Debugging the kernel using Ftrace – part 2

“The Ftrace tracing utility has many different features that
will assist in tracking down Linux kernel problems. The previous
article discussed setting up Ftrace, using the function and
function graph tracers, using trace_printk(), and a simple way to
stop the recording of a trace from user space. This installment
will touch on how user space can interact with Ftrace, faster ways
of stopping the trace, debugging a crash, and finding what kernel
functions are the biggest stack hogs.

“Trace Markers

“Seeing what happens inside the kernel gives the user a better
understanding of how their system works. But sometimes there needs
to be coordination between what is happening in user space and what
is happening inside the kernel. The timestamps that are shown in
the traces are all relative to what is happening within the trace,
but they do not correspond well with wall time.”

Complete Story