Commit 7447dce9 authored by Frederic Weisbecker's avatar Frederic Weisbecker Committed by Ingo Molnar
Browse files

tracing/function-graph-tracer: provide a selftest for the function graph tracer 



Making it more easy to do a basic regression test for this tracer.

Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 2db270a8

kernel/trace/trace.h

+2 −0
Original line number Diff line number Diff line
@@ -500,6 +500,8 @@ extern int DYN_FTRACE_TEST_NAME(void); 
#ifdef CONFIG_FTRACE_STARTUP_TEST

extern int trace_selftest_startup_function(struct tracer *trace,

					   struct trace_array *tr);

extern int trace_selftest_startup_function_graph(struct tracer *trace,

						 struct trace_array *tr);

extern int trace_selftest_startup_irqsoff(struct tracer *trace,

					  struct trace_array *tr);

extern int trace_selftest_startup_preemptoff(struct tracer *trace,

kernel/trace/trace_functions_graph.c

+3 −0
Original line number Diff line number Diff line
@@ -750,6 +750,9 @@ static struct tracer graph_trace __read_mostly = { 
	.print_line	= print_graph_function,

	.print_header	= print_graph_headers,

	.flags		= &tracer_flags,

#ifdef CONFIG_FTRACE_SELFTEST

	.selftest	= trace_selftest_startup_function_graph,

#endif

};



static __init int init_graph_trace(void)

kernel/trace/trace_selftest.c

+50 −0
Original line number Diff line number Diff line
@@ -13,6 +13,8 @@ static inline int trace_valid_entry(struct trace_entry *entry) 
	case TRACE_PRINT:

	case TRACE_SPECIAL:

	case TRACE_BRANCH:

	case TRACE_GRAPH_ENT:

	case TRACE_GRAPH_RET:

		return 1;

	}

	return 0;
@@ -227,6 +229,54 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr) 
}

#endif /* CONFIG_FUNCTION_TRACER */





#ifdef CONFIG_FUNCTION_GRAPH_TRACER

/*

 * Pretty much the same than for the function tracer from which the selftest

 * has been borrowed.

 */

int

trace_selftest_startup_function_graph(struct tracer *trace,

					struct trace_array *tr)

{

	int ret;

	unsigned long count;



	ret = tracer_init(trace, tr);

	if (ret) {

		warn_failed_init_tracer(trace, ret);

		goto out;

	}



	/* Sleep for a 1/10 of a second */

	msleep(100);



	tracing_stop();



	/* check the trace buffer */

	ret = trace_test_buffer(tr, &count);



	trace->reset(tr);

	tracing_start();



	if (!ret && !count) {

		printk(KERN_CONT ".. no entries found ..");

		ret = -1;

		goto out;

	}



	/* Don't test dynamic tracing, the function tracer already did */



out:

	/* Stop it if we failed */

	if (ret)

		ftrace_graph_stop();



	return ret;

}

#endif /* CONFIG_FUNCTION_GRAPH_TRACER */





#ifdef CONFIG_IRQSOFF_TRACER

int

trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr)