ftrace: Remove global function list and call function directly
Instead of having a list of global functions that are called,
as only one global function is allow to be enabled at a time, there's
no reason to have a list.
Instead, simply have all the users of the global ops, use the global ops
directly, instead of registering their own ftrace_ops. Just switch what
function is used before enabling the function tracer.
This removes a lot of code as well as the complexity involved with it.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index e14da5e..4dd986d 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -130,15 +130,9 @@
atomic_dec(&data->disabled);
preempt_enable_notrace();
}
-
-static struct ftrace_ops trace_ops __read_mostly =
-{
- .func = wakeup_tracer_call,
- .flags = FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_RECURSION_SAFE,
-};
#endif /* CONFIG_FUNCTION_TRACER */
-static int register_wakeup_function(int graph, int set)
+static int register_wakeup_function(struct trace_array *tr, int graph, int set)
{
int ret;
@@ -150,7 +144,7 @@
ret = register_ftrace_graph(&wakeup_graph_return,
&wakeup_graph_entry);
else
- ret = register_ftrace_function(&trace_ops);
+ ret = register_ftrace_function(tr->ops);
if (!ret)
function_enabled = true;
@@ -158,7 +152,7 @@
return ret;
}
-static void unregister_wakeup_function(int graph)
+static void unregister_wakeup_function(struct trace_array *tr, int graph)
{
if (!function_enabled)
return;
@@ -166,17 +160,17 @@
if (graph)
unregister_ftrace_graph();
else
- unregister_ftrace_function(&trace_ops);
+ unregister_ftrace_function(tr->ops);
function_enabled = false;
}
-static void wakeup_function_set(int set)
+static void wakeup_function_set(struct trace_array *tr, int set)
{
if (set)
- register_wakeup_function(is_graph(), 1);
+ register_wakeup_function(tr, is_graph(), 1);
else
- unregister_wakeup_function(is_graph());
+ unregister_wakeup_function(tr, is_graph());
}
static int wakeup_flag_changed(struct trace_array *tr, u32 mask, int set)
@@ -184,16 +178,16 @@
struct tracer *tracer = tr->current_trace;
if (mask & TRACE_ITER_FUNCTION)
- wakeup_function_set(set);
+ wakeup_function_set(tr, set);
return trace_keep_overwrite(tracer, mask, set);
}
-static int start_func_tracer(int graph)
+static int start_func_tracer(struct trace_array *tr, int graph)
{
int ret;
- ret = register_wakeup_function(graph, 0);
+ ret = register_wakeup_function(tr, graph, 0);
if (!ret && tracing_is_enabled())
tracer_enabled = 1;
@@ -203,11 +197,11 @@
return ret;
}
-static void stop_func_tracer(int graph)
+static void stop_func_tracer(struct trace_array *tr, int graph)
{
tracer_enabled = 0;
- unregister_wakeup_function(graph);
+ unregister_wakeup_function(tr, graph);
}
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
@@ -221,12 +215,12 @@
if (!(is_graph() ^ set))
return 0;
- stop_func_tracer(!set);
+ stop_func_tracer(tr, !set);
wakeup_reset(wakeup_trace);
tracing_max_latency = 0;
- return start_func_tracer(set);
+ return start_func_tracer(tr, set);
}
static int wakeup_graph_entry(struct ftrace_graph_ent *trace)
@@ -587,7 +581,7 @@
*/
smp_wmb();
- if (start_func_tracer(is_graph()))
+ if (start_func_tracer(tr, is_graph()))
printk(KERN_ERR "failed to start wakeup tracer\n");
return;
@@ -600,7 +594,7 @@
static void stop_wakeup_tracer(struct trace_array *tr)
{
tracer_enabled = 0;
- stop_func_tracer(is_graph());
+ stop_func_tracer(tr, is_graph());
unregister_trace_sched_switch(probe_wakeup_sched_switch, NULL);
unregister_trace_sched_wakeup_new(probe_wakeup, NULL);
unregister_trace_sched_wakeup(probe_wakeup, NULL);
@@ -617,6 +611,7 @@
tracing_max_latency = 0;
wakeup_trace = tr;
+ ftrace_init_array_ops(tr, wakeup_tracer_call);
start_wakeup_tracer(tr);
return 0;
}
@@ -653,6 +648,7 @@
set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag);
set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag);
+ ftrace_reset_array_ops(tr);
}
static void wakeup_tracer_start(struct trace_array *tr)