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authorSteven Rostedt <srostedt@redhat.com>2009-04-16 12:15:44 -0400
committerIngo Molnar <mingo@elte.hu>2009-04-17 17:10:35 +0200
commit9ea21c1ecdb35ecdcac5fd9d95f62a1f6a7ffec0 (patch)
treec38a7f2f30d145e7d53b24159b99bc4734d291b5
parent69abe6a5d18a9394baa325bab8f57748b037c517 (diff)
tracing/events: perform function tracing in event selftests
We can find some bugs in the trace events if we stress the writes as well. The function tracer is a good way to stress the events. [ Impact: extend scope of event tracer self-tests ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20090416161746.604786131@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--kernel/trace/trace_events.c78
1 files changed, 72 insertions, 6 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 7163a2bb021..1137f951be4 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1017,7 +1017,7 @@ static __init void event_test_stuff(void)
* For every trace event defined, we will test each trace point separately,
* and then by groups, and finally all trace points.
*/
-static __init int event_trace_self_tests(void)
+static __init void event_trace_self_tests(void)
{
struct ftrace_event_call *call;
struct event_subsystem *system;
@@ -1071,7 +1071,7 @@ static __init int event_trace_self_tests(void)
sysname = kstrdup(system->name, GFP_KERNEL);
if (WARN_ON(!sysname)) {
pr_warning("Can't allocate memory, giving up!\n");
- return 0;
+ return;
}
ret = ftrace_set_clr_event(sysname, 1);
kfree(sysname);
@@ -1086,7 +1086,7 @@ static __init int event_trace_self_tests(void)
sysname = kstrdup(system->name, GFP_KERNEL);
if (WARN_ON(!sysname)) {
pr_warning("Can't allocate memory, giving up!\n");
- return 0;
+ return;
}
ret = ftrace_set_clr_event(sysname, 0);
kfree(sysname);
@@ -1106,14 +1106,14 @@ static __init int event_trace_self_tests(void)
sysname = kmalloc(4, GFP_KERNEL);
if (WARN_ON(!sysname)) {
pr_warning("Can't allocate memory, giving up!\n");
- return 0;
+ return;
}
memcpy(sysname, "*:*", 4);
ret = ftrace_set_clr_event(sysname, 1);
if (WARN_ON_ONCE(ret)) {
kfree(sysname);
pr_warning("error enabling all events\n");
- return 0;
+ return;
}
event_test_stuff();
@@ -1125,10 +1125,76 @@ static __init int event_trace_self_tests(void)
if (WARN_ON_ONCE(ret)) {
pr_warning("error disabling all events\n");
- return 0;
+ return;
}
pr_cont("OK\n");
+}
+
+#ifdef CONFIG_FUNCTION_TRACER
+
+static DEFINE_PER_CPU(atomic_t, test_event_disable);
+
+static void
+function_test_events_call(unsigned long ip, unsigned long parent_ip)
+{
+ struct ring_buffer_event *event;
+ struct ftrace_entry *entry;
+ unsigned long flags;
+ long disabled;
+ int resched;
+ int cpu;
+ int pc;
+
+ pc = preempt_count();
+ resched = ftrace_preempt_disable();
+ cpu = raw_smp_processor_id();
+ disabled = atomic_inc_return(&per_cpu(test_event_disable, cpu));
+
+ if (disabled != 1)
+ goto out;
+
+ local_save_flags(flags);
+
+ event = trace_current_buffer_lock_reserve(TRACE_FN, sizeof(*entry),
+ flags, pc);
+ if (!event)
+ goto out;
+ entry = ring_buffer_event_data(event);
+ entry->ip = ip;
+ entry->parent_ip = parent_ip;
+
+ trace_current_buffer_unlock_commit(event, flags, pc);
+
+ out:
+ atomic_dec(&per_cpu(test_event_disable, cpu));
+ ftrace_preempt_enable(resched);
+}
+
+static struct ftrace_ops trace_ops __initdata =
+{
+ .func = function_test_events_call,
+};
+
+static __init void event_trace_self_test_with_function(void)
+{
+ register_ftrace_function(&trace_ops);
+ pr_info("Running tests again, along with the function tracer\n");
+ event_trace_self_tests();
+ unregister_ftrace_function(&trace_ops);
+}
+#else
+static __init void event_trace_self_test_with_function(void)
+{
+}
+#endif
+
+static __init int event_trace_self_tests_init(void)
+{
+
+ event_trace_self_tests();
+
+ event_trace_self_test_with_function();
return 0;
}