function-graph: use int instead of atomic for ftrace_graph_active

Impact: cleanup

The variable ftrace_graph_active is only modified under the
ftrace_lock mutex, thus an atomic is not necessary for modification.

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 7 insertions, 7 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 6ea5a1ae6a98..8e6a0b5c9940 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3092,7 +3092,7 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 
-static atomic_t ftrace_graph_active;
+static int ftrace_graph_active;
 static struct notifier_block ftrace_suspend_notifier;
 
 int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
@@ -3244,7 +3244,7 @@ int register_ftrace_graph(trace_func_graph_ret_t retfunc,
         mutex_lock(&ftrace_lock);
 
         /* we currently allow only one tracer registered at a time */
-        if (atomic_read(&ftrace_graph_active)) {
+        if (ftrace_graph_active) {
                 ret = -EBUSY;
                 goto out;
         }
@@ -3252,10 +3252,10 @@ int register_ftrace_graph(trace_func_graph_ret_t retfunc,
         ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call;
         register_pm_notifier(&ftrace_suspend_notifier);
 
-        atomic_inc(&ftrace_graph_active);
+        ftrace_graph_active++;
         ret = start_graph_tracing();
         if (ret) {
-                atomic_dec(&ftrace_graph_active);
+                ftrace_graph_active--;
                 goto out;
         }
 
@@ -3273,10 +3273,10 @@ void unregister_ftrace_graph(void)
 {
         mutex_lock(&ftrace_lock);
 
-        if (!unlikely(atomic_read(&ftrace_graph_active)))
+        if (unlikely(!ftrace_graph_active))
                 goto out;
 
-        atomic_dec(&ftrace_graph_active);
+        ftrace_graph_active--;
         unregister_trace_sched_switch(ftrace_graph_probe_sched_switch);
         ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
         ftrace_graph_entry = ftrace_graph_entry_stub;
@@ -3290,7 +3290,7 @@ void unregister_ftrace_graph(void)
 /* Allocate a return stack for newly created task */
 void ftrace_graph_init_task(struct task_struct *t)
 {
-        if (atomic_read(&ftrace_graph_active)) {
+        if (ftrace_graph_active) {
                 t->ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
                                 * sizeof(struct ftrace_ret_stack),
                                 GFP_KERNEL);