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authorSteven Rostedt (Red Hat) <rostedt@goodmis.org>2015-02-03 12:45:53 -0500
committerSteven Rostedt <rostedt@goodmis.org>2015-02-03 12:48:39 -0500
commit09d23a1d8a82e814bd56a4f121b80ea8214ac49d (patch)
tree8cbb029b9db4ae704108339a2e8c0d12ac8c6f20 /kernel/trace
parent0f67f04ffcb592d065a20862a82d4539e0f8e909 (diff)
tracing: Create cmdline tracer options on tracing fs init
The options for cmdline tracers are not created if the debugfs system is not ready yet. If tracing has started before debugfs is up, then the option files for the tracer are not created. Create them when creating the tracing directory if the current tracer requires option files. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/trace.c30
1 files changed, 21 insertions, 9 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index d4627f15407a..05e0e50539fc 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4105,9 +4105,24 @@ static void tracing_set_nop(struct trace_array *tr)
tr->current_trace = &nop_trace;
}
-static int tracing_set_tracer(struct trace_array *tr, const char *buf)
+static void update_tracer_options(struct trace_array *tr, struct tracer *t)
{
static struct trace_option_dentry *topts;
+
+ /* Only enable if the directory has been created already. */
+ if (!tr->dir)
+ return;
+
+ /* Currently, only the top instance has options */
+ if (!(tr->flags & TRACE_ARRAY_FL_GLOBAL))
+ return;
+
+ destroy_trace_option_files(topts);
+ topts = create_trace_option_files(tr, t);
+}
+
+static int tracing_set_tracer(struct trace_array *tr, const char *buf)
+{
struct tracer *t;
#ifdef CONFIG_TRACER_MAX_TRACE
bool had_max_tr;
@@ -4172,14 +4187,7 @@ static int tracing_set_tracer(struct trace_array *tr, const char *buf)
free_snapshot(tr);
}
#endif
- /*
- * Only enable if the directory has been created already.
- * Currently, only the top instance has options
- */
- if (tr->dir && tr->flags & TRACE_ARRAY_FL_GLOBAL) {
- destroy_trace_option_files(topts);
- topts = create_trace_option_files(tr, t);
- }
+ update_tracer_options(tr, t);
#ifdef CONFIG_TRACER_MAX_TRACE
if (t->use_max_tr && !had_max_tr) {
@@ -6578,6 +6586,10 @@ static __init int tracer_init_debugfs(void)
create_trace_options_dir(&global_trace);
+ /* If the tracer was started via cmdline, create options for it here */
+ if (global_trace.current_trace != &nop_trace)
+ update_tracer_options(&global_trace, global_trace.current_trace);
+
return 0;
}