Ascend C 自定义算子 Kernel Launch调用入门

本文分享自华为云社区《Ascend C 自定义算子 Kernel Launch调用入门》，作者： jackwangcumt。

1 Kernel Launch概述

根据官方说明文档的介绍，Ascend C对外开放核函数的基础调用（Kernel Launch）方式，是为了简化Ascend C 自定义算子的开发流程，提供更易用的调试调优功能。当开发者完成算子核函数的开发和Tiling实现后，即可通过AscendCL运行时接口，完成算子的调用并实现自己的推理应用；同时提供简易的kernel开发工程，开发者仅需提供kernel侧实现，基于工程框架可以快速实现Kernel Launch。本文实验前提是完成了《Ascend C 自定义PRelu算子》博文的相关算子开发工程。网址为：https://bbs.huaweicloud.com/blogs/425244 。请注意：

• 8.0.RC1.alpha002 当前版本，Kernel Launch开放式编程为试用特性，不支持应用于商用产品中。
• 8.0.RC1.alpha002 当前版本暂不支持获取用户workspace特性。

2 Kernel Launch调用方式

ACLRT_LAUNCH_KERNEL调用方式对内核调用符方式进行了功能加强，核函数的调用是异步的，调用接口的使用方法如下：

ACLRT_LAUNCH_KERNEL(kernel_name)(blockDim, stream, argument list);

• kernel_name：算子核函数的名称。
• blockDim：规定了核函数将会在几个核上执行。每个执行该核函数的核会被分配一个逻辑ID，即block_idx，可以在核函数的实现中调用GetBlockIdx来获取block_idx。
• stream，类型为aclrtStream，stream用于维护一些异步操作的执行顺序，确保按照应用程序中的代码调用顺序在Device上执行。
• argument list：参数列表，与核函数的参数列表保持一致。

为帮助开发者快速的完成算子的Kernel Launch调试，官方提供了简易的算子工程，我们可以基于该算子工程中的样例代码和工程框架进行算子开发。算子工程支持的如下：

• 该工程支持调试功能，如PRINTF功能、DumpTensor。
• 工程编译生成的应用程序，可通过msprof命令行方式采集和解析性能数据。

可以参考工程样例：https://gitee.com/ascend/samples/blob/master/operator/AddCustomSample/KernelLaunch/AddKernelInvocationTilingNeo ，其目录结构如下所示：

AddKernelInvocationNeo |-- cmake // CMake编译文件 |-- scripts | ├── gen_data.py // 输入数据和真值数据生成脚本文件 | ├── verify_result.py // 验证输出数据和真值数据是否一致的验证脚本 |-- CMakeLists.txt // CMake编译配置文件 |-- add_custom.cpp // 矢量算子kernel实现 |-- data_utils.h // 数据读入写出函数 |-- main.cpp // 主函数，调用算子的应用程序，含CPU域及NPU域调用 |-- run.sh // 编译运行算子的脚本

基于该算子工程，开发者进行算子开发的步骤如下：

• 完成算子kernel侧实现。
• 编写算子调用应用程序main.cpp。

• 编写CMake编译配置文件CMakeLists.txt。

• 根据实际需要修改输入数据和真值数据生成脚本文件gen_data.py和验证输出数据和真值数据是否一致的验证脚本verify_result.py。
• 根据实际需要修改编译运行算子的脚本run.sh并执行该脚本，完成算子的编译运行和结果验证。

3 Kernel Launch实现

在PReluSample目录下新建一个目录KernelLaunch，用于存放Kernel Launch调用方式的工程代码，我这里参考官方的https://gitee.com/ascend/samples/tree/master/operator/LeakyReluCustomSample/KernelLaunch/

LeakyReluKernelInvocation样例工程，并修改了相关参数，p_relu_custom.cpp 代码如下所示：

#include "kernel_operator.h" using namespace AscendC; constexpr int32_t BUFFER_NUM = 2; constexpr int32_t TOTAL_LENGTH = 8 * 200 * 1024; constexpr int32_t TILE_NUM = 32; constexpr float alpha = 0.002; class KernelPRelu { public: __aicore__ inline KernelPRelu() {} __aicore__ inline void Init(GM_ADDR x, GM_ADDR y, uint32_t totalLength, uint32_t tileNum, float alpha) { PRINTF("[npu debug] >>> GetBlockNum() %d", GetBlockNum()); ASSERT(GetBlockNum() != 0 && "block dim can not be zero!"); this->blockLength = totalLength / GetBlockNum(); this->tileNum = tileNum; this->alpha = static_cast<float>(alpha); ASSERT(tileNum != 0 && "tile num can not be zero!"); this->tileLength = this->blockLength / tileNum / BUFFER_NUM; // get start index for current core, core parallel xGm.SetGlobalBuffer((__gm__ float*)x + this->blockLength * GetBlockIdx(), this->blockLength); yGm.SetGlobalBuffer((__gm__ float*)y + this->blockLength * GetBlockIdx(), this->blockLength); // pipe alloc memory to queue, the unit is Bytes pipe.InitBuffer(inQueueX, BUFFER_NUM, this->tileLength * sizeof(float)); pipe.InitBuffer(outQueueY, BUFFER_NUM, this->tileLength * sizeof(float)); pipe.InitBuffer(tmpBuffer1, this->tileLength * sizeof(float)); //pipe.InitBuffer(tmpBuffer2, this->tileLength * sizeof(float)); } __aicore__ inline void Process() { // loop count need to be doubled, due to double buffer int32_t loopCount = this->tileNum * BUFFER_NUM; // tiling strategy, pipeline parallel for (int32_t i = 0; i < loopCount; i++) { CopyIn(i); Compute(i); CopyOut(i); } } private: __aicore__ inline void CopyIn(int32_t progress) { // alloc tensor from queue memory LocalTensor<float> xLocal = inQueueX.AllocTensor<float>(); // copy progress_th tile from global tensor to local tensor DataCopy(xLocal, xGm[progress * this->tileLength], this->tileLength); // enque input tensors to VECIN queue inQueueX.EnQue(xLocal); } __aicore__ inline void Compute(int32_t progress) { // deque input tensors from VECIN queue LocalTensor<float> xLocal = inQueueX.DeQue<float>(); LocalTensor<float> yLocal = outQueueY.AllocTensor<float>(); LocalTensor<float> tmpTensor1 = tmpBuffer1.Get<float>(); float inputVal = 0.0; Maxs(tmpTensor1, xLocal, inputVal, this->tileLength); // x >= 0 --> x // x < 0 Mins(xLocal, xLocal, inputVal, this->tileLength); Muls(xLocal, xLocal, this->alpha, this->tileLength); Add(yLocal, xLocal, tmpTensor1, this->tileLength); outQueueY.EnQue<float>(yLocal); // free input tensors for reuse inQueueX.FreeTensor(xLocal); } __aicore__ inline void CopyOut(int32_t progress) { // deque output tensor from VECOUT queue LocalTensor<float> yLocal = outQueueY.DeQue<float>(); // copy progress_th tile from local tensor to global tensor DataCopy(yGm[progress * this->tileLength], yLocal, this->tileLength); // free output tensor for reuse outQueueY.FreeTensor(yLocal); } private: TPipe pipe; TBuf<QuePosition::VECCALC> tmpBuffer1; //TBuf<QuePosition::VECCALC> tmpBuffer1, tmpBuffer2; // create queues for input, in this case depth is equal to buffer num TQue<QuePosition::VECIN, BUFFER_NUM> inQueueX; // create queue for output, in this case depth is equal to buffer num TQue<QuePosition::VECOUT, BUFFER_NUM> outQueueY; GlobalTensor<float> xGm, yGm; uint32_t blockLength; uint32_t tileNum; uint32_t tileLength; float alpha; }; extern "C" __global__ __aicore__ void p_relu_custom(GM_ADDR x, GM_ADDR y) { //GET_TILING_DATA(tiling_data, tiling); // TODO: user kernel impl KernelPRelu op; op.Init(x, y, TOTAL_LENGTH, TILE_NUM, alpha); op.Process(); } #ifndef __CCE_KT_TEST__ // call of kernel function void p_relu_custom_do(uint32_t blockDim, void* l2ctrl, void* stream, uint8_t* x, uint8_t* y) { p_relu_custom<<<blockDim, l2ctrl, stream>>>(x, y); } #endif

main.cpp 代码如下所示 :

