Commit 6f415672 authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt
Browse files

tracing: Allow tracers to start at core initcall 



There's times during debugging that it is helpful to see traces of early
boot functions. But the tracers are initialized at device_initcall()
which is quite late during the boot process. Setting the kernel command
line parameter ftrace=function will not show anything until the function
tracer is initialized. This prevents being able to trace functions before
device_initcall().

There's no reason that the tracers need to be initialized so late in the
boot process. Move them up to core_initcall() as they still need to come
after early_initcall() which initializes the tracing buffers.

Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent bcd83ea6

kernel/trace/ftrace.c

+2 −2
Original line number Diff line number Diff line
@@ -2868,7 +2868,7 @@ static int __init ftrace_mod_cmd_init(void) 
{

	return register_ftrace_command(&ftrace_mod_cmd);

}

device_initcall(ftrace_mod_cmd_init);

core_initcall(ftrace_mod_cmd_init);



static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,

				      struct ftrace_ops *op, struct pt_regs *pt_regs)
@@ -4055,7 +4055,7 @@ static int __init ftrace_nodyn_init(void) 
	ftrace_enabled = 1;

	return 0;

}

device_initcall(ftrace_nodyn_init);

core_initcall(ftrace_nodyn_init);



static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; }

static inline void ftrace_startup_enable(int command) { }

kernel/trace/trace_branch.c

+1 −1
Original line number Diff line number Diff line
@@ -199,7 +199,7 @@ __init static int init_branch_tracer(void) 
	}

	return register_tracer(&branch_trace);

}

device_initcall(init_branch_tracer);

core_initcall(init_branch_tracer);



#else

static inline

kernel/trace/trace_functions.c

+1 −2
Original line number Diff line number Diff line
@@ -411,5 +411,4 @@ static __init int init_function_trace(void) 
	init_func_cmd_traceon();

	return register_tracer(&function_trace);

}

device_initcall(init_function_trace);

core_initcall(init_function_trace);

kernel/trace/trace_functions_graph.c

+1 −1
Original line number Diff line number Diff line
@@ -1474,4 +1474,4 @@ static __init int init_graph_trace(void) 
	return register_tracer(&graph_trace);

}



device_initcall(init_graph_trace);
 
core_initcall(init_graph_trace);

kernel/trace/trace_irqsoff.c

+1 −1
Original line number Diff line number Diff line
@@ -698,4 +698,4 @@ __init static int init_irqsoff_tracer(void) 


	return 0;

}

device_initcall(init_irqsoff_tracer);
 
core_initcall(init_irqsoff_tracer);

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