Hi, On Sun, Oct 28, 2012 at 12:36 AM, Kumar amit mehta <gmate.amit@gmail.com> wrote:
Thank you Srivatsa. It seems that lockdep framework is enabled on my running kernel.
<snip> amit@ubuntu:/boot$ egrep -i "debug_kernel|lockdep" config-3.2.0-29-generic-pae CONFIG_LOCKDEP_SUPPORT=y CONFIG_DEBUG_KERNEL=y
You'll need CONFIG_LOCKDEP=y as well. An easy way to configure lock debugging checks is to run 'make menuconfig' and enable the required options under the "Kernel hacking" section. Regards, Srivatsa S. Bhat
<snip>
If above configuration is all that I need, then should I be seeing warning/error messages in kernel logs(/var/log/kern.log) when there is inconsistency in locking ? To test my hypothesis, I modified my simple kernel module to deliberately induce locking error (After initializing read-write semaphore, I call down_write() and do not free this semaphore lock by commenting out up_write() invocation). But still I don't see any error or warning message trace in kernel logs, I think, I'm missing something.