Commit e725c731 authored by Steven Rostedt (VMware)'s avatar Steven Rostedt (VMware)
Browse files

tracing: Split tracing initialization into two for early initialization 



Create an early_trace_init() function that will initialize the buffers and
allow for ealier use of trace_printk(). This will also allow for future work
to have function tracing start earlier at boot up.

Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent 97da3854

include/linux/ftrace.h

+2 −0
Original line number Diff line number Diff line
@@ -42,8 +42,10 @@ 
/* Main tracing buffer and events set up */

#ifdef CONFIG_TRACING

void trace_init(void);

void early_trace_init(void);

#else

static inline void trace_init(void) { }

static inline void early_trace_init(void) { }

#endif



struct module;

init/main.c

+4 −1
Original line number Diff line number Diff line
@@ -545,6 +545,9 @@ asmlinkage __visible void __init start_kernel(void) 
	trap_init();

	mm_init();



	/* trace_printk can be enabled here */

	early_trace_init();



	/*

	 * Set up the scheduler prior starting any interrupts (such as the

	 * timer interrupt). Full topology setup happens at smp_init()
@@ -570,7 +573,7 @@ asmlinkage __visible void __init start_kernel(void) 


	rcu_init();



	/* trace_printk() and trace points may be used after this */

	/* Trace events are available after this */

	trace_init();



	context_tracking_init();

kernel/trace/trace.c

+5 −1
Original line number Diff line number Diff line
@@ -7999,7 +7999,7 @@ __init static int tracer_alloc_buffers(void) 
	return ret;

}



void __init trace_init(void)

void __init early_trace_init(void)

{

	if (tracepoint_printk) {

		tracepoint_print_iter =
@@ -8010,6 +8010,10 @@ void __init trace_init(void) 
			static_key_enable(&tracepoint_printk_key.key);

	}

	tracer_alloc_buffers();

}



void __init trace_init(void)

{

	trace_event_init();

}