Crash with thrust::min_element on thrust::device_vector (CUDA Thrust)

Question

The following CUDA Thrust program crashes:

#include <thrust/device_vector.h>
#include <thrust/extrema.h>

int main(void)
{
  thrust::device_vector<int> vec;
  for (int i(0); i < 1000; ++i) {
    vec.push_back(i);
  }

  thrust::min_element(vec.begin(), vec.end());
}

The exception I get is:

Unhandled exception at 0x7650b9bc in test_thrust.exe: Microsoft C++
exception:thrust::system::system_error at memory location 0x0017f178..

In `checked_cudaMemcpy()` in `trivial_copy.inl`.

If I add #include <thrust/sort.h> and replace min_element with sort, it does not crash.

I'm using CUDA 4.1 on Windows 7 64-bit, compute_20,sm_20 (Fermi), Debug build. In a Release build, I am not getting the crash and min_element finds the correct element.

Am I doing something wrong, or is there a bug in Thrust?

Answer 1

I can reproduce the error using debug mode targeting Compute Capability 2.0 (i.e nvcc -G0 -arch=sm_20). The bug does not reproduce in release mode or when targeting Compute Capability 1.x devices, which generally suggests a code-generation problem instead of a bug in the library. Wherever the fault lies, I'd encourage you to submit a bug report so this issue gets the attention it deserves. In the meantime, I'd suggest compiling in release mode, which is more rigorously tested.