Messages in this thread | | | From | microcai <> | Date | Mon, 29 Nov 2010 16:18:09 +0800 | Subject | Re: [PATCH] Built kernel without -O2 option |
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2010/11/29 Américo Wang <xiyou.wangcong@gmail.com>: > On Mon, Nov 29, 2010 at 11:56:15AM +0800, Hui Zhu wrote: >>Hi, >> >>Now, there are a lot of ways to debug the Linux kernel with GDB, like >>qemu, kgtp or kgdb and so on. >>But the developer more like add a printk. It have a lot of reason, a big one is: >>(gdb) p ret >>$3 = <value optimized out> >>And the code execution order is not right. >> >>This is becuase the Kernel is bult with gcc -O2. Gcc will not >>generate enough debug message with file with -O2. >>So GDB cannot work very well with Linux kernel. >> >>So I make a patch that add a option in "Kernel hacking" called "Close >>GCC optimization". It will make kernel be built without -O2. >> >>I built and use it in i386 and x86_64. I will try to make it OK in other arch. >> > > The problem is that some functions _have to_ be inlined and gcc without -O2 > doesn't inline them. Have check all the cases? I doubt. > > Also, what is size of vmlinux before applying your patch and after that? > Does it increase too much? > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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