Re: loglevel 7 (debug) and pr_debug()

[Denis Pithon <denis.pithon@xxxxxxxxx>]

Martin,

I'm not sure did you enable DDEBUG when compiling your module ?

pr_debug() macro is discarded if you omit DEBUG in compile time

A sample Makefile which enable pr_debug() :

obj-m += my_modue.o

KDIR ?= /lib/modules/`uname -r`/build

CFLAGS_my_module.o := -DDEBUG

all:

make -C $(KDIR) M=$(PWD) modules

clean:

make -C $(KDIR) M=$(PWD) clean

Let me know ...

regards

On Wed, Apr 16, 2014 at 1:11 PM, Martin Kepplinger <martink@xxxxxxxxx> wrote:

Am 16.04.2014 11:58 schrieb Arun KS:

> Hi Martin,
>
> On Wed, Apr 16, 2014 at 2:46 PM, Martin Kepplinger <martink@xxxxxxxxx>
> wrote:
>> Am 2014-04-16 11:00, schrieb Arun KS:
>>> Hi Martin,
>  >>
>>> On Wed, Apr 16, 2014 at 2:13 PM, Martin Kepplinger
>>> <martink@xxxxxxxxx> 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@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.
>>
>> How do I view debug messages from 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
>  >
>> well. I tried that. The thing is, the pr_debug() symbols are in
>> "control" only after "insmod my_module". Then I can echo -n 'file
>> my_mobule.c +p' > control
>> But my pr_debug() messages get printed directly after insmod,
>> basically
>  > in my module_init function. Enabling my file doesn't output
> anything in
>> /var/log/*
> So now you know why your pr_debug is absent in logbuf.
>
> You can make your module as a built in and use bootargs.
>
> eg:
> dyndbg="file your_filename.c +p"
>
> Thanks,
> Arun
>

So it's *not* possible at all to get pr_debug() messages just like
pr_info() messages?
Of what I've read, I assumed pr_debug() is just loglevel 7.

thanks for your help!

>>
>>>
>>>
>>> Thanks,
>>> Arun
>>>>
>>>> thanks!
>>>>                      martin
>  >>>
>>>> --
>>>> Martin Kepplinger
>>>> e-mail        martink AT posteo DOT at
>>>> chat (XMPP)   martink AT jabber DOT at
>>>>
>>>> _______________________________________________
>  >>> Kernelnewbies mailing list
>>>> Kernelnewbies@xxxxxxxxxxxxxxxxx

>>>> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies [1]

>  >>
>>> _______________________________________________
>>> Kernelnewbies mailing list
>>> Kernelnewbies@xxxxxxxxxxxxxxxxx

>>> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies [1]

>  >>
>>
>>
>> _______________________________________________
>> Kernelnewbies mailing list
>> Kernelnewbies@xxxxxxxxxxxxxxxxx

>> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies [1]
>
> Links:
> ------
> [1] http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

>
> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies@xxxxxxxxxxxxxxxxx
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

_______________________________________________
Kernelnewbies mailing list
Kernelnewbies@xxxxxxxxxxxxxxxxx
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

_______________________________________________
Kernelnewbies mailing list
Kernelnewbies@xxxxxxxxxxxxxxxxx
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies