在 DPC++ 向量加法中给出更大数组大小的随机退出代码

Question

我正在尝试运行 oneAPI 的 hello-world DPC++ 示例，它在 CPU 和 GPU 上添加两个一维数组，并验证结果。代码如下：

/*
DataParallel Addition of two Vectors
*/

#include <CL/sycl.hpp>
#include <array>
#include <iostream>
using namespace sycl;

constexpr size_t array_size = 100000;
typedef std::array<int, array_size> IntArray;

// Initialize array with the same value as its index
void InitializeArray(IntArray& a) { for (size_t i = 0; i < a.size(); i++) a[i] = i; }

/*
Create an asynchronous Exception Handler for sycl
*/
static auto exception_handler = [](cl::sycl::exception_list eList) {
    for (std::exception_ptr const& e : eList) {
        try {
            std::rethrow_exception(e);
        }
        catch (std::exception const& e) {
            std::cout << "Failure" << std::endl;
            std::terminate();
        }
    }
};

void VectorAddParallel(queue &q, const IntArray& x, const IntArray& y, IntArray& parallel_sum) {
    range<1> num_items{ x.size() };
    
    buffer x_buf(x);
    buffer y_buf(y);
    buffer sum_buf(parallel_sum.data(), num_items);

    /*
    Submit a command group to the queue by a lambda
    which contains data access permissions and device computation
    */
    q.submit([&](handler& h) {

        auto xa = x_buf.get_access<access::mode::read>(h);
        auto ya = y_buf.get_access<access::mode::read>(h);
        auto sa = sum_buf.get_access<access::mode::write>(h);

        std::cout << "Adding on GPU (Parallel)\n";
        h.parallel_for(num_items, [=](id<1> i) { sa[i] = xa[i] + ya[i]; });
        std::cout << "Done on GPU (Parallel)\n";
    });

    /*
    queue runs the kernel asynchronously. Once beyond the scope,
    buffers' data is copied back to the host.
    */
}

int main() {
    default_selector d_selector;
    IntArray a, b, sequential, parallel;

    InitializeArray(a);
    InitializeArray(b);

    try {
        // Queue needs: Device and Exception handler
        queue q(d_selector, exception_handler);
        
        std::cout << "Accelerator: " 
                  << q.get_device().get_info<info::device::name>() << "\n";
        std::cout << "Vector size: " << a.size() << "\n";
        VectorAddParallel(q, a, b, parallel);
    }
    catch (std::exception const& e) {
        std::cout << "Exception while creating Queue. Terminating...\n";
        std::terminate();
    }
    
    /*
    Do the sequential, which is supposed to be slow
    */
    std::cout << "Adding on CPU (Scalar)\n";
    for (size_t i = 0; i < sequential.size(); i++) {
        sequential[i] = a[i] + b[i];
    }
    std::cout << "Done on CPU (Scalar)\n";
    
    /*
    Verify results, the old-school way
    */
    for (size_t i = 0; i < parallel.size(); i++) {
        if (parallel[i] != sequential[i]) {
            std::cout << "Fail: " << parallel[i] << " != " << sequential[i] << std::endl;
            std::cout << "Failed. Results do not match.\n";
            return -1;
        }
    }
    std::cout << "Success!\n";
    return 0;
}

相对较小的 array_size，（我测试了 100-50k 个元素）计算结果很好。示例输出：

Accelerator: Intel(R) Gen9
Vector size: 50000
Adding on GPU (Parallel)
Done on GPU (Parallel)
Adding on CPU (Scalar)
Done on CPU (Scalar)
Success!

可以注意到，在 CPU 和 GPU 上完成计算只需要一秒钟。但是当我增加 array_size 时，也就是说，100000，我得到了这个看似毫无头绪的错误：

C:\Users\myuser\source\repos\dpcpp-iotas\x64\Debug\dpcpp-iotas.exe (process 24472) exited with code -1073741571.

虽然我不确定错误开始发生的精确值，但我似乎可以肯定它发生在大约 70000 之后。我似乎不知道为什么会这样，对什么地方可能出错有任何见解吗？

Answer 1

事实证明，这是由于 VS 对 Stack size 进行了强化。元素过多的连续数组导致堆栈溢出。

如@user4581301所述，十六进制的错误代码-107374171给出C00000FD，这是Visual Studio中'stack exhaustion/overflow'的符号表示。

解决此问题的方法：

在“项目属性”>“链接器”>“系统”>“堆栈”Reserve/Commit 值中将 /STACK 保留增加到高于 1MB（这是默认值）。
使用二进制编辑器（editbin.exe 和 dumpbin.exe）编辑 /STACK:reserve。
改用std::vector，它允许动态分配（@Retired Ninja 建议）。

我在 oneAPI 中找不到更改 /STACK 的选项，链接器属性中的正常方式显示 here。

我决定采用动态分配。

在 DPC++ 向量加法中给出更大数组大小的随机退出代码

Random exit code on giving larger array sizes in DPC++ Vector Addition

c++

opencl

sycl

intel-oneapi

dpc++