tree a73edfcc1b603a921ed7e332ce614e1345385100
parent 2da03ecee6308ea174e8a02b92a3c4ec92e886c8
author Steven Rostedt <srostedt@redhat.com> 1236901349 -0400
committer Steven Rostedt <srostedt@redhat.com> 1236906901 -0400

tracing: explain why stack tracer is empty

If the stack tracing is disabled (by default) the stack_trace file
will only contain the header:

 # cat /debug/tracing/stack_trace
        Depth    Size      Location    (0 entries)
        -----    ----      --------

This can be frustrating to a developer that does not realize that the
stack tracer is disabled. This patch adds the following text:

  # cat /debug/tracing/stack_trace
        Depth    Size      Location    (0 entries)
        -----    ----      --------
 #
 #  Stack tracer disabled
 #
 # To enable the stack tracer, either add 'stacktrace' to the
 # kernel command line
 # or 'echo 1 > /proc/sys/kernel/stack_tracer_enabled'
 #

Signed-off-by: Steven Rostedt <srostedt@redhat.com>