OpenCL 内核导致应用程序无限期地 运行 并且仅在我关闭我的 IDE 后才停止

OpenCL kernel causes application to run indefinitely and only stops after I shut down my IDE

我正在尝试使用 OpenCL 在 GPU 上 运行 部分 this 代码。我现在正在尝试 运行 处理 YCbCr 到 RGB 转换的函数。

请注意,到目前为止我还没有尝试优化 GPU 代码。我只是想要一个与 CPU.

相同的输出

函数原来是这样写的:

void YCbCr_to_ARGB(uint8_t *YCbCr_MCU[3], uint32_t *RGB_MCU, uint32_t nb_MCU_H, uint32_t nb_MCU_V)
{

    uint8_t *MCU_Y, *MCU_Cb, *MCU_Cr;
    int R, G, B;
    uint32_t ARGB;
    uint8_t index, i, j;

    MCU_Y = YCbCr_MCU[0];
    MCU_Cb = YCbCr_MCU[1];
    MCU_Cr = YCbCr_MCU[2];
    for (i = 0; i < 8 * nb_MCU_V; i++) {
        for (j = 0; j < 8 * nb_MCU_H; j++) {
            index = i * (8 * nb_MCU_H)  + j;
            R = (MCU_Cr[index] - 128) * 1.402f + MCU_Y[index];
            B = (MCU_Cb[index] - 128) * 1.7772f + MCU_Y[index];
            G = MCU_Y[index] - (MCU_Cb[index] - 128) * 0.34414f -
                (MCU_Cr[index] - 128) * 0.71414f;
            /* Saturate */
            if (R > 255)
                R = 255;
            if (R < 0)
                R = 0;
            if (G > 255)
                G = 255;
            if (G < 0)
                G = 0;
            if (B > 255)
                B = 255;
            if (B < 0)
                B = 0;
            ARGB = ((R & 0xFF) << 16) | ((G & 0xFF) << 8) | (B & 0xFF);
            // ARGB = 0xFF << 8;
            RGB_MCU[(i * (8 * nb_MCU_H) + j)] = ARGB;
        }
    }
}

这个函数的变量在main.c中声明如下:

cl_uchar* YCbCr_MCU[3] = { NULL, NULL, NULL};
cl_uint* RGB_MCU = NULL;

这些变量的内存是这样分配的:

if (screen_init_needed == 1) 
{
                    screen_init_needed = 0;

.....
.....
//Some code

for (index = 0 ; index < SOF_section.n ; index++) {
YCbCr_MCU[index] = malloc(MCU_sx * MCU_sy * max_ss_h * max_ss_v);

YCbCr_MCU_ds[index] = malloc(MCU_sx * MCU_sy * max_ss_h * max_ss_v);

}

RGB_MCU = malloc (MCU_sx * MCU_sy * max_ss_h * max_ss_v * sizeof(cl_int));
}

break;
}

我直接将其复制并粘贴到我的 .cl 文件中,并进行了一些小改动以使其符合 OpenCL 标准。我修改后的 OpenCL 代码如下所示:

__kernel void YCbCr_to_ARGB(__global uchar* YCbCr_MCU[3], __global uint* RGB_MCU, uint nb_MCU_H, uint nb_MCU_V)
    {        
        __global uchar *MCU_Y, *MCU_Cb, *MCU_Cr;
        int R, G, B;
        uint ARGB;
        uchar index, i, j;

        MCU_Y = YCbCr_MCU[0];
        MCU_Cb = YCbCr_MCU[1];
        MCU_Cr = YCbCr_MCU[2];

//Same code as the first code snippet
        ......
        ......
        ......

    }

当我使用 .cl 文件中的上述内核代码构建和 运行 我的应用程序时,出现错误。其中一个错误表明 OpenCL 不允许指向指针参数的指针。

为了解决这些错误,我再次修改了我的代码,如下所示:

__kernel void YCbCr_to_ARGB(__global uchar YCbCr_MCU[3], __global uint* RGB_MCU, uint nb_MCU_H, uint nb_MCU_V)
{         
            __global uchar *MCU_Y, *MCU_Cb, *MCU_Cr;
            int R, G, B;
            uint ARGB;
            uchar index, i, j;

            MCU_Y = &YCbCr_MCU[0];
            MCU_Cb = &YCbCr_MCU[1];
            MCU_Cr = &YCbCr_MCU[2];

