立即使用 2 GB 内存的 C++ 程序:如何找到罪魁祸首? [英] C++ Program immediately using 2 GB of RAM: how to find culprit?

问题描述

我有一个程序，当在初始化时查询时，它会立即使用 > 2 GB 的 RAM.基本上代码是这样的:

I have a program that, when queried on initialisation, is immediately using > 2 GB of RAM. Basically the code is like this:

#include <blah>

int main() {
    cout << get_mem_usage() << endl;
    //Lots of things happen, but no significant memory usage
    return 0;
}

输出:[2013-02-15 18:38:05.865283] 2147.71 Mb

Output: [2013-02-15 18:38:05.865283] 2147.71 Mb

但是，我链接到了许多不同的共享对象文件:我检查了 ldd，我链接到了 58 个库，总 .so 大小为 66 MB.

I am, however, linking to a lot of different shared object files: I checked ldd and I am linking to 58 libraries, with a combined .so size of 66 MB.

我很确定 get_mem_usage 程序正在返回正确的值:这些值与 top 和 massif 输出一致.

I'm pretty sure that the get_mem_usage program is returning the correct values: these agree with top and massif output.

我还应该提到，我正在链接用于高能物理分析的 ROOT 框架.

I should also mention that I am linking against the ROOT framework for High Energy Physics analysis.

我使用的是 Linux x86_64，get_mem_usage() 函数是自产的.

I am using Linux x86_64, and the get_mem_usage() function is homegrown.

如果可能的话，我想减少程序的内存使用.

I would like to reduce the memory usage of the program, if at all possible.

推荐答案

我的第一个猜测:您正在链接的某些库中的静态初始化.

My first guess: static initizations in some of the libraries you are linking.

在 main() 的第一行插入一个长停顿，并查看/proc//以查看内存分配的位置.例如:

Insert a long pause as the very first line of main() and look through the /proc/<pid>/ to see where the memory is allocated. For example:

• /proc/12345/task/12345/maps
• /proc/12345/task/12345/smaps

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