Help: problems when I do atomic lookup on the kernel side.

Hi,

I encounter some problems when I try to do atomic lookkup
on the kernel side. Pls help me.

I want to output the information I need in main.c in TUX, first I add
printk("cach missed=%d", missed) to the function user_get_object()
in main.c, after I rebuild TUX module and start TUX, I can't find such
information in /var/log/messages.

So I think maybe the control didn't go to the user_get_object(), then I
add printk("TUX start successfully message"); to the tux_init() in main.c.
I think Whenever TUX start, I should found this message in
/var/log/messages,
but after I rebuild TUX module and start TUX, I still can't find it.

So I think maybe the message level in printk is not high enough, so I
changed
the printk like this printk(KERN_DEBUG "TUX start successfully message"); or
even higher level as printk(KERN_EMEGR "TUX start successfully message");,
after I rebuild TUX module and start TUX, I still can't find such message in
/var/log/messages.

So I think I should use Dprintk(actually Dprintk is based on printk, but I
have to try)
instead of just printk. Then I changed printk to Dprintk like this:
Dprintk("TUX start successfully message"); and also put thisd Dprintk
statement in
tux_init in main.c. After I rebuild TUX module and start TUX, I still can't
find this message
in /var/log/messages.

So think I forgot to turn on TUX_DEBUG and should set DPrintk to 1, then I
turn on TUX_DEBUG
and try to rebuild Linux kernel and all modules. I encounter an error in
"make modules_install"
as follows:
----------------------
make[1]: Nothing to be done for `modules_install'.
make[1]: Leaving directory `/usr/src/linux-2.4.9-31/arch/i386/lib'
cd /lib/modules/2.4.9-31debug; \
mkdir -p pcmcia; \
find kernel -path '*/pcmcia/*' -name '*.o' | xargs -i -r ln -sf ../{} pcmcia
if [ -r System.map ]; then /sbin/depmod -ae -F System.map  2.4.9-31debug; fi
depmod: *** Unresolved symbols in
/lib/modules/2.4.9-31debug/kernel/net/tux/tux.o
depmod:         show_stack
make: *** [_modinst_post] Error 1
----------------------
Michael K. Johnson gave me a solution just now, he said I should add a line
EXPORT_SYMBOL_GPL(show_stack) to arch/i386/kernel/i386_ksyms.c and rebuild.
OK, I will try it now.

Here're some questions I summary:

First, can I use printk directly in source code of TUX, so I don't need to
turn on or off
of TUX_DEBUG in kernel configuration.

Second, Is fprintf the only way to output information in user space modules
since printf doesn't
work?

Third, if I already built TUX as a module, then I turned on TUX_DEBUG, can
I
just build all modules again to make it effect or do  I need to build linux
kernel
with all modules again?

Sorry to ask so many questions. But I think TUX will become more and more
popular if more and more
people like me are familiar with it.

Thank you. I really want to say thanks to all of you for so much help and
encouragement to me.

Liang