page_size, self.page_size * ( index_head_dim + index_head_dim // self.quant_block_size * 4 ), ), dtype=self.index_k_with_scale_buffer_dtype, device=device, ) for _ in range(layer_num) ] self._finalize_allocation_log(size) def get_index_k_with_scale_buffer(self, layer_id: int) -> torch.Tensor: if self.layer_transfer_counter is not None: self.layer_transfer_counter.wait_until(layer_id - self.start_layer) return self.index_k_with_scale_buffer[layer_id - self.start_layer] def get_index_k_continuous( self, layer_id: int, seq_len: int, page_indices: torch.Tensor, ): if self.layer_transfer_counter is not None: self.layer_transfer_counter.wait_until(layer_id - self.start_layer) buf = self.index_k_with_scale_buffer[layer_id - self.start_layer] return index_buf_accessor.GetK.execute( self, buf, seq_len=seq_len, page_indices=page_indices ) def get_index_k_scale_continuous( self, layer_id: int, seq_len: int, page_indices: torch.Tensor, ): if self.layer_transfer_counter is not None: self.layer_transfer_counter.wait_until(layer_id - self.start_layer) buf = self.index_k_with_scale_buffer[layer_id - self.start_layer] return index_buf_accessor.GetS.execute( self, buf, seq_len=seq_len, page_indices=page_indices ) def get_index_k_scale_buffer( self, layer_id: int, seq_len_tensor: torch.Tensor, page_indices: torch.Tensor, seq_len_sum: int, max_seq_len: int, ): """ Fused method to get both index K and scale data in a single call using Triton. More efficient than calling get_index_k_continuous and get_index_k_scale_continuous separately. :param layer_id: Layer index :param seq_len: Sequence length :param page_indices: Page indices tensor :return: tuple of (k_fp8, k_scale) where k_fp8: (seq_len, index_head_dim), uint8 k_scale: (seq_len, 4), uint8 """ if self.layer_transfer_counter is not None: self.layer_transfer_counter.wait_until(layer_id - self.start_layer) buf = self.index_k_with_scale_buffer[layer_id - self.start_layer] return index_buf_accessor.GetKAndS.execute( self, buf, page_indices=page_indices, seq_len_tensor=seq_len_tensor, seq_len_sum=seq_len_sum, max_seq_len=max_seq_len, ) def set_index_k_scale_buffer( self, layer_id: int, loc: torch.Tensor, index_k: torch.Tensor, index_k_scale: torch.Tensor, ) -> None: buf = self.index_k_with_scale_buffer[layer_id - self.start_layer] index_buf_accessor.SetKAndS.execute( pool=self, buf=buf, loc=loc, index_k=index_k, index_k_scale=index_k_scale ) def get_state_buf_infos(self): data_ptrs = [ self.index_k_with_scale_buffer[i].data_ptr() for i in range(self.layer_num) ] data_lens = [ self.index_k_with_scale_buffer[i].nbytes for i in range(self.layer_num) ] item_lens = [ self.index_k_with_scale_buffer[i][0].nbytes for i in range(self.layer_num) ] return data_ptrs, data_lens, item_lens def get_kv_size_bytes(self): kv_size_bytes = super().get_kv_size_bytes() for index_k_cache in self.index_k_with_scale_buffer: kv_size_bytes += get_tensor_size_bytes(index_k_cache) return kv_size_bytes def move_kv_cache_native( k_buffer: List[torch.Tensor], v_buffer: List[torch.Tensor], tgt_loc: torch.Tensor, src_loc: torch.Tensor, ): if tgt_loc.numel() == 0: return tgt_loc_flat = tgt_loc.view(-1).long() src_loc_flat = src_loc.view(-1).long() for k_cache, v_cache in zip(k_buffer, v_buffer): k_cache[tgt_loc_flat] = k_cache[src_loc_flat] v_cache[tgt_loc_flat] = v_cache[src_loc_flat] @triton.jit def copy_all_layer_kv_cache_tiled( data_ptrs, strides, tgt_loc_ptr, src_loc_ptr, num_locs, num_locs_upper: tl.constexpr, BYTES_PER_TILE: tl.constexpr, ): """2D tiled kernel. Safe for in-place copy.""" bid = tl.program_id(0) tid = tl.program_id(1) stride = tl.load(strides + bid) base_ptr = tl.load(data_ptrs + bid) base_ptr = tl.cast(base_ptr, tl.pointer_type(tl.uint8)) byte_off = tid * BYTES_PER_TILE + tl.arange(0, BYTES_PER_TILE) mask_byte = byte_off < stride tl.multiple_of(byte_off, 16) loc_idx = tl.arange(0, num_locs_upper) mask_loc = loc_idx < num_locs src = tl.load(src_loc_ptr + loc_idx, mask=mask_loc, other=0) tgt = tl.load(tgt_loc_ptr + loc_idx, mask=mask_loc, other=0) src_ptr = base_ptr + src[:, None] * stride + byte_off[None, :] tgt_ptr = base_ptr + tgt[:, None] * stride + byte_off[None, :] mask = mask_loc[:, None] & mask_byte[None, :] vals = tl.load(src_ptr, mask=mask) tl.store(tgt_ptr, vals, mask=mask)