在OSX上NVIDIA Cuda错误“所有支持CUDA的设备都忙或不可用”

很多时候，我让CUDA库完全失败并返回错误46（"all CUDA-capable devices are busy or unavailable"），即使对于像cudaMalloc这样的简单调用也是如此 . 如果我重新启动计算机，代码会成功运行，但这远非理想 . 这个问题显然是quite common .

我的设置如下：

• OSX 10.6.8

• NVIDIA CUDA驱动程序：CUDA驱动程序版本：4.0.31（最新）

• GPU驱动版本：1.6.36.10（256.00.35f11）

我从Nvidia论坛尝试了很多解决方案，但它没有用 . 我不想每次都重启 . 我还试图卸载并重新加载驱动程序，我假设是正确的程序（可能不是）

kextunload -b com.nvidia.CUDA
kextload -b com.nvidia.CUDA

但它仍然无效 . 我怎样才能将GPU（或CUDA）恢复到理智状态？

这是设备查询结果

CUDA Device Query (Runtime API) version (CUDART static linking)

Found 1 CUDA Capable device(s)

Device 0: "GeForce 9400M"
  CUDA Driver Version / Runtime Version          4.0 / 4.0
  CUDA Capability Major/Minor version number:    1.1
  Total amount of global memory:                 254 MBytes (265945088 bytes)
  ( 2) Multiprocessors x ( 8) CUDA Cores/MP:     16 CUDA Cores
  GPU Clock Speed:                               1.10 GHz
  Memory Clock rate:                             1075.00 Mhz
  Memory Bus Width:                              128-bit
  Max Texture Dimension Size (x,y,z)             1D=(8192), 2D=(65536,32768), 3D=(2048,2048,2048)
  Max Layered Texture Size (dim) x layers        1D=(8192) x 512, 2D=(8192,8192) x 512
  Total amount of constant memory:               65536 bytes
  Total amount of shared memory per block:       16384 bytes
  Total number of registers available per block: 8192
  Warp size:                                     32
  Maximum number of threads per block:           512
  Maximum sizes of each dimension of a block:    512 x 512 x 64
  Maximum sizes of each dimension of a grid:     65535 x 65535 x 1
  Maximum memory pitch:                          2147483647 bytes
  Texture alignment:                             256 bytes
  Concurrent copy and execution:                 No with 0 copy engine(s)
  Run time limit on kernels:                     Yes
  Integrated GPU sharing Host Memory:            Yes
  Support host page-locked memory mapping:       Yes
  Concurrent kernel execution:                   No
  Alignment requirement for Surfaces:            Yes
  Device has ECC support enabled:                No
  Device is using TCC driver mode:               No
  Device supports Unified Addressing (UVA):      No
  Device PCI Bus ID / PCI location ID:           2 / 0
  Compute Mode:
     < Default (multiple host threads can use ::cudaSetDevice() with device simultaneously) >

deviceQuery, CUDA Driver = CUDART, CUDA Driver Version = 4.0, CUDA Runtime Version = 4.0, NumDevs = 1, Device = GeForce 9400M
[deviceQuery] test results...
PASSED

这是可能失败的代码示例（尽管在正常情况下它不会失败）

#include <stdio.h>

__global__ void add(int a, int b, int *c) {
    *c = a + b;
}

int main(void) {
    int c;
    int *dev_c;

    cudaMalloc( (void **) &dev_c, sizeof(int)); // fails here, returning 46

    add<<<1,1>>>(2,7,dev_c);
    cudaMemcpy(&c, dev_c, sizeof(int), cudaMemcpyDeviceToHost);
    printf("hello world, %d\n",c);
    cudaFree( dev_c);
    return 0;
}

我还发现，偶尔我会恢复到没有重启的理智行为 . 我仍然不知道触发它的原因 .