    //Same code as the first code snippet
            ......
            ......
            ......   
}

当我再次构建并 运行 应用程序时,我没有收到任何错误。这促使我为这个内核编写主机代码。

看起来像这样:

 color_kernel= clCreateKernel(program, "YCbCr_to_ARGB", &ret);

//YCbCr_MCU for YCbCrtoARGB
cl_mem colorMCU_GPU= clCreateBuffer(context, CL_MEM_READ_WRITE, 3 * sizeof(cl_uchar), NULL, &ret);


//rgb_MCU for YCbCrtoARGB
cl_mem RGB_GPU= clCreateBuffer(context, CL_MEM_READ_WRITE,  sizeof(cl_uint), NULL, &ret);

我在 main.c 中调用原始函数的地方调用了内核参数。我按以下方式为这个内核执行了剩余的步骤:

if(color&&(SOF_section.n>1)
{
ret = clEnqueueWriteBuffer(command_queue, colorMCU_GPU, CL_TRUE, 0, 3 * sizeof(cl_uchar), YCbCr_MCU, 0, NULL, NULL);

ret = clEnqueueWriteBuffer(command_queue, RGB_GPU, CL_TRUE, 0,  sizeof(cl_uint), RGB_MCU, 0, NULL, NULL);

ret = clSetKernelArg(color_kernel, 0, sizeof(cl_mem), (void *)&colorMCU_GPU);
ret |= clSetKernelArg(color_kernel, 1, sizeof(cl_mem), (void *)&RGB_GPU);
ret = clSetKernelArg(color_kernel, 2, sizeof(cl_uint), (void *)&max_ss_h);
ret |= clSetKernelArg(color_kernel, 3, sizeof(cl_uint), (void *)&max_ss_v);

ret = clEnqueueTask(command_queue, color_kernel, 0, NULL, NULL);

ret = clEnqueueReadBuffer(command_queue, RGB_GPU, CL_TRUE, 0, sizeof(cl_uint), RGB_MCU, 0, NULL, NULL);

//YCbCr_to_ARGB(YCbCr_MCU, RGB_MCU, max_ss_h, max_ss_v);

在我 运行 并使用这些参数构建代码之后,代码会无限期地保持 运行ning(其输出应该是 运行ning 上的影片剪辑 运行ning屏幕。使用此代码,我只会得到一个黑屏)。我必须关闭 Eclipse 并重新打开它才能在此之后对代码进行其他更改。

是什么导致程序出现这样的行为?有没有办法在 GPU 上安全地 运行 这个函数?

更新:

我听从了 Anders Cedronius 的建议并按以下方式更改了我的内核代码:

__kernel void YCbCr_to_ARGB(__global uchar YCbCr_MCU[3], __global uint* RGB_MCU, uint nb_MCU_H, uint nb_MCU_V)
{
   printf("Doing color conversion\n");  

    __global uchar *MCU_Y, *MCU_Cb, *MCU_Cr;
    int R, G, B;
    uint ARGB;
    uchar index, i, j;

    i= get_global_id(0);
    j= get_global_id(1);

    MCU_Y = &YCbCr_MCU[0];
    MCU_Cb = &YCbCr_MCU[1];
    MCU_Cr = &YCbCr_MCU[2];

    if (i < 8 * nb_MCU_V && j < 8 * nb_MCU_H)
    {
            index = i * (8 * nb_MCU_H)  + j;
            R = (MCU_Cr[index] - 128) * 1.402f + MCU_Y[index];
            B = (MCU_Cb[index] - 128) * 1.7772f + MCU_Y[index];
            G = MCU_Y[index] - (MCU_Cb[index] - 128) * 0.34414f -
                (MCU_Cr[index] - 128) * 0.71414f;


            /* Saturate */
            if (R > 255)
                R = 255;
            if (R < 0)
                R = 0;
            if (G > 255)
                G = 255;
            if (G < 0)
                G = 0;
            if (B > 255)
                B = 255;
            if (B < 0)
                B = 0;
            ARGB = ((R & 0xFF) << 16) | ((G & 0xFF) << 8) | (B & 0xFF);
            // ARGB = 0xFF << 8;
        RGB_MCU[(i * (8 * nb_MCU_H) + j)] = ARGB;


