Re: [Syllable-kernel] patch to fix crash when kernel compiled with -O2 or less

[Kristian V. D. V. <va...@li...>]

On Saturday 09 October 2004 5:12 am, Jake Hamby wrote:
> One more patch for today.  I tried building the kernel with "-O2"
> instead of "-O3" and got an illegal instruction crash at the beginning
> of the init process (before it prints anything).  I looked at the
> difference in assembly output in kernel/init.c and noticed that the
> Fork() function is inlined under -O3.  Since Fork() doesn't seem to be
> used anywhere outside of init.c, I changed it to a static inline
> function and commented out the prototype in include/atheos/kernel.h.
> This fixed the problem, and makes things cleaner since the function
> consists of only a single line of inline asm.

Applied.

> BTW, I would suggest using CFLAGS of "-O2 -mpreferred-stack-boundary=2",
> as Linux and FreeBSD do, instead of "-O3" when building the kernel
> because smaller code size is generally more important than the
> additional inlining.  Using the "size" command on kernel.so, I get a
> text size (data and bss sizes are the same) of:
>
> 378602 bytes for -O3
> 363546 bytes for -O2 -mpreferred-stack-boundary=2
>
> for a savings of 15K or about 4%.  Anyway, here's the patch.

Not a bad idea, so that's been done too.  Thanks Jack :)

-- 
Vanders
http://syllable.sourceforge.net/
http://www.liqwyd.com