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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>
This commit is contained in:
Steven Rostedt (Red Hat) 2015-02-03 12:45:53 -05:00 committed by Steven Rostedt
parent 0f67f04ffc
commit 09d23a1d8a
1 changed files with 21 additions and 9 deletions
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30
kernel/trace/trace.c
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@ -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;
}