Debug preemptible kernel

modulename: smp_processor_id.ko


Linux Kernel Configuration
└─>Kernel hacking
└─>Debug preemptible kernel
In linux kernel since version 2.6.12  
If you say Y here then the kernel will use a debug variant of the
commonly used smp_processor_id() function and will print warnings
if kernel code uses it in a preemption-unsafe way. Also, the kernel
will detect preemption count underflows.

This option has potential to introduce high runtime overhead,
depending on workload as it triggers debugging routines for each
this_cpu operation. It should only be used for debugging purposes.

source code: