我在编写一些C++ AMP代码时遇到问题。我已经提供了一个样本。
它可以在模拟加速器上正常运行,但会导致我的硬件(Windows 7,NVIDIA GeForce GTX 660,最新驱动程序)上的显示驱动程序崩溃,但是我的代码没有发现任何错误。
我的代码是否有问题,或者这是硬件/驱动程序/编译器问题?
#include "stdafx.h"
#include <vector>
#include <iostream>
#include <amp.h>
int _tmain(int argc, _TCHAR* argv[])
{
// Prints "NVIDIA GeForce GTX 660"
concurrency::accelerator_view target_view = concurrency::accelerator().create_view();
std::wcout << target_view.accelerator.description << std::endl;
// lower numbers do not cause the issue
const int x = 2000;
const int y = 30000;
// 1d array for storing result
std::vector<unsigned int> resultVector(y);
Concurrency::array_view<unsigned int, 1> resultsArrayView(resultVector.size(), resultVector);
// 2d array for data for processing
std::vector<unsigned int> dataVector(x * y);
concurrency::array_view<unsigned int, 2> dataArrayView(y, x, dataVector);
parallel_for_each(
// Define the compute domain, which is the set of threads that are created.
resultsArrayView.extent,
// Define the code to run on each thread on the accelerator.
[=](concurrency::index<1> idx) restrict(amp)
{
concurrency::array_view<unsigned int, 1> buffer = dataArrayView[idx[0]];
unsigned int bufferSize = buffer.get_extent().size();
// needs both loops to cause crash
for (unsigned int outer = 0; outer < bufferSize; outer++)
{
for (unsigned int i = 0; i < bufferSize; i++)
{
// works without this line, also if I change to buffer[0] it works?
dataArrayView[idx[0]][0] = 0;
}
}
// works without this line
resultsArrayView[0] = 0;
});
std::cout << "chash on next line" << std::endl;
resultsArrayView.synchronize();
std::cout << "will never reach me" << std::endl;
system("PAUSE");
return 0;
}
最佳答案
您的计算很可能超过了允许的量子时间(默认为2秒)。在那之后,操作系统进入并强制重启GPU,这称为Timeout Detection and Recovery (TDR)。软件适配器(引用设备)未启用TDR,这就是为什么计算可能超过允许的量子时间的原因。
您的计算是否真的需要3000个线程(变量x),每个线程执行2000 * 3000(x * y)循环迭代?您可以对计算进行分块,以使每个块花费不到2秒的时间进行计算。您还可以考虑禁用TDR或超过允许的量子时间来满足您的需求。
我强烈建议阅读有关如何在C++ AMP中处理TDR的博客文章,其中详细介绍了TDR:http://blogs.msdn.com/b/nativeconcurrency/archive/2012/03/07/handling-tdrs-in-c-amp.aspx
此外,这是有关如何在Windows 8上禁用TDR的单独博客文章:
http://blogs.msdn.com/b/nativeconcurrency/archive/2012/03/06/disabling-tdr-on-windows-8-for-your-c-amp-algorithms.aspx