[patch 4/4] x86, hw-branch-tracer: add selftest

[patch 4/4] x86, hw-branch-tracer: add selftest

[Markus Metzger]

Add a selftest to the hw-branch-tracer.

Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
---

Index: gits/kernel/trace/trace_hw_branches.c
===================================================================
--- gits.orig/kernel/trace/trace_hw_branches.c	2009-03-03 10:45:35.000000000 +0100
+++ gits/kernel/trace/trace_hw_branches.c	2009-03-03 10:50:04.000000000 +0100
@@ -344,7 +344,10 @@ 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)
Index: gits/kernel/trace/trace_selftest.c
===================================================================
--- gits.orig/kernel/trace/trace_selftest.c	2009-03-03 09:32:43.000000000 +0100
+++ gits/kernel/trace/trace_selftest.c	2009-03-03 10:51:27.000000000 +0100
@@ -15,6 +15,7 @@ static inline int trace_valid_entry(stru
 	case TRACE_BRANCH:
 	case TRACE_GRAPH_ENT:
 	case TRACE_GRAPH_RET:
+	case TRACE_HW_BRANCHES:
 		return 1;
 	}
 	return 0;
@@ -693,3 +694,56 @@ trace_selftest_startup_branch(struct tra
 	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;
+	}
+
+	/* start the tracing */
+	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);
+
+	/* stop the tracing. */
+	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;
+	}
+
+	return ret;
+}
+#endif /* CONFIG_HW_BRANCH_TRACER */
Index: gits/kernel/trace/trace.h
===================================================================
--- gits.orig/kernel/trace/trace.h	2009-03-03 09:32:43.000000000 +0100
+++ gits/kernel/trace/trace.h	2009-03-03 10:50:04.000000000 +0100
@@ -555,6 +555,8 @@ extern int trace_selftest_startup_syspro
 					       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);
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Re: [patch 4/4] x86, hw-branch-tracer: add selftest

[Ingo Molnar]

* Markus Metzger <markus.t.metzger@intel.com> wrote:

> +	/* the hw-branch tracer needs to collect the trace from the various
> +	 * cpu trace buffers - before tracing is stopped. */

The comment style is wrong here too.

	Ingo