}

printf("Finished color conversion\n");
}

我调用内核的主机代码现在如下所示:

color_kernel= clCreateKernel(program, "YCbCr_to_ARGB", &ret);

我按以下方式设置工作大小和内核参数:

ret = clEnqueueWriteBuffer(command_queue, colorMCU_GPU, CL_TRUE, 0, 3*sizeof(cl_uchar), YCbCr_MCU, 0, NULL, NULL);
chk(ret, "clEnqueueWriteBuffer");

ret = clEnqueueWriteBuffer(command_queue, RGB_GPU, CL_TRUE, 0,  sizeof(cl_uint), RGB_MCU, 0, NULL, NULL);
chk(ret, "clEnqueueWriteBuffer");


ret = clSetKernelArg(color_kernel, 0, sizeof(cl_mem), (void *)&colorMCU_GPU);
ret |= clSetKernelArg(color_kernel, 1, sizeof(cl_mem), (void *)&RGB_GPU);
ret = clSetKernelArg(color_kernel, 2, sizeof(cl_uint), (void *)&max_ss_h);
ret |= clSetKernelArg(color_kernel, 3, sizeof(cl_uint), (void *)&max_ss_v);


size_t itemColor[2] = {1, 1};

ret = clEnqueueNDRangeKernel(command_queue, kernel, 2, NULL, itemColor, NULL, 0, NULL, NULL);
chk(ret, "clEnqueueNDRange");

ret = clEnqueueReadBuffer(command_queue, RGB_GPU, CL_TRUE, 0, sizeof(cl_uint), RGB_MCU, 0, NULL, NULL);


clFinish(command_queue);

我 运行 这段代码,我再也不会黑屏了。但是,现在无法识别 "YCbCr to RGB" 的内核。 甚至我的 printf 注释也没有显示在输出控制台上。好像我的代码没有颜色转换功能

更新:

我没有在命令 EnqueueNDRangeKernel 中更改内核的名称。我更改了名称,现在 printf 语句出现在控制台上。但是,我仍然没有得到正确的输出。

size_t itemColor[2] = {1, 1};

ret = clEnqueueNDRangeKernel(command_queue, color_kernel, 2, NULL, itemColor, NULL, 0, NULL, NULL);

chk(ret, "clEnqueueNDRange");

clFinish(command_queue);

更新:

我听从了 pmdj 的建议并更改了我的内核代码。现在看起来像这样:

__kernel void YCbCr_to_ARGB(__global uchar* Y_GPU, __global uchar* Cb_GPU, __global uchar* Cr_GPU, __global uint* RGB_MCU, uint nb_MCU_H, uint nb_MCU_V)
{  
    __global uchar *MCU_Y, *MCU_Cb, *MCU_Cr;
    int R, G, B;
    uint ARGB;
    uchar index, i, j;

unsigned char   iid= get_global_id(0);
unsigned char   jid= get_global_id(1);

    // MCU_Y = &YCbCr_MCU[0];
      // MCU_Cb = &YCbCr_MCU[1];
      // MCU_Cr = &YCbCr_MCU[2];

      MCU_Y= Y_GPU;
      MCU_Cb= Cb_GPU;
      MCU_Cr= Cr_GPU;

    if (iid <= (8 * nb_MCU_V) && jid <= (8 * nb_MCU_H))
    {

            index = iid * (8 * nb_MCU_H)  + jid;
            R = (MCU_Cr[index] - 128) * 1.402f + MCU_Y[index];
            B = (MCU_Cb[index] - 128) * 1.7772f + MCU_Y[index];
            G = MCU_Y[index] - (MCU_Cb[index] - 128) * 0.34414f -
                (MCU_Cr[index] - 128) * 0.71414f;


            /* Saturate */
            if (R > 255)
                R = 255;
            if (R < 0)
                R = 0;
            if (G > 255)
                G = 255;
            if (G < 0)
                G = 0;
            if (B > 255)
                B = 255;
            if (B < 0)
                B = 0;
            ARGB = ((R & 0xFF) << 16) | ((G & 0xFF) << 8) | (B & 0xFF);

        RGB_MCU[(iid * (8 * nb_MCU_H) + jid)] = ARGB;

        }
}

在主机代码中,我为 4 个新变量创建并分配了内存:

Y_ForGPU= (cl_uchar *)malloc(MCU_sx * MCU_sy * max_ss_h * max_ss_v);

