loglevel 7 (debug) and pr_debug()

Arun KS getarunks at gmail.com
Wed Apr 16 05:00:18 EDT 2014


Hi Martin,

On Wed, Apr 16, 2014 at 2:13 PM, Martin Kepplinger <martink at posteo.de> wrote:
> I'm on Debian here and I don't really get pr_debug and printk(KERN_DEBUG
> ...). Let's stick to pr_debug.
>
> I have DYNAMIC_DEBUG enabled and
> root at laptop:/proc/sys/kernel# cat /proc/sys/kernel/printk
> 7       7       1       7
This shows the console log level.
This file controls the traffic to console. But all the log messages
will be present in logbuf.

>
> I write a module with pr_debug's. I load the module and I *don't* see
> anything in /var/log/messages (or anywhere in /var/log/* ). Adding
> #define DEBUG doesn't help.
>
> /sys/kernel/debug/dynamic_debug/control has the pr_debug entries I use
> in my loaded module.
>
> In short: How do I see debug log messages? Using pr_info() works as
> expected. What am I missing? Do I need to edit my Makefile?
Did you enable dynamic printing for your file?

Below command enables dynamic printing for file sdhci.c.
echo 'file sdhci.c +p' > /sys/kernel/debug/dynamic_debug/control


Thanks,
Arun
>
> thanks!
>                      martin
>
> --
> Martin Kepplinger
> e-mail        martink AT posteo DOT at
> chat (XMPP)   martink AT jabber DOT at
>
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