c++ - c++ new 运算符可以在 Windows 上自动使用大页面吗？

Question

假设我使用 Visual Studio 编写了一个 C++ 程序，它使用 new 运算符来分配内存。我想知道是否有一种方法可以让 new 自动使用大页面而不是标准的 4KB 页面（即，我的程序没有显式调用 VirtualAlloc）。

谢谢你的时间。

Answer 1

您可以覆盖所有新的和删除的运算符。例如

void * operator new(size_t size)
{
    return malloc(size);
}

void operator delete(void * pointer)
{
    free(pointer);
}

您还应该覆盖此运算符的所有变体：

• http://www.cplusplus.com/reference/new/operator%20new/
• http://www.cplusplus.com/reference/new/operator%20new%5B%5D/
• http://www.cplusplus.com/reference/new/operator%20delete/
• http://www.cplusplus.com/reference/new/operator%20delete%5B%5D/

Answer 2

Implementation specific, once again. All libraries are not restricted to doing that since all the standard says AFAIK is that new allocates memory for C++. For Microsoft's implementation, new always calls HeapAlloc.

http://cboard.cprogramming.com/cplusplus-programming/98364-new-invokes-virtualalloc.html

My understanding is that unless you're running in a virtual machine, the OS has full control over the default heap and stack memory allocation. The above link also brings up a good point in line with Raymond's response to your question: Are you sure you need to use large pages? You open yourself to a good deal of internal fragmentation by doing so.