Commit dbeafd0d authored by Steven Rostedt (VMware)'s avatar Steven Rostedt (VMware)
Browse files

ftrace: Have function tracing start in early boot up 



Register the function tracer right after the tracing buffers are initialized
in early boot up. This will allow function tracing to begin early if it is
enabled via the kernel command line.

Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent 9afecfbb

kernel/trace/trace.c

+3 −0
Original line number Diff line number Diff line
@@ -8036,6 +8036,9 @@ __init static int tracer_alloc_buffers(void) 


	register_tracer(&nop_trace);



	/* Function tracing may start here (via kernel command line) */

	init_function_trace();



	/* All seems OK, enable tracing */

	tracing_disabled = 0;

kernel/trace/trace.h

+2 −0
Original line number Diff line number Diff line
@@ -896,6 +896,7 @@ int using_ftrace_ops_list_func(void); 
void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);

void ftrace_init_tracefs_toplevel(struct trace_array *tr,

				  struct dentry *d_tracer);

int init_function_trace(void);

#else

static inline int ftrace_trace_task(struct trace_array *tr)

{
@@ -914,6 +915,7 @@ ftrace_init_global_array_ops(struct trace_array *tr) { } 
static inline void ftrace_reset_array_ops(struct trace_array *tr) { }

static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }

static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }

static inline int init_function_trace(void) { return 0; }

/* ftace_func_t type is not defined, use macro instead of static inline */

#define ftrace_init_array_ops(tr, func) do { } while (0)

#endif /* CONFIG_FUNCTION_TRACER */

kernel/trace/trace_functions.c

+1 −2
Original line number Diff line number Diff line
@@ -687,9 +687,8 @@ static inline int init_func_cmd_traceon(void) 
}

#endif /* CONFIG_DYNAMIC_FTRACE */



static __init int init_function_trace(void)

__init int init_function_trace(void)

{

	init_func_cmd_traceon();

	return register_tracer(&function_trace);

}
 
core_initcall(init_function_trace);

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