Re: Building Kernel with -O0

[linux-os (Dick Johnson)]

On Fri, 12 Sep 2008, emin ak wrote:

> 2008/9/10 Bodo Eggert <7eggert@xxxxxx>:
>> linux-os (Dick Johnson) <linux-os@xxxxxxxxxxxx> wrote:
>>
>>> If you have to single-step through kernel procedures, you
>>> are not writing proper code for a kernel. Furthermore, even
>>> when using the kernel debugger, you are not executing the
>>> exact same path that would be executed without the debugger
>>> attached.
>>
>> I sometimes single-step in order to verify my (userspace) code, instead of
>> just throwing random test data at it. It's easier and makes me feel better.
>> OTOH, -O2 never was a problem if I used it, so I don't strongly vote
>> for enabling -O0.
>>
>> --
>
> I had compiled linux-2.6.23 with -O0 for kgdb only with little
> modifications, it's  running with no error for a long time. I'am not a
> linux expert, I think talented kernel hackers can make kernel to
> compile with -O0 easly but for some reason they dont want to do it.
> Debug is much understandable for me (and for most people I think) with
> -O0. Linux kernel programming ability is not a gift, of course you can
> learn the code with printks and reading, but which age are we living
> in?
>
> Emin
>

Well, to use the ** kernel ** to single-
step through the ** kernel ** is
really not going to be much more than an
exercise. It's not going to find the bugs
that are likely to exist in kernel code.


Cheers,
Dick Johnson
Penguin : Linux version 2.6.25.17 on an i686 machine (4786.38 BogoMips).
My book : http://www.AbominableFirebug.com/
_


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