Messages in this thread | | | Subject | Re: [PATCH 1/1] ftrace - add support for tracing_thresh to function_graph tracer | From | Steven Rostedt <> | Date | Thu, 11 Feb 2010 19:26:55 -0500 |
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On Thu, 2010-02-11 at 16:01 -0800, Tim Bird wrote: > On 02/11/2010 03:10 PM, Steven Rostedt wrote: > > On Wed, 2010-02-10 at 14:52 -0800, Tim Bird wrote: > >> static struct tracer_opt trace_opts[] = { > >> /* Display overruns? (for self-debug purpose) */ > >> @@ -53,6 +54,8 @@ static struct tracer_opt trace_opts[] = { > >> { TRACER_OPT(funcgraph-duration, TRACE_GRAPH_PRINT_DURATION) }, > >> /* Display absolute time of an entry */ > >> { TRACER_OPT(funcgraph-abstime, TRACE_GRAPH_PRINT_ABS_TIME) }, > >> + /* Display function name on exit, instead of just closing brace */ > >> + { TRACER_OPT(funcgraph-exit, TRACE_GRAPH_PRINT_FUNC_EXIT) }, > >> { } /* Empty entry */ > > > > I wonder if this should be enabled on start up of the function graph > > tracer if the threshold is set? > > > > Otherwise people will wonder WTF? > > Indeed. I'm not sure exactly how to do this. > > Would it be better to set the option when current_tracer > is set with 'function_graph', and tracing_thresh is non-zero?
The above is the only one I would do. If tracing_thresh is non-zero when the function_graph tracer is set, on the start up code in the function tracer (graph_trace_init).
Just enable the option if trace_thresh is set. If you enable function graph tracer and have the trace_thresh set, then this type of tracing starts immediately. It also keeps the code nicely in the trace_function_graph.c file, and does not need to touch the setting of tracing_thresh.
-- Steve
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