Question

I’m running a C program where I call twice a cuda host function. I want to clean up the device memory between these 2 calls. Is there a way I can flush GPU device memory?? I’m on a Tesla M2050 with computing capability of 2.0

Answer 1

If you only want to zero the memory, then cudaMemset is probably the simplest way to do this. For example:

const int n = 10000000;
const int sz = sizeof(float) * n;
float *devicemem;
cudaMalloc((void **)&devicemem, sz);

kernel<<<...>>>(devicemem,....);
cudaMemset(devicemem, 0, sz); // zeros all the bytes in devicemem
kernel<<<...>>>(devicemem,....);

Note that the value cudaMemset takes is a byte value, and all bytes in the specified range are set to that value, just like the standard C memset. If you have a specific word value, then you will need to write your own memset kernel to assign the values.