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c++cuda:构造函数外部的cudaMallocManaged访问

cuda c++

Tommy · 技术社区 · 6 年前

我有一个c++类,它使用CUDAmallocManager,如下所示:

MyMatrix::MyMatrix(int new_rows, int new_cols, int padrr, int padcc)
{
  rows = new_rows;
  cols = new_cols;
  padr = padrr;
  padc = padcc;

  cout << "allocating memory" << endl;
  float *data;
  cudaError_t cudaStatus = cudaMallocManaged(&data, new_rows*new_cols*sizeof(float));
  if (cudaStatus != cudaSuccess){
      cout << cudaStatus << endl << flush;
      exit(1);
  }
  cudaDeviceSynchronize();
  cout << "allocating memory successful:" << cudaStatus << endl;
  // I CAN ACCESS DATA HERE
  //data[15] = 5.5; //fine
}
MyMatrix::~MyMatrix(void)
{
 cudaFree(data); // delete the data array
}

我有一个标题 .h

class MyMatrix
{

  public:
      MyMatrix(int new_rows, int new_cols, int padr, int padt);
      ~MyMatrix(void);

      float *data;
      int padr;
      int padc;
      int rows;
      int cols;
}

在内部 这个构造器。

但是,一旦我尝试在它之外访问它(读或写),我就会 terminated by signal SIGSEGV (Address boundary error)

MyMatrix *newmat = new MyMatrix(totalr, totalc, padr, padc);
cout << (*newmat).data[0] << endl;

或者

MyMatrix newmat = new MyMatrix(totalr, totalc, padr, padc);
cout << newmat.data[0] << endl;

2 回复 | 直到 6 年前

CygnusX1 Stack Overflow is garbage 6 年前

data :

float *data;

分配cuda内存并将值赋给局部变量之后 数据 ,内存地址似乎不会永久存储在任何地方。所以,你的记忆变得无法到达。

你有这条线吗 newmat.data ,但在构造函数中,从未为成员赋值 数据

NathanOliver 6 年前

你的问题是

MyMatrix::MyMatrix(int new_rows, int new_cols, int padrr, int padcc)
{
  rows = new_rows;
  cols = new_cols;
  padr = padrr;
  padc = padcc;

  cout << "allocating memory" << endl;
  float *data;
  cudaError_t cudaStatus = cudaMallocManaged(&data, new_rows*new_cols*sizeof(float));
  if (cudaStatus != cudaSuccess){
      cout << cudaStatus << endl << flush;
      exit(1);
  }
  cudaDeviceSynchronize();
  cout << "allocating memory successful:" << cudaStatus << endl;
  // I CAN ACCESS DATA HERE
  //data[15] = 5.5; //fine
}

这个 data 你用在 cudaMallocManaged(&data, new_rows*new_cols*sizeof(float)) float *data; 你在上面一行申报的,不是 数据 类成员

MyMatrix::MyMatrix(int new_rows, int new_cols, int padrr, int padcc)
{
  rows = new_rows;
  cols = new_cols;
  padr = padrr;
  padc = padcc;

  cout << "allocating memory" << endl;

  cudaError_t cudaStatus = cudaMallocManaged(&data, new_rows*new_cols*sizeof(float));
  if (cudaStatus != cudaSuccess){
      cout << cudaStatus << endl << flush;
      exit(1);
  }
  cudaDeviceSynchronize();
  cout << "allocating memory successful:" << cudaStatus << endl;
  // I CAN ACCESS DATA HERE
  //data[15] = 5.5; //fine
}