Tracing

Tracing is done by means of kernel tracepoints, the ftrace infrastructure, and trace-cmd.

Installing trace-cmd

1. Install the udis86 and udis86-devel packages
2. download trace-cmd:

 $ git clone trace-cmd git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/trace-cmd.git
 $ cd trace-cmd
 

1. build and install:

 $ make && sudo make install
 

Tracing

 # trace-cmd record -b 20000 -e kvm
 

(trace-cmd will wait)

run your workload, then stop trace-cmd with ctrl-C. trace-cmd will write a trace.dat file.

Analyzing the trace

 trace-cmd report
 

will format and display the contents of the trace.