x86, hw-branch-tracer: add selftest
Add a selftest for the hw-branch-tracer.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
LKML-Reference: <20090313105027.A30183@sedona.ch.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 56ce34d..e7fbc82 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -576,6 +576,8 @@
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);
diff --git a/kernel/trace/trace_hw_branches.c b/kernel/trace/trace_hw_branches.c
index a99a04c..4ca8270 100644
--- a/kernel/trace/trace_hw_branches.c
+++ b/kernel/trace/trace_hw_branches.c
@@ -342,7 +342,10 @@
.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)
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index f907a2b..3c7b797 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -16,6 +16,7 @@
case TRACE_BRANCH:
case TRACE_GRAPH_ENT:
case TRACE_GRAPH_RET:
+ case TRACE_HW_BRANCHES:
return 1;
}
return 0;
@@ -691,3 +692,55 @@
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 */
