如何清除opencl代码中的CL_INVALID_PLATFORM错误? [英] How to remove CL_INVALID_PLATFORM error in opencl code?

问题描述

使用OpenCL进行简单的矩阵乘法:

Doing simple matrix multiplication using OpenCL:

// Multiply two matrices A * B = C

#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <oclUtils.h>

#define WA 3
#define HA 3
#define WB 3
#define HB 3
#define WC 3
#define HC 3

// Allocates a matrix with random float entries.
void randomInit(float* data, int size)
{
   for (int i = 0; i < size; ++i)
   data[i] = rand() / (float)RAND_MAX;
}

/////////////////////////////////////////////////////////
// Program main
/////////////////////////////////////////////////////////

int
main(int argc, char** argv)
{

   // set seed for rand()
   srand(2006);

   // 1. allocate host memory for matrices A and B
   unsigned int size_A = WA * HA;
   unsigned int mem_size_A = sizeof(float) * size_A;
   float* h_A = (float*) malloc(mem_size_A);

   unsigned int size_B = WB * HB;
   unsigned int mem_size_B = sizeof(float) * size_B;
   float* h_B = (float*) malloc(mem_size_B);

   // 2. initialize host memory
   randomInit(h_A, size_A);
   randomInit(h_B, size_B);

   // 3. print out A and B
   printf("\n\nMatrix A\n");
   for(int i = 0; i < size_A; i++)
   {
      printf("%f ", h_A[i]);
      if(((i + 1) % WA) == 0)
      printf("\n");
   }

   printf("\n\nMatrix B\n");
   for(int i = 0; i < size_B; i++)
   {
      printf("%f ", h_B[i]);
      if(((i + 1) % WB) == 0)
      printf("\n");
   }

   // 4. allocate host memory for the result C
   unsigned int size_C = WC * HC;
   unsigned int mem_size_C = sizeof(float) * size_C;
   float* h_C = (float*) malloc(mem_size_C);

   // 5. Initialize OpenCL
   // OpenCL specific variables
   cl_context clGPUContext;
   cl_command_queue clCommandQue;
   cl_program clProgram;
   cl_kernel clKernel;

   size_t dataBytes;
   size_t kernelLength;
   cl_int errcode;

   // OpenCL device memory for matrices
   cl_mem d_A;
   cl_mem d_B;
   cl_mem d_C;

   /*****************************************/
   /* Initialize OpenCL */
   /*****************************************/

   clGPUContext = clCreateContextFromType(0, 
                   CL_DEVICE_TYPE_GPU, 
                   NULL, NULL, &errcode);
   shrCheckError(errcode, CL_SUCCESS);

   // get the list of GPU devices associated 
   // with context
   errcode = clGetContextInfo(clGPUContext, 
              CL_CONTEXT_DEVICES, 0, NULL, 
              &dataBytes);
   cl_device_id *clDevices = (cl_device_id *)
              malloc(dataBytes);
   errcode |= clGetContextInfo(clGPUContext, 
              CL_CONTEXT_DEVICES, dataBytes, 
              clDevices, NULL);
   //shrCheckError(errcode, CL_SUCCESS);

   //Create a command-queue
   clCommandQue = clCreateCommandQueue(clGPUContext, 
                  clDevices[0], 0, &errcode);
   //shrCheckError(errcode, CL_SUCCESS);

   // Setup device memory
   d_C = clCreateBuffer(clGPUContext, 
          CL_MEM_READ_WRITE, 
          mem_size_A, NULL, &errcode);
   d_A = clCreateBuffer(clGPUContext, 
          CL_MEM_READ_WRITE | CL_MEM_COPY_HOST_PTR, 
          mem_size_A, h_A, &errcode);
   d_B = clCreateBuffer(clGPUContext, 
          CL_MEM_READ_WRITE | CL_MEM_COPY_HOST_PTR, 
          mem_size_B, h_B, &errcode);


   // 6. Load and build OpenCL kernel
   char *clMatrixMul = oclLoadProgSource("kernel.cl",
                        "// My comment\n", 
                        &kernelLength);
   //shrCheckError(clMatrixMul != NULL, shrTRUE);

   clProgram = clCreateProgramWithSource(clGPUContext, 
                1, (const char **)&clMatrixMul, 
                &kernelLength, &errcode);
   //shrCheckError(errcode, CL_SUCCESS);

   errcode = clBuildProgram(clProgram, 0, 
              NULL, NULL, NULL, NULL);
   //shrCheckError(errcode, CL_SUCCESS);

   clKernel = clCreateKernel(clProgram, 
               "matrixMul", &errcode);
   //shrCheckError(errcode, CL_SUCCESS);


