From 4104d326b670c2b66f575d2004daa28b2d1b4c8d Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org>
Date: Fri, 10 Jan 2014 17:01:58 -0500
Subject: 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>
---
kernel/trace/trace_functions.c | 55 +++++++++++++++---------------------------
1 file changed, 19 insertions(+), 36 deletions(-)
(limited to 'kernel/trace/trace_functions.c')
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index ffd56351b521..2d9482b8f26a 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -26,8 +26,6 @@ function_trace_call(unsigned long ip, unsigned long parent_ip,
static void
function_stack_trace_call(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct pt_regs *pt_regs);
-static struct ftrace_ops trace_ops;
-static struct ftrace_ops trace_stack_ops;
static struct tracer_flags func_flags;
/* Our option */
@@ -83,28 +81,24 @@ void ftrace_destroy_function_files(struct trace_array *tr)
static int function_trace_init(struct trace_array *tr)
{
- struct ftrace_ops *ops;
-
- if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {
- /* There's only one global tr */
- if (!trace_ops.private) {
- trace_ops.private = tr;
- trace_stack_ops.private = tr;
- }
+ ftrace_func_t func;
- if (func_flags.val & TRACE_FUNC_OPT_STACK)
- ops = &trace_stack_ops;
- else
- ops = &trace_ops;
- tr->ops = ops;
- } else if (!tr->ops) {
- /*
- * Instance trace_arrays get their ops allocated
- * at instance creation. Unless it failed
- * the allocation.
- */
+ /*
+ * Instance trace_arrays get their ops allocated
+ * at instance creation. Unless it failed
+ * the allocation.
+ */
+ if (!tr->ops)
return -ENOMEM;
- }
+
+ /* Currently only the global instance can do stack tracing */
+ if (tr->flags & TRACE_ARRAY_FL_GLOBAL &&
+ func_flags.val & TRACE_FUNC_OPT_STACK)
+ func = function_stack_trace_call;
+ else
+ func = function_trace_call;
+
+ ftrace_init_array_ops(tr, func);
tr->trace_buffer.cpu = get_cpu();
put_cpu();
@@ -118,6 +112,7 @@ static void function_trace_reset(struct trace_array *tr)
{
tracing_stop_function_trace(tr);
tracing_stop_cmdline_record();
+ ftrace_reset_array_ops(tr);
}
static void function_trace_start(struct trace_array *tr)
@@ -199,18 +194,6 @@ function_stack_trace_call(unsigned long ip, unsigned long parent_ip,
local_irq_restore(flags);
}
-static struct ftrace_ops trace_ops __read_mostly =
-{
- .func = function_trace_call,
- .flags = FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_RECURSION_SAFE,
-};
-
-static struct ftrace_ops trace_stack_ops __read_mostly =
-{
- .func = function_stack_trace_call,
- .flags = FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_RECURSION_SAFE,
-};
-
static struct tracer_opt func_opts[] = {
#ifdef CONFIG_STACKTRACE
{ TRACER_OPT(func_stack_trace, TRACE_FUNC_OPT_STACK) },
@@ -248,10 +231,10 @@ func_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
unregister_ftrace_function(tr->ops);
if (set) {
- tr->ops = &trace_stack_ops;
+ tr->ops->func = function_stack_trace_call;
register_ftrace_function(tr->ops);
} else {
- tr->ops = &trace_ops;
+ tr->ops->func = function_trace_call;
register_ftrace_function(tr->ops);
}
--
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