From: martink@posteo.de (Martin Kepplinger)
To: kernelnewbies@lists.kernelnewbies.org
Subject: loglevel 7 (debug) and pr_debug()
Date: Wed, 16 Apr 2014 11:16:54 +0200 [thread overview]
Message-ID: <534E4A86.1070004@posteo.de> (raw)
In-Reply-To: <CABOM9ZoE6tXbZgGxbHpmD9LuaSKHAY6Qrnm17Y11fq_rPug_6A@mail.gmail.com>
Am 2014-04-16 11:00, schrieb Arun KS:
> Hi Martin,
>
> On Wed, Apr 16, 2014 at 2:13 PM, Martin Kepplinger <martink@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.
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/*
>
>
> Thanks,
> Arun
>>
>> thanks!
>> martin
>>
>> --
>> Martin Kepplinger
>> e-mail martink AT posteo DOT at
>> chat (XMPP) martink AT jabber DOT at
>>
>> _______________________________________________
>> Kernelnewbies mailing list
>> Kernelnewbies at kernelnewbies.org
>> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>
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>
next prev parent reply other threads:[~2014-04-16 9:16 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-16 8:43 loglevel 7 (debug) and pr_debug() Martin Kepplinger
2014-04-16 9:00 ` Arun KS
2014-04-16 9:16 ` Martin Kepplinger [this message]
2014-04-16 9:58 ` Arun KS
2014-04-16 11:11 ` Martin Kepplinger
2014-04-16 11:43 ` Denis Pithon
2014-04-16 11:57 ` Martin Kepplinger
2014-04-16 12:29 ` Arun KS
2014-04-16 12:30 ` Valdis.Kletnieks at vt.edu
2014-04-16 12:37 ` Denis Pithon
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