/* * Copyright (c) Huawei Technologies Co., Ltd. 2022-2023. All rights reserved. * This file constains code of cpu debug and npu code.We read data from bin file * and write result to file. */ #include "data_utils.h" #ifndef __CCE_KT_TEST__ #include "acl/acl.h" extern void p_relu_custom_do(uint32_t coreDim, void* l2ctrl, void* stream, uint8_t* x, uint8_t* y); #else #include "tikicpulib.h" extern "C" __global__ __aicore__ void p_relu_custom(GM_ADDR x, GM_ADDR y); #endif int32_t main(int32_t argc, char* argv[]) { uint32_t blockDim = 8; size_t inputByteSize = 8 * 200 * 1024 * sizeof(float); size_t outputByteSize = 8 * 200 * 1024 * sizeof(float); #ifdef __CCE_KT_TEST__ // CPU uint8_t* x = (uint8_t*)AscendC::GmAlloc(inputByteSize); uint8_t* y = (uint8_t*)AscendC::GmAlloc(outputByteSize); printf("[cpu debug]>>> inputByteSize: %d\n", inputByteSize); ReadFile("./input/input_x.bin", inputByteSize, x, inputByteSize); AscendC::SetKernelMode(KernelMode::AIV_MODE); ICPU_RUN_KF(p_relu_custom, blockDim, x, y); // use this macro for cpu debug WriteFile("./output/output_y.bin", y, outputByteSize); AscendC::GmFree((void *)x); AscendC::GmFree((void *)y); #else // NPU //CHECK_ACL(aclInit(nullptr)); CHECK_ACL(aclInit("./acl.json")); aclrtContext context; int32_t deviceId = 0; CHECK_ACL(aclrtSetDevice(deviceId)); CHECK_ACL(aclrtCreateContext(&context, deviceId)); aclrtStream stream = nullptr; CHECK_ACL(aclrtCreateStream(&stream)); uint8_t *xHost, *yHost; uint8_t *xDevice, *yDevice; CHECK_ACL(aclrtMallocHost((void**)(&xHost), inputByteSize)); CHECK_ACL(aclrtMallocHost((void**)(&yHost), outputByteSize)); CHECK_ACL(aclrtMalloc((void**)&xDevice, inputByteSize, ACL_MEM_MALLOC_HUGE_FIRST)); CHECK_ACL(aclrtMalloc((void**)&yDevice, outputByteSize, ACL_MEM_MALLOC_HUGE_FIRST)); ReadFile("./input/input_x.bin", inputByteSize, xHost, inputByteSize); CHECK_ACL(aclrtMemcpy(xDevice, inputByteSize, xHost, inputByteSize, ACL_MEMCPY_HOST_TO_DEVICE)); p_relu_custom_do(blockDim, nullptr, stream, xDevice, yDevice); CHECK_ACL(aclrtSynchronizeStream(stream)); CHECK_ACL(aclrtMemcpy(yHost, outputByteSize, yDevice, outputByteSize, ACL_MEMCPY_DEVICE_TO_HOST)); WriteFile("./output/output_y.bin", yHost, outputByteSize); CHECK_ACL(aclrtFree(xDevice)); CHECK_ACL(aclrtFree(yDevice)); CHECK_ACL(aclrtFreeHost(xHost)); CHECK_ACL(aclrtFreeHost(yHost)); CHECK_ACL(aclrtDestroyStream(stream)); CHECK_ACL(aclrtDestroyContext(context)); CHECK_ACL(aclrtResetDevice(deviceId)); CHECK_ACL(aclFinalize()); #endif return 0; }

执行如下代码进行NPU上板调试和CPU调试：

#npu bash run.sh Ascend310P1 npu_onboard # cpu bash run.sh Ascend310P1 cpu

 

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