Bug#758419: trace-cmd: Plugin function_graph missing

[Seth Forshee]

On Sun, Aug 17, 2014 at 02:02:39PM +0200, Vincent Bernat wrote:
>  ❦ 17 août 2014 13:54 +0200, Vincent Bernat <bernat at debian.org> :
> 
> > trace-cmd should come with a "function_graph" plugins (mentioned in
> > the manual pages, for example in trace-cmd-record). However, it seems
> > absent.
> 
> It seems that other plugins do not work either:
> 
> $ sudo trace-cmd record -p function -e sched_switch ls
> /sys/kernel/debug/tracing/events/sched_switch/filter
> /sys/kernel/debug/tracing/events/*/sched_switch/filter
> trace-cmd: No such file or directory
>   Plugin 'function' does not exist
> 
> Despite the presence of /usr/lib/trace-cmd/plugins/plugin_function.so.

That's working fine here. I suspect your problem is either that you
don't have debugfs mounted or that your kernel is missing something it
needs to do what trace-cmd is asking. First check that /sys/kernel/debug
is mounted, then that /sys/kernel/debug/tracing exists. If both those
are true run 'cat /sys/kernel/debug/tracing/available_tracers' and make
sure that function and function_graph are both in the list.