Cb_ForGPU= (cl_uchar *)malloc(MCU_sx * MCU_sy * max_ss_h * max_ss_v);

Cr_ForGPU= (cl_uchar *)malloc(MCU_sx * MCU_sy * max_ss_h * max_ss_v);

//Now will do it for RGB
RGB_testing= (cl_uint *)malloc (MCU_sx * MCU_sy * max_ss_h * max_ss_v * sizeof(cl_int));

我按以下方式创建了缓冲区:

cl_mem for_Y= clCreateBuffer(context, CL_MEM_READ_WRITE| CL_MEM_COPY_HOST_PTR, (MCU_sx * MCU_sy * max_ss_h * max_ss_v), Y_ForGPU, &ret);


cl_mem for_Cb= clCreateBuffer(context, CL_MEM_READ_WRITE| CL_MEM_COPY_HOST_PTR, (MCU_sx * MCU_sy * max_ss_h * max_ss_v), Cb_ForGPU , &ret);

cl_mem for_Cr= clCreateBuffer(context, CL_MEM_READ_WRITE| CL_MEM_COPY_HOST_PTR, (MCU_sx * MCU_sy * max_ss_h * max_ss_v), Cr_ForGPU, &ret);

//rgb_MCU for YCbCrtoARGB
cl_mem RGB_GPU= clCreateBuffer(context, CL_MEM_READ_WRITE, (MCU_sx * MCU_sy * max_ss_h * max_ss_v * sizeof(cl_int)), NULL, &ret);

然后我设置内核参数,执行内核并将计算的数据发送回主机:

ret = clSetKernelArg(color_kernel, 0, sizeof(cl_mem), &for_Y);
ret |= clSetKernelArg(color_kernel, 1, sizeof(cl_mem), &for_Cb);
ret |= clSetKernelArg(color_kernel, 2, sizeof(cl_mem), &for_Cr);
ret |= clSetKernelArg(color_kernel, 3, sizeof(cl_mem), &RGB_GPU);
ret |= clSetKernelArg(color_kernel, 4, sizeof(cl_uint), &max_ss_h);
ret |= clSetKernelArg(color_kernel, 5, sizeof(cl_uint), &max_ss_v);


const size_t itemColor[2] = {100, 100};

ret = clEnqueueNDRangeKernel(command_queue, color_kernel, 2, NULL, itemColor, NULL, 0, NULL, NULL);
clFinish(command_queue);

//Copy result to the host
ret = clEnqueueReadBuffer(command_queue, RGB_GPU, CL_TRUE, 0, (MCU_sx * MCU_sy * max_ss_h * max_ss_v * sizeof(cl_int)), RGB_testing, 0, NULL, NULL);

但是,现在我的代码突然终止了。为什么会发生这种情况?

更新:

我的代码现在可以工作了。这些问题可能是由于指针的差异而发生的。我将 Y、Cb、Cr 和 RGB 变量(我创建的)设置为等于主机代码中的原始变量。

//---Setting color variables equal to array elements----//

Y_ForGPU= YCbCr_MCU[0];
Cb_ForGPU= YCbCr_MCU[1];
Cr_ForGPU= YCbCr_MCU[2];

//----RGB is being assigned value-----//

RGB_testing= RGB_MCU;

我不知道这是否是导致您出现问题的唯一原因(可能还有更多我尚未发现),但您的 YCbCr_MCU 内核参数中存在类型不匹配问题。你不能有指针到指针的参数,这是真的。不过,简单地删除 * 并不能解决问题。

特别是行

MCU_Cb = &YCbCr_MCU[1];

在内核中,从 YCbCr_MCU 指向的任何内容的开始处获取 1 个字节,从主机代码来看,这实际上是指针数组的开始,而不是像素数组。

ret = clSetKernelArg(color_kernel, 0, sizeof(cl_mem), (void *)&colorMCU_GPU);

看起来 YCbCr_MCU 应该是一个包含 3 个指向包含源像素的 Y、Cb、Cr 平面的指针的数组。您需要将它们作为指向 3 个数组的 3 个直接指针而不是指向 3 个指针的指针传递给您的内核。换句话说,把它变成Y,Cb,Cr参数,在主机上设置为colorMCU_GPU[0]colorMCU_GPU[2]