windows 如何以编程方式获取 C++ 中的 CPU 缓存页面大小？
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How to programmatically get the CPU cache page size in C++?
提问by Mathieu Pagé
I'd like my program to read the cache line size of the CPU it's running on in C++.
我希望我的程序读取它在 C++ 中运行的 CPU 的缓存行大小。
I know that this can't be done portably, so I will need a solution for Linux and another for Windows (Solutions for other systems could be usefull to others, so post them if you know them).
我知道这不能移植，所以我需要一个适用于 Linux 的解决方案和另一个适用于 Windows 的解决方案（其他系统的解决方案可能对其他人有用，所以如果你知道他们，请发布它们）。
For Linux I could read the content of /proc/cpuinfo and parse the line begining with cache_alignment. Maybe there is a better way involving a call to an API.
对于 Linux，我可以读取 /proc/cpuinfo 的内容并解析以 cache_alignment 开头的行。也许有更好的方法涉及调用 API。
For Windows I simply have no idea.
对于 Windows，我根本不知道。
采纳答案by Nick
On Win32, GetLogicalProcessorInformationwill give you back a SYSTEM_LOGICAL_PROCESSOR_INFORMATIONwhich contains a CACHE_DESCRIPTOR, which has the information you need.
在 Win32 上，GetLogicalProcessorInformation将返回一个SYSTEM_LOGICAL_PROCESSOR_INFORMATION包含 的CACHE_DESCRIPTOR，其中包含您需要的信息。
回答by PiedPiper
On Linux try the proccpuinfo library, an architecture independent C API for reading /proc/cpuinfo
在 Linux 上尝试使用proccpuinfo 库，这是一个独立于体系结构的 C API，用于读取 /proc/cpuinfo
回答by robottobor
For x86, the CPUIDinstruction. A quick google search reveals some librariesfor win32 and c++. I have used CPUID via inline assembler as well.
对于 x86，CPUID指令。快速谷歌搜索显示了一些适用于 win32 和 c++ 的库。我也通过内联汇编器使用了 CPUID。
Some more info:
更多信息：
回答by Researcher
On Windows
在 Windows 上
#include <Windows.h>
#include <iostream>
using std::cout; using std::endl;
int main()
{
SYSTEM_INFO systemInfo;
GetSystemInfo(&systemInfo);
cout << "Page Size Is: " << systemInfo.dwPageSize;
getchar();
}
On Linux
在 Linux 上
回答by Evan Teran
Looks like at least SCO unix (http://uw714doc.sco.com/en/man/html.3C/sysconf.3C.html) has _SC_CACHE_LINE for sysconf. Perhaps other platforms have something similar?
看起来至少 SCO unix ( http://uw714doc.sco.com/en/man/html.3C/sysconf.3C.html) 有 _SC_CACHE_LINE 用于 sysconf。也许其他平台也有类似的东西？
回答by cubex
I think you need NtQuerySystemInformationfrom ntdll.dll.
我认为你需要NtQuerySystemInformation从ntdll.dll.
回答by metablaster
Here is sample code for those who wonder how to to utilize the function in accepted answer:
以下是那些想知道如何在接受的答案中使用该功能的人的示例代码：
#include <new>
#include <iostream>
#include <Windows.h>
void ShowCacheSize()
{
using CPUInfo = SYSTEM_LOGICAL_PROCESSOR_INFORMATION;
DWORD len = 0;
CPUInfo* buffer = nullptr;
// Determine required length of a buffer
if ((GetLogicalProcessorInformation(buffer, &len) == FALSE) && (GetLastError() == ERROR_INSUFFICIENT_BUFFER))
{
// Allocate buffer of required size
buffer = new (std::nothrow) CPUInfo[len]{ };
if (buffer == nullptr)
{
std::cout << "Buffer allocation of " << len << " bytes failed" << std::endl;
}
else if (GetLogicalProcessorInformation(buffer, &len) != FALSE)
{
for (DWORD i = 0; i < len; ++i)
{
// This will be true for multiple returned caches, we need just one
if (buffer[i].Relationship == RelationCache)
{
std::cout << "Cache line size is: " << buffer[i].Cache.LineSize << " bytes" << std::endl;
break;
}
}
}
else
{
std::cout << "ERROR: " << GetLastError() << std::endl;
}
delete[] buffer;
}
}
