C++ cuda错误:意外启动失败

C++ cuda错误:意外启动失败,c++,cuda,C++,Cuda,我是cuda的新手,我正在尝试在cuda上实现数值积分 我的代码出现错误“意外启动失败”。它看起来像是gpu内存中的某个故障。但这很奇怪,因为它依赖于变量step,该变量控制迭代次数,而不是任何内存操作。例如,当我使用step=0.00001运行integrate\u with_cuda时,它工作正常,结果是正确的,但如果我在0.000001上更改step,我的程序将失败 这是我的代码: #include "device_launch_parameters.h" #include "cuda_r

我是cuda的新手,我正在尝试在cuda上实现数值积分

我的代码出现错误“意外启动失败”。它看起来像是gpu内存中的某个故障。但这很奇怪,因为它依赖于变量
step
,该变量控制迭代次数,而不是任何内存操作。例如,当我使用
step=0.00001
运行
integrate\u with_cuda
时,它工作正常,结果是正确的,但如果我在
0.000001
上更改
step
,我的程序将失败

这是我的代码:

#include "device_launch_parameters.h"
#include "cuda_runtime_api.h"
#include "cuda.h"
#include "cuda_safe_call.h"
#include <cmath>
#include <iostream>

typedef double(*cuda_func)(double, double);

struct cuda_expr {
    cuda_func func;
    int dest;
    int op1;
    int op2;
};

enum cuda_method {
    cm_Add,
    cm_Mult
};

__device__ double add_func(double x, double y) {
    return x + y;
}
__device__ cuda_func p_add_func = add_func;

__device__ double mult_func(double x, double y) {
    return x*y;
}
__device__ cuda_func p_mult_func = mult_func;

__host__ cuda_func get_cuda_func(cuda_method method) {
    cuda_func result = NULL;

    switch (method) {
    case cm_Add:
        cudaMemcpyFromSymbol(&result, p_add_func, sizeof(cuda_func));
        break;
    case cm_Mult:
        cudaMemcpyFromSymbol(&result, p_mult_func, sizeof(cuda_func));
        break;
    }
    return result;
}

__device__ double atomicAdd(double* address, double val)
{
    unsigned long long int* address_as_ull =
        (unsigned long long int*)address;
    unsigned long long int old = *address_as_ull, assumed;
    do {
        assumed = old;
        old = atomicCAS(address_as_ull, assumed,
            __double_as_longlong(val +
            __longlong_as_double(assumed)));
    } while (assumed != old);
    return __longlong_as_double(old);
}

__device__ void computate_expr(cuda_expr* expr, int expr_length, double* vars, int vars_count) {
    for (cuda_expr* step = expr, *end = expr + expr_length; step != end; ++step) {
        vars[step->dest] = (*step->func)(vars[step->op1], vars[step->op2]);
    }
}

__device__ double simpson_step(cuda_expr* expr, int expr_length, double* vars, int vars_count, double a, double b, double c) {
    double f_a;
    double f_b;
    double f_c;
    vars[0] = a;
    computate_expr(expr, expr_length, vars, vars_count);
    f_a = vars[vars_count - 1];
    vars[0] = b;
    computate_expr(expr, expr_length, vars, vars_count);
    f_b = vars[vars_count - 1]; 
    vars[0] = c;
    computate_expr(expr, expr_length, vars, vars_count);
    f_c = vars[vars_count - 1];
    return (c - a) / 6 * (f_a + 4 * f_b + f_c);
}

__global__ void integrate_kernel(cuda_expr* expr, int expr_length, double* vars, int vars_count, double from, double to, double step, double* res) {
    int index = blockIdx.x*blockDim.x + threadIdx.x;
    int threads_count = gridDim.x*blockDim.x;
    double* my_vars = vars + index * vars_count;

    double my_from = from + index*(to - from) / threads_count;
    double my_to = from + (index + 1)*(to - from) / threads_count;

    double my_res = 0;

    double a = my_from;
    double b = my_from + step / 2;
    double c = my_from + step;

    while (c < (my_to + step / 10)) {
        my_res += simpson_step(expr, expr_length, my_vars, vars_count, a, b, c);
        a += step;
        b += step;
        c += step;
    }
    atomicAdd(res, my_res);
}

