How to compile Linux kernel with -O0 flag

[Hao Lee]

>> Hi, I also like figuring out what's happening in the OS underlying. So
>> I have some ideas about reducing optimization. Although you couldn't
>> turn off optimization completely, you can use both -O2 and other
>> options to reducing optimization as far as possible.
>> You can use -O2 -Q -v to find out which options are enabled when using
>> -O2. Then you can try -O2 -fno-defer-pop -fno-thread-jumps etc. to
>> disable some options. I once used this approach to debug kernel-2.4 in
>> bochs simulator. Unfortunately, this approach could not counteract the
>> effects of -O2 completely, but it's worth a try.
>
> No, please don't do that.  If you do, you will end up with a completly
> unsuported and unknown system and no one will be able to help you out
> with any sort of problem solving.
>
> Just use the default build options, and all should be fine.  We know
> they work.  Anything else is a total unknown, and not something that
> anyone trying to learn about the kernel should be messing with.


Thank you!!!
I didn't know this before. Thanks for your correction!

Thanks,
Hao Lee