GitLab

It comes in handy to be able to enable a set of related tracepoints
for specific tracing purposes.

The -e option can now take an optional parameter specifying a
pre-defined group of related tracepoints to enable, so far:

irq = pipeline_entry, pipeline_exit, handler_entry, handler_exit
timer = tracepoints related to timer event handling with latmus (used in
chasing latency in the timer handling path)
evl = all core tracepoints
all = all tracepoints ftrace knows about

-eall is identical to -f.

-E<tracepoint_file> enables the tracepoints mentioned in the
 user-provided <file>.

-t can be passed to dry-run the enable command, getting the list of
 ftrace settings which would have been set without this option when
 enabling the trace.
Signed-off-by: Philippe Gerum <rpm@xenomai.org>