如何对 Linux 内核进行反优化并使用 -O0 进行编译? [英] How to de-optimize the Linux kernel to and compile it with -O0?

问题描述

我想阅读和理解 Linux 内核的内存管理(尤其是碎片整理压缩迁移).

I'm wanting to read and understand the Linux kernel's Memory Management (in particular defragcompactionmigration).

所以，我关闭了 .config 中的大小优化(当然是使用 make menuconfig)并编译...这让我仍然拥有一个优化的内核.

So, I turn off optimization for size in .config (using make menuconfig of course) and compile...This leaves me with still an optimized kernel.

注意: 当我说优化内核时，我的意思是当我使用 gdb 并告诉它 next 它会跳来跳去.我不希望这样，我希望能够像处理简单的 hello world 一样逐行执行代码.

NOTE: When I say optimized kernel, I mean that when I use gdb and tell it next that it'll jump around. I don't want that, I want to be able to follow the code line by line just as I would with a simple hello world.

接下来，我编辑 Makefile 并将 -O2 与 -O0 交换，这会导致事情中断.

Next, I edit the Makefile and swap -O2 with -O0 and that causes things to break.

我发现 这个，但我不知道我想要什么文件，因为我不知道兔子洞到底有多远.

I found this, but I don't know what files I'll want because I don't know how far down the rabbit hole goes.

我可以使用更通用的选项吗?我了解内存压缩的概念；但是，我想看看一切发生在哪里以及它是如何发生的.

Is there a more generic option that I can use? I understand the concepts of memory compaction; however, I want to see where everything happens and how it exactly happens.

推荐答案

你不能去优化内核.您也许可以取消优化某些功能，如下所示:

You can't de-optimize the kernel. You might be able to de-optimize certain functions, like this:

void __attribute__((optimize("O0"))) foo(unsigned char data) {
    // unmodifiable compiler code
}

但内核作为一个整体需要 -O2，因为代码本身是在假设某些函数将以某种方式优化的前提下编写的.

But the kernel as a whole requires -O2 because the code itself is written with assumptions that certain functions will be optimized in a certain way.

很抱歉，但您确实需要知道您想要进入的兔子洞的大小.

Sorry, but you really will need to know the size of the rabbit hole you want to go down.

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