如何从linux内核获取物理内存，包括保留内存？答案

【问题标题】：how to get physical memory including reserved memory from linux kernel?如何从linux内核获取物理内存，包括保留内存？
【发布时间】：2020-07-07 01:55:03
【问题描述】：

来自linux的proc.txt：

MemTotal: Total usable ram (i.e. physical ram minus a few reserved

但是如何从linux内核获取整个物理内存包括保留内存？

【问题讨论】：

标签： c linux memory kernel

【解决方案1】：

physpages = get_num_physpages();

pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
#ifdef  CONFIG_HIGHMEM
        ", %luK highmem"
#endif
        "%s%s)\n",
        nr_free_pages() << (PAGE_SHIFT - 10),
        physpages << (PAGE_SHIFT - 10),
        codesize >> 10, datasize >> 10, rosize >> 10,
        (init_data_size + init_code_size) >> 10, bss_size >> 10,
        (physpages - totalram_pages() - totalcma_pages) << (PAGE_SHIFT - 10),
        totalcma_pages << (PAGE_SHIFT - 10),
#ifdef  CONFIG_HIGHMEM
        totalhigh_pages() << (PAGE_SHIFT - 10),
#endif
        str ? ", " : "", str ? str : "");

所以get_num_physpages << (PAGE_SHIFT - 10) 将获得整个物理内存。

【讨论】：