Hi Martin, On Wed, Apr 16, 2014 at 2:46 PM, Martin Kepplinger <mart...@posteo.de> wrote: > Am 2014-04-16 11:00, schrieb Arun KS: >> Hi Martin, >> >> On Wed, Apr 16, 2014 at 2:13 PM, Martin Kepplinger <mart...@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@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 > >> >> >> Thanks, >> Arun >>> >>> thanks! >>> martin >>> >>> -- >>> Martin Kepplinger >>> e-mail martink AT posteo DOT at >>> chat (XMPP) martink AT jabber DOT at >>> >>> _______________________________________________ >>> Kernelnewbies mailing list >>> Kernelnewbies@kernelnewbies.org >>> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies >> >> _______________________________________________ >> Kernelnewbies mailing list >> Kernelnewbies@kernelnewbies.org >> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies >> > > > _______________________________________________ > Kernelnewbies mailing list > Kernelnewbies@kernelnewbies.org > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
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