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由于发现cuda c++ 的 debug方式和c++ 差别很大,因此打算再开一篇,专门记录一些和error checking 以及debug有关的内容.
Error checks in CUDA code can help catch CUDA errors at their source. There are 2 sources of errors in CUDA source code:
1. Errors from CUDA **API** calls. For example, a call to `cudaMalloc()` might fail.
2. Errors from CUDA **kernel** calls. For example, there might be invalid memory access inside a kernel.
All CUDA API calls return a cudaError value, so these calls are easy to check:
1
2
3 if ( cudaSuccess != cudaMalloc( &fooPtr, fooSize ) )
4 printf( "Error!\n" );
5 CUDA kernel invocations do not return any value. Error from a CUDA kernel call can be checked after its execution by calling cudaGetLastError():
1fooKernel<<< x, y >>>(); // Kernel call
2if ( cudaSuccess != cudaGetLastError() )
3 printf( "Error!\n" );以及下面是一个check error的宏…
1#define CHECK_ERROR( err ) \
2 if( err != cudaSuccess ) { \
3 std::cerr << "ERROR: " << cudaGetErrorString( err ) << std::endl; \
4 exit( -1 ); \
5 }
6
7#define CHECK_LAST_ERROR \
8 { cudaError_t err = cudaGetLastError(); \
9 if( err != cudaSuccess ) { \
10 std::cerr << cudaGetErrorString( err ) << std::endl; \
11 exit( -1 ); \
12 } \
13 }