使用clEnqueueWriteBuffer - OpenCL导致内存损坏

Question

我正在使用一些从主机到设备发送大量数据的代码,并且行为不正常.

在下面的代码中,我试图从主机向设备发送一个数组.数组大小在每次迭代时递增,逐渐增加发送到设备的内存量.数组中的第一个元素填充非零值,并从内核中读取并打印到控制台.从主机和设备读取时,该值应该相同,但在某些迭代中,它不是.

这是代码:

    int SizeArray = 0;

    for(int j=1; j<100 ;j++){ 

        //Array memory allocation, starting with 4MB in first iteration to 400MB in last one
        SizeArray = j * 1000000 * sizeof(float);
        Array = (float*)malloc(SizeArray);
        memset(Array, 0, SizeArray);

        //Give the array's first element some nonzero value
        //This is the value that is expected to be printed by the kernel execution
        Array[0] = j;

        memArray = clCreateBuffer(context, CL_MEM_READ_WRITE, SizeArray, NULL, &ret);

        //Write the array contents into the buffer inside the device
        ret = clEnqueueWriteBuffer(command_queue, memArray, CL_TRUE, 0, SizeArray, Array, 0, NULL, NULL);
        ret = clSetKernelArg(kernel, 0, sizeof(cl_mem), (void *)&memArray);

        getchar();

        //Execute the kernel where the content of the first element of the array will be printed
        ret = clEnqueueNDRangeKernel(command_queue, kernel, 3, NULL, mGlobalWorkSizePtr, mLocalWorkSizePtr, 0, NULL,NULL);
        ret = clFinish(command_queue);

        /****** FAIL! Kernel prints correct value of Array's first element ONLY IN 
        SOME ITERATIONS (when it fails zero values are printed)! Depending on SizeArray :?? ******/

        free(Array);
        ret = clReleaseMemObject(memArray);
    }

测试此代码的设备具有以下功能:

- Name:                    Intel(R) HD Graphics 4000
- DeviceVersion:           OpenCL 1.1 
- DriverVersion:           8.15.10.2696
- MaxMemoryAllocationSize: 425721856
- GlobalMemoryCacheSize:   2097152
- GlobalMemorySize:        1702887424
- MaxConstantBufferSize:   65536
- LocalMemorySize:         65536

内核是否打印不正确的值,具体取决于发送到设备的缓冲区大小.

这是输出:

Array GPU: 1.000000
Array GPU: 2.000000
Array GPU: 3.000000
Array GPU: 4.000000
Array GPU: 5.000000
Array GPU: 6.000000
Array GPU: 7.000000
Array GPU: 8.000000
Array GPU: 9.000000
Array GPU: 10.000000
Array GPU: 11.000000
Array GPU: 12.000000
Array GPU: 13.000000
Array GPU: 14.000000
Array GPU: 15.000000
Array GPU: 16.000000
Array GPU: 17.000000
Array GPU: 18.000000
Array GPU: 19.000000
Array GPU: 20.000000
Array GPU: 21.000000
Array GPU: 22.000000
Array GPU: 23.000000
Array GPU: 24.000000
Array GPU: 25.000000
Array GPU: 0.000000     <-------- INCORRECT VALUE, kernel is receiving corrupted memory
Array GPU: 0.000000     <-------- INCORRECT VALUE, kernel is receiving corrupted memory
Array GPU: 0.000000     <-------- INCORRECT VALUE, kernel is receiving corrupted memory
Array GPU: 0.000000     <-------- INCORRECT VALUE, kernel is receiving corrupted memory
Array GPU: 0.000000     <-------- INCORRECT VALUE, kernel is receiving corrupted memory
Array GPU: 0.000000     <-------- INCORRECT VALUE, kernel is receiving corrupted memory
Array GPU: 0.000000     <-------- INCORRECT VALUE, kernel is receiving corrupted memory
Array GPU: 0.000000     <-------- INCORRECT VALUE, kernel is receiving corrupted memory
Array GPU: 34.000000
Array GPU: 35.000000
Array GPU: 36.000000
Array GPU: 37.000000
Array GPU: 38.000000
Array GPU: 39.000000
Array GPU: 40.000000
Array GPU: 41.000000
Array GPU: 42.000000
Array GPU: 43.000000
Array GPU: 44.000000
Array GPU: 45.000000
Array GPU: 46.000000
Array GPU: 47.000000
Array GPU: 48.000000
Array GPU: 49.000000
Array GPU: 50.000000
Array GPU: 51.000000
Array GPU: 52.000000
Array GPU: 53.000000
Array GPU: 54.000000
Array GPU: 55.000000
Array GPU: 56.000000
Array GPU: 57.000000
Array GPU: 58.000000
Array GPU: 0.000000     <-------- INCORRECT VALUE, kernel is receiving corrupted memory
Array GPU: 0.000000     <-------- INCORRECT VALUE, kernel is receiving corrupted memory
Array GPU: 0.000000     <-------- INCORRECT VALUE, kernel is receiving corrupted memory
Array GPU: 0.000000     <-------- INCORRECT VALUE, kernel is receiving corrupted memory
Array GPU: 0.000000     <-------- INCORRECT VALUE, kernel is receiving corrupted memory
Array GPU: 0.000000     <-------- INCORRECT VALUE, kernel is receiving corrupted memory
Array GPU: 0.000000     <-------- INCORRECT VALUE, kernel is receiving corrupted memory
Array GPU: 0.000000     <-------- INCORRECT VALUE, kernel is receiving corrupted memory
Array GPU: 0.000000     <-------- INCORRECT VALUE, kernel is receiving corrupted memory
Array GPU: 68.000000
Array GPU: 69.000000
...

如您所见,设备接收到不正确的值,没有明显的模式,并且clEnqueueWriteBuffer函数不返回任何错误代码.

总结:内存块被发送到内核,但是内核根据发送的总块大小接收零内存.

在不同计算机上测试的相同代码行为不同(不同迭代中的值不正确).

如何避免内存损坏？我错过了什么吗？

提前致谢.

---

这是完整的工作代码:

---

编辑:经过一些测试,需要澄清问题不在printf中.问题似乎在于在执行内核之前将数据传输到设备.

这是没有执行内核的代码.结果仍然是错误的.

Answer 1

你有没有尝试过

   CL_MEM_READ_WRITE | CL_MEM_ALLOC_HOST_PTR

因为你的GPU与CPU共享相同的内存？

设备也位于 iGPU 主机的同一位置。

创建一些缓冲区，对它们进行压力测试，如果它们都获得无效值，则安装另一个驱动程序版本（可能是较新的版本），如果这不能解决问题，请 RMA 您的卡。

如果只有一个缓冲区错误，那么这就是简单的 vram 错误，将该缓冲区标记为不可用，并根据需要创建新缓冲区并避免使用该缓冲区，但我不确定驱动程序是否在后台交换缓冲区。如果每个内核都出现故障，那么内核也可能会损坏。