TensorRT-LLMs/cpp/include/tensorrt_llm/batch_manager/kvCacheTransferManager.h
2025-03-11 21:13:42 +08:00

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2.5 KiB
C++

/*
* Copyright (c) 2022-2024, NVIDIA CORPORATION. All rights reserved.
*
* 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.
*/
#include "tensorrt_llm/batch_manager/kvCacheManager.h"
#include "tensorrt_llm/runtime/bufferManager.h"
#include "tensorrt_llm/runtime/cudaEvent.h"
namespace tr = tensorrt_llm::runtime;
#pragma once
namespace tensorrt_llm::batch_manager::kv_cache_manager
{
// The TransferManager accelerates transfers to/from the GPU by overlapping HtoD and DtoH transfers, and tracks ongoing
// transfers in order to avoid race conditions. It is functionally equivalent to the prior approach of putting all
// transfers into the forward pass stream. This is only ever used as a component of a KVCacheManager.
class KVCacheTransferManager
{
public:
explicit KVCacheTransferManager(tr::BufferManager const& bufferManager);
//! \brief Onboard a block to gpu memory.
void onboard(BlockPtr const& offloadBlock, BlockPtr const& block, std::vector<KVCacheBlockPool> const& pools,
int numTokensToCopy = 0);
//! \brief Offload a block to cpu memory.
void offload(BlockPtr const& block, BlockPtr const& offloadBlock, std::vector<KVCacheBlockPool> const& pools,
int numTokensToCopy = 0);
//! \brief Synchronize the offload/onboard streams with the bufferManager stream.
void syncTransfers();
private:
//! \brief Get pointer to pool specified by cache block.
static tr::ITensor::SharedPtr computeBlockPointer(
BlockPtr const& block, std::vector<KVCacheBlockPool> const& pools, size_t poolIdx);
//! \brief Copy content of src block to dst.
void copyBlock(BlockPtr const& src, BlockPtr const& dst, std::vector<KVCacheBlockPool> const& pools, bool isOffload,
int numTokensToCopy = 0);
runtime::BufferManager mBufferManager;
runtime::BufferManager mOnboardManager;
runtime::BufferManager mOffloadManager;
// Track the block ids offloaded in this iteration.
std::unordered_map<int32_t, tr::CudaEvent> mPendingOffloads;
};
} // namespace tensorrt_llm::batch_manager::kv_cache_manager