# SLUG Mailing List Archives

## [SLUG] Re: What level printk?

• To: slug@xxxxxxxxxxx
• Subject: [SLUG] Re: What level printk?
• From: Angus Lees <gusl@xxxxxxxxxxxxxxx>
• Date: Sat Aug 18 23:10:02 2001
• User-agent: Mutt/1.2.5i

\begin{james@xxxxxxxxxxxxxxxxxx}
> Linux. I want to add a bunch of printk's in the kernel's TCP/IP code,
> recompile the kernel and watch what happens. It prints what function it's
> in, dumps variables to a log file etc, you know, your standard debug prints.
> Idea is to print this and watch it go in a terminal when I run an echo
> client and server to exercise it.

heh. remember that when sending received packets up the stack, the
whole thing is run as a bottom-half handler (aka software interrupt
handler, etc). be careful your printk's don't block at all ;)

(i got bitten by this when doing the same thing with a freebsd
stack. took me way too long to realise why all the structures kept
changing after the printk statement ;)

--
- Gus