ManagedCuda：IllegalAddress;而执行内核 [英] ManagedCuda: IllegalAddress; While Executing a Kernel

问题描述

我在C＃项目中使用ManagedCuda库来使用GPU，目前我正在跟踪此

一切似乎都与我的代码工作正常，内核被发现，内置和方法调用执行，但我得到一个错误：

ManagedCuda.dll中发生未处理的类型为ManagedCuda.CudaException的异常

其他信息：ErrorIllegalAddress：一个内核，设备
在一个无效的内存地址上遇到一个加载或存储指令。

上下文不能使用，所以它必须被销毁（并且应该创建一个新的）。


我理解C＃抱怨在尝试传递设备指针时找不到有效地址到内核​​，唯一的区别，我可以告诉我的代码和在引用的教程中的帖子，是ManagedCuda似乎最近有一个整容，允许用户使用Lambdas，我做了一些阅读，没有找到任何东西以澄清这是否导致我的问题：

  static Func< int，int，int& cudaAdd =（a，b）=> 
 {
 // init输出参数
 CudaDeviceVariable< int> result_dev = 0; 
 int result_host = 0; 
 //运行CUDA方法
 addWithCuda.Run（a，b，result_dev.DevicePointer）; < ---代码在这里抛出错误
 //复制返回主机
 result_dev.CopyToHost（ref result_host）; 
 return result_host; 
};在原始教程代码中，OP使用 CudaDeviceVariable result_dev = 0;   code>。这可能是问题吗？我不知道为什么会这样，但也许我的演员是错误的？
 
 
 
为了清楚这里是被调用的内核：
  __ global__ void kernel（int a，int b，int * c）
 {
 * c =（a + b）* a + b）; 
} 
  
 
 
解决方案
抛出的异常是由于运行在不同的线程。在单线程环境中，示例代码运行良好，返回正确的结果。为了在多线程应用程序中使用Cuda，必须正确同步线程并将cuda上下文绑定到当前活动的线程。
 
I am using the ManagedCuda library in a C# project to utilise the GPU, currently I am following along with this tutorial regarding how to write code compatible between C# and C++ after failing to achieve it with OpenCV.

Everything seems to be working fine with my code, the kernel is found, built and the method call is executed however I am getting an error: 
An unhandled exception of type 'ManagedCuda.CudaException' occurred in ManagedCuda.dll

Additional information: ErrorIllegalAddress: While executing a kernel, the device 
encountered a load or store instruction on an invalid memory address.

The context cannot be used, so it must be destroyed (and a new one should be created).
I understand that C# is complaining that a valid address is not found when it attempts to pass the device pointer to the kernel, the only difference I can tell between my code and the post in the cited tutorial, is that ManagedCuda seems to have recently had a facelift which allows users to use Lambdas, I've done some reading and haven't found anything to clarify whether or not this is what's causing my problem:
static Func<int, int, int> cudaAdd = (a, b) =>
{
    // init output parameters
    CudaDeviceVariable<int> result_dev = 0;
    int result_host = 0;
    // run CUDA method
    addWithCuda.Run(a, b, result_dev.DevicePointer);   <--- Code throws error here
    // copy return to host
    result_dev.CopyToHost(ref result_host);
    return result_host;
};
In the original tutorial code the OP uses CudaDeviceVariable result_dev = 0;. Could this be the problem? I don't see why it would be, but maybe my cast is wrong?

For clarity here is the kernel which is being called:
__global__ void kernel(int a, int b, int *c)
{
    *c = (a + b)*(a + b);
}

解决方案
From the comments it seems that the thrown exception is due to running on different threads. In a single threaded environment the sample code runs fine returning the right result. In order to use Cuda in a multithreaded application, proper synchronization of the threads and binding the cuda context to the currently active threads would be necessary.

                        
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