   // 7. Launch OpenCL kernel
   size_t localWorkSize[2], globalWorkSize[2];

   int wA = WA;
   int wC = WC;
   errcode = clSetKernelArg(clKernel, 0, 
              sizeof(cl_mem), (void *)&d_C);
   errcode |= clSetKernelArg(clKernel, 1, 
              sizeof(cl_mem), (void *)&d_A);
   errcode |= clSetKernelArg(clKernel, 2, 
              sizeof(cl_mem), (void *)&d_B);
   errcode |= clSetKernelArg(clKernel, 3, 
              sizeof(int), (void *)&wA);
   errcode |= clSetKernelArg(clKernel, 4, 
              sizeof(int), (void *)&wC);
   //shrCheckError(errcode, CL_SUCCESS);

   localWorkSize[0] = 3;
   localWorkSize[1] = 3;
   globalWorkSize[0] = 3;
   globalWorkSize[1] = 3;

   errcode = clEnqueueNDRangeKernel(clCommandQue, 
              clKernel, 2, NULL, globalWorkSize, 
              localWorkSize, 0, NULL, NULL);
   //shrCheckError(errcode, CL_SUCCESS);

   // 8. Retrieve result from device
   errcode = clEnqueueReadBuffer(clCommandQue, 
              d_C, CL_TRUE, 0, mem_size_C, 
              h_C, 0, NULL, NULL);
   //shrCheckError(errcode, CL_SUCCESS);

   // 9. print out the results
   printf("\n\nMatrix C (Results)\n");
   for(int i = 0; i < size_C; i++)
   {
      printf("%f ", h_C[i]);
      if(((i + 1) % WC) == 0)
      printf("\n");
   }
   printf("\n");

   // 10. clean up memory
   free(h_A);
   free(h_B);
   free(h_C);

   clReleaseMemObject(d_A);
   clReleaseMemObject(d_C);
   clReleaseMemObject(d_B);

   free(clDevices);
   free(clMatrixMul);
   clReleaseContext(clGPUContext);
   clReleaseKernel(clKernel);
   clReleaseProgram(clProgram);
   clReleaseCommandQueue(clCommandQue);

}

在上面的代码中，我总是在该位置出现错误:

In the above code I keep getting error at the place :

/ * ** * ** * ** * ** * ** * ** * *** //初始化OpenCL // ** * ** * ** * ** * ** * ** * ** * * / clGPUContext = clCreateContextFromType(0， CL_DEVICE_TYPE_GPU， NULL，NULL和& errcode); shrCheckError(errcode，CL_SUCCESS);

/**********************/ / Initialize OpenCL / /**********************/ clGPUContext = clCreateContextFromType(0, CL_DEVICE_TYPE_GPU, NULL, NULL, &errcode); shrCheckError(errcode, CL_SUCCESS);

返回的错误代码为-32，表示:CL_INVALID_PLATFORM"

The error code being returned is -32 that means: CL_INVALID_PLATFORM"

如何清除此错误?

OS:Windows 7、32位，NVIDIA GPU GeForce 610

OS: Windows 7, 32 bit, NVIDIA GPU GeForce 610

推荐答案

Nvidia驱动程序希望您提供一个非NULL属性指针作为clCreateContextFromType调用的第一个参数.

The Nvidia drivers expect you to provide a non-NULL properties pointer as first argument to the clCreateContextFromType call.

clCreateContextFromType的Khronos规范指出，如果为properties参数传递NULL，则所选平台取决于实现.对于Nvidia，选择似乎是如果传递了NULL指针，则根本不会选择任何平台.有关更多信息，请参见 clCreateContextFromType .

The Khronos specification for clCreateContextFromType states that if NULL is passed for the properties parameter, the platform that is selected is implementation dependent. In case of Nvidia the choice seems to be that no platform at all is selected if a NULL pointer is passed. See clCreateContextFromType for more information.

另一方面，此行为与 cl_khr_icd扩展名，如果您通过ICD使用OpenCL，则该扩展名将适用，并指出:

On the other hand, this behavior is consistent with Issue #3 in the cl_khr_icd extension, which would apply if you are using OpenCL through the ICD, and which states:

3: How will the ICD handle a NULL cl_platform_id?

RESOLVED: The NULL platform is not supported by the ICD.

要将属性传递给clCreateContextFromType，请首先使用clGetPlatformIDs查询平台.然后使用所需的平台ID构造一个属性数组，并将其传递给clCreateContextFromType.符合C99的编译器应遵循以下内容:

To pass the properties to clCreateContextFromType, first query the platforms with clGetPlatformIDs. Then construct a properties array with the desired platform ID and pass it to clCreateContextFromType. Something along the following lines should work with a C99 compliant compiler:

   // query the number of platforms
   cl_uint numPlatforms;
   errcode = clGetPlatformIDs(0, NULL, &numPlatforms);
   shrCheckError(errcode, CL_SUCCESS); 

   // now get all the platform IDs
   cl_platform_id platforms[numPlatforms];
   errcode = clGetPlatformIDs(numPlatforms, platforms, NULL);
   shrCheckError(errcode, CL_SUCCESS);

   // set platform property - we just pick the first one
   cl_context_properties properties[] = {CL_CONTEXT_PLATFORM, (int) platforms[0], 0};
   clGPUContext = clCreateContextFromType(properties, CL_DEVICE_TYPE_GPU, NULL, NULL, &errcode);
   shrCheckError(errcode, CL_SUCCESS);

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