This special tracer records the maximum stack footprint of the
kernel and displays it in debugfs/tracing/stack_trace.

This tracer works by hooking into every function call that the
kernel executes, and keeping a maximum stack depth value and
stack-trace saved. If this is configured with DYNAMIC_FTRACE
then it will not have any overhead while the stack tracer
is disabled.

To enable the stack tracer on bootup, pass in 'stacktrace'
on the kernel command line.

The stack tracer can also be enabled or disabled via the
sysctl kernel.stack_tracer_enabled

Say N if unsure.

source code:

kernel/trace/trace_stack.c