Re: [PATCH] ftrace: Remove use of control list and ops

[Jiri Olsa <jolsa@redhat.com>]

On Tue, Dec 01, 2015 at 11:56:55AM -0500, Steven Rostedt wrote:

SNIP

> -static void ftrace_ops_recurs_func(unsigned long ip, unsigned long parent_ip,
> +static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip,
>  				   struct ftrace_ops *op, struct pt_regs *regs)
>  {
>  	int bit;
>  
> +	if ((op->flags & FTRACE_OPS_FL_RCU) && !rcu_is_watching())
> +		return;
> +
>  	bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
>  	if (bit < 0)
>  		return;
>  
> -	op->func(ip, parent_ip, op, regs);
> +	preempt_disable_notrace();
>  
> +	if (!(op->flags & FTRACE_OPS_FL_PER_CPU) ||
> +	    ftrace_function_local_disabled(op)) {

should be !ftrace_function_local_disabled(op) in here,
I passed my test with attached patch

thanks,
jirka

> +		op->func(ip, parent_ip, op, regs);
> +	}
> +
> +	preempt_enable_notrace();
>  	trace_clear_recursion(bit);
>  }

SNIP

---
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 710430fcfd9c..ad0e0e7eaea2 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -115,7 +115,7 @@ static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end;
 ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
 static struct ftrace_ops global_ops;
 
-static void ftrace_ops_recurs_func(unsigned long ip, unsigned long parent_ip,
+static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip,
 				   struct ftrace_ops *op, struct pt_regs *regs);
 
 #if ARCH_SUPPORTS_FTRACE_OPS
@@ -5180,7 +5180,7 @@ static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip,
 	preempt_disable_notrace();
 
 	if (!(op->flags & FTRACE_OPS_FL_PER_CPU) ||
-	    ftrace_function_local_disabled(op)) {
+	    !ftrace_function_local_disabled(op)) {
 		op->func(ip, parent_ip, op, regs);
 	}