__host__ double integrate_with_cuda(const cuda_expr* expr, int expr_length, double* vars, int vars_count, double from, double to, double step) {
    const int blockSize = 32;
    const int gridSize = 2;
    const int threadsCount = blockSize*gridSize;

    cuda_expr* d_expr;
    CudaSafeCall(cudaMalloc((void**)&d_expr, expr_length*sizeof(cuda_expr)));
    CudaSafeCall(cudaMemcpy(d_expr, expr, expr_length*sizeof(cuda_expr), cudaMemcpyHostToDevice));

    double* d_vars;    //allocate own vars array for every thread
    CudaSafeCall(cudaMalloc((void**)&d_vars, threadsCount*vars_count*sizeof(double)));
    for (int i = 0; i < threadsCount; ++i) {
        CudaSafeCall(cudaMemcpy(d_vars + i*vars_count, vars, vars_count*sizeof(double), cudaMemcpyHostToDevice));
    }

    double* d_res;
    double result = 0;
    CudaSafeCall(cudaMalloc((void**)&d_res, sizeof(double)));
    CudaSafeCall(cudaMemcpy(d_res, &result, sizeof(double), cudaMemcpyHostToDevice));

    integrate_kernel<<<gridSize, blockSize>>>(d_expr, expr_length, d_vars, vars_count, from, to, step, d_res);

    CudaSafeCall(cudaMemcpy(&result, d_res, sizeof(double), cudaMemcpyDeviceToHost));

    CudaSafeCall(cudaFree(d_expr));
    CudaSafeCall(cudaFree(d_vars));
    CudaSafeCall(cudaFree(d_res));
    return result;
}

int main() {
    cuda_expr expr[3] = {
        { get_cuda_func(cuda_method::cm_Add), 4, 1, 0 },
        { get_cuda_func(cuda_method::cm_Add), 3, 0, 2 },
        { get_cuda_func(cuda_method::cm_Mult), 5, 3, 4 }
    };
    double vars[6] = {0, 10, 1, 0, 0, 0};

    double res = integrate_with_cuda(expr, 3, vars, 6, 0, 10, 0.00001);

    std::cout << res << std::endl;
    system("PAUSE");
}

谢谢。对不起,我的英文是:)

当我在linux上运行你的代码时,我得到了983.333,不管我是将
步骤指定为0.00001还是0.000001。然而,对于较小的步骤,代码运行的时间要长得多

由于您是在windows上运行的,这可能只不过是您点击。在windows上运行超过2秒的内核可能会触发TDR机制。通常在这种情况下,当GPU通过windows触发重置时,您会看到屏幕闪烁为黑色,然后重新绘制自身。您还可能会看到systray消息。如果从VS内部运行代码,与从命令行运行代码相比,确切的行为也可能有所不同


有关如何修改TDR机制的信息,请参考上述链接或在CUDA标签上搜索。

是,谢谢!我实际上看到了屏幕上的闪光和关于恢复GPU驱动程序的信息。
nvcc.exe -gencode=arch=compute_30,code=\"sm_30,compute_30\" --use-local-env --cl-version 2012 -ccbin "C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\bin\x86_amd64"  -I"C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v6.0\include" -I"C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v6.0\include"     --keep-dir x64\Tests -maxrregcount=0  --machine 64 --compile -cudart static     -DWIN32 -D_DEBUG -D_UNICODE -DUNICODE -Xcompiler "/EHsc /W3 /nologo /Od /Zi  /MDd  " -o x64\Tests\integration_on_cuda.cu.obj integration_on_cuda.cu