Commit 321bb5e1 authored by Markus Metzger's avatar Markus Metzger Committed by Ingo Molnar
Browse files

x86, hw-branch-tracer: add selftest 



Add a selftest for the hw-branch-tracer.

Signed-off-by: default avatarMarkus Metzger <markus.t.metzger@intel.com>
LKML-Reference: <20090313105027.A30183@sedona.ch.intel.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent ba9372a8

kernel/trace/trace.h

+2 −0
Original line number Diff line number Diff line
@@ -576,6 +576,8 @@ extern int trace_selftest_startup_sysprof(struct tracer *trace, 
					       struct trace_array *tr);

extern int trace_selftest_startup_branch(struct tracer *trace,

					 struct trace_array *tr);

extern int trace_selftest_startup_hw_branches(struct tracer *trace,

					      struct trace_array *tr);

#endif /* CONFIG_FTRACE_STARTUP_TEST */



extern void *head_page(struct trace_array_cpu *data);

kernel/trace/trace_hw_branches.c

+4 −1
Original line number Diff line number Diff line
@@ -342,7 +342,10 @@ struct tracer bts_tracer __read_mostly = 
	.start		= bts_trace_start,

	.stop		= bts_trace_stop,

	.open		= trace_bts_prepare,

	.close		= trace_bts_close

	.close		= trace_bts_close,

#ifdef CONFIG_FTRACE_SELFTEST

	.selftest	= trace_selftest_startup_hw_branches,

#endif /* CONFIG_FTRACE_SELFTEST */

};



__init static int init_bts_trace(void)

kernel/trace/trace_selftest.c

+53 −0
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ static inline int trace_valid_entry(struct trace_entry *entry) 
	case TRACE_BRANCH:

	case TRACE_GRAPH_ENT:

	case TRACE_GRAPH_RET:

	case TRACE_HW_BRANCHES:

		return 1;

	}

	return 0;
@@ -691,3 +692,55 @@ trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr) 
	return ret;

}

#endif /* CONFIG_BRANCH_TRACER */



#ifdef CONFIG_HW_BRANCH_TRACER

int

trace_selftest_startup_hw_branches(struct tracer *trace,

				   struct trace_array *tr)

{

	unsigned long count;

	int ret;

	struct trace_iterator iter;

	struct tracer tracer;



	if (!trace->open) {

		printk(KERN_CONT "missing open function...");

		return -1;

	}



	ret = tracer_init(trace, tr);

	if (ret) {

		warn_failed_init_tracer(trace, ret);

		return ret;

	}



	/*

	 * The hw-branch tracer needs to collect the trace from the various

	 * cpu trace buffers - before tracing is stopped.

	 */

	memset(&iter, 0, sizeof(iter));

	memcpy(&tracer, trace, sizeof(tracer));



	iter.trace = &tracer;

	iter.tr = tr;

	iter.pos = -1;

	mutex_init(&iter.mutex);



	trace->open(&iter);



	mutex_destroy(&iter.mutex);



	tracing_stop();



	ret = trace_test_buffer(tr, &count);

	trace->reset(tr);

	tracing_start();



	if (!ret && !count) {

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

		ret = -1;

	}



	return ret;

}

#endif /* CONFIG_HW_BRANCH_TRACER */